Alcoholism: Clinical and Experimental Research

Both prenatal alcohol exposure (PAE) and adolescent alcohol exposure (AAE) persistently impair executive function in humans and animal models. Executive function encompasses multiple interrelated domains including working memory, inhibitory control, and behavioral flexibility. We hypothesized that a developmental "double hit" of PAE and AAE would produce more severe behavioral deficits associated with these executive domains compared to alcohol-naive and single-exposed animals. We tested this hypothesis in rats by assessing disinhibition (low-light elevated plus maze; LL-EPM), behavioral flexibility (attentional set shift test; ASST), and working memory (spontaneous alternations in a T-maze); we also tested behavioral flexibility (ASST) in mice. Pregnant Sprague Dawley rats received water or 5 g/kg alcohol from gestational day (GD)13.5-GD20.5, and offspring received water or 5 g/kg alcohol on a 2-day-on, 2-day-off paradigm from postnatal day (PD)25 to PD54. Pregnant C57BL/6J mice received water or 4.5 g/kg alcohol from GD13.5-GD17.5, and offspring received water or 4.5 g/kg alcohol on a 2-day-on, 2-day-off paradigm from PD25 to PD42. Offspring underwent behavioral testing in young adulthood. Double hit rats showed more exploration in the LL-EPM than controls and fewer alternations in the T-maze than AAE-only rats, suggesting deficits in disinhibition and spatial working memory, respectively. Double hit rats and mice exhibited more errors and/or more trials to criterion in the ASST, indicative of decreased behavioral flexibility. Overall, double hit animals showed altered performance on tests related to executive function, suggesting that the combined exposure alters executive function in a manner distinct from single-exposure models.

BackgroundEarly low-level alcohol use predicts subsequent alcohol use and problems. Impulsivity and poor inhibitory control also predict later problematic alcohol use. However, few studies prospectively examine early sipping in combination with modeling impulsivity and inhibitory control change over time as predictors of adolescent alcohol use. MethodsData Release 6.0 from the Adolescent Brain Cognitive Development (ABCD) Study was used (n=11,866; 48% Female). A series of linear mixed-effect models examined trajectories of non-religious sipping at baseline (ages 9-10) and self-reported impulsivity (UPPS-P) and task-based inhibitory control (Flanker task) over time as predictors of past year drinks and problematic alcohol use by ages 15-16. Predictors were run as separate models and a full model with all predictors together. Models were nested within the participant and study site. Interactions with age (to measure change over time from Baseline to Year 6) were included. Corrections for multiple comparisons were employed. ResultsIn individual models, four impulsivity interactions were significant: (1) negative urgency*age ({beta}=.04, FDR-p<.001), (2) positive urgency*age ({beta}=.04, FDR-p<.001), (3) lack of planning*age ({beta}=.04, FDR-p<.001), and (4) sensation seeking*age ({beta}=.04, FDR-p<.001), suggesting that as age increases, the relationship between impulsivity and alcohol use strengthens. Sipping*age ({beta}=.02, FDR-p<.001) interactions also predicted standard drinks. Regarding problematic use, there was a significant interaction in the full model: negative urgency*age ({beta}=-.07, p=.05), indicating that this relationship is more pronounced at earlier ages. ConclusionsTrait impulsivity and sipping in late childhood relate to future alcohol use, and the relationship strengthens with age. Our results found a negative interaction between negative urgency and age on problematic use, potentially indicating negative urgency as a phenotype of vulnerability to experiencing alcohol related problems at younger ages. Findings indicate the importance of understanding facets of impulsivity in the context of adolescent alcohol use for prevention and intervention efforts.

