Coping-skills training (CST) and cue-exposure treatment (CET) are two relatively new approaches in alcoholism treatment. With CST, the therapist tries to strengthen the patient’s skills in coping with situations associated with a high risk of drinking. These skills can be specific to certain high-risk situations or involve general social skills. Specific CST treatment approaches include relapse prevention training, social or communication skills training, urge-specific coping-skills training, and cognitive-behavioral mood management training. Several studies have shown that CST can be more effective than comparison treatments in improving the outcome  of alcoholic patients. CET exposes the patient to alcohol-related cues , thereby allowing the patient to practice responses to such cues in real-life situations. In addition, CET teaches a variety of coping skills for dealing with urges caused by such cues. Few studies have examined the effectiveness of CET, but the existing results demonstrate favorable treatment outcomes . In recent years, several exciting advances have provided clinicians with new tools in alcoholism treatment that have resulted in improved outcomes  for alcoholic patients. Two of these new tools are coping-skills training (CST) and cue-exposure treatment (CET). CST aims to enhance the patient’s coping skills and provide him or her with specific strategies for coping with the urge to drink. Conversely, CET exposes the patient to alcohol-related cues  during therapy, thereby allowing the patient the opportunity to practice using coping skills in response to the urge to drink within the safe environment of a treatment setting. Researchers hypothesize that as a result of coping-skills practice, patients will feel less overwhelmed by urge-provoking situations and, therefore, less likely to relapse after treatment. This article reviews the conceptual bases and methods of CST and CET and also summarizes the results of outcome studies that have assessed the effectiveness of both approaches.CST and the related treatment approach of social skills training have evolved from several decades of research based on social learning theory. According to social learning theory, several factors can increase the likelihood that an alcoholic will relapse when confronted with a stressful situation or with another situation that is associated with a high risk of drinking . Influential factors include limited skills in coping with stressful or high-risk situations, expectations that alcohol will have a positive or pleasurable effect in these situations , and the belief that the person cannot effectively cope with the situation without drinking  .Skills training is designed to address the aforementioned risk factors in several ways. First, clinicians can train patients in using coping skills specific to certain high-risk situations  to improve the patients’ skillfulness in handling similar situations in the future. Second, therapists can teach their patients general social skills that will result in improved sober relationships and reduced conflict in both family and work relationships. This improvement in social skills can diminish both the drinkers’ stress levels and the number of high-risk situations they encounter while simultaneously increasing their social supports for abstinence. Third, as a result of stronger coping and social skills, patients will likely develop increased self-efficacy expectations and, consequently, be more likely to effectively utilize those skills in high-risk situations.Several lines of evidence support the importance of skills training for alcoholics. First, studies indicate that alcoholics’ coping skills are inferior to the coping skills of nonalcoholics, particularly in situations that commonly pose a risk of relapse, such as a family conflict or parties at which alcohol is served . Second,Social learning theory also suggests that several types of personal and environmental factors and situations place a drinker at a particularly high risk for relapse. An understanding of these high-risk situations can help treatment providers design skills training programs that teach their patients the specific skills needed to cope with those situations.One personal factor that contributes to a high risk of relapse is the lack of ability to control one’s positive  and negative  emotional states . AnalyseAnother common risk factor for relapse is the presence of alcohol or drinking-associated stimuli , which may be combined with either direct or indirect peer pressure . ConsequAll CST approaches generally begin with an assessment of the patient’s areas of vulnerability . This asBecause some intrapersonal factors can influence relapse risk, the clinician should assess those that are relevant, including the patient’s current skill in controlling mood states, such as euphoria, anger, depression, and stress. In addition, the treatment provider should evaluate the extent to which situations involving various mood states have posed a risk of heavy drinking to the patient in the past.At the beginning of CST, the clinician also should assess the patient for interpersonal risk factors, including general social skills, conflict resolution skills, and refusal skills, as well as the types of interpersonal situations that have contributed to heavy drinking in the past. Finally, the treatment provider must determine the extent to which the patient will be exposed to alcohol cues. For example, patients whose jobs involve being around alcohol  or whose family or extended social network includes drinkers or alcoholics may require cue-specific coping skills or CET.A valuable way to obtain specific information about these various risk factors, particularly for outpatients, who are not treated in a controlled environment, is to have the patients themselves monitor both high- and low-risk situations by maintaining a detailed daily log. Such logs can help the treatment provider and the patient identify both the risk factors and the protective factors to which the patient is exposed. Although clinicians have developed several types of CST, the following four approaches have been used most extensively .Through this process, the patients are taught to define the situational problem by identifying its relevant elements , to generate several possible responses, and to think about the consequences of each response. To practice their new skills, participants discuss and role play a sample situation before identifying specific personal examples of that type of situation. Each patient role plays his or her specific high-risk situation and receives feedback on how to enhance the effectiveness of his or her response. The patient then repeats the same role play using the new and more effective response. In addition, the patient reports what he or she was thinking when generating the response so that thoughts or emotions such as anger or hopelessness can be addressed.In contrast to relapse prevention training, communication skills training does not focus on high-risk situations but, instead, focuses on communication skills that can be used to handle a variety of risky situations . This apCommunication skills training generally is conducted in a group setting. Each session begins with a summary of the meeting’s goals and the reason why the skill is important for sobriety, followed by a brief presentation and discussion of the skill involved. Depending on the participants’ initial skill level, the therapist can role play a sample vignette illustrating the skill to be discussed. The patients then generate personal examples of possible scenarios in which the skill may be needed. As with relapse prevention training, the sessions include instruction in effective coping skills, modeling of those skills by therapists and group members, behavior rehearsal in role plays with feedback, and coaching of responses and of cognitive aspects of the response.Several studies have evaluated CST’s effectiveness in improving patient outcome and have compared it with the effectiveness of other approaches. A second study  compared communication skills training, either for the alcoholic alone or for both the alcoholic and his or her family members, with another approach, cognitive-behavioral mood management training . Again, Measures of patients’ skill levels as determined by standardized tests  gathered during some of these studies provide further information about the mechanisms underlying CST’s beneficial effects. For example, in the study by Other studies, such as the Project MATCH trial, however, did not find greater benefits of skills training approaches compared with other approaches. In the multisite Project MATCH study, alcoholic patients who either had completed inpatient therapy  or had received only outpatient care  were randomly assigned to receive either cognitive-behavioral therapy , motivational enhancement therapy, or 12-step facilitation. This study did not find any differences in overall outcome between the three treatment approaches among either the aftercare or the outpatient sample . HoweverThe cognitive-behavioral approach in the Project MATCH study combined communication skills training modules with cognitive-behavioral mood management training. As described previously, however, mood management training benefits only a limited number of patients and may thereby reduce the effectiveness of the overall cognitive-behavioral approach.The three treatment approaches in Project MATCH were administered only to outpatients  or to patients who had already successfully completed an intensive inpatient treatment program. Consequently, the study allows no conclusions regarding the effectiveness of these approaches when they are administered as a component of  intensive inpatient or partial hospitalization programs. Studies in which skills training was administered during such intensive programs generated more favorable results .Each of the treatment approaches in Project MATCH was the sole form of treatment that the patients received during the study period. In regular treatment settings, however, the various treatment approaches are commonly administered together with other measures as part of a full treatment program. Thus, skills training along with the other two approaches might be more beneficial if they were administered as one component in a comprehensive treatment program.No process measures assessing the acquisition of skills were collected during the Project MATCH study period; consequently, researchers cannot determine whether the patients actually learned the skills that they were taught. Without such measures, it is difficult to determine whether patient outcomes had not improved because the patients had learned new skills but those skills did not affect outcome or because the patients did not attain the necessary skills . Other studies that did include process measures of skill acquisition reported beneficial results from skills training