Alcoholism: Clinical and Experimental Research

Understanding the neurobiological systems that regulate alcohol cue-induced craving is of utmost importance for the development of novel intervention strategies for alcohol use disorders (AUDs). However, although a human experimenter is required to conduct alcohol self-administration studies in the lab, the cues associated with the experimenter are seldom if ever factored into the experimental design. Thus, although we have learned much to date about alcohol cue-induced behavior and neurobiology, and in particular about discrete cues presented many times throughout a single daily alcohol self-administration session, we know relatively little about how responses to alcohol availability cues might predict subsequent alcohol consumption. For the current experiment, mice were exposed daily to auditory cues that preceded 2 hours of alcohol or water access using drinking-in-the-dark (DID) methods. An additional control group experienced cues but were not otherwise manipulated. Importantly, cues were initiated remotely from outside the animal facility, avoiding the experimenter being the first cue predicting ethanol availability. Head direction, location in the home cage, and movement velocity were the primary variables on interest. Surprisingly, during the cue period, there were no significant differences between groups in any of these measures, despite meaningful alterations over days. However, we observed many significant correlations between behaviors and drinking variables. First, we observed significant positive associations between ambulatory velocity during cues and subsequent total alcohol (R2=0.14; p<0.0001) and total water (R2=0.12; p=0.0002) consumption, but only in females. We also observed a significant positive relationship (R2=0.25; p<0.0001) between the amount of time oriented toward the sipper port during the auditory cues and the average rate of subsequent alcohol consumption (i.e. front-loading), but only in females. In males, head direction was found to be positively associated with subsequent total water consumption (R2=-0.21; p<0.0001), but not alcohol (R2=-0.01; p=0.2267). We also observed a significant negative relationship (R2=-0.15; p<0.0001) between proximity to the sipper during the cue period and subsequent total 2-hour alcohol intake in males. Although these associations were modest in strength, they suggest potential sex-specific behavioral predictors of alcohol consumption that are regulated by different neural dynamics.

Food addiction (FA) has been proposed as a phenotype sharing features with substance use disorders. Despite increasing recognition of food addiction as a behavioral phenotype with features overlapping substance use disorders, little is known about its prevalence or clinical significance among individuals with alcohol use disorder (AUD). Objective: To examine the prevalence of FA and to evaluate demographic, psychological, and alcohol-related correlates in individuals with AUD. Design, Setting, and Participants: This cross-sectional analysis included 743 adults with AUD who were either treatment seeking (Tx) (n = 534) for AUD and were enrolled in an inpatient program at the National Institutes of Health Clinical Center or not treatment-seeking (non Tx) (n = 209). Main Outcomes and Measures: FA symptoms were assessed using the Yale Food Addiction Scale, with >=2 symptoms categorized as FA in this report. Multivariable logistic regression models adjusted for age, education, and income were conducted separately within each cohort. Results: Among 743 adults with AUD, 238 (32.1%) met criteria for FA symptoms, with similar prevalence among Tx (32.6%) and nonTx (30.6%) participants despite marked differences in clinical characteristics. Across both cohorts, FA was independently associated with higher body mass index, greater psychological distress, and greater alcohol dependence severity. Childhood trauma and poorer sleep quality were additionally associated with FA among treatment-seeking participants, whereas alcohol-related measures differed according to treatment status. Conclusions and Relevance: FA was common among adults with AUD and was associated with greater psychological, behavioral, and metabolic burden regardless of treatment-seeking status. These findings suggest that FA identifies a clinically meaningful subgroup of individuals with AUD who may benefit from more comprehensive assessment and integrated treatment approaches.