Excessive alcohol drinking is a leading cause of preventable death in the United States. High alcohol consumption and persistent drinking despite adverse events, also known as compulsive drinking, are key criteria that contribute to the development and progression of alcohol use disorder (AUD). There is a clear need to better understand the mechanisms that support these related but distinct behaviors. The serotonin (5-HT) system has been associated with alcohol consumption and risk of alcohol dependence, however given the complexity of this system, there remains much to discover regarding specific alcohol related phenotypes. The current study uses a combination of volitional home-cage drinking and operant conditioning to phenotype mice based on ethanol intake and persistence of alcohol drinking following quinine adulteration, a model to study compulsive drinking. Brain tissue of 10 regions known to be implicated in regulating executive function, reward, and stress was collected, and gene expression of serotonergic receptors, transporters, and enzymes was quantified. Three opioid receptors were included given their well-established roles in alcohol-related behaviors and interactions with the 5HT system. Region-specific gene expression patterns emerged, with serotonergic and opioid receptor expression differentially associated with alcohol drinking phenotype. 5-HT and opioid receptors displayed opposing directionality across regions, consistent with functional heterogeneity within the system. These findings identify region-specific molecular alterations following chronic alcohol that may contribute to individual differences in alcohol drinking phenotypes, highlighting candidate targets for biomarkers of increased alcohol use disorder susceptibility or as interventions aimed at preventing the progression of AUD.

BackgroundPrenatal stress (PNS) is a well-established risk factor for neuropsychiatric vulnerability, yet its sex-specific behavioral consequences remain incompletely defined. Because males and females follow distinct neurodevelopmental trajectories, clarifying how early-life stress differentially shapes behavior is essential for developing targeted interventions. However, few preclinical studies directly compare male and female offspring within the same experimental framework, limiting the ability to identify true sex-dependent effects. MethodsUsing a validated mouse model of gestational restraint stress, we conducted a comprehensive, within-study assessment of sex-dependent behavioral outcomes in adult offspring. Behavioral domains included locomotor activity, anxiety-like behavior, sociability, fear learning and extinction, recognition memory, and alcohol-related responses (ethanol preference and behavioral sensitivity), all measured using identical paradigms across sexes. ResultsPNS broadly disrupted behavior and cognition in both sexes, increasing locomotor activity and anxiety-like behavior, impairing fear extinction and recognition memory, and altering behavioral sensitivity to ethanols sedative effects. Direct comparison revealed distinct sex-dependent vulnerabilities: males showed reduced social interaction, whereas females exhibited numerically greater impairment in fear extinction and a significantly stronger ethanol preference. Baseline fear responses, total fluid intake, and sucrose consumption were unaffected. ConclusionPrenatal stress programs neurobehavioral trajectories in a sex-dependent manner, conferring vulnerability to anxiety-related behavior, cognitive disruption, and alcohol use. By directly comparing males and females within the same experimental design, this study provides one of the most integrated evaluations of sex-specific PNS outcomes to date and offers a robust framework for investigating the biological mechanisms underlying divergent pathways to stress-related psychopathology.

Alcohol use disorder is a major public health concern worldwide and there is a high comorbidity with psychiatric disorders. The basolateral amygdala (BLA) has been implicated in both mood and alcohol use disorders; however, the mechanisms contributing to the shared pathophysiology remain unknown. Extensive evidence indicates that ethanol modulates GABAergic signaling in the BLA, including actions on neurosteroid-sensitive, extrasynaptic {delta} subunit-containing GABAA receptors (GABAARs), which has been suggested to mediate many of the behavioral effects. In fact, several studies have suggested that 5-reduced neurosteroids, such as allopregnanolone, may mediate some of the behavioral effects of alcohol. Here we demonstrate that chronic intermittent ethanol (CIE) exposure impairs endogenous neurosteroidogenesis via downregulation of key neurosteroidogenic enzymes, 5-reductase type 1 and type 2. To examine the impact of impaired endogenous neurosteroidogenesis of the behavioral consequences of chronic alcohol exposure, including withdrawal-induced anxiety and increased alcohol consumption, we used CRISPR/Cas9 mediated knockdown of 5-reductase in the BLA. Reduced expression of 5-reductase in the BLA did not impact post-CIE alcohol intake or anxiety-like behaviors during withdrawal, perhaps because endogenous neurosteroidogenesis is already impaired following CIE. Therefore, we examined the impact of enhancing neurosteroid levels, treating mice post-CIE with SGE-516, a synthetic GABAAR positive allosteric modulator, which increased voluntary alcohol intake. These findings implicate endogenous neurosteroidogenesis in behavioral outcomes associated with withdrawal from chronic alcohol exposure. Further, this study suggests that targeting endogenous neurosteroidogenesis may be a novel and useful therapeutic target.

