During foetal life, the liver plays the important roles of connection and transient hematopoietic function. Foetal liver cells develop in an environment called a hematopoietic stem cell niche composed of several cell types, where stem cells can proliferate and give rise to mature blood cells. Embryologically, at about the third week of gestation, the liver appears, and it grows rapidly from the fifth to 10th week under WNT/β-Catenin signaling pathway stimulation, which induces hepatic progenitor cells proliferation and differentiation into hepatocytes. Development of new strategies and identification of new cell sources should represent the main aim in liver regenerative medicine and cell therapy. Cells isolated from organs with endodermal origin, like the liver, bile ducts, and pancreas, could be preferable cell sources. Furthermore, stem cells isolated from these organs could be more susceptible to differentiate into mature liver cells after transplantation with respect to stem cells isolated from organs or tissues with a different embryological origin. The foetal liver possesses unique features given the co-existence of cells having endodermal and mesenchymal origin, and it could be highly available source candidate for regenerative medicine in both the liver and pancreas. Taking into account these advantages, the foetal liver can be the highest potential and available cell source for cell therapy regarding liver diseases and diabetes.  In adult life, the liver is the biggest gland in the body, with both endocrine and exocrine functions. The major exocrine secretion consists of the production of bile, while endocrine functions include the secretion of several hormones such as insulin-like growth factors, angiotensinogen, and thrombopoietin. The liver is also indispensable for glycogen storage, drug detoxification, control of metabolism, regulation of cholesterol synthesis and transport, urea metabolism, and secretion of a wide number of plasma proteins including albumin and apolipoproteins . In the In foetal life, the liver takes up a very large portion of the abdominal cavity. In this stage, it does not perform the traditional digestive and filtration functions because nutrients are normally carried to the foetus from the mother via the placenta. Blood flow, rich in nutrients, arrives from the placenta to the foetus by the umbilical vein. It enters the abdomen at the umbilicus, passing upward along the free margin of the falciform ligament of the liver to its inferior surface. Blood flow in the umbilical vein has an oxygen saturation of approximately 80% compared with the 98% of the arterial adult circulation . The ducThe location of hematopoiesis during gestation varies from the first weeks until birth . The firAt 10 weeks gestational age, hematopoietic progenitor cells gradually migrate from the aorta-mesonephros-gonad region to colonize the liver, which becomes the major hematopoietic organ .Liver hematopoiesis in the prenatal period can be subdivided in four stages. It gradually rises in Stages I and II, reaches a peak in Stage III, and slowly regresses through Stage IV. This is consistent with the fact that primitive hematopoiesis is localized in the yolk sac during the first weeks of development and later on appears in the liver. The first signs of hematopoiesis in the human foetal liver are reported as soon as 5–8 weeks . During During Stage III, in the foetal liver, an increase in hematopoiesis activity in notiedas hematopoietic cells occupy at least 70% of the liver parenchyma. The greatest part of the cells comprising the hematopoietic foci are cells from the erythrocytic lineage, but a significant number of mature granulocytes is present, suggesting the presence of cells of myeloid lineage still in an undifferentiated state.Stage IV is characterized by a reduction in hematopoietic activity. In this phase, hematopoietic cells occupy less than 30% of liver parenchyma.In general, the erythropoietic lineage was the most representative lineage in terms of quantity in every stage, and its quantity was at least three times higher than myelomonocytic, suggesting how the liver could be mainly responsible for erythropoiesis .Megakaryopoietic activity is described in the foetal liver but in scarcely represented. These cells are always solitary and are mostly located between hepatoblasts ,18.Hematopoietic stem cells are pluripotent and can form any hematopoietic cell. Their first step in intrahepatic maturation is to commit to a more limited range of lineage options, typically an erythromyeloid precursor or a common myelolymphoid progenitor ,20,21.Proerythroblast is the earliest morphologically identifiable erythroid precursor, which differentiates sequentially into an erythroblast, which can then enucleate to form a reticulocyte. The precursors show a gradual reduction in cell and nuclear size. On the other hand, an increase in hemoglobin concentrations is registered . Liver-dAlso, a granulocyte population develops throughout gestation. Granulocyte progenitors can be found in low numbers scattered throughout the liver parenchyma between 12 weeks and five days and 15 weeks and five days, then they clustered in small foci throughout of the liver. These foci get larger as development proceeds.With advancing gestational age, a change in hematopoiesis sites are encountered. In particular, from about 13 weeks, T lymphocytes shift from the liver to the thymus. At about 15 weeks, erythroid and myelolymphoid precursors move to spleen and the and finally to bone marrow (16 weeks) ,26, whicEmbryologically liver, gallbladder, and biliary ducts system appears at about the third week of gestation as a ventral outgrowth of the endodermal epithelium  at the distal end of the foregut  . The embIt has been hypothesized that the origin of both hepatic diverticulum and ventral bud of the pancreas is derived from two cell populations of the embryonic endodermis. Sufficient levels of fibroblast growth factors (FGFs) secreted by the developing foetal cardiac mesoderm interact with bipotential cells, inducing hepatic diverticulum formation .A rapid hepatic cell proliferation causes the extension of hepatic diverticulum into the septum transversum, a mass of splanchnic mesoderm separating the pericardial and peritoneal cavities. The septum trasversum forms the ventral mesogastrium in this region. The hepatic diverticulum expands quickly and divides into right and left branches . Each brMeanwhile the liver cells continue their penetration into the septum trasversum, the link between hepatic diverticulum and the anterior gut narrows, thus forming the biliary pathway. The hepatic diverticulum has a cranial part representing the primordium of the liver. The caudal part becomes the primordium of the gallbladder. The proliferation of endodermal cells causes the formation of hepatocyte cords. These give rise to the epithelial lining of the intrahepatic part of the bile apparatus. The hepatic cords anastomose at the endothelium-lined spaces, the primordia of the hepatic sinusoids. The role of vascular endothelial growth factor signaling seems to be important in the development of the hepatic sinusoids. The formations of the bile by hepatic cells starts during the 12th week above the small caudal part of the hepatic diverticulum gives rise to the gallbladder, and the stalk of the diverticulum forms the cystic ducts. Originally, epithelial cells occlude the extrahepatic biliary apparatus but later canalize by means of vacuolization mechanism resulting from degeneration of these cells. The part of the diverticulum connecting the hepatic and cystic ducts to the duodenum becomes the bile duct. At first, this duct is connected to the ventral part of the duodenal loop. However, as a result of duodenum growth and rotation, the entrance of the bile duct is carried to the dorsal part of the duodenum. The fibrous hematopoietic tissue and Kupffer cells of the liver are derived from mesenchyme in the septum transversum. The liver grows rapidly from the fifth to the 10th weeks and fills a large part of the upper abdominal cavity representing approximately 10% of the total body weight in the 10th week of development. Liver development and functional segmentation are determined by the amount of oxygenated blood flowing from the umbilical vein to the liver. Initially, the right and left lobes are approximately the same size, but the right lobe soon becomes larger. Thus, developmental change in the liver is possibly related to its function. Glycogen is not present in the liver of young foetuses, but it appears at about the 30th week and gradually increases in amount . HepaticThe foetal umbilical portal venous system forms in the embryo between the fourth and 10th week and is derived from two distinct embryologic precursors—vitelline veins originating from the yolk sac and the umbilical veins originating from the placenta . These tVitelline veins are paired structures connected by three anastomotic channels interrupted by developing hepatic trabeculae. As the embryo is folded laterally, the vitelline veins assume the drainage of the gut and the developing hepatic primordium. These veins are largely incorporated into the developing liver as hepatic sinusoids; only some parts of caudal and cranial vitelline segments persist as separate structures. As the left vitelline vein regresses, the cranial portion of the right vitelline vein widens to form the right hepato-cardiac channel. This forms the intrahepatic portion of the inferior vena cava (IVC) and contributes to the formation of ductus venosus. The ductus venosus allows placental blood to pass from the single left umbilical vein through the portal and then into the IVC and the right atrium. The caudal portions of the vitelline vein merge to form the portal vein. The umbilical vein system is formed by the division of the pre-hepatic trunk into two. One branch goes directly inside the hepatic parenchyma, and the other runs along the liver to open into the sinus venosus of the foetal heart .The left umbilical vein also contributes to a portion of the left portal vein. The hepatic artery is visible for the first time at the eighth gestational week as a brunch of celiac trunk. Its development is dependent on the advanced intrahepatic portal system. After birth and following separation from the placental flow, umbilical circulation