Background Alcohol-associated injury is a leading cause of emergency department (ED) utilization in the United States and a clinically important driver of preventable morbidity across the adult lifespan. Prior surveillance research has characterized how the rate and severity of alcohol-associated injury vary by patient age, but whether the seasonal timing of injury risk is equally predictable across age groups (a question directly relevant to the timing of clinical screening intensification and public health intervention) has not been formally tested. Methods We conducted a retrospective surveillance analysis of 45,876 alcohol-associated ED visits among adults aged 18 years and older, identified from the National Electronic Injury Surveillance System (NEISS), 2019-2025 (weighted national estimate: 2,092,319 visits), using the structured Alcohol_Involved indicator introduced into NEISS case abstraction in 2019. Patients were stratified by sex and five age groups (18-24, 25-34, 35-49, 50-64, and [&ge;]65 years). Single-harmonic cosinor (Poisson) regression was used to estimate the seasonal peak day of injury risk (acrophase) for each stratum. To assess reliability, we performed leave-one-year-out jackknife resampling (seven iterations per group), case-resampling bootstrap confidence intervals (1,000 iterations), and likelihood-ratio tests of seasonal-phase interactions. Results Peak injury timing differed significantly across age groups (X^2 [8] = 2356.2, p < .0001). Adults aged 25-64 years showed a highly reproducible early-to-mid-July peak, with jackknife estimates shifting [&le;]14 days when any single study year was excluded. Adults aged [&ge;]65 years showed significant seasonal variation annually (all p < .0001, amplitude comparable to younger groups) but a pooled peak estimate that shifted by up to 100 days across jackknife iterations. Sex-stratified analyses revealed that this instability was driven entirely by females aged [&ge;]65 years (jackknife range: 332 days, peak consistently in late October through early January) rather than males aged [&ge;]65 (jackknife range: 31 days, peak consistently in early August). Hospital admission rates increased monotonically with age from 9.0% (18-24 years) to 31.8% ([&ge;]65 years). Conclusions Alcohol-associated injury follows a reproducible, calendar-stable summer seasonal pattern in adults aged 25-64 years. Among adults [&ge;]65 years, the previously reported temporal instability is concentrated in the female subgroup, whose seasonal injury risk does not converge on a fixed calendar window. These findings suggest that fixed-calendar prevention and screening strategies are well suited to working-age adults and older men, but older women may require a year-round, individually tailored approach. Keywords: Alcohol-related injury; Emergency department; Seasonality; Age factors; Sex differences; Injury surveillance; Cosinor analysis; Older adults

Background: Alcohol use and physical activity are common, interrelated behaviors with opposing associations to mental health, yet little is known about their joint relationship with anxiety and depression. This study evaluated whether the association between alcohol use and anxiety and/or depression symptoms differed by physical activity level in a large U.S. longitudinal cohort. Methods: Using data from 5,152 adults in the CHASING COVID Cohort (2021-2023), alcohol use was categorized as low-, moderate-, or high-risk based on repeated AUDIT-C assessments, and physical activity was classified as active versus sedentary using items adapted from the 2023 Behavioral Risk Factor Surveillance System. Moderate to severe symptoms of anxiety/depression, assessed subsequent to the exposure assessment period, was defined as a PHQ-8 or GAD-7 score [&ge;]10. Log-binomial regression estimated adjusted risk ratios (aRRs) for associations between alcohol use and anxiety/depression symptoms within strata of physical activity. Effect modification by physical activity was evaluated on the additive and multiplicative scales. Analyses were repeated among healthier participants without chronic conditions or poor self-rated health to reduce sick-quitter bias (N=3,141). Results: Most participants had low-risk or no alcohol use (70.3%), followed by moderate-risk (21.9%) and high-risk use (7.8%); 29.5% were sedentary. Sedentary participants had higher risk of moderate to severe anxiety/depression symptoms than active participants across alcohol use levels overall and in the healthier subsample. In the overall sample, active participants with high-risk alcohol use had elevated risk compared with active participants with low-risk or no alcohol use (aRR = 1.44, 95% CI: 1.15-1.80) and physical activity did not modify the association between alcohol use and anxiety/depression symptoms on either scale. Among healthier participants, risk was highest among sedentary participants with moderate-risk alcohol use compared with active participants with low-risk or no alcohol use (aRR = 1.92, 95% CI: 1.50-2.45); physical activity modified the association between moderate-risk alcohol use and moderate to severe anxiety/depression symptoms on the additive scale (RERI = 0.61, p=0.013) and multiplicative scales (ratio of aRRs = 1.49, p=0.001). Conclusions: Among healthier adults, physical activity modified the association between moderate alcohol use and symptoms of anxiety or depression on additive and multiplicative scales. Findings suggest sedentary behavior may amplify mental health vulnerability associated with moderate drinking; future studies are warranted to clarify these relationships, including those with larger numbers of high-risk drinkers.