Astrocytes are the most abundant glial cells in the brain and an integrative component of the neural network. Studies have shown that ethanol altered expression of an astrocyte marker, i.e., glial fibrillary acidic protein (GFAP), in two key corticolimbic regions, the medial prefrontal cortex (mPFC) and nucleus accumbens (NAc). These regions comprise anatomically and functionally different subregions, i.e., the prelimbic (PL) and infralimbic (IL) cortex of the mPFC, the shell and core subregions of the NAc. However, ethanol effects on GFAP expression within these subregions remain largely unknown. In addition, effects of pharmacological manipulation of astrocytes on alcohol drinking have been understudied. Western blot was conducted to determine GFAP expression in subregions of the mPFC and NAc after chronic ethanol drinking. Fluorocitrate, an astrocyte-specific metabolic inhibitor, was administered to inhibit astrocytes and was tested on ethanol drinking. Ethanol drinking enhanced GFAP protein expression in the PL cortex and NAc core, but not in the IL cortex or NAc shell. Intra-ventricular administration of fluorocitrate reduced ethanol intake and preference, but increased water consumption during choice ethanol drinking. In addition, fluorocitrate did not affect total fluid consumption or basal locomotor activity. These results indicate that chronic ethanol drinking induced GFAP elevation in a subregion-specific manner within the mPFC and NAc, and that metabolic inhibition of astrocytes selectively attenuated ethanol drinking without non-specific effects on water drinking or general activity. Together, these results suggest that astrocytes may play an important role in ethanol drinking. HighlightsO_LIEthanol drinking enhanced GFAP levels in the PL cortex and NAc core. C_LIO_LIFluorocitrate inhibition of astrocytes reduced intermittent ethanol drinking. C_LIO_LIFluorocitrate did not alter total fluid consumption or basal locomotor activity. C_LI

BackgroundLoss of control over drinking is a hallmark feature of alcohol use disorder (AUD) that is modeled preclinically through escalation of ethanol consumption and aversion-resistant drinking. Prior work with other reinforcers suggests that within-session unpredictable, intermittent access (uIntA) promotes loss of control over intake. However, the effect of uIntA on voluntary ethanol consumption is unknown. MethodsMale and female Long-Evans rats (n=9-10/group) underwent seven weeks of daily voluntary ethanol (20% v/v) drinking sessions under either a continuous access (ContA) or uIntA schedule. Following four weeks of baseline, rats were rendered dependent using a two-week chronic intermittent ethanol vapor exposure procedure. Daily testing was maintained through one week into withdrawal from vapor exposure. On the final day of testing, ethanol was adulterated with quinine (30 mg/L) to assess aversion-resistant drinking. ResultsRats drinking under ContA and uIntA exhibited similar levels of average daily ethanol consumption at baseline. However, uIntA elicited a more robust dependence-induced escalation of ethanol consumption compared to ContA, with uIntA sustaining escalation through early protracted withdrawal. Additionally, while rats with ContA to ethanol remained sensitive to quinine even after chronic ethanol vapor exposure, uIntA promoted aversion-resistant drinking in ethanol dependent rats. ConclusionsThese results demonstrate that, compared to ContA, uIntA maintains ethanol drinking and exacerbates AUD-related symptomatology while also providing researchers with the ability to capture additional measures of motivation and drinking patterns without increasing experimental burden. This work positions uIntA as a powerful tool to assess psychological and neurobiological factors underlying loss of control over drinking.

Background: Alcohol use disorder is associated with dysregulated glutamatergic signaling within mesocorticolimbic circuits that govern reinforcement and excessive ethanol intake. Group II metabotropic glutamate receptors (mGlu2/3) act primarily as presynaptic autoreceptors that regulate glutamate release. However, how voluntary alcohol intake alters mGlu2/3 expression within reward circuitry remains unclear. Methods and Results: We examined the effects of operant alcohol self-administration on mGlu2/3 protein expression and assessed the functional impact of group II receptor modulation on binge-like ethanol intake. Male C57BL/6J mice self-administered sweetened ethanol or sucrose under behaviorally matched conditions for 35 days. Immediately after the final session, tissue punches from the nucleus accumbens (NAc), amygdala, and prefrontal cortex were collected for Western blot analysis. Operant ethanol self-administration selectively reduced mGlu2/3 protein expression in the NAc, with no changes detected in the amygdala or prefrontal cortex. Both monomeric and dimeric mGlu2/3 protein levels were reduced, and a composite index revealed coordinated downregulation of receptor expression. In separate cohorts, systemic administration of the mGlu2/3 agonist LY379268 dose-dependently reduced binge-like ethanol intake in a limited-access home-cage drinking model, whereas positive allosteric modulation of mGlu2 receptors with LY487379 was ineffective. Conclusions: These results show that low-dose operant ethanol self-administration produces an ethanol- and region-specific reduction of mGlu2/3 protein expression in the NAc and that pharmacological activation of group II receptors, potentially involving mGlu3-specific receptors, is sufficient to suppress binge-like ethanol consumption. These data identify presynaptic mGlu2/3 dysregulation as a mechanism contributing to ethanol-related behaviors and support group II metabotropic glutamate receptors as therapeutic targets for alcohol use disorder.

