With regard to germ cell induction from human iPS cells, progress has been made particularly in the male germline, demonstrating in vitro generation of haploid, round spermatids. Although iPS-derived germ cells are expected to be developed to yield a form of assisted reproductive technology (ART) that can address unmet reproductive needs, genetic and/or epigenetic instabilities abound in iPS cell generation and germ cell induction. In addition, there is still room to improve the induction protocol in the female germline. However, rapid advances in stem cell research are likely to make such obstacles surmountable, potentially translating induced germ cells into the clinical setting in the immediate future. This review examines the current status of the induction of germ cells from human iPS cells and discusses the clinical potential, as well as future directions.Recently, fertile spermatozoa and oocytes were generated from mouse induced pluripotent (iPS) cells using a combined  Second, human germ cell induction research will establish a precious platform for modeling infertility and congenital anomalies that have been difficult to study using animals. Third, the in vitro induction of germ cells from autologous pluripotent stem cells should lead to a new form of assisted reproductive technology (ART) for infertile patients who wish to have genetically-related children.There are various reasons to generate germ cells from human pluripotent stem cells in the laboratory. First, in vivo induction system, their work established an important step on the path to the in vitro recapitulation of gametogenesis. Significant progress has also been made in the differentiation from both human ES cells [in vitro formation of bona fide human spermatozoa and oocytes.Recent advances in stem cell research have made it conceivable that human sperm (spermatozoon) and oocytes will be induced from pluripotent stem cells in the near future. Notably, a Japanese group reported that mouse embryonic stem (ES) cells and induced pluripotent (iPS) cells could be differentiated into fertile spermatozoa and oocytes via primordial germ cell (PGC)—like cells, and demonstrated that viable offspring could be derived from pluripotent stem cells ,2. AlthoES cells ,5,6,7,8 ES cells ,11,12,13ES cells ,12,13. RIf functional oocytes and spermatozoa can be differentiated from human iPS cells, the use of such cells for research will contribute to the molecular elucidation of gametogenesis, as well as the onset and progression of various diseases in obstetrics, gynecology, and neonatology/pediatrics. However, with regard to the reproductive use of such germ cells induced from autologous iPS cells, sufficient preclinical research will need to be performed to confirm the safety of the offspring. Remarkably, the overview of ART  using inTwo fundamental cell types constitute multicellular eukaryotes. Somatic cells proliferate by mitosis and form the tissues and organs comprising the body. Germ cells undergo meiosis as well as mitosis, resulting in the generation of gametes that can transfer half the genetic material to the next generation. The lineage of germ cells is referred to as the germline.If germ cells can be efficiently induced from human iPS cells, the availability of such germ cells could contribute to various biomedical fields. First of all, the research use of human female germ cells and embryos is largely difficult owing to ethical reasons and the scarcity of oocytes and embryos for research. In contrast, patient-specific induced germ cells can model diseases that are derived from aberrant germ cells or that occur during embryogenesis. A wide variety of somatic cells which are differentiated from patient-specific iPS cells have already been used for disease-modeling to enhance the understanding of the pathogenesis of diseases . Currentin vitro fertilization (IVF), or intracytoplasmic sperm injection (ICSI)  . Otherwiin vivo spermatogenesis could be restored by transplanting spermatogonial stem cells (SSCs) derived from autologous iPS cells into the testis of a male patient [Recent progress in germ cell induction research is increasing the possibility of a new form of ART using germ cells induced from autologous iPS cells for patients with no viable gametes . If fert patient ,25,26. I patient , resulti patient . However patient . If thisHuman iPS cells were initially generated from somatic cells by the ectopic expression of four transcription factor genes  in 2007 . The curet al. [The differentiation of human male iPS cells has so far produced PGCs ,9,10, goet al.  reportedet al. compared the potential of human iPS cells, derived from adult and fetal somatic cells to form primordial and meiotic germ cells [DAZ, DAZL, and BOULE, iPS cells formed meiotic cells with extensive synaptonemal complexes and post-meiotic haploid spermatid-like cells. These results show that human iPS cells generated from adult somatic cells can form germline cells other than PGCs. More recently, similar results using the overexpression of VASA and/or DAZL was reported, demonstrating that both human ES cells and iPS cells differentiated into PGCs, and the maturation and progression of these cells through meiosis was enhanced [VASA alone. Therefore, such RNA-binding proteins appear to promote the meiotic progression of human iPS cell-derived germ cells in vitro.In 2011, Panula rm cells . As a coenhanced . Again, et al. demonstrated that without the overexpression of germline related factors, postmeiotic haploid cells were consistently obtained from human iPS cells of different origins (keratinocytes and cord blood), generated with a different number of transcription factors [et al. also reported a similar direct differentiation approach without the overexpression of genes [in vivo by differentiating these pluripotent stem cells into UTF1-, PLZF-, and CDH1-positive spermatogonia-like cells; HIWI- and HILI positive spermatocyte-like cells; and haploid, round spermatid-like cells expressing acrosin, TP1, and Prot1. Such spermatids had uniparental genomic imprints similar to those of human sperm on two loci: H19 and IGF2. These results demonstrate that male iPS cells have the ability to differentiate directly into haploid, round spermatids in vitro.In contrast to these studies, Eguizabal  factors . Their tof genes . They adof genes  and demoet al. warned that transplantation of stem cells, not differentiated cells, in a patient could cause an adverse event [in vitro needs to be examined in preclinical research.Therefore, male germ cell induction from iPS cells has rapidly advanced since 2009. Although transplantation of autologous SSCs to restore spermatogenesis has already succeeded in infertile monkeys , clinicase event . They rese event ,40, theyse event ,42,43. Set al. [Igf2r, Snrpn, H19, and Kcnq1ot1), and cellular dynamics during PGCLC induction from EpiLCs resembled those associated with PGC specification from the epiblasts. Remarkably, they identified Integrin-b3 and SSEA1 as markers that could be used to isolate PGCLCs from differentiated cells. More recently, Ramathal et al. demonstrated that human iPS cells transplanted directly into mouse seminiferous tubules differentiated extensively to form germ cell-like cells with morphology indistinguishable from that of fetal germ cells, and these cells expressed PGC-specific proteins including VASA, DAZL, and STELLA [Based on the recent mouse work by Hayashi et al. , primordd STELLA .in vitro.These findings revealed the significance of differentiation pathway from iPS cells to germ cells and elaborated the need for culture conditions that mimic the stem cell niche in the testis to efficiently and effectively direct human iPS cells to form more advanced germ cells et al. consistently observed between 1.0%–2.0% haploid cells per human female iPS cell line (derived from keratinocytes or cord blood) in their two-step differentiation protocol [et al. also reported a similar result regarding the differentiation of female iPS and ES cells into meiotic germ cells by the overexpression of the intrinsic regulators [et al. showed that germ cells differentiated from human ES cells in vitro express both male and female genetic programs regardless of their karyotype [In contrast to male germline induction, the differentiation of iPS cells or ES cells into female germ cells has been insufficiently studied . Eguizabprotocol . Their fgulators . Moreovearyotype .et al. clearly noted that mouse ES cell-derived oocyte maturation ultimately fails in vitro [et al. showed that mouse female ES cells and iPS cells were differentiated into fertile oocytes via EpiLCs and PGCLCs [in vitro and in vivo system which led to the successful induction of fertile spermatozoa in 2011 [in vitro maturation and fertilization. Therefore, the differentiation of female iPS cells into germ cells largely depends on the use of an in vivo system.With regard to mouse systems, there have been attempts to induce female germ cells from ES cells since 2003 ,46,47,48in vivo oogenesis. Human gametogenesis initiates around the 23–26th day post-conception [The difficulty in female germ cell induction from pluripotent stem cells is more likely to reflect nception . The prein vivo for a long time. In addition, human SSCs can be maintained in vitro for a long term. Sadri-Ardekani et al. demonstrated that the human SSC numbers increased 53-fold within 19 days in testicular cell culture and increased 18,450-fold within 64 days in a germline stem cell subculture [In males, SSCs are maintained, and contribute to spermatogenesis by self-renewal bculture . The sigbculture ,53,54,55bculture ,57,58. Iin vivo is vital. In addition, creating human embryos is likely to require the assessment of the developmental potential of induced germ cells. The conditions to permit the creation of human embryos for these functional assays should be discussed, because such experiments are frequently associated with ethical concerns or issues [In order to improve the induction efficiency and functional completeness of germ cell induction from human iPS cells, deeper insight into iPS cell generation and gametogenesis r issues .As mentioned in the Introduction, the ART using induced germ cells appears to be against the Weismann barrier. Induced germ cells are likely to be subject to genetic and/or epigenetic instabilities during iPS cell generation and germ cell induction. The genetic stability of iPS cells significantly impacts their research use, in addition to their safe medical use. Some cytogenetic analyses have suggested that human iPS cells and ES cells are likely to acquire trisomies in chromosome 12, and 17, indicating an underlying mechanism of growth advantage associated with culture adaptation ,60,61. Met al. tested 16 human ES cell lines and showed that they carry a plethora of diverse mtDNA deletions [et al. reported a unique result using a mutator mouse model with an error-prone mtDNA polymerase [The genetic instabilities might occur not only in nuclear DNA, but also in mitochondrial DNA (mtDNA). The copy number of mtDNA, which encodes proteins required to produce ATP for motility of spermatozoon ranges from 2.8 to 226 copies of mtDNA . In conteletions . The mtDlymerase . They inIn addition, epigenetic aberrations in human iPS cells have been pointed out, indicating defects in DNA methylation, including regions subject to imprinting . InteresOct4  transcription by its distal enhancer, globally reduced DNA methylation, prominent deposition of the repressive histone modification H3K27me3, and bivalent domain acquisition on lineage regulatory genes [Human ES and iPS cells are more similar to mouse EpiSCs that were derived from epiblasts in postimplantation embryos than mouse naive, ground state ES cells ,77. The ry genes . Moreovery genes ,80,81. Try genes ,81, or iin vivo has already been introduced to induce spermatogenesis in vitro. Park et al. improved PGC generation using a co-culture system with human fetal gonadal cells [et al. reported that PGC generation from