It is becoming increasingly clear that chronic exposure to lower levels of ethanol impact learning and behavior. To determine the impact of chronic low-dose ethanol exposure on sensitivity to changes in stimulus value, a conditioned taste aversion procedure was used. Adult male and female mice underwent a sucrose two bottle-choice drinking paradigm. Each day, mice received an injection of either low-dose ethanol (0.5g/kg) or saline two hours after sucrose access for 20 days. This was followed by a lithium chloride (LiCl)-induced conditioned taste aversion (CTA) paradigm in which 0.15M LiCl or vehicle injection was administered immediately after sucrose consumption for three days. On the fourth day, changes in sucrose consumption were analyzed. Chronic exposure to low-dose ethanol did not affect sucrose consumption in either female of male mice during two-bottle choice. In female mice, a history of chronic low-dose ethanol exposure blocked the development of LiCl-induced CTA. A history of chronic low-dose ethanol did not impact LiCl-induced CTA in male mice as both ethanol-naive and -exposed male mice who underwent LiCl pairing reduced sucrose consumption. This suggests that low-dose ethanol alters aversion-related learning in female mice which may have implication for development of aberrant behavior and risk for alcohol use disorder (AUD).

A body of research suggests that autistic individuals are less likely to drink alcohol than neurotypicals. However, emerging studies support a link between autism and alcohol use. This complex relationship is also reflected in studies that have examined the genetic overlap between the two traits. However, it is unclear whether there is a direct causal relationship between them. To explore this, we applied a combination of polygenic score and Mendelian randomisation analyses using publicly available genome-wide summary statistics and phenotypic measures of autism and alcohol consumption from UK Biobank. LD score regression analyses did not provide evidence of a genetic correlation between genetic liability for autism and drinks consumed per week (rg=-0.08; CI95%=-0.19, 0.03). Further, findings from polygenic score analyses did not support an association between genetic liability for autism and overall monthly alcohol intake. Univariable Mendelian randomisation analyses showed little evidence for a total effect of autism, attention deficit hyperactivity disorder (ADHD) or depression on overall monthly alcohol consumption. Multivariable Mendelian randomisation analyses also showed little evidence of a direct effect of autism on drinks per week when controlling for ADHD and depression. It is plausible that genetic liability for autism does not directly increase the amount of alcohol consumed but instead operates via commonly co-occurring difficulties in the autistic community. However, our findings may be due to methodological shortcomings, including weak instruments biasing effects towards to the null. Consequently, results should be interpreted with caution and further research conducted to address these issues.

Background: Observational studies frequently report a J- or U- shaped association between alcohol use and anxiety and depression, with moderate drinkers appearing to have lower risk than abstainers. However, this pattern may be driven in part by confounding due to health-related selection into abstinence or low-risk drinking (sick-quitter bias), whereby individuals reduce or stop drinking in response to declining health that is independently associated with worse mental health outcomes. We aimed to evaluate whether this association reflects a causal effect or residual confounding driven by sick-quitter bias. Methods: We analyzed data from 4,673 participants in the CHASING COVID Cohort, a U.S. longitudinal study with repeated measures from September 2021 through December 2023. Alcohol use was assessed at five timepoints using the AUDIT-C and categorized as abstinent, low-risk, moderate-risk, or high/severe-risk. Using a target trial emulation framework, we estimated the effects of sustained alcohol use strategies on anxiety and depression symptom severity (GAD-7 and PHQ-8) at follow-up. Artificial censoring and stabilized inverse probability weighting were applied to account for time-varying confounding and loss to follow-up. To assess the role of sick-quitter bias, we compared the abstinent versus moderate-risk contrast across strata of health status at time zero. Results: In the full sample, a J-shaped pattern was observed, with moderate-risk drinkers having the lowest predicted symptom scores. The abstinent versus moderate-risk symptom score contrast was 1.38 for depression (PHQ-8: 95% CI: 0.65, 2.14), and 0.95 for anxiety (GAD-7: 95% CI 0.24, 1.65). Among participants without underlying conditions or poor self-rated health, this pattern attenuated, with contrasts near zero for both outcomes. In contrast, the J-shaped pattern was amplified among participants with poorer baseline health, with abstinent versus moderate-risk contrasts of 3.31 for depression (95% CI: 2.14, 4.32) and 2.83 for anxiety (95% CI: 1.61, 3.86). High-risk drinking was consistently associated with higher symptom scores across all analyses. Conclusions: The J-shaped pattern between alcohol use and anxiety and depression symptoms observed in the full cohort was attenuated among participants without poorer baseline health, consistent with sick-quitter bias. Findings underscore the importance of addressing confounding due to declining health in observational alcohol research and caution against interpreting moderate drinking as beneficial for symptoms of anxiety and depression.