BackgroundFetal alcohol spectrum disorder (FASD) encompasses a variety of disorders that occur after a fetus has been exposed to alcohol. Hippocampal related issues are a common neurological deficit found in FASD. The dentate gyrus within the hippocampus is a unique area of the brain that continues to generate new neurons into adulthood. This neurogenesis can be enhanced by an enriched environment (EE); however in prenatal alcohol exposed (PAE) mice this EE-mediated neurogenesis is impaired. In addition to EE, selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, also promote neurogenesis. Here we examine if fluoxetine restores the impaired EE-mediated neurogenesis of PAE mice. MethodPAE mice were generated using a voluntary limited access model where mice received a 10% ethanol (w/v) solution during gestation. To evaluate neurogenesis, we use a NestinCreT2:tdTomato transgenic mouse line in which newborn dentate granule cells (nDGCs) can be evaluated by tdTomato flourescence. PAE and saccharine control (SAC) mice were placed in either standard housing (SH) or enriched environment (EE). Subsequently, we administered fluoxetine (FLX) or vehicle (VEH) after which neurogenesis was evaluated. ResultsPAE resulted in impaired EE-mediated neurogenesis. This neurogenic impairment was not restored by FLX. Interestingly, FLX did increase neurogenesis in PAE mice while housed in SH. ConclusionThese results suggest that there is a neurogenic ceiling in PAE mice that cannot be increased by fluoxetine in EE. However, fluoxetine can increase neurogenesis while the environment is less complex.

ImportancePolysubstance use is common, but substance use associations with neuroimaging measures have largely been investigated within individual drug types. Whether effects are substance-specific or -general, and how predispositional risk and exposure contribute, remains unclear. ObjectiveIdentify shared and unique associations between substance use and brain structure, and characterize the contributions of predispositional risk and environmental exposure, in a large sample of young adults in the US. DesignThis cross-sectional family-based study used data from the Human Connectome Project (2017 release, collected from 2012-2015). SettingData were collected at Washington University in St. Louis, MO, USA. ParticipantsTwins, non-twin siblings, and singletons with magnetic resonance imaging (MRI) and substance use self-report were included in the analysis. Data were analyzed in 2025. ExposureHistory of substance use was assessed using the Semi-Structured Assessment for the Genetics of Alcoholism. Variables included lifetime use, heavy or past-year hazardous use, and age of use onset for alcohol, marijuana, tobacco, and illicit drugs. Additionally, alcohol and marijuana dependence were assessed. Main Outcomes and MeasuresLinear mixed-effect models examined associations between substance use and brain structure, with an initial focus on past-year hazardous alcohol use, as 95% of the sample endorsed lifetime alcohol use. Analyses then tested associations with other substance use variables, and whether effects were shared or substance-specific. Between-family, within-family, and genetic variance component analyses tested risk and exposure effects. Results1,113 participants (N = 445 families; ages 22 - 37; M=28.8, SD=3.7) had no missing data for the primary analyses. Hazardous alcohol use was negatively associated with global brain thickness ({beta} = -0.12, p < 0.001), which explained all other regional and global associations. Of the drugs with a shared-effect on global brain thickness, only lifetime marijuana use explained unique variance over alcohol ({beta} = -0.08, p = 0.013). Within-family analyses found evidence for unique putative exposure effects of both alcohol ({beta} = -0.11, p < 0.001) and marijuana use ({beta} = -0.07, p = 0.002) on global thickness. Marijuana use further showed a predispositional effect, both in between-family comparisons ({beta} = -0.11, p = 0.007) and genetic variance component analyses ({rho}G = -0.2, p = 0.004), which were not explained by alcohol use. Conclusions and RelevanceBrain structural associations with substance use reflect substance-general and -specific effects, as well as a combination of predispositional and exposure effects. Findings suggest that the negative consequences of polysubstance use may reflect the additive effects of multiple unique exposures.