human ES cells was accompanied by the development of Sertoli-like support cells [in vitro [et al. have used co-culture with ovarian granulosa cells in the induction of oocyte-like cells expressing oocyte-specific genes including Figalpha, GDF-9, and ZP1-3 from mouse ES cells [et al. differentiated mouse Oct4-GFP ES cells in vitro, isolated GFP positive germ cells by FACS and co-aggregated the cells with dissociated mouse newborn ovarian tissue [et al. differentiated PGCLCs, which were induced from mouse ES and iPS cells into fertile oocytes, by using in vitro aggregation with female gonadal somatic cells and transplantation of germ cells under the mouse ovarian bursa. The spatio-temporal factors associated with human gametogenesis in vivo should be further considered to develop more elaborate culture or differentiation systems in order to increase the possibility of inducing more mature germ cells from human iPS cells.Currently, germ cell induction from human iPS cells is advancing primarily in the male germline. A better understanding of gametogenesis would facilitate the induction of female germ cells, as well as the terminal differentiation into spermatozoa. Following puberty, spermatogenesis occurs at the seminiferous tubules in the testis in which Sertoli cells co-exist with Leydig cells. In inducing male germ cells, co-culture with Sertoli cells that foster and differentiate spermatocytes al cells . Moreovert cells . Moreovein vitro . More elin vitro . A recenin vitro . RegardiES cells . Interesn tissue . Subsequn tissue , HayashiIn order to confirm whether induced human germ cells possess the correct biological functions, creating embryos and culturing them for a short term is indispensable prior to considering the use for clinical applications. In doing so, a subsequent biological analysis would necessitate the establishment of ES cells from the embryos. Nonetheless, these experiments are likely to raise ethical concerns owing to the fact that such embryos are created and destroyed for research purposes, not for reproduction. In some countries, creating a human embryo and monitoring the development of human embryos until the 14th day post-conception or until the beginning of the formation of the primitive streak may be permitted with approval of an institutional review board (IRB) and/or national authorities . HoweverAs discussed above, human germ cell induction has advanced primarily in the male germline, progressively reaching to a final differentiation stage. Meticulously selecting human iPS cell lines with higher pluripotency and genetic integrity is expected to improve the efficiency of the formation of PGCs and entrance into meiosis. Moreover, placing the differentiated cells in culture systems similar to the niche in human gonadal tissues will likely produce not only spermatozoa, but also female germ cells that are more similar to oocytes. Further considerations of the intrinsic regulators that could be overexpressed are also likely to advance meiotic progression, complete meiosis, and functionally mature these germ cells.bona fide spermatozoa within the next decade or less. Recently, perplexing ethical and social concerns associated with the careless use of induced germ cells have been raised [Rapid advances in stem cell research will likely enable human iPS cells to differentiate into elongated spermatids or n raised . The use


Centrally acting oxytocin (OT) is known to terminate food consumption in response to excessive stomach distension, increase in salt loading, and presence of toxins. Hypothalamic-hindbrain OT pathways facilitate these aspects of OT-induced hypophagia. However, recent discoveries have implicated OT in modifications of feeding via reward circuits: OT has been found to differentially affect consumption of individual macronutrients in choice and no-choice paradigms. In this mini-review, we focus on presenting and interpreting evidence that defines OT as a key component of mechanisms that reduce eating for pleasure and shape macronutrient preferences. We also provide remarks on challenges in integrating the knowledge on physiological and pathophysiological states in which both OT activity and macronutrient preferences are affected. Macronutrient composition of ingested food affects functioning of the organism during various physiological and pathophysiological challenges, such as pregnancy, lactation, and aging. A dynamic endocrine balance facilitates the coupling of mechanisms that link appetite regulation, metabolism, and cellular/tissue-specific responses, and one of the key hormonal regulators is oxytocin (OT) , 2. OT aFrom the very early stages of experimental work, it became apparent that OT promotes termination of feeding associated with generalized satiation as well as stemming from consumption-related adverse phenomena that jeopardize homeostasis –7.Neuroanatomical studies have shown that most OT neurons are localized in the hypothalamus, and its paraventricular nucleus (PVN) is the main source of OT fibers innervating central targets, most prominently, the dorsal vagal complex in the brain stem –12. AsidA number of satiety inducing neuropeptides have been shown to affect appetite, at least partially, by acting via OT containing pathways. Those peptides include – among others – alpha melanocyte-stimulating hormone  and glucagon-like peptide-1 (GLP-1), key components of the brainstem-hypothalamic appetite circuit , 23. FurIt should be emphasized that the intake of a sufficient amount of energy does not appear to be the main or the necessary factor that induces OT neuronal activity underlying termination of ingestive behavior. In fact, OT neuronal activity and release coinciding with termination of feeding occur upon changes in calorie-independent parameters associated with consumption. Those parameters include excessive stomach distension and elevated plasma osmolality –30. In aThough the protection of internal milieu during consumption appears to be the key neuroregulatory function of OT within the CNS, its importance for facilitating important competing behaviors, particularly with regard to reproductive and social behaviors, should not be disregarded. Sexual intercourse, lactation, and bonding within family and non-family groups are well-known stimuli to cause OT secretion in various species –38. InteWhile the involvement of OT in the “homeostatic” regulation of food intake has been a widely recognized phenomenon, the past several years have brought exciting discoveries that strongly suggest an implication of central OT in another aspect of consumption: macronutrient preferences and feeding reward. These discoveries have capitalized on linking evidence pertaining to neuroanatomy and functional significance of the OT system outside the realm of classical satiety/feeding termination mechanisms, and they have refined our understanding of OT as not just a “homeostasis rescue molecule,” but also as a neuroregulator of intricate and complex dietary choice processes. Numerous reports have shown widespread distribution of the OT receptor throughout the brain and, importantly, specific sites involved in reward processing, such as the nucleus accumbens and the ventral tegmental area, appear to be prominent central targets of OT signaling , 40. PVNNeuroendocrine and behavioral processes governing food intake and addiction show a partial overlap. For example, an appetite stimulating hormone, ghrelin , activatPioneering studies were performed on OT knockout (KO) mice. Amico and colleagues found that genetic deletion of OT leads to the enhanced initial and sustained intake of palatable sucrose solutions in the KO mice compared to the wild-type (WT) counterparts . The effad libitum access to a 10% sucrose solution versus animals consuming isocaloric Intralipid during that time  penetrant OT receptor antagonist, L-368,899, in both choice and no-choice feeding paradigms , 65. WheMullis and colleagues have recently reported an important piece of evidence linking OT to feeding reward . They eqIntriguingly, while central OT suppresses certain types of feeding reward  and contributes to a reduction of intake and a transient shift in dietary choices, it appears that orexigenic opioid receptor ligands  diminish meal-end activity of hypothalamic OT neurons thereby likely promoting continuation of ingestive behavior. For example, butorphanol tartrate at a dose that promotes overeating of sugary foods dampens OT PVN neuronal activity in rats that have consumed the amount of high-sucrose powder diet that is satiating for saline-treated controls . In ratsEvidence indicates that, aside from facilitating generalized feeding termination, central OT under certain circumstances plays a role of a carbohydrate -specific satiety mediator and, therefore, it may influence the composition characteristics of a freely selected daily diet (a schematic overview of key anatomical components of OT-dependent feeding mechanism are depicted in Figure Aging is associated with disturbances in food intake, notably with a decrease in energy consumption and anhedonia , and thoOne of the greatest challenges is to identify in which of the many physiological and pathophysiological states associated both with shifts in dietary preferences and changes in OT system’s activity, the modified OT tone serves as the causative factor of undesirable modifications in a consumption profile. Unfortunately, our knowledge of changes in the OT system in aging, especially those within the central nervous system, is far from being systematized. The relatively few studies published thus far have presented conflicting evidence in regard to the density of the OT receptor, number of OT neurons, and functional outcomes of exogenous and endogenous OT during the aging process. For example, Fliers and Swaab  reportedThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The emergence of new motor skills, such as reaching and walking, dramatically changes how infants engage with the world socially and cognitively. Several examples of how motor experience can cascade into cognitive and social development have been documented, yet a significant knowledge gap remains in our understanding of whether these observed behavioral changes are accompanied by underlying neural changes. We propose that electroencephalography (EEG) measures such as power, coherence, and mu desynchronization are optimal tools to quantify motor experience in the infant brain. In this mini-review, we will summarize existing infant research that has separately assessed the relation between motor, cognitive, or social development with coherence, power, or mu desynchronization. We will discuss how the reviewed neural changes seen in seemingly separate developmental domains may be linked based on existing behavioral evidence. We will further propose that power, coherence, and mu desynchronization be used in research exploring the links between motor experience and cognitive and social development. For infants, learning new motor skills can fundamentally alter their experiences with the world and with others . Learninneural reorganization play a role in subsequent cognitive and social changes? EEG readily provides the tools to answer such questions regarding motor experience in the infant brain.Using electroencephalography (EEG), researchers have begun to elucidate links between motor experience and neural plasticity . CrucialIn this mini-review, we synthesize existing infant EEG literature on motor, cognitive, and social development. We discuss how seemingly isolated EEG findings within each domain may relate to motor development based on behavioral evidence linking motor experience with cognitive and social abilities. First, however, we provide an overview of EEG and optimal EEG measures for quantifying motor experience in the brain: power, coherence and mu desynchronization.Electroencephalography measures real time electrical activity at the scalp via electrodes in a non-invasive and comfortable manner . EEG hasElectroencephalography power reflects