e.g., .In Project MATCH, the skills training was conducted with individual patients. Researchers generally consider group therapy superior, however, because it allows for multiple sources of feedback . ConsistAn alcoholic can encounter numerous alcohol-related cues in his or her environment. These cues can include the sight and smell of a favorite alcoholic beverage; mood states or situations in which drinking previously occurred; and people, places, times, and objects that had previously been associated with alcohol’s pleasurable effects. Two types of models—learning theory models and social learning theory—have been used to explain the relationship between alcohol-related cues and relapse to drinking.Classical learning theory models of alcohol cues and relapse suggest that environmental cues that were associated with drinking in the past can elicit conditioned responses,In addition to classical learning theory models, social learning theory suggests that the presence of cues may increase the risk of relapse by increasing the relevance to the drinker  of the positive effects of alcohol, which can make the drinker want to consume more alcohol. According to this theory, alcohol cues also can trigger cognitive and neurochemical reactions that may undermine a drinker’s ability to use coping skills as well as the drinker’s beliefs that he or she can effectively use those skills in the situation . The expSeveral lines of evidence support the hypothesis that exposure to alcohol cues can increase the risk for relapse. For example, These studies suggest several strategies for designing more effective treatment approaches. For example, treatment could be designed to reduce the degree of the reactions alcoholics experience in the presence of cues by repeatedly exposing the patients to those cues in a safe environment. As a result of such an approach, the disruptive effects of alcohol cues on attentional processes and on the ability to use coping skills should be reduced. Alternatively, treatments could provide alcoholics with practice in using coping skills while in the presence of alcohol cues. Such an approach should allow an alcoholic to use his or her coping skills more effectively even when experiencing a strong reaction to alcohol cues.CET may exert its beneficial effects through two different mechanisms. First, learning theory posits that repeated presentation of a cue  while preventing the usual response  should result in decreasing reactions across sessions  and possibly the permanent loss  of the elicited response  over time. However, such habituated reactions are specific to the particular cues used. Accordingly, the reaction is easily reinstated if the alcoholic is exposed to a different cue . Second, social learning theory suggests that engaging in coping skills practice in the presence of alcohol-use cues should increase both the effectiveness of those skills when in the presence of cues and the drinker’s beliefs about his or her ability to respond skillfully when confronted by similar cues in real-life situations. As a result of this repeated practice, internal reactions to alcohol cues likely will interfere less with the drinker’s ability to use his or her coping skills in the future.Various approaches to CET exist  .The patients, who were experiencing alcohol-related problems but were not alcohol dependent, consumed three standard drinksAnother approach, which was abstinence oriented, involved exposure to cues with no drinking allowed . In 40-mSeveral treatment approaches have combined CET with urge-specific CST. In one such approach, which was aimed at achieving moderate drinking patterns, alcoholics received two drinks as a priming dose, then either looked at a third drink while being instructed to resist drinking or imagined being exposed to alcohol and successfully refusing the drink . HoweverA more elaborate approach, combining the learning and practicing of urge-specific coping skills with exposure to actual alcohol cues and to imagined high-risk situations, has since been developed for alcoholics in abstinence-oriented treatment programs . This trCue reactivity assessment, in which the patient holds and smells a glass of his or her usual alcoholic beverage while salivation, urge to drink, and other responses are measuredDrinking Triggers Interview, a questionnaire used to identify the situations in which the patient experiences the strongest urges to drink.Each treatment session begins with the alcoholic holding a glass of his or her usual alcoholic beverage; smelling it, if that will increase the urge; and focusing on the aspects of the beverage that produce the strongest urge. During that time, the patient reports every change in the level of urge in terms of a 0 to 10 scale. Once the patient’s urge level has peaked , one of two events occurs. In the first session, the patient is asked to continue focusing on the beverage to “see what happens to your urge.” Experience has shown that the urge generally decreases within 15 minutes, an effect that usually is quite different from what the patient had expected. In all later sessions, the patient is asked to imagine using the urge-specific coping strategy that he or she was taught most recently to reduce the urge.After the part of each session that involves actual beverage exposure, one or more trials involving imaginary exposure are conducted in the same session, using similar procedures. In these trials, the patient is asked to imagine being in one of the high-risk situations identified in the Drinking Triggers Interview, starting with the situation that had received the highest urge rating. After the patient’s urge has peaked, he or she is asked to continue to imagine being in the situation and to either “wait out” the urge (first session only) or apply the coping skill most recently taught. A variety of different urge-specific coping skills are taught in the sessions, including the following:Using delay as an active cognitive coping tool—that is, the drinker tells himself or herself that the urge will “go away” if he or she just “waits it out”Thinking about the negative consequences of consuming alcohol in the imagined situationThinking about the positive consequences of staying sober in the imagined situationUsing urge-reduction imagery developed by Using behavioral substitution—that is, imagining engaging in an alternative activityUsing consummatory substitution, such as consuming favorite foods and sodas instead of alcoholEmploying mastery statements, such as “I am strong; I can get through this without drinking”Using pleasant imagery—that is, imagining escaping to a pleasant place.This CET approach incorporates both the classical learning theory and social learning theory aspects. Thus, an alcohol cue  is present throughout the treatment session, both during times when the alcoholic is actively focusing on the cue  and during all other parts of the session . Habituation or extinction processes come into play as a result of exposure without drinking. In addition, alcoholics are taught useful coping skills and can practice using those skills while their urges are elevated, either by alcohol exposure or by imagining being in high-risk situations.Social learning theory predicts several results of this approach:Practicing coping skills while experiencing an urge for alcohol should decrease the likelihood that future urges will disrupt the use of coping skills in the real-life environment.Alcoholics will experience the benefits of coping skills because their urges will decrease more rapidly when they apply the skills. This experience should increase both the patients’ confidence that they can apply the skills and their expectancies that the urge will decrease if they use the coping skills.This procedure should allow treatment providers to tailor the coping skills to be used in high-risk situations to the individual needs of each patient. Thus, patients are asked to try various skills for coping with each drinking trigger situation during treatment and to identify the skills that are most effective for each particular trigger situation. At the end of treatment, each patient then receives a printed copy of his or her individualized “tool box” for future reference.Few controlled CET studies—that is, studies in which researchers compared CET’s effectiveness with that of other treatment approaches—have been conducted. Two studies assessed CET’s effectiveness when drinking was allowed during treatment because moderate drinking was a treatment goal. More recently, Two additional controlled studies of CET were conducted in abstinence-oriented programs and therefore did not involve any alcohol consumption. In one study, CET  was compared with a control treatment involving relaxation training, both provided in addition to standard inpatient treatment . In thatMeasures of the variables the treatments were intended to affect  gathered during the study conducted by As the studies reviewed in this article indicate, CST has a strong track record of improving drinking outcomes when used in combination with comprehensive alcoholism treatment programs. Thus, CST approaches, regardless of whether they focus on coping with specific high-risk situations or on general communication skills, have resulted in improved skills and decreased drinking severity. Few controlled trials have evaluated the effectiveness of CET, however, although the studies that do exist indicate that CET is a promising approach and should be investigated further. Moreover, those studies have demonstrated that although cue exposure alone can result in favorable outcomes, the opportunity to practice urge-specific coping skills while experiencing cue-induced urges may be particularly beneficial. Researchers are currently developing and investigating additional approaches for combining skills training with cue exposure, and the results of those investigations should provide guidance for clinicians in the future.Researchers also are investigating the usefulness of therapy approaches that combine CST and CET with pharmacotherapy involving the medication naltrexone. This medication is one of only two agents approved for alcoholism treatment and has been shown to reduce relapse rates in alcoholics who are also receiving psychosocial therapy. Naltrexone acts on brain chemicals involved in mediating alcohol’s pleasurable effects and may thereby reduce a drinker’s desire to consume alcohol. Preliminary results of a recently completed study have suggested that naltrexone treatment can significantly reduce the number of patients reporting any urge to drink during alcohol exposure . These fIn summary, the past decade has seen important advances in effective behavioral and, more recently, pharmacological treatment approaches for alcoholism. This progress will likely continue in the coming years, particularly as various promising approaches are combined to develop more effective ways of treating alcohol dependence.