Acute stress activates the immune system, leading to the release of pro-inflammatory cytokines, such as interleukin-6 (IL-6). Chronic alcohol consumption alters the physiological stress systems and is associated with increased chronic inflammation. However, it remains unclear how IL-6 responds to acute stress in individuals with alcohol use disorder (AUD). Forty patients with AUD during early abstinence and 37 healthy controls (HC) completed two study visits. On one day, an acute stress induction task was performed, and on the other, a non-stressful control task, with the order of tasks being balanced. Plasma IL-6 and C-reactive protein (CRP) were measured as inflammatory markers at baseline and changes in IL-6 were assessed 90 minutes after the experimental manipulation. Patients with AUD showed significantly elevated baseline IL-6 and CRP compared to HC. In HC, inflammatory parameters were positively correlated with age and BMI, whereas in patients with AUD, they were correlated with the amount of consumed alcohol. IL-6 responses to the stress intervention did not differ between groups. Increases in IL-6 were observed on stress and control days and were larger when samples were collected via an indwelling catheter than with a butterfly needle. These findings suggest that heavy chronic alcohol use may mask the typical associations between inflammatory markers and physiological factors. However, IL-6 responses to acute stress do not differ between AUD and HC, despite increased baseline inflammation. Furthermore, the results indicate that blood collection methods can influence IL-6 measurements and highlight the importance of methodological considerations.

BackgroundRates of binge drinking have converged significantly between the sexes over recent decades, driven by increased rates of alcohol misuse in women. However, understanding of fundamental circuitry and neurobiology driving alcohol use in females, or how this may differ from male subjects remains underexplored. MethodsWe quantified c-Fos expression across 40 brain regions in alcohol naive, alcohol anticipating and binge drinking male and female mice. In vivo fiber photometry examined sex differences in basolateral amygdala (BLA) activity changes to alcohol intake. Chemogenetic BLA inhibition investigated a functional role in binge drinking. We then assessed sex differences in BLA efferent projection activation following binge drinking. Finally, we functionally interrogated the BLA to nucleus accumbens core (AcbC) projection in binge drinking. ResultsBinge drinking reduced network modularity (number of communities with similar activation patterns) in both sexes relative to alcohol naive and anticipating same-sex counterparts. Female binge drinking mice had increased BLA c-Fos expression compared to female naive and male binge drinking counterparts. In vivo fiber photometry revealed greater and more prolonged BLA responsivity at the onset of alcohol intake in females. Global BLA inhibition reduced reward intake in both sexes. However, the BLA to AcbC projection was preferentially activated in female binge drinking mice, and inhibition of this pathway reduced binge alcohol intake exclusively in females. ConclusionsWe identified sex differences in the neural circuits engaged in binge drinking, highlighting the BLA to AcbC projection may in part underpin sex differences in alcohol misuse. This provides further evidence of distinct neurobiological drivers of alcohol-related behaviors between the sexes.

Alternative polyadenylation (APA) is a common posttranscriptional mechanism to regulate gene expression. APA generates mRNAs with varying lengths of 3' UTRs or transcripts that encode distinct protein carboxy-terminal ends. APA is especially important in neurons, where different mRNA variants are often asymmetrically localized to dendrites and axons, and can be locally translated into proteins. Local protein synthesis is crucial for axon guidance, synaptic plasticity, and learning and memory, key processes associated with the development of alcohol use disorder (AUD). We investigated the role of APA in AUD using a mouse model of alcohol dependence characterized by increased voluntary drinking after chronic intermittent ethanol (CIE) exposure. We examined APA during protracted withdrawal from alcohol in three brain regions of male and female mice. Our analyses revealed hundreds of genes undergoing APA in males, but substantially fewer in females, suggesting sex-specific effects of CIE on APA. Notably, male and female mice displayed distinct APA signatures. APA genes were different from differentially expressed genes (DEGs), suggesting that these molecular processes are regulated independently. We also determined that the expression of APA genes was associated with neurons, while DEGs were associated with non-neuronal cells. Many of the APA genes were involved in synaptic integrity, neuroplasticity, and neuronal maintenance, which was consistent with their enrichment in neurons. Our study suggests that APA is a crucial sex- and cell type-specific mechanism in AUD with the potential to influence localized neuronal protein expression during protracted withdrawal and to modify alcohol consumption behavior. HIGHLIGHTSO_LIChronic ethanol exposure in mice results in profound changes of APA genes in brain. C_LIO_LICommonly regulated cleavage and polyadenylation sites and genes were identified in male but not in female mice. C_LIO_LIThere was a minimal overlap between APA and differentially expressed genes (DEGs). C_LIO_LIAPA genes were primarily associated with neurons, whereas DEGs were associated with non-neuronal cells. C_LI