ceases, and the two umbilical arteries close first, followed by the umbilical vein. Blood to the liver through the umbilical vein is interrupted, and the ductus venosus closes.The foregut endoderm has the potential to express liver-specific genes and to differentiate into liver tissue. However, this expression is blocked by inhibitory factors produced by surrounding tissues, including ectoderm, noncardiac mesoderm, and particularly the notochord. The cardiac mesoderm and endothelial cells that form the blood vessels secrete fibroblast growth factors 2 (FGF2) that block the inhibitory substances described above. In this way, the intestinal endodermis is instructed to express liver-specific genes. The septum trasversum produces bone morphogenic proteins (BMPs), which participate in this induction mechanism, increasing the endodermal response to the FGF2. Once this “instruction” is received, cells in the liver field differentiate into both hepatocytes and biliary cell lineages, a process that is at least partially regulated by hepatocyte nuclear transcription factors (HNF3 and HNF4).The liver, bile duct system, and pancreas share a common origin from the definitive ventral endoderm forming the foregut ,38. In hNature by Aizarani et al. adds further information in this debated topic, indicating that EpCAM+ population exhibits only stochastic expression of proliferation markers [The involvement of bipotential hepatic stem/progenitor cells in liver regeneration has been challenged by the evidence on hepatocyte plasticity . Specifi markers . This is markers .Orthotopic liver transplantation (OLT) represents the only curative treatment for acute liver failure and end-stage chronic liver disease . However“exogenous cueing of the directed differentiation of postnatal ‘mesenchymal’ stem cells is perhaps best seen as reprogramming  rather than differentiation ”. In fact, as far as the liver cell therapy is concerned, it has been clarified that the role of MSCs does not depend on the repopulation and regeneration determined by differentiation in liver parenchymal cells but by the production of factors and cytokines with multiple effects and by the expansion of macrophages concurrent with an upregulated expression of genes involved in inflammatory and regenerative pathways [Citing the great expert Paolo Bianco , “exogenpathways ,83,84,85pathways . A recenpathways ,82. Finapathways . The pospathways , resultsAs far as pluripotent stem cells are concerned, they attract enormous interest worldwide. Generally, Embryonic Stem Cells (ESCs) evoke ethical concerns regarding their origin from human embryos, and they bear a clinical risk since their pluripotent nature makes undifferentiated ESCs capable to form malignant teratocarcinomas in vivo ,88. Alth6 hBTSCs in the portal circulation. This is associated with amelioration of serologic levels of transaminases and liver function indexes and with amelioration of the liver histology. Thus, in this context, the large availability of hBTSCs, especially from foetal livers, and their biological properties, comprising scarce or null immunogenicity and tumorigenicity [Hepatic stem/progenitors (HpSCs) reside in adult human liver and are located within the canals of Hering and bile ductules, where their potential to differentiate into functional mature hepatocytes and cholangiocytes can be stimulated, and new born mature cells can repopulate the specific diseased tissue ,58,101. genicity ,52, guargenicity . Finallygenicity ,105, beigenicity . Adult hgenicity  describegenicity  found thgenicity ,8. As fagenicity ,109.+ cell infusions into the liver via the hepatic artery. At a six-month follow-up, multiple diagnostic and biochemical parameters showed clear improvement, and there was a significant decrease in the patients’ MELD scores [Clinical applications of ESCs evoke ethical concerns regarding their origin from human embryos and teratocarcinogenesis in vivo, while the clinical application of reprogrammed iPSCs raises concerns because the open possibility to undergo to uncontrolled tumorigenic expansion within recipient. Although autologous MSCs and HSCs are clinically safe, the recent negative results of RCTs limit future application of this strategy. It can be argued that the state of art of regenerative medicine of liver reached a point where further rigorous preclinical studies and high quality RCTs are required. These efforts could prove its efficacy. The foetal liver is the major candidate on the block. Human foetal liver comprises two stem cell niches—the ductal plates containing HpSCs, and PBGs containing BTSCs. HpSCs are facultative stem cells able to differentiate into functional mature hepatocytes and cholangiocytes, residing into the foetal human liver. To date, several case reports and a completed trial with HpSCs held in India by Habibullah and co-workers focused on patients affected by chronic liver disease of different etiologies, such as, biliary atresia, inborn errors of metabolism (Crigler-Najjar), non-alcoholic steato-hepatitis, viral cirrhosis, alcoholic cirrhosis, and drug toxicity. These anecdotal results suggest that human HpSCs can be effective in treating patients with liver disease . More reD scores . In westD scores ,111. IndD scores  treated hBTSCs are a possible source for stem/progenitor cells for liver regenerative medicine ,44,113. As widely demonstrated in hepatocyte transplantation, low cell engraftment is a major limitation to address in order to improve efficacy of liver cell therapy, even when it is based on stem cell populations. Cell therapy of liver diseases with human biliary tree stem cells (hBTSCs) may be biased by low engraftment efficiency. Several strategies targeting engraftment into the liver have been reported so far as. We have reported that coating the hBTSCs with hyaluronans (HAs), the primary constituents of all stem cell niches, could facilitate cell survival, proliferation, and, specifically, liver engraftment, given that HAs are cleared selectively by the liver ,74,113. Organoid culture is an advanced three-dimensional technology in which the cells can recapitulate the native physiology of cells in the healthy tissue of origin as well as the pathology of the cells in patient-derived tissue. This system allows the long-term expansion of cells in vitro and has been proposed as an in vitro disease-modelling tool for several genetic diseases. Recently, Clevers and Huch have developed the organoids culture for adult intestine , stomachHuch and Clevers have also established a protocol for the long-term expansion and genetic manipulation of adult bile duct–derived bipotent progenitor cells in 3D condition . Where tA recent study showed that human foetal liver organoids mimic human liver development, including several aspects of hepato-biliary organogenesis, and can differentiate toward hepatocyte and cholangiocyte structures with improved function .Despite decades of basic research on biliary developmental biology, cholangiocyte pathophysiology, and the endogenous mechanism of biliary regeneration, the treatment of common bile duct disorders (CBD) is restricted to a few studies by the lack of biliary tissue . MoreoveTherefore, organoid culture derived from bile ducts and gallbladder can be a very relevant system to study human biology, physiology, regeneration, and the development of the biliary tree and even the liver. In addition, 3D organoid culture enables the study of molecular mechanisms driving pathologies and at the same time can provide potential tools to manipulating genomes and facilitate gene correction for regenerative medicine and autologous therapy. Researchers have expanded organoids from A1AT-deficiency patients in vitro when it recapitulated the pathology in vivo. Similarly, organoids from Alagille syndrome patients mimicked structural duct defects of these patients and presented the genetic disorders of this pathology . The easSince organoids replicate key structural and functional features of the corresponding in vivo organ, their stem cells of origin acquire phenotype and functions of mature cells. Thus, the application of organoids to regenerative medicine highlights the need to face the question of whether, among mature versus stem/progenitor cells, a determined cell source is better suitable for a specific clinical need. Some years ago, Forbes and Newsome presented a very conveyable paradigm according to which the different available cell sources should be tailored for the specific pathological conditions according to the specific and peculiar properties they are endowed with . There iThe state of art of regenerative medicine of liver reached a point where further rigorous preclinical studies and high quality RCTs are required. These efforts could determine a cell source when this will finally prove its efficacy. Foetal liver is the major candidate on the block. The foetal liver possesses a unique feature given the co-existence of endodermal and mesenchymal derived cells and is hypothetically the more useful and qualified largely available source to address the main areas (fibrosis remodeling and liver repopulation) required for an effective cure of liver cirrhosis. Moreover, it contains a population of pluripotent stem cells, the hBTSCs, and thus is the unique highly available source candidate contemporarily for the regenerative medicine of the liver and pancreas. However, researchers and clinical investigators in regenerative medicine of the liver should adopt rigorous clinical studies for the foetal liver, as done only recently concerning the use of autologous MSCs in cirrhotic patients. Moreover, preclinical studies should be solid and tailored to address the questions raised by the clinical trials. Importantly, repopulation of the liver and the proliferation and differentiation of transplanted cells should be investigated systematically in the tissues along different and long-term time points. Different experimental models should be evaluated to investigate specific etiopathogenetic features that may impact the outcomes of the cell therapy. For example, models of liver fibrosis are best candidate to study intrahepatic factors associated with the interactions and effects of transplantation of exogenous cells, while NAFLD/NASH models may reveal potential systemic factors impacting on the effects of exogenous cells transplanted into the liver.