The relationship between boundary completion and surface filling-in, two core mechanisms of mid-level vision, remains unclear. Here, we integrate recent empirical findings to shine new light onto the neural mechanisms of boundary completion and surface filling-in as well as their relation to each other. Specifically, we discuss several psychophysical and neurophysiological studies that, when taken together, support a model where object boundaries and visual surfaces are interpolated in parallel, with one process impacting the other. We suggest that visual boundary completion and surface filling-in are two interacting processes that are supported by neural processes that are distributed throughout several areas of the early visual system. Visual perception is thought to arise from a series of hierarchically organized processing steps that extract increasingly complex visual features from raw sensory input . This idAt the main entry point of retinal information, the primary visual cortex (V1), neurons are highly selective for steep local luminance gradients, which aid the visual system in detecting the location and orientation of high contrast luminance edges within the two-dimensional (2D) retinal image . HoweverOne way the visual system seems to overcome the inherent limits of edge detection is to perceptually complete object boundaries even if some edges are physically absent . This phAn intuitive notion that follows from the above is that the early visual system performs a series of computational steps to extract increasingly complex visual features from retinal input. First, linear edges are extracted from the raw retinal input. Following this step, individual edges are spatially interpolated into outlines that delineate 2D image elements from each other and the background. Once these borders have been completed, each location within the visual field can be assigned to be within or outside of contour-defined shapes, and each enclosed shape is assigned respective surface attributes (filling-in).Supporting this serial model, several psychophysical studies have demonstrated that image boundaries profoundly influence the perception of visual surfaces. In particular, a number of visual illusions suggest that a boundary’s contrast and color spreads rapidly across visual space to “fill in” the intervening surface . This inA recently described visual illusion demonstrates the causal influence of visual boundaries over perceptual surface filling more directly. In contour adaptation (CA), prolonged inspection of a contrast-inversing outline suppresses the perceptual visibility of a monochrome version of the encompassed surface if presented subsequently at the same location of visual space . CriticaA second recently described visual illusion that strikingly demonstrates the deterministic effect of boundaries on surface filling-in employs perceptual afterimages. Typically, when a colored shape is viewed for a prolonged period of time and then removed, a shape with complementary color  is briefly perceived at the same location in visual space. However, the perceptual outcome of such afterimages can be profoundly altered by imposing a divergent contour . More spSeveral neurophysiological studies suggest a similar rank order of boundary representations and surface perception. Voltage sensitive dye imaging (VSD) in monkey V1, for example, revealed that population responses initially correspond to individual stimulus elements . Once thOne interpretation of these findings is that neuronal processes related to visual boundary completion precede the computations underlying surface filling-in. This interpretation would be consistent with the causal effects of visual boundaries on surface perception discussed above. However, a strictly sequential view of visual spatial interpolation, where boundary completion serves as a precursor or prerequisite of surface filling, has been repeatedly challenged on theoretical grounds . GeneralSupport for the claim that boundary completion is not required for surface filling-in is derived from observations that demonstrate that the visual perception of surfaces can be established independently of the perception of encompassing boundaries . One of Another line of evidence pointing toward the existence of surface filling mechanisms that are dissociable and partially independent from boundary completion stems from the phenomenology of illusory figures . Notably, for certain classes of illusory figures, such as the popular Kanizsa square , the cenSince the perception of illusory figures requires interpolation of both boundaries and surfaces across different regions of a physically homogeneous visual field, this class of stimuli also provides a unique opportunity for studying the neurophysiological correlates and the respective spatiotemporal relationship between boundary completion and surface filling-in. Two recent studies using these stimuli have posed challenges to a strictly serial hierarchical model of boundary completion and surface filling-in. In the first study, transcranial magnetic stimulation (TMS) was used to investigate the role of both early and late cortical areas in the visual processing of illusory figures. Online TMS was used to disrupt signaling in V1/V2 and in the shape-selective lateral occipital area (LOC) at various time points while participants performed a discrimination task involving a Kanizsa-type illusory figure (Further support for non-sequential ordering of boundary completion and surface filling-in stems from recent single neuron recordings in macaque monkeys viewing Kanizsa-type illusory figures a–b. StriThe combined results of the empirical studies outlined above suggest that a certain degree of surface segregation, based on partial boundaries or other aspects of global stimulus configuration, may sometimes occur before surface boundaries are completely delineated by the visual system. Several possible relationships between surface filling-in and boundary completion can be conceptualized to explain these findings. One possibility is that both processes are initiated in parallel. While boundary completion operates on input from edge detection, the extraction of visual surfaces might operate on the low spatial frequency components of the retinal image that provide information about global variations in brightness and hue . Another


Our original review, “Heterogeneity and Diversity of Striatal GABAergic Interneurons,” to which this is an invited update, was published in December, 2010 in Frontiers is Neuroanatomy. In that article, we reviewed several decades’ worth of anatomical and electrophysiological data on striatal parvalbumin (PV)-, neuropeptide Y (NPY)- and calretinin(CR)-expressing GABAergic interneurons from many laboratories including our own. In addition, we reported on a recently discovered novel tyrosine hydroxylase (TH) expressing GABAergic interneuron class first revealed in transgenic TH EGFP reporter mouse line. In this review, we report on further advances in the understanding of the functional properties of previously reported striatal GABAergic interneurons and their synaptic connections. With the application of new transgenic fluorescent reporter and Cre-driver/reporter lines, plus optogenetic, chemogenetic and viral transduction methods, several additional subtypes of novel striatal GABAergic interneurons have been discovered, as well as the synaptic networks in which they are embedded. These findings make it clear that previous hypotheses in which striatal GABAergic interneurons modulate and/or control the firing of spiny neurons principally by simple feedforward and/or feedback inhibition are at best incomplete. A more accurate picture is one in which there are highly selective and specific afferent inputs, synaptic connections between different interneuron subtypes and spiny neurons and among different GABAergic interneurons that result in the formation of functional networks and ensembles of spiny neurons. Heterogeneity and Diversity of Striatal GABAergic Interneurons, Tepper et al., When we sat down to write the first iteration of this review , CR, low threshold spike (LTS) and THINs, refer to the original  and a prolonged plateau potential leading them to be termed PLTS (see “LTS Interneurons” section below for explanation of terminology) interneurons  were examined two distinct cell types were readily apparent, both of which were immunopositive for NPY , and both the dendritic and axonal arborizations were markedly different. Simple visual inspection of the neuronal reconstructions as well as Sholl plot analyses revealed that the somata of these neurons issues 5–9 primary dendrites, and the dendritic tree was far denser and more highly branched, as well as significantly more compact than that of the LTS interneuron, averaging 200 μm or less in diameter. The axonal arborization was also much denser, more highly branched and more compact than that of the LTS interneuron, and expressed prominent small round varicosities, presumably synaptic boutons along the length of most axonal segments. The axonal field was anisotropic and extended throughout and beyond the dendritic tree, exceeding 400 μm in diameter as shown in Figure h, LTS or plateau potentials , are not spontaneously active , with either electrical , NGF interneurons synapse onto SPNs Figures . The conA receptors and is completely blocked by bicuculline. However, unlike that of all other striatal interneurons known to date, the NGF synapse elicits an IPSC/P with unusually slow kinetics, with a rise time around 10 ms and decay time over 120 ms, about 10 times slower  or NPY  or TH. In total, 19.5% of the transduced neurons did not express any of the markers listed above. It was possible to divide a subset of these remaining neurons on the basis of subsequent electrophysiological and morphological experiments into two additional novel subtypes of striatal GABAergic interneurons: FAI  and a relatively high input resistance . Suprathreshold depolarizations elicit a high initial firing rate followed by a pronounced spike-frequency adaptation, giving rise to their name. In some cases, FAIs displayed irregular membrane potential fluctuations following spike trains. Unlike THINs and SABIs (see below) that undergo depolarization block and complete spike failure during modest depolarizing current injections, FAIs increase their firing rate linearly to current injection pulses up to at least 250 pA. These intrinsic characteristics demonstrated some similarities to Type II and Type IV THINS, with key differences being the absence of spontaneous activity, plateau potentials, and rebound spiking from low threshold depolarizations in the FAI. These intrinsic properties, together with the absence of TH expression and the failure to observe these characteristic in any neurons labeled in slices from TH-EGFP or TH-Cre transgenics, served to characterize the FAI as a unique interneuron type.Compared to most other striatal GABAergic interneurons, FAIs exhibited a relatively depolarized RMP , these cells have been termed SABIs . They fire nearly 100% of their spikes in highly adapting bursts of from about 25 to over 125 spikes fired at an average frequency of 100–300 Hz Figure .In whole cell recordings, SABI exhibited a relatively high input resistance (>600 MΩ), and similarly to THINs, they exhibited dramatic depolarization inactivation when injected with moderate positive somatic current. SABI are also spontaneously active in whole cell mode where they exhibited two distinct firing patterns. About half of the neurons fired tonically at low rates and the other half exhibited large membrane potential fluctuations, similar to up and down states in described SPNs Wilson,  with shoThe inputs to the SABI are still largely unknown. Our preliminary unpublished data show a strong glutamatergic innervation from the PfN and the cortex . We also used double transgenic animals by crossing mice natively expressing ChR2 in cholinergic neurons -ChR2) with Htr3a-Cre mice to examine potential cholinergic inputs to the