BackgroundAlcohol use disorder is characterized by continued alcohol use despite negative consequences, also known as aversion-resistant drinking. Alcohol related cues can invigorate motivation to seek and consume alcohol. It is currently unknown whether alcohol related cues can invigorate drinking despite negative consequences. Materials and MethodsLong-Evans rats were trained in a discriminative stimulus (DS) task with cues predicting the available of alcohol reward. They were then tested in the task for aversion-resistant drinking by measuring consumption of alcohol adulterated with increasing concentrations of quinine. As a control for an environment free of reward-related cues, rats were also tested for aversion-resistant drinking in the home cage. ResultsWe found that rats displayed robust aversion-resistant drinking in the DS task. When we compared alcohol consumption in the task with home cage consumption, we found that rats were more aversion-resistant in the task than in the home cage. We also found that individual differences in aversion-resistant drinking were correlated within behavioral context (i.e. home cage or DS task) but not between the home cage and the DS task. ConclusionsWe found that aversion-resistant drinking is invigorated during cue-induced alcohol seeking relative to free drinking without explicit cues. Home cage quinine-sensitivity is unrelated to quinine-sensitivity in the presence of cues. This suggests that cues motivate drinking despite negative consequences in a way that is unique from aversion-resistance driven by drinking history. While many behavioral measures use cues and ultimately test aversion-resistant drinking, this is the first explicit test of cue-evoked aversion-resistant drinking.

Neuroimmune signaling is increasingly implicated in alcohol use disorder (AUD). Microglia, the brains resident immune cells, signal in part through the adaptor protein myeloid differentiation primary response 88 (MyD88), a key mediator of innate immune responses. Here, we investigated whether microglial-specific MyD88 signaling regulates voluntary alcohol consumption in adulthood, as whole-body loss of MyD88 was previously shown to increase drinking. We further determined if alcohol altered parvalbumin-expressing interneurons (PVIs) and microglia within the pre-frontal cortex, based on our previously described role for MyD88 signaling on perineuronal net (PNN) deposition on PVIs in several brain regions, and the well characterized role of inhibitory signaling in alcohol use disorders. Loss of microglial-MyD88 had minimal effects on voluntary alcohol intake and anxiety-like behaviors. Alcohol exposure did not modify observed MyD88-dependent changes in PVIs/PNNs, despite altering microglial morphology in the male prefrontal cortex independent of genotype. The addition of an early life endotoxin challenge was sufficient to induce an increase in adult alcohol consumption in both MyD88-deficient and control males. However, injection of saline alone also induced an increase in adult drinking in MyD88-deficient males. These findings suggest that microglial-MyD88 signaling does not strongly regulate alcohol intake under baseline conditions in a one-bottle, voluntary binge-drinking paradigm, however there may be a role for microglial-MyD88 signaling in modulating the impact of developmental environmental contexts, such as stress, in later-life male drinking behavior. This work highlights the importance of developmental context, such as stress or inflammatory history, in understanding underlying microglia signaling mechanisms in conferring AUD risk.