Recently, several red-green-blue near-infrared (RGB-NIR) multispectral filter arrays (MFAs), which include near infrared (NIR) pixels, have been proposed. For extremely low light scenes, the RGB-NIR MFA sensor has been extended to receive NIR light, by adding NIR pixels to supplement for the insufficient visible band light energy. However, the resolution reconstruction of the RGB-NIR MFA, using demosaicing and color restoration methods, is based on the correlation between the NIR pixels and the pixels of other colors; this does not improve the RGB channel sensitivity with respect to the NIR channel sensitivity. In this paper, we propose a color restored image post-processing method to improve the sensitivity and resolution of an RGB-NIR MFA. Although several linear regression based color channel reconstruction methods have taken advantage of the high sensitivity NIR channel, it is difficult to accurately estimate the linear coefficients because of the high level of noise in the color channels under extremely low light conditions. The proposed method solves this problem in three steps: guided filtering, based on the linear similarity between the NIR and color channels, edge preserving smoothing to improve the accuracy of linear coefficient estimation, and residual compensation for lost spatial resolution information. The results show that the proposed method is effective, while maintaining the NIR pixel resolution characteristics, and improving the sensitivity in terms of the signal-to-noise ratio by approximately 13 dB. Recently, several attempts have been made to utilize near infrared (NIR) band information. Multispectral images observed in various spectrum bands, including both visible and NIR bands, have been used in remote sensing applications ,2. As eaMost digital imaging devices use a color filter array (CFA) to reduce equipment cost and size instead of using three sensors and optical beam splitters. The Bayer CFA, comprising the primary colors red, green, and blue , is a widely used CFA . Figure Generally, to utilize the RGB-NIR MFA, two steps are involved : DemosaiVarious post-processing algorithms have been studied using the NIR band for this problem. For example, image fusion methods  fuse theIn this paper, we propose a post-processing method that can enhance the spatial resolution, while improving the brightness and signal-to-noise ratio (SNR) of the RGB channels, by reflecting the sensitivity of the NIR channel. High sensitivity NIR channels, at very low light levels, have better spatial resolution and sensitivity than noisy RGB channels. On the other hand, RGB channels contain color information and local contrasts that represent the colors. Hence, we propose a method to improve the resolution and SNR of the R, G, and B channels by reconstructing the NIR channel. In particular, we propose a smoother method to improve the accuracy of linear coefficients of guided filtering in extremely low light conditions. In addition, we propose residual information compensation to recover spatial resolution information and texture, lost in the guided filtering process.This paper proposes an edge preserving smoother based pre-processing algorithm to estimate the linear coefficients of the guided filter accurately. The edge preserving smoother proposed in  estimateThe remainder of this paper is organized as follows. In The color restoration results of the RGB-NIR MFA under extremely low light conditions include a high level of spatial and color noise, as shown in In short, the rationale of the proposed post-processing method is that the reconstructed image has NIR channel level brightness and sensitivity. Moreover, the color image has an NIR channel level SNR and color reproduction at the color restored RGB result level. The proposed post-processing algorithm follows the guided filtering method . The guiTo solve the problem of noise, linear coefficients, and texture information of the NIR channel, under extremely low light conditions, this paper proposed a post-processing method based on guided filtering. The proposed algorithm comprises three steps: edge preserving smoothing, guided filtering, and residual compensation. First, the color restored RGB channel, converted into the YUV domain, is divided into luminance and chrominance channels, and the Y channel is inputted to the edge preserving smoother along with the NIR channel. The reason for converting to the YUV domain is to separate color components of RGB, such as saturation and hue, to prevent color change during the algorithm execution. The U and V channels, except for the luminance component, contain color components and represent color information and color noise.The edge preserving smoother can accurately preserve the strong edges and occlusions of the object by estimating the edge from the sensitive NIR channel. The smoothing kernel, estimated from the NIR channel, has little influence on the Y channel in terms of the noise. Thus, it can remove the low frequency noise and preserve the strong edges. In addition, the color noise, existing in the U and V channels, is removed through the kernel estimated from the NIR channel, thus maintaining the correct color at the boundary of the object. In this paper, a cross bilateral filter (CBF)  was usedGuided filtering estimates the linear coefficients through linear regression. The estimated linear coefficients help reconstruct the NIR channel to create a new Y channel with improved sensitivity. The proposed algorithm smoothens the estimated linear coefficients by using the CBF kernel estimated from the NIR channel. This stabilizes the small errors that occur in the estimation process and preserves the linear coefficients in the occlusion of the object. In addition, the proposed algorithm updates the reconstructed Y channel, by estimating the texture and high frequency components  that have not yet been compensated via guided filtering.Finally, the Y channel, reconstructed from the NIR channel, has a local contrast of the input Y channel and local brightness characteristics. In addition, the reconstructed Y channel has NIR level sensitivity, noise, and spatial resolution characteristics. Similarly, the smoothened U and V channels are suppressed from noise in all the frequency bands, and they can maintain local color characteristics.th position, respectively. The linear coefficients are assumed to be constant in The key assumption in the guided filtering is the local linear model between the NIR and Y channels. The local linear model can be expressed as follows:proposed :(3)aS=CoThe linear coefficients of the guided filter, mentioned in th pixel, obtained by applying a bilateral filter kernel estimated from the NIR channel, th pixel. For smoother results in th pixel, obtained by applying a bilateral filter kernel estimated from the NIR channel, th pixel, obtained by applying a bilateral filter kernel estimated from the NIR channel, and th pixel. For conditions similar to the smoothed Y channels with texture information and noise removed, the NIR channel also needs to pass through the same bilateral filter kernel. This process minimizes the effect of texture on the covariance estimate and improves the accuracy of estimating the correlation between the local brightness of the objects on each channel. The linear coefficients A Gaussian filter is incorporated in the guided filtering method  to improThe linear coefficients estimated from the smoothed image, are more accurate than the original values, but pass through the estimated bilateral filter kernel from the NIR channel to eliminate some possible estimation errors. The linear coefficients passing through the CBF kernel are expressed as follows:The texture information, in the channel reconstruction results of the guided filter, is lacking. Because of the area wise computation of the linear coefficients, it is difficult to reconstruct the texture. To obtain spatial resolution at the NIR channel level, this paper proposes a residual information compensation process. The residual information is defined as the information lost in the NIR channel among the textures resulting from guided filtering. To estimate the residual information, the NIR channel is reconstructed using the Y channel. This process traces the loss process through the channel other than the NIR channel to estimate the texture information lost during guided filtering. The process of reconstructing the NIR channel, by using the linear coefficients estimated in the previous sub section is as follows:To verify the performance of the proposed algorithm under extremely low light conditions, we used directly captured images. The image, shown in In this section, we compare various conventional methods (CM) to verify the performance of the proposed algorithm. First, we compared the core process guided filtering (CM1) . This alSNR  was usedIn addition to incandescent lamps, the same experiment was conducted in an extremely low illumination environment, including the NIR band such as a sodium lamp. This is to verify the proposed method in different lighting conditions (color temperature and lighting spectrum). Fluorescent lamps or LED lamps are excluded from the comparison because they cannot utilize the NIR band without artificially adding NIR bands. We used an RGB-NIR MFA to replace the existing Bayer CFA. However, this method has limitations in reflecting the sensitivity of the NIR channel through the demosaic and color restoration algorithms. To solve this problem, post-processing is proposed, and an algorithm is developed to reflect three characteristics: SNR and color noise suppression at the NIR channel level, improved resolution at the NIR channel level, and RGB color image level color reproduction. For the three characteristics, we propose an edge preserving smoother that is most suitable under extremely low light conditions, by pre-processing a guided filter and estimate the linear coefficient more accurately. The edge preserving smoother helps detect the quality degradation component of the RGB-NIR MFA, such as the noise in the RGB channels. Moreover, a CBF kernel estimated from the NIR channel is applied to the U and V channels to remove color noise. The residual information is compensated by post-processing the guided filter. The proposed algorithm can estimate and compensate for the missing texture information of the guided filter result and the information of the erroneously reconstructed strong edge regions from the NIR channel. The proposed method can estimate the residual information lost in the guided filtering process by reconstructing the luminance channel into an NIR channel by using a linear coefficient. The compensation of the residual information helps improve the resolution of the output image and correct the artifacts in the strong edge areas. The experimental results show that the proposed algorithm results in a resolution and SNR similar to that of the NIR channel, under extremely low light conditions, and strictly follows the colors of the RGB channels.