SABI. Optogenetic stimulation of cholinergic neurons evoke a strong depolarization of the SABI and action potential firing . This excitatory response is nicotinic as it is blocked by mecamylamine but not DHβE or MLA, indicating that it is a Type III nicotinic receptor, distinct from the Type II nicotinic receptor  of GABA release and the CINs. However, the GABAergic interneuron subtype mediating these responses does not appear to be any of the previously characterized Type II nicotinic receptors expressing interneurons  and its identity, while unknown at present, may constitute yet another novel class of GABAergic interneurons.In Sullivan et al. , showed As mentioned in the “Spontaneously Active Bursty Interneurons” section above, whole cell recordings in Htr3a-Cre mice injected with halorhodopsion 3.0 showed that inhibition of spontaneously active GABAergic neurons targeted in Htr3a-Cre mice  elicits temporally coincident barrages of large amplitude IPSCs in most SPNs. We hypothesize that the IPSCs originate from the disinhibition of a different population of striatal interneurons (not transduced in Htr3a-Cre mice) that are spontaneously active in the slice but whose activity is normally suppressed by the SABI. Candidates include the THINs and the LTS interneurons, but might also be another, as yet unidentified striatal GABAergic interneuron.ex vivo whole cell recordings  and indirect pathway (iSPNs) projection neurons. Scgn− FSIs were more likely to precede firing of iSPNs than dSPNs while the converse was true for Scgn+ FSIs, consistent with the preferential innervation of iSPNs and dSPNs described above. Thus, the two subtypes of FSIs seem specialized to selective control feedforward inhibition of the direct and indirect pathways.With subsequent in vivo recording studies have characterized the spontaneous activity of putative FSIs, identified as such primarily on the basis of their very narrow extracellularly recorded action potential waveform . These thalamostriatal inputs seem to be significantly denser in primates than in rodents  have used the original abbreviation coined by Kawaguchi , PLTS, t+-dependent and in fact can be induced by TTX, although TTX-induced oscillations are slower (~4 Hz) than spontaneous oscillations occurring spontaneously (~8 Hz). Also in contrast to FSIs, the amplitude of the oscillations is dependent on Cav1 and Cav2.2 channels .Anatomical and physiological data show that striatal LTS neurons receive a monosynaptic excitatory input from the cortex that can evoke both spikes and long lasting plateau potentials  release of dopamine, but on the lesioned side, there was no measurable release of dopamine despite the fact that the optical stimulus caused spiking in simultaneously recorded THINs and GABAergic IPSPs and suppression of induced firing in SPNs. These data demonstrate conclusively that THINs are non-dopaminergic, GABAergic striatal interneurons that do not release dopamine, and further, that activation of THINs in vivo in experimental models of Parkinson’s disease does not activate “cooperative” synthesis and release of dopamine with other striatal interneurons, at least in brain slices, and likely in vivo as well, despite claims by others  are one of the three first, classically identified GABAergic interneurons in the rodent striatum, characterized largely on the basis of immunocytochemistry. Unlike the FSIs and the LTS interneurons, along with the more recently described THINs, NGF interneurons, FAIs and SABIs, we still know very little about striatal CR interneurons due to the lack of any transgenic Cre-driver or fluorescent reporter mice that works reliably in striatum, much as was the case in 2010.in vivo recordings and juxtacellular labeling of CR interneurons identified post hoc by immunocytochemistry were reported  have a very variable firing pattern during cortical slow wave activity. During cortical activation, all recorded CR interneurons displayed tonic activity  we now know of the existence of at least four additional cell types ; and it is likely that we have not yet found all of them; at least the interneuron responsible for recurrent inhibition of striatal CINs and the interneuron(s) responsible for the disinhibitory IPSCs measured in SPNs after inhibition of Htr3a targeted interneurons remain unknown.Of equal importance, our knowledge of the striatal interneuronal circuitry has greatly expanded. We know about fast excitatory synaptic interactions mediated by nicotinic synapses between CINs (and possibly brainstem cholinergic afferents) and GABAergic interneurons that provide a third source of potent excitation in addition to the cortical and thalamic glutamatergic inputs. And there is now evidence for some significant differences between cortical and thalamic inputs to different GABAergic interneurons  exhibit different “best” or spiking resonance frequencies (Beatty et al., The existence of large-scale ensembles of SPNs acting as functional units in striatum has been hypothesized for a long time (e.g., Jog et al., The data reviewed reveal highly selective and specific synaptic connections between different interneuron subtypes and SPNs and also among different GABAergic interneurons themselves, suggesting the existence of a hierarchical control of other striatal interneurons. We suggest that this highly organized striatal circuitry is a major factor in the formation and maintenance of functional networks and ensembles of SPNs.JT, TK and MA designed some of the experiments reviewed. OI-S, FT, TK, TF and MA performed some of the experiments reviewed. JT and MA wrote the 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.


While structural factors may drive health inequities, certain health-promoting attributes of one’s “place” known as salutogens may further moderate the cumulative impacts of exposures to socio-environmental stressors that behave as pathogens. Understanding the synergistic relationship between socio-environmental stressors and resilience factors is a critical component in reducing health inequities; however, the catalyst for this concept relies on community-engaged research approaches to ultimately strengthen resiliency and promote health. Furthermore, this concept has not been fully integrated into environmental justice and cumulative risk assessment screening tools designed to identify geospatial variability in environmental factors that may be associated with health inequities. As a result, we propose a hybrid resiliency-stressor conceptual framework to inform the development of environmental justice and cumulative risk assessment screening tools that can detect environmental inequities and opportunities for resilience in vulnerable populations. We explore the relationship between actual exposures to socio-environmental stressors, perceptions of stressors, and one’s physiological and psychological stress response to environmental stimuli, which collectively may perpetuate health inequities by increasing allostatic load and initiating disease onset. This comprehensive framework expands the scope of existing screening tools to inform action-based solutions that rely on community-engaged research efforts to increase resiliency and promote positive health outcomes. The environment is a multifaceted system as it relates to health, encompassing not only physical, chemical, and biological factors that are external to a person, but social and cultural aspects as well . SalutogSocio-environmental stressors do not work independently and are often additive and/or multiplicative in nature; thereby creating cumulative impacts that may lead to adverse health outcomes over the life course. Exposures to environmental stressors modify aspects of gene expression in the epigenome that may cause individuals to deviate from a life course trajectory of optimal health . DiffereWhile many screening tools have evolved to include environmental stressors, they have not traditionally accounted for resilience factors that may modify the impact of exposure to chemical and non-chemical stressors. As a result, these screening tools may inaccurately depict risk and a community’s ability to overcome adverse exposures. This work proposes a hybrid resiliency-stressor conceptual framework that may be used to inform the development of EJ and CRA screening tools that can be used to identify opportunities for resilience within vulnerable communities. We explore various aspects of CRA and resilience, their proclivity to be addressed in silos, and the limitations of neglecting their synergistic relationship when designing EJ and CRA screening tools. We also explain the conceptual framework and variables that represent each domain. By considering the unique combination of variables described in our hybrid resiliency-stressor conceptual framework, we aim to broaden the discussion on how to better address environmental health inequities and cultivate resilient communities. In addition, our framework demonstrates how community-engaged research approaches and exposures to salutogens are the impetus to promoting community resilience and health equity.Improving our understanding of ways to eliminate environmental injustice and reduce health inequities requires the deliberate consideration of combined risks of chemical and non-chemical stressors on various populations over time. Previously, a single-chemical risk assessment approach was used to identify threats to human health through hazard identification, dose-response-assessment, exposure assessment, and risk characterization . When coFramework for Cumulative Risk Assessment to guide the process of understanding combined risks to human health and the environment from multiple agents or stressors. The essential components of CRAs include: (1) an ability to account for multiple stressors, (2) consideration of interactions between various stressors, and (3) a focus on how a multitude of stressors may impact populations versus individuals [The US Environmental Protection Agency (EPA) responded to the constraints of conventional risk assessment methods by developing a ividuals ,17. Otheividuals . Anotherividuals .Though CRA has evolved from conventional risk assessment methods, there are still several challenges inherent in current methods that demonstrate the need to approach CRAs and respective tools from a systems science lens instead of operating in silos. Some of the challenges of CRAs involve characterizing multiple stressors with varying toxicities and pathways that lack a common endpoint  and beinDespite these limitations, there are certain “best practices” that support dismantling CRA silos by using a systems science approach. A systems science approach to CRA would involve examining the interaction of various environmental factors  at different levels  using expertise from a multidisciplinary, multi-racial/ethnic, and multi-level SES group of stakeholders. Stakeholder engagement is an essential component of any CRA since community members provide a level of local expertise that may not be found in the literature . SeveralAnother study suggests developing a conceptual model during the problem formulation phase of a CRA to identify relationships between various stressors and assets that may impact risk . While dThe challenges of operating in CRA silos has been the catalyst to unveiling opportunities to improve CRA and EJ screening tools that represent a more complete system of individual, family, and community exposures. These opportunities are endless as we continue to develop new methodologies, gain a better understanding of gene-environment interactions, and recognize the importance of including a diverse group of stakeholders to inform the tools. Most screening tools have the ability to quantify the negative impacts of environmental stressors on vulnerable communities using indices, community assessment maps, or a combination of the two metrics ,34,35. HResilience is defined as the “the ability of a community to use its assets to strengthen public health and healthcare systems and to improve the community’s physical, behavioral, and