Alcohol use disorder (AUD) is marked by substantial heterogeneity in drinking behaviors and health outcomes, underscoring the need for preclinical models that capture interindividual variability. We recently developed open-source capacitive lickometer systems for high-resolution monitoring of mouse fluid intake. Using LIQ PARTI and LIQ HD, we found substantial individual differences in alcohol intake that varied across sex and housing status in C57Bl6/J mice. Here, we conducted a secondary analysis of this continuous access ethanol drinking data to quantify behavioral variability in group and singly housed mice. We introduce a fluid "meal" pattern analysis that integrates drinking across ethanol and water sippers to define discrete drinking episodes. Using this approach, we observed sex- and housing-dependent reorganization of drinking structure across group and single-housed settings, with group-housed male mice exhibiting fewer but faster liquid meals. To further characterize multidimensional drinking patterns, we applied principal component analysis to meal variables and identified a "distributed meal" phenotype defined by increased meal number, reduced meal size, earlier onset of drinking, and higher ethanol preference. Considering factors that influence behaviors in a social environment, we next examined whether social hierarchy was associated with these patterns using a tube test dominance assay. Social rank was unrelated to ethanol and meal measures; however, offensive dominance behavior positively correlated with principal component scores in males. Together, these findings demonstrate that high-resolution, longitudinal analysis of ethanol drinking reveals distinct behavioral phenotypes that are associated with key components of social behaviors, providing a potential framework for understanding heterogeneity in AUD-related drinking. HighlightsO_LILIQ PARTI and HD enable high-resolution analysis of ethanol drinking patterns. C_LIO_LIFluid meal analysis captures sex- and housing-dependent drinking structures. C_LIO_LIBehavioral phenotyping reveals individual differences beyond total ethanol intake. C_LIO_LIPCA identifies a meal phenotype associated with male offensive dominance behavior. C_LI

Alcohol use disorder (AUD) is a widespread psychiatric condition, yet the molecular mechanisms underlying its development remain poorly understood. While prior studies have largely focused on protein-coding genes, long non-coding RNAs (lncRNAs) remain underexplored in AUD. Malat1, a highly abundant and evolutionarily conserved lncRNA, is elevated in post-mortem brain tissue of human AUD subjects and rodents chronically exposed to ethanol; however, its causal contribution to AUD-relevant behaviors remains unknown. Using CRISPR/Cas9 genome editing, we generated two complementary global Malat1 knockout models to assess its role in alcohol intake and related phenotypes. Constitutive knockout selectively attenuated acute functional tolerance rate and every-other-day two-bottle-choice alcohol intake in females. These results were supported by an inducible adult conditional global knockout model, which reduced ethanol consumption in females without altering taste preference. Together, our findings provide the first causal evidence that Malat1 regulates alcohol consumption in a sex-specific manner, supporting further investigation into its underlying mechanisms in AUD.

Importance: Cannabis use remains prevalent in youth despite concerns regarding its potential impact on cognitive function. Unraveling whether the association between cannabis use and cognition is partially due to preexisting differences or primarily related to use is vital to understanding underlying mechanisms. Objective: To estimate the longitudinal association between cannabis initiation and cognitive trajectories, indexed by task performance and P3 event-related potential (ERP), and to estimate whether baseline cognition is associated with cannabis initiation. Design: Data were analyzed from the ongoing longitudinal Collaborative Study on the Genetics of Alcoholism (COGA) cohort, which was followed up approximately every 2-5 years from 2004 to 2025. Setting: 6 sites across the United States. Participants: Adolescent and young adult offspring of past COGA participants and control families who reported on their cannabis use and who had Visual Oddball (VOP) performance and P3 ERP data (N=4814; 52.4% female, 68.4% white) were grouped based on the timing of cognitive data collection relative to cannabis initiation into Pre-onset (n=2,449; [&ge;]1 assessment) and Post-onset (n=998; [&ge;]3 assessments) subsamples. Main Outcomes and Measures: VOP measures include performance accuracy (%), reaction times (ms), and P3 amplitude (V) and latency (ms) during target trials. Cannabis measures included lifetime use of cannabis (i.e., ever used) and age at first use. Results: High P3 amplitude, and prolonged P3 latency and reaction time were associated with a reduced hazard of cannabis initiation (All Hazards Ratio, [H.R.s]< 0.91, p's<.008). Following initiation, cannabis use was associated with steeper declines in P3 amplitude (b=-0.29, p=0.02) and stabilized reaction time (b=0.35; p=0.005). Steeper decline in P3 amplitude (i.e., slope) was associated with greater cannabis progression (e.g., Cannabis Use Disorder, Odds Ratio, [O.R.]=2.34, p<.001), whereas steeper decline in reaction time was associated with reduced progression (O.R.=.79, p=.002). Conclusion: Baseline P3 indices and reaction time were associated with cannabis initiation, while cannabis use was associated with subsequent changes in P3 amplitude and reaction time trajectories. These findings indicate that accelerated neurodevelopment may modify the likelihood of cannabis initiation which, in turn, may further contribute to neurocognitive changes that deepen cannabis involvement.