Prenatal alcohol exposure (PAE) can lead to a range of deficits falling under the umbrella of Fetal Alcohol Spectrum Disorder (FASD), which included higher risk for adverse neurodevelopmental and mental health outcomes. Although the biological mechanisms underlying the link between PAE and mental health remain unclear, DNA methylation (DNAm), an epigenetic modification responsive to environmental exposures, may explain these relationships. Here, we applied a two-sample Mendelian randomization (MR) framework to assess whether DNAm loci previously associated with PAE or FASD are linked to 11 psychiatric outcomes. Using summary statistics from the Genetics of DNA Methylation Consortium (GoDMC) mQTL database and large-scale GWAS, we analyzed DNAm loci from two epigenome-wide association studies: one examining FASD by Lussier et al. (2018) and one examining PAE patterns by Sharp et al. (2018). A total of 106 associations (Lussier) and 28 associations (Sharp) reached nominal significance (p<0.05) and passed sensitivity tests, with several surviving multiple testing correction. Notably, schizophrenia and bipolar disorder had the highest number of associated loci across both studies. Functional analysis showed that DNAm loci were enriched in signaling pathways, embryonic development, and neuron differentiation. Regional enrichment analysis revealed that FASD-related loci were more likely to occur in enhancer and south shore, implicating distal regulatory elements. PAE patterns conferred heterogeneous effects on DNAm and mental health risk, underscoring the complexity of timing-specific epigenetic vulnerability. These findings offer novel insights into the potential mechanism of DNAm linking PAE to mental health, and demonstrate the utility of MR in epigenetic epidemiology.

BackgroundAlcohol use disorder (AUD) is a chronic condition characterized by compulsive drinking and high relapse risk. Craving in early abstinence is a strong predictor of relapse, yet its underlying neurobiological mechanisms remain unclear. Guided by Menons Triple Network Model (TNM) of psychopathology, this study investigates whether altered connectivity between the salience (SN), default mode (DMN), and central executive (CEN) networks --previously implicated in alcohol-related behaviours -- underlies craving during early abstinence. MethodsA final cohort of 27 individuals with AUD recruited from an inpatient alcohol withdrawal program completed resting-state fMRI scans on day 1 of withdrawal and 18 days later. Additionally, 17 healthy controls underwent fMRI at two sessions spaced two weeks apart. Craving was assessed in the AUD group at both timepoints using the obsessive thoughts subscale of the Obsessive Compulsive Drinking Scale (OCDS). Functional connectivity between brain networks was computed by referencing each individuals between-network connectivity to normative models derived from large-scale reference data to generate scores reflecting their deviations from normative values. Proposed analysesPlanned analyses will leverage large-scale lifespan normative models to test associations between patient deviation scores in SN-DMN connectivity and craving during acute withdrawal, along with longitudinal associations during abstinence. Exploratory analyses will assess correlations between craving and connectivity of other network pairs of the TNM. ConclusionsThis report aims to identify functional neurobiological markers of craving during early abstinence in AUD employing normative models. Findings may advance understanding of relapse vulnerability and inform personalized interventions targeting large-scale brain network dysfunctions in AUD. This submission corresponds to Level 3 of the Peer Community In (PCI) Registered Report bias-control taxonomy: data were collected and pre-processed prior to hypothesis formulation, but key variables (subject-level values) have not been observed and no statistical analyses have been performed.