social health to withstand, adapt to, and recover from adversity” . While tSince communities are unique entities with varying needs, it is important to use an approach that addresses community resilience from a local perspective that may indirectly affect change on a higher level. Studies have shown that prioritizing and meeting the needs of a community’s most vulnerable populations may foster macro-level improvements in overall resilience ,39. Thisi is vulnerability, f represents function, exposurerisk is indicative of one’s risk of exposure, and Ri is resilience. As a result, any changes in resilience or one’s risk of exposure may directly influence vulnerability [Consequently, a dose-response relationship may exist between exposure to stressors and allostatic load that can promote a heightened level of vulnerability . Allostarability . While vrability . A recenrability .The resiliency-stressor conceptual framework was developed by performing a comprehensive literature review of factors that may influence resilience, promote stress, and perpetuate health disparities. The nomenclature of the conceptual framework is based on the synergistic relationship that exists between resilience buffers and stressors; therefore, both types of variables are represented to better understand human health risks. While this conceptual framework presents a more American health perspective of resilience and stressors, the same concepts may be applied to other parts of the world by altering some of the variables to reflect salutogens and pathogens in other countries.In our conceptual framework , we explAn exposome layer encapsulates our resiliency-stressor conceptual framework , which iAllostatic load refers to the cumulative biological tax on the human body that may result from chronic exposures to daily stressors . ConsequSocial and environmental stressors play a critical role in perpetuating health inequities ,55,56 duChronic exposures to socio-environmental stressors that are social and physical in nature may contribute to increases in allostatic load and promote inequities in health. For example, populations with less educational attainment may have a higher morbidity or mortality rate for stroke, high cholesterol, ulcers, asthma, hypertension, diabetes, and high cholesterol . They maRegarding unemployment status, a few studies have shown unemployed individuals have worse psychological and physical health than those who are currently employed ,75. MoreIncome inequality models elucidate the chronic stress response of poverty in the body and have been associated with low levels of trust and social cohesion . Income In addition, several studies have noted the relationship between environmental health inequities and residential segregation that may perpetuate health inequalities among populations of color ,88,89,90Like the aforementioned social stressors, physical environment stressors have the same capacity to increase one’s susceptibility to adverse health conditions. For example, exposures to toxicants from environmental hazards like brownfields have been strongly associated with ‘not good health’, limiting long-term illness, and premature all-cause mortality . Leaking2.5), have been associated with a higher risk of respiratory  [2), volatile organic compounds (VOCs), nitrogen oxides (NOx), as well as PM emissions. Heavily trafficked roadway emissions have been linked to several adverse health outcomes, including increased risk of asthma exacerbation [Physical stressors, such as exposures to particulate matter ≤2.5 microns (PM asthma)  and card asthma) , LBW [10 asthma) , pre-mat asthma) , and hos asthma) . Diesel  asthma) , inflamm asthma) , and exa asthma)  like the asthma)  and neur asthma) . High trerbation , cardiacerbation , additioerbation .Poor housing quality is another physical stressor that is extremely important for health and wellbeing due to its ability to contribute to various adverse health conditions. Not only are physical conditions  important, there are also chemical, biological, and social conditions to consider as factors that may impact health . SpecifiLand use planning and zoning practices have also played a role in escalating exposures to neighborhood stressors and minimizing the presence of health-promoting infrastructure in communities with EJ issues ,123,124.Perceptions of exposures to environmental stressors are a salient aspect of our framework due to its relationship with the body’s physiological and psychological stress response. While some environmental exposures directly affect the stress response  , other eThe brain’s perception of an environmental stimulus as a stressor may be moderated by one’s memory or previous experiences, current physiological state, traits, and genotype . FurtherOur conceptual framework is further comprised of resilience buffers that may counteract physiological and psychological responses to the cumulative impacts of environmental stressors at various levels . Resiliency generally refers to one’s ability to withstand, adapt to, or recover from adversity, which can occur at both an individual and/or community level. To effectively respond to stressors and become resilient, communities must have available assets that are accessible so they can function during and/or after a disturbance . These aGreen space is one example of a resilience buffer since access to this ecosystem service has been associated with a reduced risk of cardiovascular disease ,139,140,Studies have further demonstrated an association between increased primary care availability and better health outcomes ,147, as Aside from equity access to health-promoting resources, there are still infrastructure considerations that may impact community resiliency. For example, access to transportation where individuals live and work may influence active commuting behaviors such as walking, cycling, or using public transit in combination with walking or cycling ,154. IncThere are a few challenges that may arise when integrating resilience factors into CRA and EJ screening tools; however, we have been able to overcome many of those obstacles through the development and implementation of a Cumulative Stressors and Resiliency Index (CSRI). The details of this screening tool have been published in a previous study, but the CSRI is a community-informed index tool that uses various socio-environmental stressors and resilience buffers to rank human and environmental for South Carolina (SC) census tracts . This CRThe same challenges characteristic of CRAs are inherent in modified CRAs that may contain resilience factors; however, the complexity of interaction mechanisms between stressors and chemicals now include the relationship between salutogens and pathogens at multiple levels. The synergistic or other possible effects  are still not completely understood, nor are the precise exposure doses to resilience buffers that are necessary to counteract the negative impacts of environmental exposures. Nevertheless, several studies have shown how a community’s assets  may offset many of these impacts ,42,137 aThis conceptual framework has major public health implications since it involves strengthening CRA screening tools so they incorporate socio-environmental stressors and resilience factors from our proposed framework to more accurately examine risk and address health inequities. Improving the variable inputs for CRA and EJ screening tools as well as community-engaged research efforts that inform those inputs will produce more meaningful outputs. Specifically, these changes will allow us to: (1) better identify opportunities for improving resilience , (2) develop a blueprint of communities that are thriving to serve as a model to advance less resilient communities, (3) improve equity by linking low-resourced communities with neighboring assets, and (4) promote community resilience and sustainability. By using our framework to expand the scope of CRA and EJ screening tools, we will now be equipped to develop action-based solutions that are individualized to meet the unique needs of any community. Nevertheless, action-based solutions for reducing risk should focus more on improving community resilience through asset building since communities impacted by EJ issues are not always able to evade environmental stressors.Formulating action-based solutions to truly improve community resilience requires a concerted effort from various stakeholders; therefore, operating in silos to address issues of resilience has become an obsolete practice. As previously mentioned, community-engaged research is the cornerstone of any resiliency work that is further enhanced by collaborations with multi-level stakeholders that span many disciplines . This concept of using a multidisciplinary team has been effectively applied to both acute stressors like natural disasters  and chronic stressors  that may challenge community resilience. For example, the Los Angeles County Community Disaster Resilience (LACCDR) project uses a collaborative partnership between the Los Angeles County Department of Public Health, local community members, academics, and business stakeholders to address issues of community resilience related to disaster preparedness . Other cAddressing resiliency in high-risk areas is known to foster macro-level improvements in overall community resilience , which eAs developing Green Zones becomes the standard for achieving community resilience through action-based solutions, it is important that screening tools continue to evolve at the pace of stakeholders’ needs. The framework we introduced exemplifies a comprehensive CRA model, that when applied through a community-engaged research lens, could change the way we identify and prioritize high-risk communities. Future research should focus on updating CRA and EJ screening tools and methodologies based the concepts presented in our framework to incorporate both socio-environmental stressors and resiliency buffers. Though we were able to develop the CSRI in a previous study using this framework, our index was a pilot version that merely demonstrated how principles from our framework could be used to address gaps in current screening tools.We are in the process of developing other versions of the CSRI that will incorporate greater stakeholder input through community-engaged research practices. The new versions of the CSRI will not only allow community stakeholders to participate in the variable selection process, they will also have an opportunity to prioritize the indicators in a way that contributes to one layer of the weighting feature. The second layer of weighting will be based on the correlation between socio-environmental stressors and resilience factors. Lastly, we plan to explore the possibility of including an additional layer that captures physiological/psychological stress responses. These modifications will allow CRAs to operate in more of a precision public health capacity, and may ultimately improve the efficiency of projects like the Green Zone Initiative and other action-based solutions that can increase community resilience and reduce health inequities.This work introduced a hybrid resiliency-stressor conceptual framework that may be used to modify existing EJ and CRA screening tools or inform the development of new tools to identify resilience opportunities within vulnerable communities. While the indicators within this framework are adjustable, including both cumulative pathogens and salutogens within the same model are critical to understanding a community’s true health and environmental risk. When these factors are considered collectively with perceptions of socio-environmental stressors and physiological and psychological stress responses, we gain a better understanding of how differences in allostatic load may contribute to health inequities over the life course. The information presented in this framework will ultimately allow us to design better EJ and CRA screening tools that strengthen our capacity to address health inequities and improve community resilience.