Having a creative mind is one of the gateways for achieving fabulous success and remarkable progress in professional, personal and social life. Therefore, a better understanding of the neural correlates and the underlying neural mechanisms related to creative ideation is crucial and valuable. However, the current literature on neural systems and circuits underlying creative cognition, and on how creative drives such as motivation, mood states, and reward could shape our creative mind through the associated neuromodulatory systems  seems to be insufficient to explain the creative ideation and production process. One reason might be that the mentioned systems and processes are usually investigated in isolation and independent of each other. Through this review, we aim at advancing the current state of knowledge by providing an integrative view on the interactions between neural systems underlying the creative cognition and the creative drive and associated neuromodulatory systems see . Creativity and innovative thinking have been a vast construct of questioning to scholars, psychologists, therapists and, more lately, neuroscientists  might be a core process involved in creative problem solving and idea generations  could have a mediating impact on the association between the positive emotion and the insight problem solving, but not between the positive emotion and DT. Bledow et al.  revealedConcerning mindset, regulatory focus and creativity, Bittner and Heidemeier  observedA number of researchers highlighted the strong connection between reward and creativity  and posterior cingulate cortex (PCC), left middle frontal gyrus (MFG) and inferior parietal lobule (IPL), and the right postcentral gyrus (PoCG) and fusiform gyrus (FG), as well as bilaterally the cerebellum.The network for verbal creativity was left-hemispheric dominated and comprised of several activation foci in the left MFG, inferior parietal lobule (IPL), SMG, middle occipital gyrus (MOG), and middle and superior temporal gyrus (MTG and STG), and the bilateral inferior frontal gyrus (IFG) and insula, and the right lingual gyrus (LG) and cerebellum.Visuospatial creativity relied on a slightly right-hemispheric dominated network including activation foci in the right MFG and IFG, the left precentral gyrus (PrCG), and the bilateral thalamus.Concerning underlying brain networks, Mok  further Regarding WM, Takeuchi et al.  exploredAnother study revealed that DT was positively correlated with the strength of the RSFC between the mPFC and the MTG , a meta-analytic evaluation by Mihov et al.  implied Only a few animal studies also provided valuable insights into the link between brain and creative cognition. For example, a framework developed by Kaufman et al.  suggesteThe DA system is involved in various aspects of cognitive functions related to reward, addiction, attention, compulsions, and others. Recent studies imply that the DA system may act to coordinate the integration of information through selective potentiation of circuits and pathways Grace, . SeveralFor example, Flaherty  reportedFurthermore, Zhang et al.  investigRecently, Boot et al.  providedDespite the existence of a consistent number of functional imaging studies on creativity, the relationship between individual creativity and volumetric morphological changes in the regional gray matter (rGMV) within the DA system has not been explored adequately until recently. Salgado-Pineda et al.  reportedAn exciting study by Kulisevsky et al.  describeAlong with the same line, Lhommée et al.  explaineOne critical step towards a better understanding of creativity is to unveil its underlying genetic architectures. Many studies reported the first candidate genes for creativity  was provided by Zhang et al. . This stBased on these findings, one can conclude that human creativity principally relies on the interplay among frontal and striatal DA pathways. The dynamical interaction between these two pathways might assist to explain the inconsistencies due to the independent evaluation in measuring genes and creativity during the past decade.According to Flaherty , the indResearchers observed that when 5-HT and NE lower motivation and flexibility, they can inhibit creativity. For example, antidepressants (ADs) that inhibit fear-driven motivation  could inhibit goal-oriented motivation as well. On the other hand, ADs that boost goal-directed motivation  may remediate this effect. As for benzodiazepines and alcohol, they might have a counterproductive effect. Although DA agonists might stimulate creativity, their actions may inappropriately disinhibit this creative behavior through suppressing its motivational drive. Moreover, it was suggested that the presence of NE induces fluctuations in levels of other catecholamines, such as DA, which has been extensively discussed in the schizophrenia literature.The link between the noradrenergic (NE) system, arousal and the creative process has been examined either through the direct pharmacological manipulation of the NE system, or by investigating the influences of endogenous changes in the NE system  on behavior and cognition ; Walther et al., Accumulated evidence suggests a strong connection between developing the drive of creativity and a number of brain illnesses , frontotemporal dementia (FTD), and autism spectrum disorders (ASDs); see Flaherty, Flaherty  tested aAbraham et al.  examinedConsequently, the lesion area posed selective obstacles to the ability to generate novel  responses in distinctive contexts, but not on the ability to generate relevant responses (which was compromised in most patient groups). Thereby, Mula et al.  discusseOn the link between creativity and bipolarity, researchers aimed at dissecting principal components of mania showing that feeling creative is usually told by patients with bipolar disorders  and whether such interactions could mark creative signatures of individuals. In other words, getting more insight into the creative thinking and ideation necessitates the ability to identify: (1) the core cognitive, motivational, and emotional processes underlying creative thought; and (2) the brain circuitries and neuromodulators underlying the creative ideation.Prospective research should further specify the neural mechanisms by which the neuromodulator systems influence the creative process. Particularly their modulatory effect on the creative cognition and the creative drive in pathological conditions such as depression, bipolar disorders, PD and schizophrenia remains elusive. DA requires additional exploration regarding the interplay between frontal and striatal DA pathways, the underlying genetic architecture and CAs in healthy and pathological conditions. On the other hand, research on creativity and the noradrenergic (NE) system is implicated in the stress-related modulation of cognitive flexibility in problem-solving, however there is a prominent demand to determine the range of cognitive tasks modulated by the NE system more precisely. Also, studies on the relation between the fluctuations in the level of NE, the level of arousal and its modulation signature on the creative process before and after treatment in pathological conditions such as depression, bipolar disorders, and schizophrenia remain dispersed and isolated. Concerning 5-HT, there is an ultimate need for elaborative research on the relationship between 5-HT and CAs since it is a fundamental mediator of emotional, motivational and cognitive elements of reward processing and representation.In summary, advancing the research on creativity demands providing an integrative framework assembling the neural, cognitive, motivational, and emotional correlates of creativity. Furthermore, computational approaches such as neural network models could assist to provide a predictive perspective for this integrative framework for creativity  creative cognition and the associated neural systems in human and animal models; (2) creative drives such as mood states, emotion, motivation and regulatory focus and how their interactions could shape the creative performance; and (3) the impacts of three central neuromodulator systems, i.e., DA, NE, and 5-HT, on the interplay between creative cognition and creative drives.via their influence on resistance and cognitive flexibility  and creative drive , and the underlying neuromodulator mechanisms .Lastly, we highlighted the possibility of implementing a neural network model as a predictive tool for the suggested integrated framework of creativity. For more insights on the computational model of creativity and emotion, see Perlovsky and Levine  and LeviRK and BG outlined the structure of the review and wrote the manuscript. AK participated in the conceptualization of the manuscript and the final editing.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.


As most common primary brain cancer, glioblastoma is also the most aggressive and malignant form of cancer in the adult central nervous system. Glioblastomas are genetic and transcriptional heterogeneous tumors, which in spite of intensive research are poorly understood. Over the years conventional therapies failed to affect a cure, resulting in low survival rates of affected patients. To improve the clinical outcome, an important approach is to identify the cells of origin. One potential source for these are neural stem cells (NSCs) located in the subventricular zone, which is one of two niches in the adult nervous system where NSCs with the capacity of self-renewal and proliferation reside. These cells normally give rise to neuronal as well as glial progenitor cells. This review summarizes current findings about links between NSCs and cancer stem cells in glioblastoma and discusses current therapeutic approaches, which arise as a result of identifying the cell of origin in glioblastoma. Glioblastoma (GB) is the most frequent form of brain tumor in adults and is associated with a poor prognosis and a short median patient survival . LimitedGlioma is an umbrella term, compromising around 30 percent of all brain tumors that are thought to grow from intrinsic glia cells. As an umbrella term glioma consolidates different types of tumors including ependymoma, astrocytoma, and oligodendroglioma, which vary in their symptoms, aggressiveness, malignancy, and treatment strategy.Glioblastoma multiforme (GB) belongs to the category of astrocytoma, is the most common and most aggressive of all malignant glial tumor in adults , and is Diagnosis of GB comes with a poor prognosis with high morbidity and mortality . The medGB features a complex pathogenesis that involves mutations and alterations of several key cellular pathways, associated with cell proliferation, angiogenesis, migration, and survival . HoweverThe most common mutations in GB are found in p53 (85.3–87%) ,14, the The current therapy of GB is limited and inefficient and focuses on surgical resection of as much of the tumorigenic tissue as possible with subsequent radiation- and chemotherapy, hereby mostly using oral alkylating agent temozolomide . HoweverDespite ongoing research, survival of GB patients could not be increased in the last years. However, there are rare case reports about long-term survival and zero recurrence of single patients with GB, which are explained by young age, as well as aggressive and complete surgical removal ,25. ThesNeural stem cells (NSCs), a subpopulation of astroglial cells, are self-renewing cells with the capacity to differentiate into multiple neural cell types like neurons and glial cells (astrocytes and oligodendrocytes) (reviewed in ). DuringNSCs have a relative slow division rate and generate progenitor cells, which are able to differentiate into one of the three major cell lineages of the brain: neurons, astrocytes and oligodendrocytes ,29,30. TThe impact and consequence of adult neurogenesis in humans is largely unknown and can only be estimated. However, many studies suggest that the generation of new neurons in the adult brain could be important for learning and memory, degradation as well as regeneration processes underlying aging, injury and diseases, including dementia and cancer ,52,53,54The SVZ is the largest neurogenic niche in the adult mammalian brain. It is located at the border of both lateral cerebral ventricles, fitting in between the ependyma and the parenchyma of the striatum. The NSCs in the SVZ are found in an astrocytic ribbon in the sub-ependymal zone. They are surrounded by ependymal cells, vascular endothelial cells, astrocytes, and oligodendrocytes , which aIn adult rodents, the SVZ contains four major cell types: ependymal cells, NSCs, fast proliferation precursors and neuroblasts. The ependymal cells form a monolayer-border to the ventricle. This layer is followed by the other three cell types, which are not arranged in layers and keep close contact to the ependymal layer. Astrocyte-like NSCs have an apical cilium, which extends into the ventricle lumen and might influence cell proliferation and differentiation ,58,59. TNSCs in the adult human SVZ were first described in 2004 by Sanai et al. , followe(I) The human SVZ features a hypocellular gap between the ependymal layer and the neurogenic astrocytes, which mainly contains ependymal and astrocytic expansions ,38,68. T(II) The SVZ in humans can be separated into four distinct layers, whereas the rodent SVZ is not separated into layers. The first layer  lines the ventricle and is composed of ependymal cells that possess several apical microvilli and basal expansions . This la(III) In the human SVZ, multipotent transit-amplifying cells (in rodents: type-C cells) are missing. Only NSCs and neuroblasts can be found in the human SVZ.