Addiction is a complex and heritable trait which progresses through several developmental stages, each of which is presumably influenced by multiple partially overlapping genetic factors. Cocaine initially produces rewarding effects, followed by aversive effects including anxiety, craving, anhedonia, and withdrawal. These aversive effects have been suggested to contribute to the etiology of cocaine use disorders (CUD), as repeated exposure is thought to desensitize the rewarding effects and sensitize the aversive effects through a process involving both aberrant reward-based learning and aberrant avoidance-based learning. We examined the genetic basis of aversion learning using both food-based and cocaine-based behavioral assays in outbred Heterogenous Stock (HS) rats. A total of 1,074 HS rats (35.3% male) underwent runway operant cocaine-seeking, food-based progressive ratio and punishment testing, and locomotion testing. These phenotypes were significantly heritable (with h2 estimates as high as 0.307) and identified significant (p < 0.05) genetic loci related to avoidance-based learning including from the punishment task on Chromosomes 2, 3, 5, and 6, and the cocaine-operant runway latency task on Chromosome X. 172 positional candidate genes were identified from significant and suggestive loci, including Cdh10, Cdh12, Cdh18 which have previously been associated with smoking initiation from human GWAS, Adcy3, Cfap206, and Drc1 which are associated with primary neuronal cilia, as well as SNPs associated with novelty-related and social interaction phenotypes in independent samples of HS rats. Our results suggest that these aversion learning phenotypes are themselves complex heritable traits influenced by multiple genetic loci, which may pleiotropically affect other aspects of addiction biology.

Alcohol use disorder demonstrates ~50% heritability, much of which remains unexplained by genetic sequence alone. Chronic alcohol exposure before conception changes offspring phenotypes through epigenetic mechanisms that are still being elucidated. Preconception ethanol exposure studies have focused on paternal exposure, neglecting maternal and biparental exposure. To address this, we exposed adult male and female mice to five cycles of chronic intermittent ethanol vapor interleaved with two bottle choice ethanol drinking and mated them to produce male and female F1 offspring with paternal, maternal, or biparental preconception ethanol exposure or controls. Whole blood and medial prefrontal cortex from adult, ethanol-naive offspring underwent RNA-sequencing. We also analyzed previously unpublished RNA-sequencing data from male and female preimplantation embryos derived from preconception ethanol-exposed sires. Here, we report transcriptomic patterns of preconception ethanol exposure that depend on the exposed parent, offspring sex, and tissue which suggest metabolic and immune dysfunction in offspring.