Occurring against the backdrop of an overdose crisis, stimulant use and stimulant-involved deaths in North America are increasing at an alarming rate. Many of these deaths are being attributed to fentanyl and related analogs, which have been increasingly found within street-level stimulant supplies. Within this, people experiencing socio-economic marginalization are at the greatest risk of overdose and other harms from adulterated stimulants. Current treatments for stimulant use disorder have limited effectiveness, and even less applicability to the lived realities of marginalized stimulant users. Emerging technologies, such as drug checking, are being implemented to support safer stimulant use, but the accessibility and utility of these technologies to stimulant users are framed by experiences of vulnerability that render them largely ineffective.Solutions that provide a legal and safe supply of non-adulterated stimulants of known quality, and within a health care framework, are needed to directly address the risk of an increasingly adulterated stimulant supply. Similar innovative opioid-focused interventions are being piloted with medications that have a similar pharmacological effect as their illicit counterparts. While there are currently no approved pharmacotherapies for stimulant use, research has demonstrated a number of stimulant medications that are promising substitutes for cocaine and methamphetamine use. Much like with opioid-focused pharmacotherapies, having a consistent and safe supply of stimulants can lead to improved health outcomes and will drastically reduce overdose risk. However, for a stimulant safe supply intervention to be a success, it must provide the high and performance-enhancing effects that people seek from the illicit market, which requires doses and user agency that trials to date have not provided.Efforts are needed to investigate the feasibility of pharmacological stimulant-based interventions that address safe supply needs. The promise of similar opioid-focused approaches in addressing both overdose-related risks and experiences related to vulnerability underscores the need to advance safe supply approaches targeted towards people who use stimulants. Given the current overdose crisis and rising stimulant use across North America, the implementation and evaluation of such novel stimulant-focused interventions should be a public health priority. Illicit stimulant use has been steadily rising globally, with reports estimating that more than twice as many people use stimulants than opioids . North AThe United States Centers for Disease Control (CDC) reported a 52% increase in overdose deaths involving cocaine, and a 33% increase in deaths involving other psychostimulants from 2015 to 2016, with surveillance data suggesting synthetic opioid involvement is the main driver of this increase in mortality . ProvisiSimilar Canadian data is limited. However, in British Columbia (BC), Canada, cocaine has been found in 50% of illicit drug overdose deaths, and methamphetamine in 37% of deaths . NotablyAlongside these growing concerns, there is increased awareness that structurally oppressed people who use drugs experience a disproportionate burden of drug-related harms, including overdose . These pAlmost 90% of individuals who meet the criteria for any substance use disorder in the USA have not received substance use treatment in the past year, and this is also true for those with stimulant use disorders . In a syUnlike opioid use, which is discussed in the current discourse as a medical issue to be pharmacologically treated, traditional treatment of stimulant use disorders generally involves psychosocial interventions such as twelve-step facilitation (TSF), cognitive behavioral therapy (CBT), and contingency management (CM). TSF is among the most common psychosocial approachs used in North America today , groundePsychosocial interventions can also serve to reinforce social norms that frame stimulant use solely as a ‘behavioral problem’ and which overlooks evidence that stimulant use is largely driven by structural and environmental factors, including instrumental uses of stimulants. For some people who use stimulants, particularly those reliant upon methamphetamine’s performance-enhancing effects , promoting abstinence does not address instrumental uses of stimulants or underlying conditions that frame stimulant use. Promoting abstinence also minimizes the very real role that satisfaction and pleasure can play in sustaining stimulant use and that may not immediately be met by pursuing abstinence. Given this, interventions to address stimulant use should shift beyond ‘treating’ stimulant use disorder by promoting reduced or abstinent stimulant use to supporting provision of a safe supply of stimulants, especially within the context of an increasingly adulterated illicit stimulant supply.While interventions, such as DCTs, are progressively being promoted as strategies to support safer stimulant use, these often fail to account for the lived realities of those most vulnerable to drug-related risks . Recent studies have found acceptability of DCTs to be high among people who use drugs , 23, butSolutions that seek to minimize, or eliminate altogether, the risks of an adulterated drug supply through the provision of a safe supply  of stimulants are urgently needed as part of a more comprehensive response to the overdose crisis. There has been recent debate regarding the need for a legal and safe supply for opioids, administered as a part of health and social care. Multiple studies have also piloted innovative injectable diacetylmorphine and hydromorphone , 27 as mThe United Nations Office on Drugs and Crime’s (UNODC) recent report on treatment of stimulant use disorders summarizes emerging evidence demonstrating the treatment potential of prescription psychostimulant substitution and provides recommendations for a pharmacological treatment model that is instructive for stimulant safe supply approaches . The repAccess to a consistent supply of stimulants of known quality can possibly lead to the same improved health outcomes observed among participants in injectable hydromorphone and diacetylmorphine interventions, such as reductions in abscesses , transmiDrug user activist groups have recently argued the necessity of a safe stimulant supply in Canada, acknowledging that any form of medication-based approach is likely to fail if it does not mirror what people who use drugs seek  in the illicit market . CurrentMeaningfully involving people who use stimulants in intervention planning and implementation will be further important in acknowledging their lived realities. Models that include people with lived experience as partners in their own care exist and have demonstrated success in implementing programs and interventions that are more responsive and relevant which, importantly, have a high likelihood of uptake within their intended communities , 40. ThiThere is an urgent need to pursue stimulant safe supply approaches and the importance of meaningfully involving people who use stimulants in the planning of these interventions cannot be overstated. Within the context of drug criminalization, the risk of adulteration is inherent to the illicit drug market, which with continued prohibition has the potential to become increasingly more lethal. While all people using stimulants are at risk, the risk is especially pronounced among socially and economically marginalized individuals for whom multiple intersecting oppressions limit agency and produce vulnerability to risk and harm. Extending safe supply interventions to include stimulants would provide opportunities to address overdose risk and drug-related harms in ways current models of psychosocial treatment are unable. Possible models that could inform the implementation of pilot stimulant safe supply interventions exist, including low-threshold injectable hydromorphone and diacetylmorphine interventions, and could be adapted to meet the needs of people who use stimulants through participatory planning processes. Such a move would signal that illicit stimulant use and associated health impacts indeed matter. Importantly, the ways in which stimulant use is differentiated from opioid use in the current discourse, with the latter more widely accepted as a medical concern and treated with medication-based therapies, risks undermining efforts to make more treatment options  available. Given the current overdose epidemic in North America, and rising stimulant and polysubstance use, the implementation and evaluation of novel stimulant-focused interventions are of critical importance.