Neuroimmune signaling is increased in postmortem brain tissue from individuals with alcohol use disorder (AUD), and growing evidence suggests that it contributes to persistent alcohol-related neuroadaptations. Interferon regulatory factor 7 (IRF7), a transcription factor downstream of endosomal Toll-like receptor signaling, is induced in alcohol-relevant brain regions and may contribute to escalated drinking. Here, we tested whether chronic intermittent ethanol (CIE) vapor exposure engages IRF7 signaling during subsequent alcohol self-administration and whether this is associated with altered molecular E/I balance in the aIC and altered functional E/I balance in aICnucleus accumbens projection neurons. Female Wistar rats (n=30) were trained to self-administer alcohol (15% v/v; FR2 vs inactive lever) during 30-minute sessions. After establishing baseline drinking, rats underwent 1-3 cycles of CIE, which increased alcohol self-administration at the 72 h post vapor test. This increase positively correlated with IRF7 levels in the anterior insular cortex (aIC) and nucleus accumbens, while molecular, and immunofluorescence showed that CIE shifted aIC excitatory/inhibitory (E/I) balance toward reduced excitation. Electrophysiological recordings further showed reduced functional E/I balance in aIC neurons projecting to the nucleus accumbens. Knockdown of IRF7 in the aIC attenuated CIE induced escalation of alcohol self-administration, supporting a role for insular IRF7 signaling in alcohol related neuroadaptations that promote escalated drinking.

IntroductionNeural cue reactivity is increasingly being investigated as a biomarker of treatment response and relapse prediction in addiction disorders. Whilst aberrant brain responses to salient cues (e.g. drugs) have been widely reported in addiction, it is unclear whether these brain responses persist during longer-term abstinence, how they compare between substance use disorder and obesity, and relate to potential differences in eating behaviours. As part of the Gut Hormones in ADDiction (GHADD) neuroimaging study, we investigated how salient cue reactivity to drugs or food, craving and eating behaviours compare in three clinical populations where alterations have been previously observed: abstinent nicotine use disorder (NUD) and alcohol use disorder (AUD), and obesity. MethodsThis study compared group differences in salient cue reactivity and eating behaviours between ex-smokers (n=25, ExS), adults with alcohol dependence who are abstinent (n=26, AAD), adults with obesity who were actively dieting (n=26, OB). Participants completed a high-energy food, preferred alcohol and cigarette functional magnetic resonance imaging (fMRI) cue reactivity task, along with eating behaviour questionnaires, appetite visual analogues scales and an ad libitum test meal. ResultsExS exhibited greater blood oxygen level dependent (BOLD) signal to high-energy food pictures in several reward processing regions in both whole brain and region of interest (ROI) analyses, compared with the OB and AAD groups, with no difference in their appeal rating. Compared with the OB group, ExS exhibited greater BOLD signal to cigarette pictures in the frontal gyrus, orbitofrontal cortex, frontal pole and insula, with no difference in their appeal rating. There were no group differences in preferred alcohol cue reactivity. The AAD group rated sweet taste as more pleasant, and consumed more calories from sweet dishes in the ad libitum meal than the OB and ExS groups. ConclusionsThe presence of heightened cue reactivity to high-energy foods in ex-smokers could contribute to post-quitting weight gain after smoking cessation. Neuroimaging findings were consistent with persistence of some salient drug cue reactivity, despite absence of craving, after medium term abstinence in ExS, but not in AAD. This study also adds to the body of evidence supporting a sweet taste preference endophenotype predisposing individuals to AUD. These changes in eating behaviour in NUD and AUD may provide targets for treatments to reduce substance misuse and facilitate abstinence.

OBJECTIVEUsing two cohorts and synthetic datasets, we estimated effects of prospectively reported alcohol use on memory outcomes across middle age. METHODSData were from National Longitudinal Study of Youth 1979 (NLSY79, n=7540, alcohol reports from ages 18-26), Health and Retirement Study (HRS age 50-56 at enrollment, n=13,090), and a synthetic cohort matching early life exposure information from 3,259 NLSY79 participants to later life memory information from 5,451 HRS participants. Covariate-adjusted linear mixed models regressed memory (word list recall) on alcohol use (none, light/moderate, heavy). RESULTSIn NLSY, we found no evidence that associations between light/moderate drinking in early adulthood and mid-life memory score significantly differed from associations between drinking abstention ({beta} = -0.09 (95% CI: -0.30, 0.11)) or heavy drinking ({beta} = -0.26 (-0.48, -0.04)) with memory score. In HRS, both abstaining from alcohol ({beta} = -0.14 (-0.25, -0.02)) and heavy drinking ({beta} = -0.25 (-0.42, -0.07)) were negatively associated with cognitive level. Results from the synthetic cohort mirrored NLSY, suggesting no significant association between abstention ({beta} = 0.13 (-0.10,0.36)) nor heavy drinking ({beta} = 0.02 (-0.25,0.28)) with mid-to-late life memory score. DISCUSSIONAlcohol consumption may not have an effect on memory until later life, though associations may be affected by residual confounding.