Background: Alcohol consumption is a modifiable risk factor linked to anxiety and depression, yet the population-level impact of reducing alcohol use on the prevalence of anxiety and depression symptoms remains unclear. Prior studies are limited by methodological challenges including health-related selection into abstinence, time-varying confounding and reverse causation. Methods: We used data from 2,813 participants without documented underlying health conditions in a U.S. national longitudinal cohort (September 2021-December 2023) and applied the parametric g-formula within a target trial emulation framework to estimate the effect of a hypothetical intervention reducing alcohol consumption to low-risk levels on the prevalence of moderate-to-severe anxiety (GAD-7 [&ge;]10) and depression (PHQ-8 [&ge;]10) symptoms. The intervention set moderate- and high-risk drinking to low-risk at each follow-up, while leaving abstinent and low-risk drinking unchanged. Models adjusted for time-varying and baseline covariates, with uncertainty estimated using bootstrap resampling. Results: Under the natural course, the estimated prevalence of moderate-to-severe depressive symptoms was 12.67% (95% CI: 12.17, 13.23), compared to 12.77% (95% CI: 12.26, 13.29) under the intervention (risk difference: 0.10 percentage points; 95% CI: -0.22, 0.50). For anxiety symptoms, prevalence was 10.40% (95% CI: 8.89, 11.89) under the natural course and 10.25% (95% CI: 8.76, 11.98) under the intervention (risk difference: -0.15 percentage points; 95% CI: -0.68, 0.35). Conclusions: Under a hypothetical population-wide intervention reducing alcohol consumption to low-risk levels, differences in the prevalence of moderate or severe anxiety and depression symptoms were near null. These findings suggest that reducing alcohol use alone may be insufficient to meaningfully shift the population-wide burden of common mental health disorders.

Adolescent substance use is a major public health concern due to increased risk of future physical and mental health conditions. Fronto-striatal functioning - particularly regarding inhibition and reward processing - may increase vulnerability to high-risk substance use. However, it remains unclear if these neurobiological differences precede substance use or are consequences of it. The ongoing Adolescent Brain Cognitive Development (ABCD) Study follows over 10000 youth, offering an unprecedented opportunity to longitudinally examine substance use patterns throughout development. We utilized family-clustered time-varying Cox proportional hazard models to prospectively examine main and interaction effects of right Inferior Frontal Gyrus (IFG) inhibitory control and bilateral nucleus accumbens (NAc) reward response, alongside early life adversity and peer substance use as predictors of alcohol and cannabis onset in the ABCD Study. We identified a significant crossover interaction such that left NAc activity had a slight positive association with first full alcoholic drink in the context of higher right IFG activity but a negative association in the context of lower right IFG activity. However, peer alcohol and cannabis use emerged as the strongest predictors of outcomes. Alcohol onset was also more common in females, and early life adversity was associated only with cannabis onset. Findings indicate that interactions between inhibition- and reward-related brain regions may impact risk for early substance use onset, but these effects may be modest relative to socioenvironmental factors. Additionally, divergent alcohol and cannabis findings suggest that risk profiles are substance specific. Peer-focused strategies should be considered in preventive efforts.

Dysregulation of the dynorphin (DYN) / kappa-opioid receptor (KOR) system is heavily implicated in symptoms of alcohol use disorder (AUD) including negative affective-like states that can drive maladaptive behavioral regulation. Substantial efforts have been made towards understanding the neurobiology of DYN / KOR dysregulation; however, the role of dynorphinergic islands of Calleja within the ventral striatum remain poorly understood. Presently, adult male Wistar rats were trained to self-administer 10% alcohol, exposed to either air or alcohol vapor for eight weeks, and alcohol self-administration and 22-kHz ultrasonic vocalizations (USVs) assessed during acute withdrawal. Subsequently, brains were extracted during acute withdrawal and DYN A-like immunoreactivity was measured in the ventral striatum. Alcohol vapor-exposed rats demonstrated increased alcohol consumption and 22-kHz USVs compared to air-exposed controls. Vapor-exposed rats additionally demonstrated increased DYN A-like immunoreactivity in the islands of Calleja. Moreover, the average DYN A neuron size positively correlated with the number of 22-kHz USVs in vapor exposed animals, but not in air-exposed controls. The present findings identify the islands of Calleja as a novel DYN-associated region that may be recruited during alcohol dependence with enhanced DYN plasticity in the islands of Calleja contributing to affective dysregulation in AUD and other neuropsychiatric conditions.