Stem Cell Research & Therapy by Izrael and colleagues reports about embryonic stem cell-derived astrocytes as a potential cell therapy for ALS. Such cells behave as highly trophic “young astrocytes”, being able to delay disease onset and prolong survival when injected intrathechally in murine models of ALS overexpressing the SOD1G93A mutation. The safety and therapeutic potential of these cells are currently being evaluated in a clinical trial in ALS patients. This commentary discusses the mechanisms of action and potential therapeutic effects of these “young astrocytes” in ALS.Amyotrophic lateral sclerosis (ALS) is a fatal paralytic disease with no cure or treatment to stop disease progression. Because ALS represents an urgent unmet medical need, a significant number of therapeutics are being tested in preclinical and clinical studies. A recent publication in  Extensive evidence supports the notion that the pathogenesis of neurodegenerative disease involves a disruption of the normal functional interplay between vulnerable neurons and non-neuronal cells, with a key neurotoxic role played by phenotypically abnormal astrocytes and microglia as well infiltrating immune cells , 2.In particular, astrocytes become toxic for motor neurons in amyotrophic lateral sclerosis (ALS), losing their ability to provide trophic, metabolic, and synaptic support to cultured motor neurons (reviewed in ). This tSeveral mechanisms have been proposed to explain the deleterious activity of astrocytes in ALS: release of inflammatory and pro-apoptotic mediators , inductiIzrael and collaborators  developeOne remarkable feature of this study is the development of a method to produce large quantities of clinical grade astrocyte progenitor cells that can be expanded and stored frozen in a controlled and reproducible manner. These cells can be induced to final differentiation before transplantation, thus becoming a valid cell therapy approach ready to be tested in clinical trials.Izrael and colleagues study raises several questions and speculations about the significance of therapy using young astrocytes in ALS patients. Firstly, while multiple pathogenic pathways involving neural and non-neural cells are thought to mediate neurodegeneration in ALS, it is intriguing how transplanted young astrocytes protect the host. Is their protective activity solely mediated by the production and release of soluble factors that permeate the degenerated microenvironment to prevent disease? The authors propose a central trophic mechanism of action underlying protection by young and committed astrocytes in murine models of ALS. The young astrocytes were found to secrete factors with supporting activity on neurons as well as several antiproteases which could remodel extracellular matrix, thereby shedding new light on the possible mechanisms of action underlying the observed therapeutic effect in ALS models. These factors include Osteopontin (OPN/SSP1), which was found to stimulate regeneration of motor axons, TIMP-1 and 2 inhibitors of MMP9 and other matrix metalloproteases which play a major role in preventing degradation of extracellular matrix (ECM), CXCl-16 chemokine, which was found to increase neuron survival, Clusterin, Midkine, and the well-studied GDNF, BDNF, and VEGF trophic factors. However, other complementary mechanisms could also be involved, including the production of exosomes or microvesicles delivering tiny amounts of other mediators or microRNAs, which may have been under the detection limit in the current secretome analysis. It is also possible that young implanted astrocytes could antagonize oxidative stress in ALS-affected regions by releasing glutathione as well as other antioxidants into the extracellular medium. Thus, young transplanted astrocytes would likely behave as protective A2 astrocytes previously characterized in rodents . By exteAge-dependent senescent astrocytic phenotypes have been shown to lose their trophic support of motor neurons and promote inflammation . BecauseAnother important question about young astrocytes is whether these cells represent a potential cellular therapy to target neuroinflammation in ALS. Evidence indicates that inflammatory or immune mechanisms also influence the degeneration of the cellular microenvironment, with discrete infiltration of T cells, monocytes, and mast cells . PotentiThe two current FDA-approved drugs for ALS, riluzole and edaravone, only modestly attenuate disease progression. Both these small molecule drugs are based on a single mechanism of action. ALS is a multifactorial disease and therapeutic approaches should take into account the multiplicity of mechanisms that underlie motor neuron degeneration in this disease. Thus, young astrocytes that act through multiple mechanisms of action to treat the broad pathological aspects of the disease are more likely to be effective. Would cell replacement with young astrocytes prevent or revert neuronal damage or the emergence of activated astrocytes in neurodegenerative or demyelinating diseases other than ALS? Future studies should test these possibilities.


Geneticiabetes)  or exerciabetes) . The maiFilonov et al. aims to answer the question whether donor-specific cells could be used as a proxy for an individual in characterizing cellular response to environmental toxicants. While individual responses to toxicants have been previously characterized using transformed lymphoblastoid cells  technical improvement in primary cell isolation and culture techniques; (b) the development of methods of making cellular organoids, in particular, an ability of growing different cell types in three-dimensional space; (c) the introduction of donor-derived induced pluripotent cells including disease-specific cells; and (d) the progress of “organ-on-chip” concept to working prototypes. Many questions will be resolved or brought forth in future studies. Since cells specialize within the body, it is important to determine which cell types can best characterize the susceptibility (or resilience) of a person. Such studies can examine correlations between responses of different cell types isolated from the same individual. Moreover, a study that examines correlations between cellular and total body responses to a challenge would be very informative. For example, such studies can be conducted in groups of patients undergoing chemotherapy, as experimental exposure of humans to chemicals would be unethical. Also, it is important to examine how accumulation of somatic mutations and epigenetic changes with aging changes cellular responses to chemicals. Together with advancement in computational toxicology the presented manuscripts describe conceptual and methodological approaches to studying human variability in response to chemicals. All these developments applied to human populations will create a continuum between toxicology and epidemiology.DI provided initial draft. AK discussed and provided edits.AK is a founder and executive director of Creative Scientist, Inc. 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.


The cancer research community has lacked an in vivo and intravital metastatic cancer model that could be imaged as motility developed, in real-time. To address this, we developed a novel quantitative in vivo screening platform based on intravital imaging in shell-less ex ovo chick embryos. We applied this imaging approach to screen a human genome-wide short hairpin RNA library (shRNA) versus the highly motile head and neck cancer cells (HEp3 cell line) introduced into the chorioallantoic membrane (CAM) of chick embryos and identified multiple novel in vivo cancer cell motility-associated genes. When the expression of several of the identified genes was inhibited in the HEp3 tumors, we observed a nearly total block of spontaneous cancer metastasis.Cancer cell motility is a key driver of metastasis. Although the intravasation of cancer cells into the blood stream is highly dependent on their motility and metastatic dissemination is the primary cause of cancer related deaths, current therapeutic strategies do not target the genes and proteins that are essential for cell motility. A primary reason for this is because the identification of cell motility-related genes that are relevant  Given that the genes and signaling networks that drive in vivo motility and intravasation are different from those required for efficient primary tumor formation we sought to develop an in vivo approach to feasibly screen for genes required for motility, and therefore intravasation and metastasis. Metastasis is dependent on a tumor cell’s ability to intravasate, disseminate, evade immune detection, survive, proliferate, colonize elsewhere in the host, and do this repeatedly. We were able to visualize tumor colonies with expression-inhibited cell motility genes, and found that they form compact colonies instead of diffuse ones. This in vivo colony phenotype was distinctive enough to utilize this approach to screen for therapeutic targets of cell motility that would in turn impact intravasation and metastasis. Using our three-dimensional, intravital tumor-development screening approach in chick embryos to identify functional metastatic genes showed the importance of using an in vivo microenvironment because these phenotypes are not well recapitulated in two-dimensional culture.Currently, many cancer patients undergo chemotherapy, which is aimed at mitigating the risk of future metastasis. These treatments, however, have numerous system-wide off-target effects that negatively impact the patients’ quality of life. Although cancer cells are not recognized by the host immune system as "other" and so cannot be depended on to potentiate an immunogenic response, cancer cells do differentially express genes compared to normal cells. We’ve found that this is the case in vivo multiphoton imaging.Structurally, the chicken embryo CAM is a highly vascularized, thin, transparent organ, surrounded by a dense collagen-rich matrix, very similar to mouse lung tissue. Human cancer cells robustly interact with the collagen fiber network in both tissues. These features make the CAM very advantageous for human cancer cell tumor development because it can be easily visualized using Figure 1a).In our work, HEp3 cells were transformed with the 79 805-shRNA vector library so that each HEp3 cell contained a single shRNA vector. The transformed HEp3 cancer cells were then intravenously injected into the chick embryo where they disseminated throughout the vasculature. Roughly 10% of the 25,000 injected tumor cells arrested individually in the CAM and extravasated into the extravascular stroma. They then proliferated into isolated, invasive metastatic colonies, each arising from a single transformed cell . We utilized a high throughput sequencing approach to characterize the shRNAs present in each compact colony and identified eleven unique shRNA-targeted genes  whose expression is associated with in vivo cancer cell motility.HEp3 cells are highly motile and as they proliferate in the CAM they form a "spread out" morphology because the cells migrate a significant distance from the point of extravasation. When their motility is reduced, however, the resulting colonies adopt a more compact morphology that was easily distinguished from those formed from highly motile HEp3 tumor cells. Since the in vivo cell migration and invasion through collagen remodelling. Time-lapse imaging of the primary tumor fronts showed that control HEp3 cells actively invade along aligned collagen bundles perpendicular to the tumor primary front . Inhibition of screen-identified genes such as KIF3B resulted in an inability to reorganize the collagen fiber network at the primary tumor periphery in the chick embryo CAM, resulting in an almost complete absence of collagen bundles. Accordingly, invasion of the KIF3B-mutant cell lines was significantly reduced when visualized in a 3D collagen invasion assay. From