BackgroundFatty foods and alcohol (i.e., ethanol) produce strong reinforcing effects, in part by altering cholinergic interneuron (CIN) activity and tonic dopamine (DA) release within the nucleus accumbens (NAc). Ethanol and fatty foods also both stimulate hepatic and possibly local brain bile acid (BA) synthesis, which raises the possibility that BAs may act as a common upstream regulator of these substances shared mesolimbic effects. MethodsThe current study investigated whether BAs can directly alter mesolimbic activity. Electrophysiological data from acute mouse brain slices was collected to assess BA effects on NAc CIN firing, as well as on excitatory and inhibitory postsynaptic CIN inputs. Bile effects on NAc DA release and clearance rates were measured through voltammetry. ResultsWe found that low concentrations of a 1:1 mixture of BAs cholic acid (CA) and deoxycholic acid (DCA; 1-10 M) increased CIN firing rate, whereas high BA concentrations (1-10 mM) decreased CIN firing. We further demonstrated that BA-induced excitatory effects on CIN firing are independently mediated by at least two mechanisms: Takeda G-protein-coupled receptor 5 (TGR5) activation and suppression of inhibitory CIN currents. Additionally, our results indicate that BAs modulate inhibitory input in a complex manner, reducing frequency at low concentrations, but increasing at high concentrations, and increasing amplitude at low concentrations current amplitude, and the distribution of postsynaptic current amplitude sizes across concentrations. Finally, our voltammetry data indicate that while low BA concentrations enhance NAc DA release without affecting DA uptake, high BA concentrations robustly inhibit accumbal DA release. ConclusionOur findings provide evidence that BAs exert direct modulatory effects on neural activity in the striatum.

IntroductionMaternal mental health conditions, comprising maternal suicide and drug overdose, are currently the leading cause of maternal mortality in the United States. However, the relationship between suicidality and drug use behavior in the perinatal period is not well understood. We examined the association between suicidality and drug use behavior among perinatal individuals. Given the racial disparities in both drug use and suicide rates in the U.S., we also examined any differences in suicidality and drug use behavior by race. MethodsParticipants were recruited from a High-Risk Obstetric & Gynecological Clinic in the Midwestern U.S that specializes in providing obstetric care to perinatal individuals who have histories or current use of opioids and other illicit drugs. Participants (N = 66) were a sub-sample of a larger cohort enrolled in an mHealth intervention to support recovery from opioid and stimulant use disorders. We performed chi-square tests and t-tests to examine any significant associations between lifetime suicidality and drug use behavior during the perinatal period. ResultsThe final analytic sample included participants who had responded to the suicidality survey questions (n=43). Nearly 40% (n=16) of our sample endorsed a lifetime history of suicidal thoughts and behaviors (SITB). Of those, 87% (n=15) reported a previous suicide attempt. SITB was significantly associated with cravings for opioids during the perinatal period (p = .01) as well as comorbidities with perinatal anxiety symptoms? ( p < .05), depression symptoms? (p < .05), and bipolar disorder (p < .05). A higher proportion of recent cannabis use was found among mothers with SITB, compared to those without SITB (p=0.04). Mothers with SITB also had a strong positive correlation between preconception and postnatal nicotine use compared to mothers without SITB (p < .01). Finally, while white mothers endorsed more lifetime overdoses (p= 0.01), Black mothers endorsed higher cravings for opioids during pregnancy (p = 0.03). ConclusionsA history of SITB is a distinct risk factor for both illicit and recreational drug use behavior in the perinatal period, and frequently co-occurs with other perinatal mental health conditions. Further research is needed to better understand the directionality of this relationship and the complex interplay between high risk drug use behavior and suicidality.