RationaleAlcohol use disorder is defined by drinking alcohol despite knowledge of negative consequences, often referred to as aversion-resistant drinking (ARD). The dorsomedial (DMS) and dorsolateral striatum (DLS) are necessary for goal-directed and habitual action selection, respectively. Leading hypotheses posit that once drug use becomes compulsive, DMS dependence degrades while DLS dependence increases. This shift may be mediated by changes in synaptic weights from glutamatergic inputs. ObjectivesUsing a combination of western-blot, micro-injections, and ex-vivo electrophysiology, we investigated the role of -Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors AMPAR, which drive glutamatergic transmission, during quinine-adulterated alcohol (QuA) drinking in the DMS and DLS across the development of ARD. ResultsWe found that AMPAR subunit composition and function change in the DMS across the development of ARD whereby, calcium permeable (CP) - AMPARs drive behavior. Western blots revealed a negative relationship between DMS GluA1 and QuA drinking in aversion-sensitive mice and positive relationships between DMS or DLS GluA1/A2 ratios and QuA drinking in ARD mice. DMS CP-AMPAR antagonism caused an increase in QuA drinking suggesting that CP-AMPARs in the DMS prevent ARD. Ex-vivo electrophysiology of DMS spiny projection neurons (SPNs) revealed that ARD mice had a greater rectification index than aversion-sensitive mice indicating that SPNs in the DMS express more CP-AMPARs following the development of ARD. ConclusionsThese data provide evidence that repeated alcohol binges alter DMS CP-AMPAR activity, where initial DMS activity acts to prevent ARD but after repeated binges that result in ARD, DMS SPNs recruit CP-AMPARs.

Despite growing evidence that neuroimmune dysfunction contributes to Alcohol Use Disorder (AUD) pathology, the underlying neuroinflammatory mechanisms that may promote alcohol consumption are not as clear. We recently report that specific knockdown of interferon regulatory factor 7 (IRF7) in the anterior insula (aIC) mitigates escalation in ethanol self-administration in rats. In addition, we find pro-inflammatory activation of microglia contributes to other AUD-related behavioral impairments. Here, we sought to determine if pro-inflammatory activation of microglia from ethanol contributes to elevations in IRF7 and ethanol self-administration in rats. Male Wistar rats were trained under our ethanol self-administration paradigm (15% v/v; FR2 vs inactive lever) followed by 1-4 cycles of chronic intermittent ethanol exposure (CIE). To inhibit microglia, rats were treated with minocycline (30mg/kg, i.p.) before and after each ethanol vapor session. Escalation in self-administration and biochemical markers were assessed 72 hours into abstinence. We found CIE increased ethanol self-administration, which was positively correlated with aIC IRF7 levels. Minocycline treatment blunted IRF7 expression and alleviated ethanol self-administration following CIE. These data suggest a role for microglia in driving both IRF7 levels and escalation in ethanol self-administration in early abstinence.

Alcohol misuse leads to a range of health complications and induces various metabolic perturbations that impacts multiple physiological systems, including the cardiovascular system, liver, and gut microbiota. However, limited research has been reported on these metabolic profile changes, particularly using models of alcohol dependence such as after chronic intermittent ethanol (CIE) vapor exposure. This study investigated CIE-induced metabolomic alterations of CIE were investigated using fecal, liver, and serum samples of adult male and female C57BL/6J mice following 72 hr withdrawal. Significant metabolite changes were observed in both fecal and liver extracts and these changes were sex-specific. Both liver and fecal metabolites had systematic changes, while blood serum influences were limited after CIE. Female fecal samples showed higher metabolite perturbations than male samples according to PCA studies. The female samples showed significant butyrate downregulation and acetate upregulation, which are critical microbial products as beneficial microbe cell energy sources and influence intestinal absorption in the host. In addition, the female fecal samples showed significant downregulation of branched-chain amino acids including leucine, isoleucine, and valine, while male samples showed downregulation of glucose and taurine, with upregulated phenylalanine and tyrosine. In contrast, in the liver study, phenylalanine and tyrosine were upregulated while taurine was downregulated in females. Both sexes showed downregulation of liver glycine and glucose. These data indicate that CIE induces sex-specific metabolic perturbations in the mouse liver and fecal metabolome, and have implications for guy disturbances and liver damage observed following alcohol dependence. This study provides potential targets for future examination of mechanisms and treatment approaches for alcohol dependence.