(IV) The migration of neural progenitor cells from the SVZ along the RMS to the olfactory bulb is still under discussion and the migration of non-neuronal progenitor cells is at least reduced ,34,67,71Gradually, many studies have reported that tumor cells are not homogenous, but that a tumor consists of a variety of cell types forming a hierarchical organization containing slowly dividing cancer stem cells (CSCs) rapidly dividing precursor cells and non-dividing differentiated cells ,86. ThisThe transformation of a cell into a tumorigenic cell includes multiple mutations. There are two prominent theories about the origin of cancer cells. One property of at least some cancer cells is the ability to divide. However, do cancer cells acquire this ability or do they arise from a stem cell population that already possesses this ability?The first theory about the origin of CSCs states that any body cell can become a cancer stem cell by mutation, meaning that already differentiated, somatic cells become tumorigenic. Therefore, an accumulation of mutations is needed in oncogenes (gain of function) or tumor suppressor genes (loss of function), which regulate cell growth, to transform somatic cells into CSCs ,88,89. T+ CD24−/low lineage−) [The idea of stem cells derived CSCs was minted by studies using human leukemia cancer cells, which were transferred into immunodeficient mice ,92. Whenineage−) . Thus, tIn addition to their tumorigenic properties and extensive proliferative potential, CSCs share various qualities with normal stem cells: (I) The capacity of multipotency, meaning the ability to differentiate into multiple lineages, self-renewal, and the capacity to divide into either new stem cells or into differentiated cells . (II) A The hypothesis of CSCs can also be extended to brain tumors, here referred to as brain tumor propagating cells (BTPCs), however, with some minor deviations. As discussed above, stem cells are scarce in the adult brain and can only grow in protective stem cells niches, including the hippocampus and the SVZ ,32. ThesLike other stem cells, NSCs have the ability of self-renewal and by asymmetric cell division, another NSC and differentiated daughter cell is created. To ensure that the number of NSCs remains constant, proliferation is strictly regulated by intrinsic and extrinsic factors from proliferative cells themselves, neighboring cells, as well as the adjacent blood vessels (reviewed in ). DisrupTumorigenic mutations in migratory SVZ neural precursor cells would be of advantage, because of their ability to migrate over long distances ,62. HoweOver the years, various studies on mouse models of brain tumors suggested that the cell of origin for brain tumors are NSCs located in the neurogenic niches ,117,118.Over the years of glioblastoma research, various theories emerged about the cell of origin, including tissue-specific stem cells like NSCs or committed precursor cells, like astrocyte precursor cells (APCs) and oligodendrocyte precursor cells (OPCs) ,120. Gradually, several groups identified that glioblastomas are organized hierarchically and contain tumorigenic cells, which could correspond to BTPCs ,124,125 One of the neurogenic niches, the SVZ, came into the focus of BTPC research. Already in the early 21st century, GB was linked to the NSCs of the SVZ. Ignatova et al. isolated cancer cells from human glioblastoma, took them in culture and discovered that these tumors contain neurosphere-forming cells . Those BOne novel factor involved in both GB and SVZ NSCs is the extracellular matrix protein epidermal growth factor-like protein 7 (EGFL7), which was previously described to be secreted by endothelial cells as well as NSCs in the SVZ ,149,150.Analyses of the survival of patients with GB revealed that it is crucial if the tumor has a direct connection to the SVZ ,152. PatThe origin of the tumor can influence the malignance and survival of the patients. A study in mice showed the induction of GB originating in NSCs of the SVZ increases tumor development and resistance to cancer drugs, giving a hind to the aggressiveness and the malignance of glioblastoma . FurtherRecently, Lee et al. showed direct genetic evidence that brain BTPCs arise from cells of the SVZ using human patients and glioblastoma mouse models . The autAnother theory about the cell of origin states that glioblastoma BTPCs arise from committed precursor cells, like APCs or OPCs. Proliferating multipotent NSCs can create committed neuronal precursor cells that may further divide and differentiate into mature neurons and committed glial precursor cells (GPCs) that can further differentiate into OPCs to generate mature oligodendrocytes and into APCs to generate mature astrocytes ,163.For a long time, astrocytes were believed to be the only proliferating cells in the adult brain  und thusLindberg et al. and Hide et al. introduced OPCs as the cell of origin by specific mouse models to study OPCs in glioblastoma development, like the MADM-based lineage tracing model to mutate sporadically p53/Nf1 ,169. HidTaken together, the current data suggests that BTPCs might develop from various stem or progenitor cells, which needs to be considered when developing treatment strategies. NSCs, ASCs, OPCs, and GPCs might all be the cell of origin, which lead to the development of GB. However, most recent studies using state of the art techniques clearly point to an involvement of NSCs in GB .Traditional glioma treatments include chemotherapy, radiation, and surgery. However, these approaches are limited due to multiple factors like the development of therapy resistance coming with a decreasing sensitivity of tumor cells towards ionizing radiation, the unspecific targeting of both cancer and healthy brain cells, as well as the recurrence of the tumor after treatment. Recent advances suggest that the failure of therapies might be caused by the assumption that the tumor consists of a homogenous group of cells. In fact, the tumor is distinguishable into many subgroups of cells varying on genetics, epigenetics and phenotype as well as their capabilities to replicate and migrate. Thus, elimination of BTPCs is a promising alternative to specifically target the cell of origin of the tumor, which raises the possibility to prevent tumor proliferation, tumor cell differentiation and BTPC regeneration.Due to specific BTPC characteristics, like slow cell division rate, self-renewal properties, high capacity for DNA repairing and high expression of drug transporters, the identification and targeting of this cell population represents a challenge to this day. Moreover, BTPCs are capable of developing resistance mechanisms in multiple ways complicating conventional drug efficacies. High expression of ATP-binding cassette drug transporters can impede cytotoxic agents to enter the cell , resultiAnother way how BTPCs escape especially surgery is by forming stem cell niches and using ultra-long membrane protrusions, tumor microtubes, which can be found in various brain tumors and can be used as migration routes for cells located in BTPCs niches scattered in the brain. Disconnecting these tumor microtubes was suggested as a new target for treatment of GB ,108.The brain and especially brain tumors are always considered as extremely difficult for treatment, due to the blood–brain barrier (BBB). The BBB normally hinders harmful substances and toxins to enter the brain via different cellular and molecular components as well as divers transport systems. However, the location of the SVZ at the border to the lateral ventricle introduces a new aspect to the system, the CSF, which is secreted by the choroid plexus, forming the blood–cerebrospinal fluid barrier (CSFB). This barrier is functionally distinct and is not as tight as the BBB; mostly all non-cellular substances can enter the CSF . It raisOver the years, different approaches to target BTPCs were developed and tested , mostly The most prominent marker to target the cell surface with antibody-drug conjugates is CD133, which is expressed not only in brain tumors , but alsTargeting aberrant signaling pathways is a common approach in all forms of cancer. As for many cancer cell types, Notch signaling, the Wnt/β-catenin pathway and the PI3K/Akt cascade are among the pathways, which are significantly up-regulated and in the focus for targeting BTPCs in glioblastoma ,186,187.Another way to target BTPCs is to inhibit or modify the signaling from their microenvironment that sustains the growth of the cells and is necessary for fundamental processes e.g., the regulation of hypoxia and angiogenesis. These processes are closely linked, with angiogenesis being regulated through hypoxia. The hypoxia-inducible factor (HIF) is regulating numerous genes, including vascular endothelial growth factor (VEGF) expression. The overexpression of HIF-1α and HIF-2α have been linked to poor prognosis in many cancer types . HIF-2α-A further approach to diminish the number of BTPCs and to erase the tumors origin is the induction of apoptosis. Apoptosis includes a complex signaling network and the evasion of this system is crucial for the stem cell survival as well as tumor development. Agents to manipulate apoptotic pathways include the inhibition of tumor necrosis factor related apoptosis inducing ligand (TRAIL) and bortezomib, a proteasome inhibitor, which, given in combination, could trigger stem cell death in glioblastoma . Also, bAutophagy, a process of degradation and recycling of cellular components, has also been studied in glioblastoma BTPCs, especially in the context of drug-therapy resistance . ModulatStem cell differentiation also displays a promising strategy to limit the number of cells with tumorigenic potential and to produce cells with higher sensitivity to radio- and chemotherapy. Among the anti-cancer drugs affecting cell differentiation are bone morphogenetic proteins (BMP), retinoic acid and histone deacetylase (HDAC) inhibitors . The appHDAC inhibitors are belonging to the category of epigenetic drugs and target reversible histone acetylation and methylation. HDAC inhibitor vorinostat is approved by the Food and Drug Administration  and is bImmune cell therapy has a lot of potential and receives increasing attention in the field of cancer treatments. The dendritic cell vaccine ICT-107 consists of six synthetic peptides derived from tumor-associated and on glioma BTPCs overexpressed antigens . It is currently tested in phase III studies and it was already reported that ICT-107 treatment decreased CD133-positive cells and prolonged survival of the patients .Mutated tumor cells might reside in the SVZ and other BTPCs niches, forming a reservoir of BTPCs leading to increased tumor recurrence and decreased outcome of GB patients. An approach to overcome distribution of tumor cells as well as radio resistance would be to decrease the number of BTPCs in the SVZ by radiation. Studies in this field however report conflicting results, depending on the dose of radiation and the size of the resected area ,214,215.Besides controversy of the benefit of this treatment, side effects are difficult to estimate. Delivering high doses of radiation to healthy SVZ tissue could decrease quality of life by loss of memory. One recent study on a large group of patients could not find any improvement in survival . This miAll these therapeutical approaches are only a small selection of the broad range of agents under development and examination to target BTPCs in GB and how this, especially in combination with classical therapies, may bring benefits in erasing cancer stem cells for a successful treatment of GB patients.Each year, 240,000 cases of glioma are recorded worldwide, with GB accounting for most of these cases. As the most aggressive and malignant form of primary brain cancer, GB leads to thousands of deaths per year. The current standard care of therapy consists of a combination of surgery, radiation, and chemotherapy but the therapeutical success remains poor. This may be due to invasive tumor cells infiltrating neighboring brain regions, intra-tumoral heterogeneity and the capacity of distinct tumor cell populations to develop therapy resistance mechanisms. In this review we summarized various studies, which show that major reasons for the almost inevitable tumor recurrence are BTPCs, which are often spared by conventional therapy. It is suggested that these cells originate from astrocytic-like NSCs in the SVZ with the ability to leave the niche and to migrate over long distances. Through division into either differentiated cells or new BTPCs, they can provide an infinite pool of tumor cells and, additionally, the cells’ chemo- and radio-resistance in turn leads to resistance of recurrent GB to standard therapy. The identification of BTPCs and their origin raises hope to identify new molecular, epigenetic and genetic characteristics for the development of combination therapies to erase tumor cells as well as BTPCs. Current research focuses on multiple ways to target BTPCs including targeting specific cell surface markers, signaling pathways or the microenvironment, inducing either apoptosis or cell differentiation, inhibiting autophagy or applying vaccines or epigenetic drugs. Some of the agents are already investigated in clinical trials, showing promising outcomes. Further research is still needed to verify the latest results and technical advantages will help to discover specific GB BTPC treatment to terminate tumor stem cell proliferation and thereby increase the survival of GB patients. Taken together, this leads towards the development of a cure for this dreadful disease.