the electrical activity of a particular group of neurons, providing a measure of activity within a cortical region as projected to the scalp. Power is calculated as voltage squared within a given frequency band. Because it is measured over time, power can identify sustained area specific patterns of electrical activity at baseline or during a task . In infa1. Coherence is the squared cross-correlation of activity between spatially distinct electrode sites, providing the degree of interconnection between regions (e.g., strength and number of axons; Finally, mu desynchronization is largely a motor experience-dependent electrical pattern measured over the sensorimotor cortex, typically at central electrode sites . When inIn the following sections we review extant EEG literature on infant motor, cognitive and social development implementing power, coherence, and mu desynchronization. Throughout, we discuss how seemingly disconnected EEG findings across all three domains may be linked based on documented behavioral connections between motor development and cognitive and social abilities.To our knowledge, Coherence is an excellent measure of neural changes as infants shift from non-crawling to crawling, and from crawling to walking . Bell anability and mu desynchronization. Nine-month-olds observed an adult reaching for a toy, and were given the opportunity to reach for the toy themselves. Infant reaching and grasping skill was measured by assessing latency to reach, errors, pre-shaping of the hand, and bimanual reaching. Reach latency was related to mu desynchronization during action observation, with shorter latency correlating with greater desynchronization (Mu desynchronization has quickly gained prevalence in investigating motor related neural changes during infancy . van Elknization . Marshalnization . FindingThe results reviewed here on motor experience and neural activity lend strong support to the idea of a dynamic motor–neural interaction. Nonetheless, power, coherence, and mu desynchronization have not been used in studies documenting motor development longitudinally. Moreover, it is unknown how these motor-related neural shifts are implicated in behaviorally observed motor cascades. These gaps in the literature must be addressed, as information pertaining to motor-related neural changes over time may help elucidate the role of motor development as a “setting event” in non-motor domains.A common measure of infant cognitive development used in conjunction with EEG measures is performance on the A-not-B task, a behavioral measure of working memory and inhibitory control. A-not-B performance has been implicated in individual differences in power. Measuring power and A-not-B performance from 7 to 12 months, Studies measuring coherence during the A-not-B task find that high A-not-B performers at 8 months display significantly lower right hemisphere coherence between frontal pole-medial frontal regions compared to left frontal pole-medial frontal hemisphere coherence, while low performers show no hemispheric differences in coherence between these regions . LongituCurrently, no study has implicated mu desynchronization with cognitive performance. Perhaps researchers conceptualize mu desynchronization as an index of motor experience only, without considering the behavioral links between motor and cognitive development. We speculate that infants who are successful at tasks like A-not-B may display increased mu desynchronization during observation and execution, but actual research is needed to assess how cognition and mu rhythm relate. We know from motor activity in response to novel events (Research on power and infant social development has focused on asymmetrical power between hemispheres. Differential power between left and right frontal regions is considered a marker of individual differences in emotional reactivity to stress with withdrawal-related behaviors being related to greater right versus left frontal activation . Ten-monl events .Coherence has also served as a neural tool in relation to infant social development, specifically in research on initiating joint attention IJA; , 2003. MMu desynchronization has been used as a neural measure in studies of infants’ action perception and imitation . When 8-From behavioral work, it is known that motor experience plays an important role in social development . For exaisolated domains. Research has yet to gain traction on implementing these EEG tools toward understanding the neural mechanisms underlying documented motor cascades in infant cognitive and social development. Development in one domain is likely not isolated from development in other domains, but instead involves dynamic interactions throughout development (As reviewed here, research utilizing power, coherence, and mu desynchronization provides great insight on motor, cognitive, and social development as elopment . Much woelopment , inclusiConceived and wrote the paper: SG, BR-S, and EN.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Medical management of newborn infants often necessitates recurrent painful procedures, which may alter nociceptive pathways during a critical developmental period and adversely effect neuropsychological outcomes. To mitigate the effects of repeated painful stimuli, opioid administration for peri-procedural analgesia and ICU (intensive care unit) sedation is common in the NICU . A growing body of basic and animal evidence suggests potential long-term harm associated with neonatal opioid therapy. Morphine increases apoptosis in human microglial cells, and animal studies demonstrate long-term changes in behavior, brain function, and spatial recognition memory following morphine exposure. This comprehensive review examines existing preclinical and clinical evidence on the long-term impacts of neonatal pain and opioid therapy. Intensive care of sick and premature newborn infants includes multiple painful interventions. During the first two weeks of admission to the NICU , neonates experience an average of 14 painful procedures per day with the majority occurring during the first few days of life [Management of neonatal pain often includes opioid therapy. A growing body of evidence suggests long-term harm associated with neonatal opioid exposure. Morphine increases apoptosis in both human microglial cells  and neurClinicians face many dilemmas in the treatment of neonatal pain. Recent studies have demonstrated a reduction in the number painful procedures performed daily . HoweverIntensive care facilitating survival of infants born at younger gestational ages often entails lifesaving but painful procedures, yet the long-term developmental impact of repeated exposure to noxious stimuli in early life remains poorly understood. Sensory receptors appear early in fetal life , with anPublished data are on the effects of neonatal pain are limited due to a variety of challenges. First, it is difficult to consistently and objectively measure the effects of painful procedures. Most pain assessment tools rely on both objective measures  and behavioral cues . Vital signs can be affected by other factors such as drug administration, body temperature, and intravascular volume status; it can be difficult to discern in a critically ill infant whether a change in vital signs is attributable to discomfort or to the infant’s comorbidities. Behavioral changes are affected by postmenstrual age and temperament, and behavioral responses in preterm infants may be blunted and delayed relative to their term counterparts . Very feInfants born prematurely are at risk for neurodevelopmental delay and disability. While poor neurologic outcomes are likely multifactorial in etiology, the potential for painful stimuli in early life to alter neurologic development remains incompletely understood. For the first two weeks of admission to the NICU, neonates experience an average of 14 painful procedures per day with the majority occurring during the first few days of life ,17. SuchUnderstanding alterations in sensory processing associated with pain is dependent on both the method of evaluation and the age of the child . DespiteAlteration of neuronal responsiveness may explain why repeated exposure to noxious stimuli may alter development of pain perception, leading to hypersensitivity and chronic pain. Although integrated nociceptive pathways are functional by 24–28 weeks gestation, systems modulating pain remain immature . For preSurgery is an obvious source of pain for some neonates, and several studies have focused on how analgesia can mitigate the short- and long-term consequences of postoperative pain. Although it is difficult to assess neonatal perception of pain, postoperative morbidity and mortality are useful endpoints for effective control of postoperative pain. Anand  first deParents play an important role in helping providers assess pain in older children and in those neonates who have been stable enough for discharge home. When parents of former preterm infants were surveyed at 18 months corrected age, they reported lower sensitivity to pain of everyday bumps and bruises. A study of pain response at the eight-month follow-up visit showed that despite ex-preterm infants having hypersensitivity to pin prick, they had faster recovery times than their term counterparts . InteresAlthough it is difficult to control for the effects of comorbidities , it is increasingly clear that pain-related stress can produce long-term changes in the developing brain. Increased numbers of skin-breaking procedures have been recently associated with lower scores on mental and psychomotor indices . FunctioDespite repeated evidence that pain is detrimental to neonates, recent studies have demonstrated that only one third of patients receive preemptive analgesic therapy . Quantifet al. [in vitro on fetal microglia, , astrocytes, and neurons, using caspase-3 expression as a marker for apoptosis. Caspase-3, part of a family of intracellular cysteine proteases, has been directly linked to apoptosis. Microglia, neurons, and astrocytes, were exposed to control, low dose (10−6 M) or high dose (10−4 M) morphine for five days. Their results demonstrated a significant increase in apoptosis of morphine-exposed microglia and neurons via a caspase-3 dependent pathway. Astrocytes did not show this relationship. Apoptosis of morphine-exposed microglia and neurons were reversed by the coadministration of naloxone, strengthening the argument that this is an opioid-mediated phenomenon.While there is mounting evidence supporting the benefits of analgesia for newborns and pre-term infants, opioids have been shown in preclinical and clinical studies to influence neuronal cell death. Multiple opioid receptor agonists have been investigated on their roll in apoptosis including morphine. Researches have utilized multiple assays for assessing morphine’s affect on apoptosis in numerous types of cells including microglia and neurons. Specifically, Hu et al.  investiget al. [et al. [While Hu, et al.  explored [et al.  devised et al. [Katebi et al.  exploredGiven the aforementioned studies, it can be concluded that there is some evidence of morphine altering apoptotic protein expression in various regions of both human and rat brain tissue. However, it should be noted that in all of these animal models, morphine was administered in the absence of noxious stimuli, which provides an incomplete model of analgesia in the NICU and cannot assess the adverse effects of opioid administration weighed against the adverse effects of pain. Extrapolation of data from the preclinical model to human neonates is also complicated by the mature age of the animals, as well as the large doses of morphine used. Adult animal brains are likely to demonstrate less plasticity and recovery while large morphine doses may lead to additional injury by other factors such as hypotension and hypoventilation. In the realm of pediatric anesthesia, it is of vital importance to understand the clinical context, benefits, and potential adverse effects of