this, we hypothesized that genes required for in vivo cell motility and directional cell migration would also be required for spontaneous metastasis.When cancer cells invade into the stroma surrounding a tumor, they must first actively reorganize the collagen rich matrix at the tumor front to create areas of densely bundled, aligned collagen fibers that can be exploited as motility pathways. We surmised that our screen-identified genes, identified by their requirement for cancer cell motility, might be involved in the coordination of directional in vivo, intravital imaging approach.We then explored the physiological relevance of the screen-identified genes in human cancer progression and metastasis. The top hit genes identified in our screen were found to be significantly upregulated in the metastatic lesions of several solid cancer types including: melanoma, prostate cancer, head and neck cancer, lung cancer, ovarian cancer and colon cancer. In addition, several of the genes identified in this screen were linked previously with cancer cell invasion and/or migration, which validated our in vitro screening approaches. Another hit, SRPK1, is a VEGF splice regulator previously linked to cancer progression and metastasis. While we observed that reduction of SRPK1 expression was linked with a compact colony phenotype, we did not observe an inhibition of primary tumor growth. SRPK1 was also recently identified as a cell migration-mediator using an in vitro screening approach, which, together with our results, supports the idea that SRPK1 plays a more direct mechanistic role in cell migration and metastasis. These various findings highlight the importance of identifying the overlapping mechanisms responsible for productive cell migration in vivo compared to in vitro.We found that several of the top eleven gene hits had previously-described functions, but had not been shown previously to be associated with metastasis. Others have unknown function. Identification of KIF3B as a top metastasis target is intriguing since this gene is part of the kinesin motor machinery responsible for transporting multiple therapeutically relevant molecules such as β-catenin and MT1-MMP to the cancer cell front. KIF3B has been shown to be essential for collagen fiber matrix remodeling, which is necessary for intravasion and ultimately metastasis. This is consistent with our finding that inhibiting KIF3B expression efficiently inhibits these processes and blocks cancer cell metastasis. The identification of the actin isoforms ACTB and ACTC1 in our screen was not surprising because they are known to be central in cell migration machinery and have been previously identified using We also identified several genes and non-coding RNAs of unknown function in this screen, suggesting a yet-to-be-described role in cancer progression and metastasis. Certainly, the identification of pro-metastatic genes and RNAs warrant future investigation and potential development as potential therapeutic targets.in vivo cancer cell motility phenotype and its requirement for successful metastatic spread. This demonstrates that our quantitative in vivo imaging-based screening approach is a powerful tool to identify potential therapeutic targets for metastasis, paving the way for the development of new therapies to block this deadliest aspect of human cancer. By coupling the highly accessible ex ovo chick embryo tumor model with fluorescence time-lapse intravital imaging and high-throughput sequencing, we designed a rapid and quantitative method to detect clinically-relevant metastasis phenotypes. In particular, three of the genes discovered using this intravital imaging platform, KIF3B, SRPK1 and NR2F1, represented very promising therapeutic targets for metastasis. Future work would be to test these metastasis-associated genes and gene-products as drug targets aimed at blocking metastasis in vivo.Overall, we found an extraordinarily tight link between a gene’s Therapies designed to specifically target the rate limiting steps of metastatic dissemination of tumor cells could significantly improve cancer treatment by directly blocking the systemic spread of cancer. Cancer treatment could also shift away from the use of chemotherapies with detrimental side-effects which would dramatically improve the quality of life of cancer patients.


Increased experience, smaller sheaths, rigorous pre-procedural planning and improved vascular closing techniques have resulted in markedly lower rates of vascular complications. The next step is the simplification of the procedure, which should contribute to a further decrease in complications, and also reduce procedural time, hospital stay as well as staff workload and costs. Moving to conscious sedation, no predilatation, no temporary pace maker and use of the radial approach as the contralateral approach are all instrumental in achieving this ultimate refinement.Since its introduction in 2002, TAVI has evolved dramatically and is now standard of care for intermediate risk patients when the femoral approach can be implemented safely. The development of innovative transcatheter heart valves (THVs) and refinement of technical skills have contributed to the decrease in complication rates associated with TAVI Since the first successful procedure was carried out in 2002 , transcaImprovements in technique, devices, operator's experience, and patient selection have contributed to a dramatic decrease in procedural complications, thus allowing further technical simplification at every step of the procedure –9. In thPatient clinical and anatomical criteria may influence per- and post- procedural outcomes. Therefore, a truly minimalist approach should be considered only when femoral access is possible. Recently, Barbalios et al. compared minimalist TAVI performed in the catheterization laboratory to standard TAVI performed in the hybrid room demonstrating shorter procedure and intensive care unit time, as well as reduced hospitalization duration and costs in the minimalist approach group without differences in terms of short- and long-term survival .Multislice CT (MSCT) is instrumental in procedural simplification. Image quality and optimal analysis are therefore crucial for anticipating the potential difficulty of the procedure as well as for optimal valve selection and working view. The role of MSCT has also been central in allowing a shift from general anesthesia to conscious sedation by obviating the need for transesophageal echocardiography (TOE) during the procedure. MSCT became the gold standard for evaluation of the aortic root in our center in 2009.The use of the TRA for preprocedural evaluation of the coronary arteries is also part of the simplification process. It helps not only to reduce the risk of vascular complications related to the screening phase, but also to assess femoral access by performing a selective bilateral iliac injection using a long multipurpose catheter. Recently, screening of coronary artery disease and ad hoc percutaneous coronary intervention (PCI) during TAVI has been described by Barbanti et al. showing to be feasible without increased periprocedural complications .A minimalist approach can be performed in routine practice with two operators, two nurses and an anesthesiologist Figure . A cardiAlthough the first in-man TAVI cases in Rouen were initially performed on conscious sedation , the proData from registries demonstrated the feasibility, safety, and cost-effectiveness of local anesthesia with conscious sedation in comparison to general anesthesia, with potential advantages in terms of bleeding and hospitalization length. It has been adopted as the default approach in our center since April 2009.Initially, TAVI procedures were performed exclusively via surgical cut down . Over thPercutaneous closure has been progressively adopted in routine practice in most centers for TF TAVI procedures . Indeed,In addition to the selection of the most appropriate percutaneous device, the percutaneous technique should be rigorous in order to limit access site complications. Indeed, the common femoral artery puncture site should be carefully selected on the CT-scan or angiography before the procedure. During the procedure, puncture should be performed under angiographic or ultra-sound guidance at the center of the anterior arterial wall . PercutaThus, percutaneous transfemoral access is as safe as the surgical approach and feasible in the majority of cases with a very high rate of success after the learning phase. Most vascular complications can be managed percutaneously. It is an essential component of TAVI's simplification process allowing early discharge.Although vascular complications dramatically decreased in parallel with enhanced operator experience, availability of low profile sheaths and better patient selection, 25–30% of these complications occurred at the contralateral femoral access site, . TherefoTherefore, by reducing contralateral vascular complications and simplifying the procedure, TRA will probably follow the predominant tendency observed in other interventional cardiology settings and become the gold standard contralateral approach for TAVI.During balloon valvuloplasty (BAV) or balloon expandable TAVI procedures, rapid ventricular pacing is mandatory. Traditionally, rapid pacing is performed through a venous access with temporary pacemaker implantation . HoweverThis new technique has been shown to be feasible and safe, allowing stable stimulation with a low rate of complications and a potential reduction in procedural time. A randomized trial comparing left ventricle guide wire rapid pacing to conventional pacing (Easy TAVI) is ongoing in France (NCT02781896).In the early days of TAVI, BAV was considered a mandatory step. However BAV have been shown to be associated with a higher risk of cerebral embolization, and severe acute aortic regurgitation may occur after predilatation in up to 3% of cases. TAVI without BAV was evaluated for the first time in 2011 by Grübe et al.  and was We moved progressively to this approach between 2012 and 2015 in our center. Today, more than 90% of cases are performed without predilatation. Only very complex anatomies or highly calcified valves are predilated before valve deployment (5–10%). Post dilatation is performed mainly after self-expandable valve deployment in the presence of significant paravalvular leak or transvalvular gradient (10–15%).Thus, avoiding balloon predilatation may reduce complication rates, decrease the need for permanent pace-maker and reduce procedural time. A large randomized trial  with theAfter TAVI, systematic close monitoring with special attention to hemodynamic and cardiac rhythm is mandatory to allow early detection of periprocedural complications. In many centers, monitoring is performed for at least 12 to 24 h in the ICU before transferring the patient to a CCU after clinical and paraclinical status re-assessment. Recently, TAVI without subsequent ICU admission has been evaluated and has been shown to be feasible and safe in selected patients after rigorous preprocedural and postprocedural evaluation . Indeed,Early discharge was evaluated in the literature demonstrating safety in patients with hospitalization duration shorter than 48 h . Indeed,TAVI simplification has already been adopted in routine practice in experienced centers, resulting in a low rate of complications, shorter procedural time, improved patient comfort, as well as decreased costs and staff workload. However, rigorous patient selection, and risk stratification are key factors in ensuring successful “PCI-like” procedures. On-going randomized trials may confirm preliminary results, thus leading to a “simple” but not “simpler” procedure in the near future with lower profile devices.All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.TL is proctor for edwards and Abbott vascular MA received research grants from Edwards Lifescience and Medtronic.