Important approaches such as high-throughput screening (HTS) have increasingly been used in combination with emerging strategies relying on genomics, chemical biology and molecular modeling  with a combination of experimental techniques  connects recent applications of LBDD and SBDD with the study of drug activity, as well as drug absorption, distribution, metabolism, excretion (ADME) and toxicity. We were able to collect 31 articles connecting more than 200 scientists from all around the world. Molecular modeling strategies for different conditions such as cancer, leishmaniasis, malaria, coronary heart disease, diabetes, and Alzheimer's disease are addressed. A broad variety of topics including the development of scoring functions, nuclear magnetic resonance (NMR)-assisted molecular docking, and the interplay between molecular docking and molecular dynamics are covered. In addition, this RT highlights the use of natural products as inhibitors of molecular targets such as the epidermal growth factor receptor (EGFR) and tumor necrosis factors (TNFs). New ligands targeting protein arginine methyltransferases, Kirsten rat sarcoma viral oncogene homolog (KRAS), G protein-coupled receptors (GPCRs), matrix metalloproteinases, heat shock proteins (HSPs), and mammalian Disheveled, are also considered. The design and implementation of online platforms for the prediction of It is our aim that the high-quality material enclosed in this RT contributes to the dissemination of outstanding science across the worldwide research community dedicated to the fascinating universe of drug discovery.All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.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.


Over the past decade, the advent of next-generation-sequencing tools has revolutionized our approach to understanding the human gut microbiota. However, numerical data on the gut bacterial groups—particularly low-cell-count microbiota, such as indigenous pathobionts, that are otherwise important components of the microbiota—are relatively limited and disparate. As a result, the comprehensive quantitative structure of the human gut microbiota still needs to be fully defined and standardized. With the aim of filling this knowledge gap, we have established a highly sensitive quantitative analytical system that is based on reverse transcription—quantitative PCR and targets microbial rRNA molecules. The system has already been validated in the precise, sensitive, and absolute quantification of more than 70 target bacterial groups belonging to various human gut bacterial clades, including predominant obligate and facultative anaerobes. The system demonstrates sensitivity several hundred times greater than that of other rRNA-gene-targeting methods. It is thus an efficient and valuable tool for exhaustive analysis of gut microbiota over a wide dynamic range. Using this system, we have to date quantified the gut microbiota of about 2,000 healthy Japanese subjects ranging in age from 1 day to over 80 years. By integrating and analyzing this large database, we came across several novel and interesting features of the gut microbiota, which we discuss here. For instance, we demonstrated for the first time that the fecal counts of not only the predominant bacterial groups but also those at lower cell counts conform to a logarithmically normal distribution. In addition, we revealed several interesting quantitative differences in the gut microbiota of people from different age groups and countries and with different diseases. Because of its high analytic sensitivity, the system has also been applied successfully to other body niches, such as in characterizing the vaginal microbiota, detecting septicemia, and monitoring bacterial translocation. Here, we present a quantitative perspective on the human gut microbiota and review some of the novel microbial insights revealed by employing this promising analytical approach. Clostridium coccoides group, Clostridium leptum subgroup, Bacteroides fragilis group and Bifidobacterium, (b) low-cell-count microbiota (LCCM) including facultative anaerobic groups such as Enterobacteriaceae, Lactobacillus, Enterococcus, and Staphylococcus, and (c) low-population-level indigenous pathobionts such as Clostridium difficile and Clostridium perfringens at various population densities  of LCCM including pathobionts remains controlled. However, in a state of dysbiosis , these LCCM can multiply and cause serious problems in clinical settings  methods (detection limit: 105 to 108 cells/g feces); LCCM can be enumerated at sensitivities comparable to those of culture methods  . Also, although sequencing methods generate tens of thousands of rRNA gene sequences per DNA sample, there could be several hundred operational taxonomic units in a given sample and hence it is possible that taxa with very low abundance could be overlooked  from standard strains of various gut microbiota Table . A straiIn subsequent sections, we demonstrate some interesting features of the human gut microbiota that have been revealed with the use of this quantitative analytical system. We also introduce the potential application of the system in the clinical diagnosis of bacteremia.The last decade has seen remarkable advances in elucidating the intimate relationship between the intestinal microbiota and aging  and low-cell-count facultative anaerobes  follow an approximately logarithmic normal distribution in a cohort of healthy Japanese volunteers aged 3 to 102 years  have previously been reported to exhibit bimodal abundance distributions and to form stable states at certain abundance levels associated with host factors such as age and obesity , which consist of many bacterial genera or species with a wide variety of functions, into 19 species and three genetically similar subgroups, and specific primers were newly developed for each  the genus Dorea and the species Fusicatenibacter saccharivorans were present in high-cell-counts in adults, whereas (c) Clostridium scindens (a secondary bile-acid-producing bacterium) prevailed in the elderly. Various factors, such as diet and lifestyle, have an impact on differences in the predominant anaerobes among age groups , the microbial nucleic acids in the homogenized samples can be stably maintained  than in healthy controls  patients are lower than those in patients with quiescent UC or in healthy individuals  patients than in healthy controls  for 6 months  and increased levels of beneficial bacterial groups (bifidobacteria and lactobacilli) after long-term continuous consumption of probiotics (the same probiotic beverage used in the above-mentioned study of elderly residents). In several other studies, too, we have normalized gut dysbiosis by probiotic administration to different cohorts of gastrectomized subjects and residents of aged-care facilities  becomes indispensable. In a study of patients with febrile neutropenia  it is difficult to arrive at a clear-cut diagnosis. In this context, we have been exploring the potential of YIF-SCAN in identifying pathogenic microbes. For example, selection pressure in the targeted culturing of Lactobacillus subgroups and species, as well as pathobionts such as Gardnerella vaginalis and Atopobium vaginae and pathogens causing sexually transmitted diseases. This YIF-SCAN is based on the analysis of RNA extracted from vaginal mucosal samples and is highly sensitive (Kurakawa et al., Lactobacillus community, we noticed that the counts of several bacterial-vaginosis-associated bacteria were quite high in a number of asymptomatic subjects (Kurakawa et al., The Human Microbiome Project is analyzing the bacterial gene content of the microbiota in a variety of body niches, including the gastrointestinal tract, oral cavity, skin, and vagina. In the context of the core microbiome concept, the importance of maintaining the stability of the bacterial microbiota of the intestine and vagina has been particularly emphasized (Huse et al., This novel approach to bacterial enumeration using rRNA-molecule-targeting RT-qPCR has been remarkably helpful in quantifying the dynamic changes occurring in the gut microbiota during host aging, especially during infancy and early childhood. By using a large integrated database of healthy Japanese people, we have revealed that not only the predominant obligate anaerobes but also facultative anaerobes constitute the core microbiota, and that the counts of each bacterial group approximate a log-normal distribution. We are sure that the information generated from this large integrated cohort will be helpful in further elucidating the features of the gut microbiota in prospective studies. All in all, microbial investigations using YIF-SCAN-based analyses have increased our knowledge of the structure, function, and dynamics of the complex microbial ecosystem both in health and in disease. The ultimate goal is to capitalize on this knowledge to improve human health. We are convinced that expanding the detection range of this analytical system to more microbial clades will provide a more comprehensive picture of the microbiota. Certainly, the scope of this valuable analytical tool will be realized in settings beyond the gastrointestinal tract, and its range of applications will broaden to cover various other niches of the human body and the microbiota of other host species in other biological settings.HT analyzed data. HT and KN wrote manuscript. HT, KM, and KN checked and revised manuscript. HT, KM, and KN approved final version of manuscript.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.