all medications administered. Although these data do not directly test neuronal apoptosis in human children exposed to opioids, they at least suggest further investigation into what signaling pathways opioids are involved with in addition to pain pathways.The studies of murine and human fetal models discussed above showed that opiate-toxicity may inhibit growth, promote apoptosis, and impair regeneration of glial cells. Based on these studies, there are mounting concerns regarding the use of opiates in human neonates. This is a conundrum particularly in the neonatal ICU, where opiates are utilized to ameliorate pain and decrease agitation, which also have deleterious effects on early neurodevelopment. To adequately assess the impact of opioid therapy on outcomes of sick neonates, a model that takes into account the competing adverse effects of pain and opioid therapy is required.It is well known that pain stimuli reach the cortex, induce pain-specific activation, and alter peripheral and central pain processing in neonates. Repetitive neonatal pain in rats accentuates neuronal excitation and increased cell death in several cortical and subcortical areas, suggesting that pain may have widespread effects on brain development with short- and long-term ramifications. Neonatal rats subjected to repetitive painful injections showed histological evidence of increased brain cell death in the frontal and parietal cortex compared to untreated rats. These effects were exacerbated by increased pain intensity: neonatal rats exposed to severe, inflammatory-type pain had significantly higher brain-cell apoptosis scores and altered expression of proteins involved in early thalamic and cortical development compared to rats exposed to mild pain . EarlierAlthough pain and environmental stressors clearly lead to altered neurodevelopment, assessing the combined effects of stress and opioids on neurodevelopment is complex. Emerging evidence suggests that morphine may have protective effects against nerve cell apoptosis under conditions of pain and stress . Both neAlthough pre-emptive analgesia appears to be neuroprotective, the modulatory effect is limited to specific situations. In neonatal mouse models, morphine exposure had different effects on hippocampal gene expression depending on the severity of environmental stress. Treatment of mild stress with morphine led to increased expression of specific gene sets related to neurodevelopment. In contrast, treatment of severe stress with morphine down-regulated genes involved in RNA processing and neurodevelopmental processes, which could be a mechanism by which morphine leads to decreased brain growth . PotentiMany studies have shown deleterious neuromodulatory effects of opiates, but upcoming research has demonstrated that morphine may have protective effects in specific conditions of pain and stress. Therefore, opioid pharmacotherapy may have an appropriate role in the NICU if appropriately tailored to individual babies who have pain. It remains unclear how long human neonates can safely be exposed to opiates or whether morphine has any significant neuroprotective effects in human neonates. Limited data in human preterm neonates suggests adverse effects from prolonged preemptive exposure to analgesia.There is a growing body of clinical literature on long-term neurodevelopmental outcomes of neonatal morphine administration. Several recent studies have examined large cohorts and employed well-established outcome measures. Three studies are summarized below in Effects on Head Circumference, Social Behavior, and Response Latencies in Early Childhood . This stvs. placebo-treated infants in the original NEOPAIN trial. Notably, early growth in the NICU has been more predictive of developmental outcomes at 5 years of age than growth in the first years following discharge [Somatic growth parameters showed no difference between the groups in height or BMI, but significantly lower weight (effect size 0.81) and head circumference (effect size 2.81) in the morphine-exposed group. One potential explanation for this significant decrease in weight and head circumference measures is the delay in reaching full enteral feeds in morphine ischarge .Neuropsychological outcomes were assessed using standardized tests  and parent questionnaires . Although there were no significant differences between morphine- and placebo-treated children in Stanford-Binet IQ scores or academic achievement as measured by the WRAT4, parental surveys suggested increased social problems in morphine-treated infants. The Conners’ Comprehensive Behavior Rating Scales showed a statistically significant increase in social problems, specifically in the areas of creating and maintaining peer relationships, as rated by parents in the morphine treated group. The Vineland Adaptive Behavior Scale also showed some adverse effects of morphine, but is of limited significance as scores could only be computed for one placebo-treated child.Operant testing was also conducted, in which progressive ratio (PR) task measuring the number of reinforcers earned and delayed matching to sample (DMTS) tasks using press plates and levers to match images and gauge latency and response times were performed. There were no statistically significant differences between the groups in the PR task. However, DMTS testing showed a significant negative effect on task completion in morphine-treated infants (effect size 0.96) and increased choice response latencies  in the morphine group. Incorrect choice latency did not differ between placebo and morphine treated groups.This small study showed no difference in IQ, self-sufficiency, motivation or school-related performance between the placebo and morphine treated groups. These results are consistent with prior studies showing that preemptive morphine administration does not cause significant IQ or academic performance alterations ,49. Howen = 73) or placebo (n = 77), with open-label morphine used for children with clinical evidence of pain [n = 49) and placebo-treated (n = 41) infants in visual-motor integration (Beery VMI score), behavior (parent-completed Child Behavior Checklist and teacher-completed Teacher Report Form), chronic pain, or health related quality of life . Overall IQ scores were slightly but significantly lower in the morphine-treated group, however the negative impact of preemptive morphine treatment vanished when the regression model was revised to adjust for the propensity score and to include open-label morphine therapy and primary ventilation as explanatory variables. In contrast with overall IQ scores, the visual analysis subtest of the IQ test was significantly lower in the preemptive-morphine group, even in multivariate models.“Does Neonatal Morphine Use Affect Neuropsychological Outcomes at 8 to 9 Years of Age?”  is a lon of pain . In a fo of pain , no signThe current study follows up the same children at 8–9 years of age with a goal of extensively assessing the effects of morphine on executive function , intelligence , visual-motor integration (Beery VMI), and behavior (parent-completed Child Behavior Checklist and teacher-completed Teacher Report Form). The CANTAB tests executive function by challenging response speed and movement, short-term memory capacity, rapid recognition of patterns, spatial planning, rule acquisition, set shifting, and response inhibition. The BRIEF questionnaire, completed by parents and teachers, assesses behavioral regulation  and metacognition , in which estimated full-scale IQ is highly predictive of later full-scale IQ.n = 43) and placebo (n = 46) groups in growth parameters, IQ scores, academic skills, visual-motor integration, or in the proportion of children attending mainstream education. Executive function as measured by the CANTAB did not differ between the groups, however the parent-scored BRIEF questionnaires showed that the preemptive morphine group had improved scores in the behavioral regulation (p = 0.006), metacognition (p = 0.03), and global executive composite indices (p = 0.009). Teacher-scored BRIEF questionnaires showed similar trends toward improved executive function in the preemptive morphine group, but these were not statistically significant. Behavioral scores were inconsistent, with the placebo group having more children with externalizing problems identified by parent questionnaire and the preemptive morphine group having more children with internalizing problems identified by teachers.There was no difference between the preemptive morphine  were not observed in this larger study. Notably, the morphine infusion rate that these infants were exposed to (10 mcg/kg/h) was lower than the infusion rates used in the NEOPAIN trial (10–30 mcg/kg/h). Long-term neurologic sequelae related to morphine therapy may be dose-dependent.Neonatal pain, parenting stress and interaction, in relation to cognitive and motor development at 8 and 18 months in preterm infants  investigp = 0.02), and the parents of preterm infants had significantly higher PSI scores than the parents of their term counterparts at both 8 months (p = 0.04) and 18 months (p = 0.03). Several neonatal variables  were significantly correlated with lower MDI and PDI. All of the above were statistically significant correlations at both 8 and 18 months, with the sole exception of morphine exposure, which was correlated with lower PDI but not MDI at 8 months. At 18 months, higher Parent Organization scores and higher maternal education were correlated with better MDI and PDI scores. Hierarchical regression analysis controlling for early illness severity, morphine exposure, and dexamethasone treatment showed that more skin-breaking procedures and more days on the ventilator predicted lower MDI at 8 and 18 months; higher parental education predicted higher MDI at 18 months. Similar analysis of PDI score predictors showed that, when controlled for early illness severity and dexamethasone exposure, both the number of skin-breaking procedures and greater morphine exposure were associated with lower PDI scores (morphine exposure only significant at 8 months), while a greater number of children at home was associated with higher PDI scores.Preterm infants had significantly lower MDI and PDI scores than full-term controls at 18 months (Overall, poor motor and cognitive function were associated with more severe illness, more painful procedures, greater duration of ventilation and greater morphine exposure. Although these variables may be viewed as mere surrogates for increased disease burden, their significant predictive value when controlling for early illness severity suggest that both exposure to painful procedures and exposure to morphine may play a role in the pathogenesis of adverse neurodevelopmental outcomes.Pain management is increasingly recognized as a vital aspect of neonatal care as infants are subject to many painful interventions . Acute pDespite the potential benefits of morphine administration in ameliorating both acute and chronic response to repeated painful stimuli in the preclinical model ,53, therSeveral clinical studies have attempted to examine the long-term developmental impact of neonatal morphine therapy . InteresBased on available evidence, it is clear that morphine reduces the known harmful impact of pain but also acts on multiple developing neurologic pathways. There is no compelling evidence to support severe long-term harm, but subtler behavioral changes have been noted. Morphine use should continue to be based on clinical judgment, with treatment providers continuing to remain aware of an evolving body of evidence. Meanwhile, future studies should focus investigate the role for and long term effects of alternative analgesics such as acetaminophen and remifentanil. The limitations of the data on the long-term effects of neonatal morphine therapy may be seen as a reflection of the dilemma faced by all physicians caring for neonates, who must carefully weigh the benefits of acute interventions against the potential for long-term harm.


Hemifacial spasm (HFS) is characterized by involuntary unilateral contractions of the muscles innervated by the ipsilateral facial nerve, usually starting around the eyes before progressing inferiorly to the cheek, mouth, and neck. Its prevalence is 9.8 per 100,000 persons with an average age of onset of 44 years. The accepted pathophysiology of HFS suggests that it is a disease process of the nerve root entry zone of the facial nerve. HFS can be divided into two types: primary and secondary. Primary HFS is triggered by vascular compression whereas secondary HFS comprises all other causes of facial nerve damage. Clinical examination and imaging modalities such as electromyography (EMG) and magnetic resonance imaging (MRI) are useful to differentiate HFS from other facial movement disorders and for intraoperative planning. The standard medical management for HFS is botulinum neurotoxin (BoNT) injections, which provides low-risk but limited symptomatic relief. The only curative treatment for HFS is microvascular decompression (MVD), a surgical intervention that provides lasting symptomatic relief by reducing compression of the facial nerve root. With a low rate of complications such as hearing loss, MVD remains the treatment of choice for HFS patients as intraoperative technique and monitoring continue to improve. HFS starts with tonic-clonic contractions of the orbicularis oculi muscle, resulting in involuntary eyelid closure and eyebrow elevation. Over time, the contractions progress to the region affecting the frontalis , platysma , and orbicularis oris  muscles –5. EventP < 0.001) of presenting with rosacea, a chronic condition characterized by facial erythema, fine telangiectasia, papules ocular irritation, and rhinophyma [Some patients will report worsening of spasms with fatigue, situations of anxiety, and changes in position of the head  . One stuinophyma .HFS is prevalent in 9.8 per 100,000 persons –13. ThisFamilies with HFS present with autosomal dominant inheritance and low penetrance although there have been only a few reported cases . In addiThe accepted underlying pathophysiology of HFS suggests that the disease process is caused by facial nerve root entry zone myelin breakdown and ephaptic transmission, which is the passage of neural impulses through artificial chemical or chemical synapses. The root exit zone of the facial nerve is defined as the transition point between central (oligodendrocytes) and peripheral (Schwann) cell myelination , 21. ThiEctopic excitation can result from an area along the nerve that generates impulses independently of the natural synapse when the excitation threshold is low due to processes such as demyelination. One study examined orbicularis oris muscle response using EMG after supraorbital nerve stimulation and lateral spread tests with diazepam injections; the study results showed consistent latent muscle responses, which implicate ectopic excitation and ephaptic transmission .Two hypotheses for the hypotheses of the HFS pathophysiology exist. The nuclear/central hypothesis suggests that injury to the facial nerve causes regressive medullary changes with functional connective reorganization in the facial nucleus, causing nuclear hyperexcitability because of dendritic spike generation . The perAnother hypothesis is the sympathetic hypothesis. The adventitia of arteries contains sympathetic endings and is worn down in HFS, causing neurotransmitters to induce ectopic action potentials that travel to the neuromuscular junction and induce involuntary contraction of facial muscles . Using HThe etiology of HFS can be divided into two types: primary and secondary. Primary HFS is defined by vascular compression of the facial nerve root entry zone in the posterior fossa , 31. ImpSecondary HFS occurs with damage anywhere along the facial nerve from the internal auditory canal to the stylomastoid foramen . Cases oCollectively, these underlying issues of secondary HFS are thought to cause neural dysfunction and/or irritation of the facial nerve pathway . HearingThe diagnosis of HFS is made clinically. The “Babinski-2 sign,” “other Babinski sign,” or “brow-lift sign” is a physical exam maneuver that is positive when a patient lifts his/her eyebrow with ipsilateral eye closure, signaling the synchronized activity of the frontalis and orbicularis oculi muscle during HFS –44. ThisEMG, MRI, and computerized tomography (CT) are used to confirm the diagnosis and differentiate primary from secondary HFS. Of these modalities, T2-weighed MRI sequences and high resolution fast imaging employing thin section steady-state free precession MR images are most commonly used to display possible vascular compressions . Fusion All these diagnostic techniques help differentiate HFS from other craniofacial dyskinesias such as blepharospasm (BSP), tic disorders, myokymia, and synkinesis in addition to other disorders such as partial motor seizures, craniocervical dystonia (Meige syndrome), tardive dyskinesias (TD) and neuromyotonia. Other conditions such as psychogenic HFS, facial myoclonus, oromandibular dystonia, and hemimasticatory spasm can masquerade as HFS, resulting in diagnostic difficulty . One casComorbidity between HFS and other craniofacial dyskinesias can occur. Trigeminal neuralgia (TN) is irritation of the trigeminal nerve that causes facial pain. It can present concurrently with HFS in a syndrome called tic convulsif. Studies have shown that HFS can follow Bell's palsy, which is facial paralysis from dysfunctional facial nerve caused by brain tumor, stroke, myasthenia gravis, and Lyme disease . HFS hasThe standard medical treatment for HFS is botulinum neurotoxin (BoNT) injections. Having been used since the early 1980s, BoNT injections provide low-risk symptomatic relief in 85% of HFS patients, making it the treatment of choice for patients with high anesthetic risk and those who refuse surgery . One stuBoNT's mechanism of action is to block calcium-mediated release of acetylcholine at the synaptic junction. Two serotypes are available: BoNT-A and BoNT-B, as well as four different commercial formulations: abobotulinumtoxinA, onabotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB . After iBoNT-A is the primary serotype used for HFS treatment. BoNT-A injections occur in several sites in the pretarsal and preseptal portions of the facial nerve and are effective with a mean onset of action of 3 to 5 days. In one longitudinal multicenter center study, the effectiveness of BoNT-A in relieving HFS symptoms remained unchanged in the first and tenth year with patients needing statistically similar doses . HoweverPharmaceuticals such as anticonvulsants and GABAergic drugs may be used as alternative to BoNT injections. These drugs are generally less effective compared to BoNT at treating HFS. No controlled studies have found demonstrated long-term effectiveness of these medications, limiting their treatment utility. However, they can be used for symptomatic relief in early HFS patients who have mild and infrequent symptoms as well as patients who decline BoNT injections and/or surgical intervention.As an alternative to BoNT injections, microvascular decompression (MVD) provides a curative treatment with long-term relief of symptoms by alleviating vascular compression of the facial nerve root. The underlying principle of MVD is to separate the nerve-vessel conflict rather than isolate it with prostheses; important intraoperative considerations include prompt identification of the neurovascular conflict site, sharp dissection of arachnoids for maximal nerve root visualization, and electrophysiological monitoring to distinguish offending vessels . MVD hasAn analysis of twenty-two papers representing 5,685 patients treated with MVD for HFS found that an average of 91.1% of patients had complete resolution of symptoms over a median 2.9-year follow-up period . Even wiBefore MVD, MRI imaging is used to identify the offending vessel and exclude structural pathology such as meningioma, acoustic neuromas, or epidermoid tumors. One study showed that preoperative assessment of HFS using T2-weighted MR cisternography predicted 79.1% of offending vessel invagination into the brainstem, allowing for better preoperative planning .Under general anesthesia, the patient is typically placed in either supine or the lateral decubitus position ; a craniIntraoperative EMG monitoring of facial nerve AMR increases safety of the operation and improves MVD outcomes. Outcomes of MVD can be optimized when the full length of the facial nerve is confirmed to be clear of the offending vessel, all offending vessels double-checked to be removed from the nerve, and AMRs disappear . One stuIndividual surgical methods vary. One postoperative study with an average follow-up term of 13 years suggested a “supine, no retractor” system having fewer adverse effects during general anesthesia with lower risks of postoperative nausea/dizziness, peripheral nerve palsy, and deafness . TechniqResolution of HSF after MVD may take several months to several years with small percentage of patients who fail to improve. In these patients, failure to improve may be attributed to inadequate decompression of the offending vessel, presence of a previously unidentified secondary offending vessel, or implant compression/migration against the facial nerve . GeneralA few cases of cerebrospinal fluid (CSF) leakage, cerebellar injury, and lower cranial nerve complications have been reported as well as life-threatening complications, such as space-occupying hemorrhages and cerebellar/brainstem infarctions . A retroHospital-wide protocols are also optimizing patient outcomes and containing costs. After one institution implemented enhanced-recovery perioperative protocols and diagnosis-specific clinical pathways in patients undergoing MVD for HFS and trigeminal neuralgia, it reported decreased operating room times, hospital stay length, and a reduction in rates of complications and readmissions . ConcurrOverall, MVD remains the treatment of choice for patients with HFS as the development of intraoperative technique and monitoring continues to improve.


While numerous changes in human lifestyle constitute modern life, our diet has been gaining attention as a potential contributor to the increase in immune-mediated diseases. The Western diet is characterized by an over consumption and reduced variety of refined sugars, salt, and saturated fat. Herein our objective is to detail the mechanisms for the Western diet’s impact on immune function. The manuscript reviews the impacts and mechanisms of harm for our over-indulgence in sugar, salt, and fat, as well as the data outlining the impacts of artificial sweeteners, gluten, and genetically modified foods; attention is given to revealing where the literature on the immune impacts of macronutrients is limited to either animal or in vitro models versus where human trials exist. Detailed attention is given to the dietary impact on the gut microbiome and the mechanisms by which our poor dietary choices are encoded into our gut, our genes, and are passed to our offspring. While today’s modern diet may provide beneficial protection from micro- and macronutrient deficiencies, our over abundance of calories and the macronutrients that compose our diet may all lead to increased inflammation, reduced control of infection, increased rates of cancer, and increased risk for allergic and auto-inflammatory disease. The Western diet is characterized by a high intake of saturated and omega-6 fatty acids, reduced omega-3 fat intake, an overuse of salt, and too much refined sugar . Most arIntake of adequate calories and micronutrients is vital for optimal immune function. Deficiency in total calories and/or protein, as seen in parts of the world stricken with starvation, severely reduces the immune system’s ability to respond . As one Adipocytes release inflammatory substances including interleukin (IL-) 1, IL-6, and tumor necrosis factor (TNF) . In animObese individuals have fewer white blood cells to fight infection and those cells they do possess have reduced phagocytosis capability ,12. WhilEating disorders currently attributed to image obsession are also an unfortunate part of modern dietary habits and their immune impacts have gone relatively ignored compared to obesity. While the nutrient deficiencies seen in eating disorders are not nearly as severe as for the starvation seen in developing nations, subtle deficiencies appear to lead to subtle immune defects . Both anIn vitro evidence suggest processed, simple sugars also reduce white blood cell phagocytosis and possibly increase inflammatory cytokine markers in the blood ,25; of nAnimal studies