Whereas light-microscopy can achieve these with genetically-encoded probes or dyes, this modality does not allow mesoscale imaging of entire intact tissues. Non-invasive imaging techniques, such as magnetic resonance imaging (MRI), outperform light microscopy in field of view and depth of imaging, but do not offer cellular resolution and specificity, suffer from low signal-to-noise ratio and, in some instances, low temporal resolution. In addition, the origins of the signals measured by MRI are either indirect to the process of interest or hard to validate. It is therefore highly warranted to find means to enhance MRI signals to allow increases in resolution and cellular-specificity. To this end, cell-selective bi-functional magneto-fluorescent contrast agents can provide an elegant solution. Fluorescence provides means for identification of labeled cells and particles location after MRI acquisition, and it can be used to facilitate the design of cell-selective labeling of defined targets. Here we briefly review recent available designs of magneto-fluorescent markers and elaborate on key differences between them with respect to durability and relevant cellular highlighting approaches. We further focus on the potential of intracellular labeling and basic functional sensing MRI, with assays that enable imaging cells at microscopic and mesoscopic scales. Finally, we illustrate the qualities and limitations of the available imaging markers and discuss prospects for  However, LM offers but a glimpse of the brain in vivo, typically providing access to very small fields-of-view and depths of the mammalian brain  imaging of neurons an brain . Thus, n2+ concentration changes or neurotransmitter release. In recent years, several technological advances, including magnetic fields significantly higher than those commonly used in clinical settings, novel radio-frequency coils with a large number of densely-spaced small coil elements, and the use of unique dielectric materials, allow to indirectly track the activity of smaller and smaller populations of neurons in the brain  is also indirect . Intrinshe brain . Despitehe brain . As contin vivo  approach  along unperturbed fluorophore loading, with an overall diameter of ∼100 nm. Weller and co-workers . This so-called “yolk-shell” morphology prevents the undesired interactions within the hybrid that would diminish the properties of the semiconductor and magnetic domains. Furthermore, this architecture offers a high level of tunability with respect to size, composition and surface functionalization. The photoluminescence quantum yield of the yolk-shell nanoparticles was typically ∼16% (at 450 nm excitation light), comparable to the ∼12% photoluminescence quantum yield (at 405 nm) of the silica coated core-shell superparticles. This yield was sufficient for single particle tracking  magneto-fluorescent nanoparticles . In lieust agent . Despitetracking , and fortracking . The decin vivo applications. This adjustment will also minimize the spectral overlap between the absorption of the core and that of the hollow shell, and is expected to improve the photoluminescence quantum yield.Noteworthy is the fact that for the morphologies presented in An interesting alternative for multimodal imaging is provided by incorporation of manganese ions into the QD, hence offering the semiconductor itself paramagnetic characteristics . These sParticle-size is a critical criterion that will determine the mechanism by which it will be internalized into the cell, with major influences on cellular uptake efficiency and kinetics, and subcellular distribution . Note thin vivo imaging is the effect of the hydrodynamic diameter of the contrast agent on its resident circulation time  were functionalized first with Tiron  for their incorporation to cells ethane-N,N,N’,N’-tetraacetic acid (BAPTA) or Calmodulin, respectively. A plausible scenario would be that following neural activity and sharp rise in cytoplasmic Ca2+-concentration, intracellular nanoparticles would bind Ca2+, thus altering the reactivity of the coating. Ca2+ binding may influence the effective columbic repulsion of the coating, or enhance the affinity and binding to a secondary moiety on the surface of surrounding nanoparticles. Regardless the exact mechanism, it is expected to change the particles’ dispersivity in a manner that would result with strong aggregation. This aggregation, once it exceeds a certain size, is expected to result in a detectable MR signal localized to the cell. As Ca2+-binding is reversible, this phenomenon would also be reversible, providing MRI-readout for neuronal activity.The observation of aggregates was surprising, as the nanoparticles consistently remain monomeric in solution a2+-ions . In thisa2+-ions  that binIntracellular magneto-fluorescent contrast agents are of great significance for the development of imaging methodologies for single cell longitudinal measurements in the intact brain. These bi-functional markers enable coupling between high resolution LM with the non-invasive mesoscale imaging capabilities of MRI. Yet the roadmap towards enhancement of MRI signals from select specific cells requires improved understanding of cellular internalization and accumulation mechanisms. In particular, modes of cellular uptake, their efficiency and kinetics, subcellular distribution of contrast agents following uptake, clearance and, notably, toxicity need to be better understood and accurately characterized. These are all influenced, and at times dictated, by the size, shape and surface chemistry of the contrast agent nanoparticles, and should be properly considered when choosing the synthetic strategy. We envision that insights on the correlation between the agents’ characteristics and their intracellular distribution would enable manipulation of the latter for improved specificity, and ultimately for functional readout of neuronal activity.All of the experiments involving animals were conducted in accordance with the United States Public Health Service’s Policy on Humane Care and Use of Laboratory Animals and study protocol was approved by the Institutional Animal Care and Use Committee of Technion – Israel Institute of Technology.LA, SB, and IK developed the concepts described in this work and wrote the manuscript. SO, SP, and SB carried out the experiments. All authors analyzed the results described in the manuscript and approved the final version of the manuscript. This work is in partial fulfilment for the Degree of Doctor of Philosophy (Ph.D.) for SO.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.


There is a paucity of research on women offenders in the South African context, particularly those referred for forensic psychiatric observation. Little is known about their life histories, the nature of their offences or the psycho-social contexts that enable, or are antecedents to, women’s criminal offending.This research study, the largest of its kind in South Africa, examined the psycho-social contexts within which women offenders referred for psychiatric evaluation come to commit offences. The profiles of both offenders and victims, as well as reasons for referral and forensic mental health outcomes, were investigated.A retrospective record review of 573 cases, spanning a 12-year review period, from 6 different forensic psychiatric units in South Africa, was conducted.The findings describe a population of women offenders who come from backgrounds of socio-demographic and socio-economic adversity, with relatively high pre-offence incidences of being victims of abuse themselves, with significant levels of mental illness and alcohol abuse permeating life histories. The majority of index offences which led to court-ordered forensic evaluations were for violent offences against the person, with murder being the single most common index offence in the sample. Most victims of violence were known to the accused. There were also relatively high rates of psychotic and mood-spectrum disorders present, with relatively low rates of personality disorders. The majority of women were deemed to be trial competent and criminally responsible in relation to their index offences.It is recommended that more standardised and gender-sensitive forensic mental health assessment approaches, documentation and reporting be employed throughout the country. Future research should compare male and female offending patterns and forensic mental health profiles.