suggest that high salt in the diet might also increase IL-17-mediated inflammation and could worsen autoimmune diseases, although predictions on how this may affect humans should only be seen as preliminary ,42. Ther2) pathways [2 is pro-inflammatory, increasing IL-17 production and macrophage activation among other pathways [One potentially harmful effect of fat is enhancement of the prostaglandin system as it feeds into the arachadonic and prostaglandin E2 . While complex in its workings, when the immune system comes across a potential invader these receptors are designed to evaluate if it is bacterial, viral, or fungal. If the body finds evidence of any of these organisms, the immune system can begin its attack immediately while the adaptive immune system assesses what specific pathogen it is facing . One of ogenesis ,52,59,602 and concluded that the lack of detectable impact in human clinical trials indicates that the cell-culture and animal based evidence against n-6 fails to accurately reflect the complexity of human physiology. However, one confounder shared by many of the clinical trials investigating the immune impacts of fatty acids may be their exclusion of unhealthy subjects and subsequent lack of disease context. While retrospective studies are limited in their own ways, an intervention study investigating an ubiquitous exposure like dietary n-6 that excludes everyone with pre-existing inflammation may be excluding the biologically susceptible portion of the population and thus may be predestined to find no impact of their intervention; while the lack of baseline inflammation in clinical trails could alleviate the concern for omega-6 as a universal inducer of chronic inflammation, since these trials occur in the absence of either infectious challenge or underlying inflammatory disorders they make no comment on potential for n-6 intake to impact the risk for, control of, or inflammation during, acute pathology. Additionally, clinical trials involving n-6 have yet to measure inflammatory markers that are downstream of the elevated PGE2 (such as IL-17 and the Th17 pathway) [While saturated fats are the most inflammatory ,61,62, opathway)  or direcpathway) . Furtherpathway) . Thus, fThe immune impact of trans unsaturated fatty acids (trans fats) have gone under investigated whilst researchers focus on their deleterious cardiovascular effects, however one study found an increase in IL-6 and CRP but only in the overweight female subgrouping . In contRecent animal and cell-culture models have found that elements in gluten can stimulate inflammation through TLR4 ; while tThe notion that diet, stress, and environment can, for better or worse, imprint upon the bowel has been around since the ancient Egyptian pharaohs . HoweverWhat is perhaps of larger concern is that the harmful effects of diet can actually stretch across generations. A mother’s diet may potentially shape her child’s flavor preferences even before birth, potentially skewing their palette towards anything from vegetables to sugary sweets in ways that could influence subsequent propensity for obesity and/or unhealthy dieting . In addiHowever, lest fathers believe that their diet does not impact the offspring, paternal epigenetics related to methylation of DNA and histones can also be inherited by the offspring and could alter early development of the immune system . EpigeneIn addition to altering TLR-mediated inflammation and potentially DNA epigenetics, a mechanism by which alteration in microflora may drive immune-mediated disease involves the gut bacteria’s effect on regulatory T-cells (Tregs), the cell tasked with keeping the immune system in balance during both inflammation and homeostasis . AlteratLactobacillus species including alleviating traveler’s diarrhea, reducing respiratory infections, and serving as adjunct treatment for allergic rhinitis, asthma, and atopic dermatitis [Lactobacillus, Lactococcus, and Bifidobacterium species reduce the rate and severity of childhood atopic dermatitis when fed to pregnant women during the later weeks of gestation [Clostridium difficile[Blautia species and increases levels of both colonic and blood IL-10 in mice, although a direct link between the two was not established [Blautia were found in children with type-I diabetes [Blautia were seen in human patients with inflammatory bowel disease [Eubacterium is associated with increased incidence of Crohn’s disease [Clostridium coccodies and C. leptum are protective against inflammatory bowel disease [Unraveling which specific bacterial strains are either the protectors or pathogens has not yet been elucidated in either mice or humans, however the field of microbiota research has many informative discoveries. The desire to foster a healthy microbiome is the driving force behind the therapeutic use of probiotics. Some studies have shown a positive impact for probiotic use including numerous and well reviewed immune beneficial effects of rmatitis . Supplemestation . Additioestation  and evenestation ,134. Eviestation . As statestation ,92 whileablished . Reductidiabetes  and, amodiabetes  and micediabetes . However disease , possibl disease  while in disease  and infl disease . MeanwhiHowever, any hope for long-term benefits from probiotics may be limited by the need for dietary modification. Gordon and colleagues demonstrated that alterations in the mouse gut microbiome could prevent obesity, however these effects were dependent upon changing from a high-fat, low-fiber Western-style diet, to a healthier standard mouse diet . While tH. pylori for stomach [Although dietary factors are thought to account for up to one-third of cancers in Western nations , the com stomach , hepatit stomach , and Hum stomach ). In gen stomach , whether stomach . Colon c stomach -159. Exc stomach ,160. Evi stomach .Palmitic acid may potentiate iron-mediated toxicities and increase the rates of DNA mutations while inhibiting the normal apoptotic pathways -163. DieThere is some evidence suggesting anti-tumor properties for vitamin E -175, vitS. bovis and certain adhesive/invasive strains of E. coli[The exact mechanism of how any individual dietary element impacts cancer development is far from fully understood. Many of the reportedly protective vitamins and minerals share anti-oxidant properties, suggesting a mechanism more related to protection of DNA from damage than altered immune function -193. Dief E. coli-199. YetAnother area of concern involves genetically modified organisms (GMO) in the food supply. While the debate around GM foods tends to be conducted in an all-are-good or all-are-bad format, some distinctions are notable in the literature. Potential benefits are highlighted by GM rice strains modified to produce high levels of beta-carotene. Vitamin A deficiency severely impairs immune function and thus any alleviation could produce dramatic benefit in parts of the world with both low nutrient supply and high exposure to pathogens . While nThe possibility of inducing allergic reactions through genetic modification was outlined when genetic elements from Brazil nuts were grafted into soy with deleterious consequences . HoweverHowever, an additional concern was raised when studies revealed that functional genes, from both industrial and natural sources, ingested by animals could be internalized by gut bacteria, these bacteria transcribe the engrafted genes into functional proteins, and the genetic changes could be inherited by offspring via microbiome transfer -218. HumThe original name for TNF-alpha was cachectin, derived from its observed ability to induce profound weight loss (cachexia) and appetite suppression . AlthougBeyond the well-known common antigens, coloring and flavoring additives such as annatto and carmine may cause anaphylaxis in sensitized patients and drive labeling laws that influence dietary choices . UnfortuFinancial limitations are often cited as a primary factor behind the higher consumption of unhealthy food products in a nation’s poor ,228. Yetsecondary immune dysfunction through resultant diseases such as diabetes, adding greater emphasis on eating a healthy diet; the impacts of diet on the risk of metabolic disorders and the immune defects in diabetes have also been well reviewed [While the plentiful bounty of the Western world may protect us from the harmful immune effects of micro- and macronutrient deficiencies, the over abundance of many substances simultaneously enhance inflammation while muting our immune system’s ability to respond to and ultimately control infections. The nutritional elements discussed herein are certainly not the entire explanation for the disease patterns seen in industrialized societies, and additional immune harms stemming from our increasingly sedentary lifestyles, altered infectious exposures, as well as increased exposure to pollutants warrant their own reviews ,234,235.reviewed -240. Addreviewed ,242. Onereviewed , fruits reviewed ,244-246.Table The author declares that he has no competing interests.


Sepsis, a leading cause of death in critical care patients, is the result of complex interactions between the infecting microorganisms and the host responses that influence clinical outcomes . ReliablCritical patients with suspected sepsis admitted to the Unit of Intensive Care of the University Hospital of Catanzaro  were recruited into this study; healthy volunteers were also included as controls. Plasma samples in EDTA from each patient were collected at multiple time points; samples were tested for CRP, PCT and presepsin. Blood cultures were also evaluated and processed by a BacT/Alert 3D system ; CRP was measured by immunonephelometry  and PCT was assayed by an enzyme-linked fluorescent assay ; presepsin levels were measured by rapid automated PATHFAST immunoanalyzer , based on chemiluminescent enzyme immunoassay. A statistical analysis was carried out by Mann-Whitney test.Presepsin and PCT levels were significantly higher in culture-positive subjects versus negative controls; such difference was found even at the admission time. The presepsin values in worsening/dead patients exhibited a significantly higher level at admission time. On the contrary, in the same group of patients, PCT exhibited a decrease of its level. In poor prognosis patients CRP showed a quite irregular kinetic, although in such a group the admission value was higher than the same marker in live subjects.In this preliminary study, presepsin and PCT levels exhibited substantial higher values in culture-positive patients. The kinetic curves of presepsin, obtained from both survival and worsening/dead subjects, revealed the optimal performance of this biomarker, particularly in severely ill patients, as also shown in other studies. During sepsis, increase of presepsin levels may be a more reliable marker, indicating an unfavorable outcome ,4. Furth


A recently discovered dimension of post-transcriptional gene regulation involves co-regulatory crosstalk between RNA transcripts, which compete for common pools of microRNA (miRNA) molecules. These competing endogenous RNAs (ceRNAs), or natural miRNA sponges, have an active role in regulating miRNA availability within the cell and form intertwined regulatory networks. Recent reports have implicated diverse RNA species including protein-coding messenger RNAs and non-coding RNAs as ceRNAs in human development and diseases including human cancer. In this review, we discuss the most recent discoveries that implicate natural miRNA decoys in human cancer biology, as well as exciting advances in the study of ceRNA networks and dynamics. The structure and topology of intricate genome-scale ceRNA networks can be predicted computationally, and their dynamic response to fluctuations in ceRNA and miRNA levels can be studied via mathematical modeling. Additionally, the development of new methods to quantitatively determine absolute expression levels of miRNA and ceRNA molecules have expanded the capacity to accurately study the efficiency of ceRNA crosstalk in diverse biological models. These major milestones are of critical importance to identify key components of ceRNA regulatory networks that could aid the development of new approaches to cancer diagnostics and oligonucleotide-based therapeutics. MicroRNAs (miRNAs) comprise a class of small non-coding RNAs implicated in post-transcriptional RNA regulation. These RNA molecules are approximately 22 nt in length and bind to miRNA response elements (MREs) on target transcripts through sequence complementarity, usually inducing repression or destabilization of the target transcript ,2. A sinAlthough the miRNA field is relatively young, a miRNA-based therapeutic has already entered phase 2 clinical trials ,12. In cArabidopsis thaliana [Herpesvirus saimiri [In a similar fashion to how artificial miRNA sponges regulate the expression of endogenous miRNAs, it has been recently demonstrated that endogenous transcripts which contain MREs can interact and co-regulate each other through competition for common miRNA pools in the cell, acting as endogenous miRNA sponges or competing endogenous RNAs (ceRNAs) ,18. Thisthaliana , the pri saimiri , zebrafi saimiri , and mic saimiri ,24.The implication of ceRNAs in humans has been extended from normal cell differentiation to tissue development and pathology, since relevant ceRNA functionality has been associated with the self-renewal capacity of embryonic stem cells , muscle in cis but also the associated ceRNA interactions. The dysregulation of ceRNA interactions may, in turn, have profound implications for cancer initiation, maintenance, or progression. Thus, it is perhaps unsurprising that significant research efforts thus far on ceRNA-mediated post-transcriptional regulation have focused on cancer initiation, maintenance, or progression  is perhaps that of the tumor suppressor gene t manner . In a refor PTEN . Additiofor PTEN -36.Recent reports have provided increasing support for the ceRNA activity of long non-coding RNAs (lncRNAs), suggesting that the characterization of ceRNA networks may enable researchers to systematically study the function of these largely uncharacterized RNA transcripts. In addition, lncRNAs often display specific expression patterns in different cell types, tissue types, developmental stages, and disease , making One such example is linc-RoR, which had already been shown to control self-renewal and maintain pluripotency of human embryonic stem cells by acting as a miR-145 ‘sponge’ and thus controlling OCT4, NANOG, and SOX2 expression . SimilarBARD1. The newly discovered lncRNA BARD1 9′L is transcribed from an alternative intronic promoter of the BARD1 gene, and was found to share both miR-203 and miR-101 MREs with BARD1 mRNA in their homologous 3′UTRs [BARD1 and cancer-associated BARD1 mRNAs were downregulated by miR-203 and miR-101, and lncRNA BARD1 9′L counteracted the effect of these miRNAs. These data support a role for BARD1 9′L as a tumor suppressor transcript through its ceRNA activity.Another example of lncRNA-mediated ceRNA regulation involves the tumor suppressor gene s 3′UTRs . MoreoveConversely, the ceRNA activity of lncRNAs has also been shown to have an oncogenic effect: The lncRNA HOTAIR was shown to display ceRNA activity in gastric cancer cells, in which it was found to specifically bind the tumor suppressor miR-331-3p, modulating HER2 de-repression . In addiBRAF pseudogene (BRAFP1) in regulating the expression of BRAF in a miRNA-dependent manner [BRAFP1 functions as a ceRNA for BRAF in part by sponging miR-30a, miR-182, and miR-876, and that the oncogenic effect of BRAFP1 overexpression in vitro was at least partly mediated by the upregulation of BRAF expression and subsequent activation of MAPK. Moreover, the authors presented a mouse model overexpressing full-length murine B-Raf pseudogene that developed an aggressive malignancy resembling human diffuse large B cell lymphoma. This study is the first one to demonstrate the oncogenicity of a pseudogene in an engineered mouse model, and provides further in vivo support for the role of ceRNA-mediated miRNA sequestration on cancer development.A very recent report explored the role of the t manner . This stbona fide ceRNA interactions in diverse biological settings, several open questions remain about the physiological relevance of these interactions [Although there are increasing reports describing ractions . Factorsractions ,43,44. Iractions .in silico mathematical mass-action model to determine the optimal conditions for ceRNA interactions, Ala et al. identified several molecular determinants for effective ceRNA crosstalk [Several recent reports have described various computational models that have shed light on the specific molecular requirements for effective ceRNA interactions both at steady-state conditions, and in dynamic conditions when the system transiently responds to perturbations around the threshold level -50. Usinrosstalk . These drosstalk . Interesrosstalk , as wellrosstalk . In addiDespite the differences in the mathematical approaches, interaction parameters, and assumptions for these studies, several common conclusions can be drawn. For instance, optimal ceRNA-mediated regulation was observed to depend heavily on the miRNA/ceRNA ratio ,47,50, cInterestingly, ceRNA crosstalk appeared to represent a viable mechanism to achieve fast, positive changes in transcript levels . AdditioThese mathematical models also led to some unexpected findings. For example, ceRNAs may interact with other ceRNAs directly and/or indirectly . In the As an essential complement to the above-mentioned analyses, which were largely computational, a number of recent studies have sought to experimentally quantify miRNA and target cellular abundance as well as miRNA target affinity. In a landmark study, a quantitative assessment of genome-wide miRNA regulation in the context of ceRNA crosstalk was performed in embryonic and mesenchymal stem cells, using Ago2 individual-nucleotide resolution UV crosslinking and immunoprecipitation, together with absolute miRNA and mRNA quantification . They foHMGA2 mRNA was shown to decoy the highly abundant let-7 miRNA family, thus regulating TGFBR3 expression and enhancing TGF-β signaling [HMGA2 transcript was proposed to promote lung cancer progression. Critically, the authors found that HMGA2 and TGFBR3 transcripts were expressed at similar levels, and that total let-7 family expression was within an order of magnitude of these transcripts in the lung cancer cell line tested. These data suggest that in certain settings, even highly abundant miRNAs such as let-7 may be effectively regulated by ceRNA interactions. Furthermore, the precise topology of ceRNETs may result in bona fide ceRNA regulation which may seem improbable based purely on specific miRNA/mRNA ratios. For example, mathematical modeling has predicted that effective interactions between two ceRNAs can be mediated by a large number of shared miRNAs, which may each only have a weak effect on ceRNA levels [As discussed above, several computational and experimental studies have suggested that high abundance miRNAs may not be susceptible to effective ceRNA regulation. However, exceptions to this hypothesis may exist. The ignaling . This ceA levels . This suIndeed, the effectiveness of ceRNA crosstalk has been shown to vary in different physiological settings. For example, two recent studies examined the effect of sequestering the liver-specific miR-122. Denzler et al. analyzed the stoichiometric relationship between miR-122 and its targets in hepatocytes in both physiological and pathological conditions . Due to in silico and in vitro evidence indicating that the overall stoichiometry of the interacting molecules and miRNA/ceRNA binding affinity are critical determinants of effective crosstalk between ceRNAs in vivo. These factors should be considered when investigating novel ceRNA transcripts and networks, especially those of relevance to specific human disease conditions, to facilitate the successful translation of research results to clinical settings.These studies present accumulating Most ceRNA interactions reported to date have been between a pair of interacting transcripts. However, the ability of a single miRNA to bind and regulate multiple transcripts and the regulation of a single transcript by multiple different miRNA molecules allow the effects of relative changes in miRNA/ceRNA ratios to percolate through intertwined ceRNETs and affect the expression of distant ceRNAs. It is thus critical to begin to unravel the complexities of this regulatory crosstalk in genome-scale ceRNETs.in silico prediction of ceRNA crosstalk. These predictions can be expanded, with the appropriate statistical treatment, to potentially generate genome-scale ceRNA network data for different biological processes, including cancer. Using this approach, breast and thyroid cancer-specific mRNA ceRNETs were recently described by two independent groups [The availability of genome-wide miRNA-, mRNA-, and other transcript expression data in large cancer patient datasets, together with the development of novel algorithms and bioinformatic tools, enable the t groups ,58. Altht groups , and to Recently, a lncRNA-miRNA-mRNA ceRNET was predicted computationally in breast cancer patients . This reRecently, an intriguing new facet of ceRNET dysregulation in cancers was reported. Exome sequencing data from a large set of prostate cancer patients was analyzed to examine the effect of alternative cleavage on 3′UTRs and polyadenylation dynamics on putative ceRNET interactions . Cancer The potential of studying ceRNA crosstalk in the context of larger interconnected networks, rather than isolated ceRNA pair interactions, opens exciting possibilities for the study of ceRNA-mediated post-transcriptional regulation in cancer in a setting that is closer to physiological and pathological conditions. However, there are still several considerations limiting the practical applicability of ceRNET study. One main limitation is the dependence of many ceRNA prediction tools on miRNA target prediction algorithms. Despite improvements in the field, these algorithms are not fool-proof due to our incomplete understanding of the rules for miRNA target recognition. This is particularly relevant for the prediction of mammalian miRNA and subsequent ceRNA networks, as mammalian miRNAs often pair with imperfect complementarity to their target transcripts. Although ceRNA prediction analysis has been successfully performed using validated miRNA interactors in the context of PTEN , miRNA tAdditionally, given the scale of high-throughput data and the number of interactions taken into account, careful statistical treatment of the data needs to be performed for global ceRNET study. Moreover, the discovery of novel ceRNA interactions rely, in many cases, on the significant co-regulation of transcripts in cancer patient expression data. However, it has been reported that significant expression correlation among ceRNAs can emerge in experimental readouts due to transcriptional fluctuations even in the absence of miRNA-mediated crosstalk .The development of high-throughput experimental validation of ceRNA interactions would thus be central to the expansion of our knowledge about ceRNETs and applicability for clinical practice in the future. Recent advances in techniques enabling the high-throughput sequencing of immunoprecipitated RNAs after crosslinking  provide a biochemical method to identify relevant miRNA target interactions . For insIn recent years, diverse RNA species including mRNAs, pseudogenes, small non-coding RNAs, lncRNAs, and circular RNAs have all been shown to possess ceRNA activity in defined biological settings. Given the vast amount of genome-wide transcript expression data, and advances in the computational management of this publicly available data, we anticipate that reports of the ceRNA function of various RNA transcripts will continue to increase. Since miRNA decoying capacity is independent of protein-coding function, it has been proposed that the ceRNA activity of coding transcripts may allow them to exert independent and even opposing roles to their encoded protein in initiating or maintaining tumorigenic properties . This inIn addition, ceRNA-mediated post-transcriptional regulation has opened the exciting possibility of methodically studying and functionalizing the non-coding transcriptome. In this respect, the identification of previously uncharacterized lncRNAs as ceRNA counterparts for mRNAs is flourishing. Interestingly, protein-coding genes that produce lncRNAs are over-represented in cancer association studies, being twice as likely to be associated to cancer as human protein-coding genes overall . MoreoveMost of the work done so far has focused on the study and quantification of key interacting RNA species such as miRNAs, mRNAs, lncRNAs, and other ceRNA transcripts. Future work investigating the potential interplay of ceRNAs with RNA binding proteins (RBPs) will provide further insights into the complexities of ceRNA crosstalk. Interestingly, the dynamic recruitment of Ago-interacting RNA-biding proteins has been shown to alter miRNA/target affinity ,67. A reOne of the most exciting advances in the ceRNA field in recent times has been the potential ability to computationally determine the structure and topology of miRNA