The basal ganglia are a complex subcortical structure that is principally involved in the selection and implementation of purposeful actions in response to external and internal cues. The basal ganglia set the pattern for facilitation of voluntary movements and simultaneous inhibition of competing or interfering movements. In addition, the basal ganglia are involved in the control of a wide variety of non-motor behaviors, spanning emotions, language, decision making, procedural learning, and working memory. This review presents a comparative overview of classic and contemporary models of basal ganglia organization and functional importance, including their increased integration with cortical and cerebellar structures. Their contribution is also linked to the control of a wide range of complex non-motor behaviors, including emotions, language, decision making, procedural learning, and working memory.The basal ganglia are a group of interconnected subcortical nuclei that include the putamen and caudate nucleus , globus pallidus , substantia nigra (its pars compacta SNc and pars reticulata SNr), and the subthalamic nucleus (STN). The limbic portion of the basal ganglia is composed of the nucleus accumbens, ventral pallidum, and ventral tegmental area. The basal ganglia are principally involved in the selection and implementation of purposeful actions in response to external and internal cues. Most prominently, the basal ganglia set the pattern for facilitation of voluntary movements and simultaneous inhibition of competing or interfering movementsContemporary views about the expanded structural and functional organization of the basal ganglia are informed by several key discoveries that have been made in the past few years. These have important implications not only in regard to normal functioning of the basal ganglia and larger neural networks in general but also in terms of unraveling piece-by-piece yet-unknown mechanisms of various neurological and psychiatric disorders, such as Parkinson’s disease, dystonia, obsessive–compulsive disorder, and Tourette syndrome, to name a few. This review presents a comparative overview of classic and contemporary models of basal ganglia organization, including their increased envelopment with cortical and cerebellar structures, and a discussion of the functional importance of basal ganglia and their significance in brain disorders.3 includes top-down cortical projections to the striatum, which further converge on GPi and SNr either directly or indirectly via GPe and STN (1-family receptors expressed on medium spiny neurons (MSNs) predominantly within the net excitatory direct pathway and D2-family receptors expressed predominantly within the net inhibitory indirect pathway, thus balancing excitation and inhibition within the thalamo-cortical circuitry.There are several levels of complexity in the organization of basal ganglia. Since the late 1980s, the classic model of the basal ganglia in both humans and animals has been built on the presence of intrinsic direct and indirect pathways, both comprising a consecutive set of excitatory glutamatergic and inhibitory GABAergic projections. The intrinsic modeland STN . The out6. The density of bridging collaterals was found to modulate the functional balance within the basal ganglia such that an increase in bridging collaterals led to enhanced pallidal inhibition6. In line with these findings, a recent positron emission tomography (PET) study in human subjects demonstrated a great degree of overlap between the direct and indirect basal ganglia pathways7.Building on the framework of this original model, recent studies discovered a much denser intrinsic basal ganglia connectivity . One of 10. The paramount significance of this finding is in its clinical relevance to the treatment of brain disorders, such as Parkinson’s disease, where STN is a target for deep brain stimulation (DBS). Thus, detailed knowledge of its involvement in extrinsic cortical (hyperdirect pathway) and intrinsic basal ganglia (direct and indirect pathways) networks provides advanced knowledge, allowing fine-tuning of the DBS procedure and programming.Another revision to the classical model of basal ganglia involved the expansion of STN’s responsibility within its network. The STN is now considered a major input relay station receiving direct projections from various cortical and subcortical regions, including the recently identified hyperdirect cortico-subthalamo-pallidal pathway12. GPe has been found to contain heterogeneous populations of neurons, including Arky-GPe neurons targeting striatal GABAergic interneurons13, Lhx6-GPe neurons strongly projecting to the SNc and STN, and PV-GPe neurons predominantly projecting to the STN and parafascicular thalamic nucleus14, which collectively contribute to distinct motor and non-motor behaviors via different pallidal circuits17. Overall, this higher level of integrity and interactions between basal ganglia structures allows their enhanced functional importance in contributing to and controlling an array of human and animal behaviors.The reciprocity between basal ganglia structures is further established by expanded circuitry of GPe, which not only projects downstream to STN but also sends direct collaterals to GPi and SNr as well as feedback projections to the striatum20. An increase in the number of striatal dopaminergic neurons has been observed as a potentially compensatory response to the loss of nigrostriatal dopaminergic innervation, with the significance of implications for neurological disorders involving the basal ganglia and abnormal dopaminergic function, such as in Parkinson’s disease and dystonia. However, a recent study has challenged these assumptions by defining the vast majority of striatal tyrosine hydroxylase (TH) interneurons in transgenic enhanced green fluorescent protein (EGFP)-TH mice as medium-sized, aspiny, or very sparsely spiny interneurons expressing low levels of TH and making GABAergic synapses onto spiny projection neurons21.Although the SNc is known as the main structure harboring dopaminergic neurons that project to different basal ganglia and cortical divisions, dopaminergic neurons were also found to be scattered throughout the primate striatum and abounded in its ventral portion28. These areas receive projections from corresponding motocortical regions, with the somatotopy preserved at the entire rostro-caudal extent and in their output to the thalamus, which loops back to the corresponding cortical representations. In the striatum, pallidum, and thalamus, the distribution of body regions is along the dorsal–ventral axis, with primary motor and premotor cortical projections forming parallel homunculi. The STN, on the other hand, forms a mirror set of homunculi, with the primary motor cortex predominantly projecting to its lateral part and the premotor cortex predominantly projecting to the medial part, although some areas receive a convergent input from both motocortical regions. Finally, SNr and SNc projections with the striatum have an inversed dorsoventral topography, such as the dorsal parts of the striatum project to the ventral SN regions, while the ventral striatal regions project dorsally. The dorsal one-third of SN carries the orofacial representation as a continuation of the same regions of the GPi, and the more ventral region receives an input from the premotor territories of the putamen30. The rostromedial two-thirds contain projections from prefrontal striatal areas31, and the most medial part receives limbic striatal input32. The SNc dopaminergic neurons give rise to topographically organized striatal projections36. Specifically, the dorsal tier and the most medial part of the ventral tier of the SNc project to the ventromedial striatum; the remaining ventral tier projections are directed to the associative striatum, and the ventrally extending cell columns of the ventral tier are connected to the sensorimotor striatum38. The nigrostriatal connections, at least those of the striatal matrix, are reciprocal, and dopaminergic neurons synapse on MSNs, which in turn reach back to the somata and dendrites of SNc neurons40. However, reciprocal nigrostriatal connections do not form a closed loop; instead, the ventral tier of SNc that receives input from the ventromedial striatum projects to the more dorsolateral striatum42. In addition, while the nigral projections are topographically organized and directed to a particular striatal region, the extending weaker fibers also reach all other striatal divisions43. Thus, such feedforward connections allow the interplay between different striatal divisions that are responsible for the control of different aspects of a behavior.In addition to these discoveries of cellular composition of the basal ganglia, an important feature of intrinsic organization is that their input is arranged in a highly topographic manner . Similar8, whereas the alternative view pertained to information convergence across the loops9  or parvalbumin (PV+) and differ in their target cell preference and the modulatory effects of a motor behavior47. On the other hand, while it is established that the basal ganglia modulate the cortex indirectly via the inhibitory (GABAergic) output to thalamus, a direct GABAergic/cholinergic projection between the GPe and frontal cortex does also exist48. Again, two cell types comprise this connectivity and differ in their electrophysiological properties, cortical target projections, and expression of choline acetyltransferase (ChAT).In regard to extrinsic basal ganglia neuromodulatory projections, it has recently been demonstrated that, in addition to the major excitatory (glutamatergic) cortico-basal ganglia input54. However, the development of a retrograde transneuronal tracer, herpes simplex virus type 1 (HSV1), allowed the important discovery that different subdivisions of the basal ganglia  and cerebellum  have, in fact, a widespread output via distinct target thalamic nuclei to other cortical regions, such as subdivisions of premotor, oculomotor, prefrontal, and inferotemporal areas. Based on a revision of anatomical connectivity, it was proposed that the basal ganglia and cerebellum influence not only the motor behaviors but also various cognitive and limbic functions67. However, it was still believed that the basal ganglia-thalamo-cortical and cerebello-thalamo-cortical pathways form anatomically independent loops that converge and communicate mainly at the level of target cortical regions69.Another drastic revision to the organization of extrinsic basal ganglia connectivity is the addition of the cerebellum to this circuitry. The original view of the cerebellum and basal ganglia was that of a “funneling” system, where both structures receive and process information from prefrontal, parietal, and temporal areas with a subsequently integrated output to the primary motor cortex for execution of a motor command75. Specifically, the STN was identified as an output region of dense disynaptic projections via the pontine nuclei to the cerebellar cortex. On the other hand, the dentate nucleus was found to be the main output structure, primarily via intralaminar thalamic nuclei, of dense disynaptic projections to the striatum and trisynaptic projections to the GPe but not the GPi. In addition, other deep cerebellar nuclei  were demonstrated to be sources of striatal disynaptic projections, albeit to a lesser extent than the dentate nucleus. Given the participation of the GPi and GPe in the intrinsic direct and indirect basal ganglia pathways, respectively, it was suggested that the cerebellar output may preferentially influence the indirect basal ganglia pathway76. Similar to the basal ganglia-thalamo-cortical output, the basal ganglia-cerebellar anatomical network is topographically organized in such a manner that the motor, associative, and limbic regions are interconnected between the two structures. This bidirectional communication between the basal ganglia and cerebellum at both subcortical and cortical levels is assumed to provide a backbone of the integrated functional network where motor and non-motor information is processed at multiple stages before its final cortical output.Further modifications to this view came with the development and use of another retrograde transneuronal tracer, the rabies virus, which led to the discovery of basal ganglia and cerebellar connectivity at the subcortical levelIn conclusion, the development of new methodologies and the conduct of parallel research in animal models and human subjects paved the way for a more complex view of basal ganglia structural organization. These advances have enhanced our understanding of the functional importance of this structure within the large-scale brain network, expanding their role in both motor and non-motor domains. Importantly, detailed knowledge of basal ganglia organization informed our views of their contribution to the pathophysiology of a range of neurological and psychiatric disorders and played a critical role in the development of novel therapeutic opportunities targeting specific anatomical or functional links (or both) of basal ganglia connectivity. Continued progress in the field of basal ganglia research will further refine and characterize the multi-layer organization of this structure, including both intrinsic and extrinsic connectivity.