and ceRNA interactions in interconnected ceRNETs, and harness mathematical modeling to study the dynamic behavior of these ceRNETs in response to fluctuations in the expression of ceRNAs and miRNAs in the network. Furthermore, the quantitative determination of absolute expression levels of miRNA and ceRNA molecules expands the capacity to accurately study the efficiency of ceRNA crosstalk in diverse physiological and pathological conditions. We anticipate that the systematic analysis of ceRNET dynamics would allow for the discovery of new oligonucleotide gene therapies, targeting highly connected nodes, which, unlike non-essential players in the network, may cause severe cellular damage when disrupted .in vivo need to be carefully examined to determine whether this dysregulation will lead to significant perturbation of ceRNA crosstalk in specific biological settings. The integration of this information with genome-scale ceRNET dynamics will be important to determine which ceRNAs are highly connected target hubs, less likely to be susceptible to compensation by alternative signaling pathways.A better understanding of the molecular conditions in which ceRNA interactions occur is of critical importance to facilitate the study of this dimension of post-transcriptional regulation. Fluctuations in both miRNA and ceRNA levels Multiple mechanisms may contribute to the dysregulation of miRNA and associated ceRNA interactions in cancer. For example, single nucleotide polymorphisms (SNPs) located in specific miRNA binding sites have been shown to modulate the binding of miRNAs to these target sites. A panel of 30 proto-oncogene associated SNPs that may impair miRNA target interactions was recently identified, and a subset of these was further associated with therapeutic outcome in cancer patients . In addiin vivo [In conclusion, the study of miRNA and ceRNA networks will open up new avenues for basic cancer research, as well as facilitate the development of novel diagnostic and therapeutic tools. For example, the silencing of aberrantly expressed miRNAs in cancer has been achieved through antisense oligomers, and recent advances in targeted delivery to tumor cells have shown promise in mouse models in vivo . The ide


Disruptions to inhibitory control are believed to contribute to multiple aspects of drug abuse, from preexisting vulnerability in at-risk individuals, through escalation to dependence, to promotion of relapse in chronic users. Paradigms investigating the suppression of actions have been investigated in animal and human research on drug addiction. Rodent research has focused largely on impulsive behaviors, often gauged by premature responding, as a viable model highlighting the relevant role of dopamine and other neurotransmitters primarily in the striatum. Human research on action inhibition in stimulant dependence has highlighted impaired performance and largely prefrontal cortical abnormalities as part of a broader pattern of cognitive abnormalities. Animal and human research implicate inhibitory difficulties mediated by fronto-striatal circuitry both preceding and as a result of excessive stimulus use. In this regard, response-inhibition has proven a useful cognitive function to gauge the integrity of fronto-striatal systems and their role in contributing to impulsive and compulsive features of drug dependence.This article is part of a Special Issue entitled SI:Addiction circuits. •Human and animal response-inhibition can inform substance dependence theorizing.•Response-inhibition difficulties contribute to impulsivity and compulsivity.•Response-inhibition can serve as a useful measure of fronto-striatal integrity. The psychological construct of response-inhibition has been applied broadly in several contexts but particularly to the psychological functions pertaining to overriding a planned action, or stopping a repetitive maladaptive behavior . Investi2prior to cocaine exposure suggests the possibility that at least some impulsivity is not simply caused by drug abuse but can also be antecedent to it .The psychological construct of response-inhibition has been influential in at least two aspects of the animal literature pertaining to the neurobiology of drug addiction. Both impulsivity and compulsivity require the notion of response-inhibition. Impulsivity can be defined as risky or premature behavior, for example when it is necessary to wait for the appropriate signal to perform a prepared response, whereas compulsivity can be defined as maladaptive preservative behavior . Drug abThe most parsimonious explanation of this deficit is that behavioral inhibition impairment is caused by a malfunctioning nucleus accumbens. However, other data indicate that the role of the nucleus accumbens in modulating this premature responding is influenced by both ‘top-down’ and ‘bottom-up’ neural influences: structures contributing to ‘top-down’ control include the infralimbic cortex and cingulate cortex  whereas The high impulsive rats also show impairments of impulsive choice; that is, they consistently choose small immediate food rewards rather than larger, delayed ones , similarThis work on impulsivity is also relevant to research on relapse, where exposure to drugs, stress or conditioned stimuli may elicit drug-taking and drug-seeking behavior . There a3The classic phenomenon is the reinstatement of drug-seeking behavior following its extinction by stress, drug primes or conditioned stimuli . The parFor drug-primed relapse in rodents, manipulations of the ventromedial PFC, such as inactivation by a mixture of GABA-A and GABA-B agonists (muscimol and baclofen), identify the prelimbic cortex to be the major controlling influence over the nucleus accumbens core, which, again, appears to be a key structure that drives the disinhibited drug-seeking behavior . MoreoveN-acetylcysteine, a cysteine pro-drug that indirectly increases extracellular glutamate  is clearly manifold. First and foremost, the symptoms manifested feature many aspects of impaired self-control and difficulties in inhibiting inappropriate behaviors. It is this loss of control that leads to persistence in drug-taking with larger amounts consumed for longer than intended, despite a desire to quit and despite adverse personal and social consequences . As noteIn accordance with such reasoning, many contemporary theories emphasize disrupted inhibitory control in drug use in combination with impulsive decision making and altered motivational and reward processes . DisruptThere is broad agreement that response-inhibition is impaired in SDI e.g., . Below wOnly a handful of papers have investigated response-inhibition in children or adolescents at risk for abuse for any substance. This is despite evidence from other paradigms of inhibitory control suggesting response-inhibition as a likely indicator of neurobiological risk for substance use disorders . In adolA more substantial body of evidence speaks to worse response-inhibition performance in SDI with a mixed pattern for response execution. . FunctioThe relatively few reported abnormalities in the striatum may seem surprising given its role in response-inhibition and in mediating addiction in animal research. However, this is likely due to fMRI studies largely utilizing tasks that do not efficiently model response execution processes separately from baseline. Future studies may consider the benefits of introducing sequences that allow more sensitive assessment of striatal involvement. Additionally, evidence for anatomical striatal abnormalities in SDI has been particularly inconclusive, possibly due to its susceptibility to individual differences in recent history of abuse and/or abstinence .Acute administration of cocaine or intravenous methylphenidate has led to improved response-inhibition performance in active or recently abstinent SDI , and occGiven that inhibitory control probably plays a role in abstinence and relapse avoidance, it is significant that abstinent SDI show less robust patterns of impairment, suggestive of possible recovery or compensation. After short term to intermediate cessation of use , response-inhibition appears impaired in some studies  but not how precisely response disinhibition may serve as a risk factor for relapse though the mediating neural structures have been reported to be modulated by abstinence (In summary, the evidence points to response-inhibition deficits accompanied by reduced PFC recruitment in current SDI that ameliorates with acute stimulant dosing, and may normalize to some degree with abstinence. This conclusion is highly consistent with evidence from other forms of cognitive control in SDI involving fronto-striatal systems . There rstinence .predate or follow stimulant abuse is unclear, though findings from at risk individuals indicate both are in play. Given the temporal evolution of addiction, it is only the difficulty of conducting longitudinal and prospective studies that has prevented their more pervasive use to help disentangle causal associations between cognition and drug use. Nonetheless, several such projects are set to shed light on how response-inhibition as part of a larger set of top-down control functions may typify stimulant use over time. Finally, it is possible that response-inhibition deficits, which progressively grow with age (Based on evidence from SDI cross-sectional studies, the degree to which neurobiological fronto-striatal abnormalities with age , may conwith age .6Relevant to the issue of the extent to which response-inhibition deficits predispose or result from stimulant dependence, are two additional lines of evidence. First, is the investigation of not only SDI but also their biological first degree siblings to detect common vulnerability markers. The notion that response-inhibition might prove a useful endophenotype, mediating genes and clinical symptoms  is plausA second line of evidence is the investigation of recreational cocaine users, loosely identified by self-reported regular cocaine use, without fulfilling DSM-IV criteria. Response-inhibition disruptions were reported in recreational users in one small study  though nTaken together, the findings elucidate how disruptions in response-inhibition contribute via multiple pathways to drug dependence. High impulsivity, manifested in part by impaired inhibition, hypothetically facilitates initial exposure and subsequent escalation, whilst elevated sensation seeking contributes only to the former. Elevated compulsivity likely contributes in parallel. Evidence that high impulsivity and to some extent compulsivity may predate drug use, is evidenced in the unaffected biological siblings . Age at 7Despite a superficially coherent picture, several issues merit discussion within the broader context of cognition and addiction models. First, chronic stimulant use has been associated with disruptions, not only in response-inhibition, but across a broad set of cognitive domains associated with fronto-striatal systems such as planning, working memory, decision-making and attention . Effect Another issue is polysubstance use, which is an inherent part of the common SDI phenotype . ResponsResponse-inhibition difficulties are also apparent across a broad spectrum of neuropsychiatric conditions . MoreoveResearch to date has not revealed a strong link between response-inhibition as measured in GNG and SST per se and OFC and vmPFC integrity, despite both regions being implicated in compulsivity  and addi8Response-inhibition is one of several complex interacting processes such as impulsive choice, altered decision making, salience attribution and motivational/reward and emotional dysregulation which contribute to the dependence phenotype . Both huHow might better understanding of response-inhibition be of relevance to treatment of SDI? From a conceptual standpoint, cognitive difficulties, although largely of medium effect size, may have pronounced consequences on daily functioning and can negatively affect treatment outcome and prevention. General inhibitory control impairments tend to be associated with poor treatment retention and increased dropout . From a Present evidence regarding neurostimulation, either via repetitive transcranial magnetic stimulation or transcranial direct current stimulation, has focused on the DLPFC circuit as a viable therapeutic procedure for improving symptoms such as craving . EvidencThe field has benefitted thus far from translational cross-species paradigms, with response-inhibition constituting a key element of the impulsivity construct. Use of such paradigms in experimental animals is highlighting a fractionation of the impulsivity construct in terms of fronto-striatal circuits  implying