Alcoholism: Clinical and Experimental Research

Stress exposure contributes to the development of drug and alcohol use disorders. In animal models, stress exacerbates escalations in alcohol consumption in alcohol-dependent animals. The nucleus of the solitary tract (NTS) is a critical brainstem region for integrating and relaying peripheral signals to regulate stress responses. To define the molecular adaptions within this brain region that may contribute to stress-induced alcohol drinking, we exposed animals to chronic intermittent bouts of ethanol vapor (CIE), forced swim stress (FSS), or both (CIE + FSS) and then transcriptionally profiled the NTS at three different timepoints after the last vapor exposure (0-hr, 72-hr, and 186-hr). We identified interferon (IFN) signaling as a critical gene network correlated with alcohol consumption levels. Using a likelihood ratio test, we identified genes that were differentially expressed across time and between groups. Clustering analysis of these genes to identify unique expression patterns identified a subset of genes that fail to normalize in the CIE + FSS group, but not the others. These genes were enriched for cell-to-cell interaction and cellular movement pointing to long-term structural and functional changes in this brain region caused by the unique interaction of alcohol dependence and stress. Specific genes of interest identified in this group include Aqp4, Il16, Reln, Grm4, Gabrd, and Gabra6. We also compared gene expression changes in the NTS to the PFC and found a significant overlap of genes between the two brain regions. Overlapping NTS/PFC genes in the CIE + FSS group were enriched for type I IFN signaling. Finally, we tested the hypothesis that activation of type I IFN signaling increases alcohol consumption based on the three lines of evidence identifying type I IFN signaling as critical for escalations in alcohol intake. Mice treated with recombinant IFN{beta} showed significantly elevated levels of alcohol intake in a two-bottle choice procedure compared to saline-treated controls. Overall, these results define the transcriptomic changes across time in the NTS that may be critical to the development of stress-induced increases in alcohol consumption and alcohol dependence.

Cerebellar Purkinje cells (PCs) are among the most vulnerable neurons to alcohol neurotoxicity. Alcohol can induce endoplasmic reticulum (ER) stress and alter the structure and function of PCs. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an ER stress inducible protein highly expressed in PCs. It is neuroprotective in various pathological conditions where ER stress is induced. However, it is unknown whether MANF plays a role in protecting PCs from alcohol induced ER stress. In this study, we generated PC-specific MANF knockout (KO) mouse model to test the hypothesis that MANF deficient PCs are more susceptible to binge alcohol exposure induced ER stress and neurodegeneration in the adult brain. We found that PC-specific MANF KO animals show moderate motor function deficit, which was exacerbated by alcohol exposure. Interestingly, female KOs were more sensitive than male KOs to alcohol-induced motor function impairments. In accordance with the behavior changes, alcohol exposure also caused UPR activation, increased intranuclear expression of calcium binding protein Calbindin, and PC degeneration in female but not male MANF KO mice. Spatial transcriptomics and high throughput in situ analyses demonstrated that MANF deficiency altered the transcriptomic landscape in PCs in a sex-specific manner and triggered the expression of genes involved in protein folding and response to ER stress. These results suggests that MANF KO PCs may be predisposed with a higher risk to UPR activation and ER stress in a sex dependent manner, contributing to their vulnerability to alcohol neurotoxicity.

Alcohol Use Disorder (AUD) is a heterogenous category with many unique configurations of symptoms. Previous investigations of AUD heterogeneity using molecular genetics methods studied the association between genetic liability and individual AUD symptoms at the latent level or focusing on a small number of genetic variants. Notably, these studies did not investigate potential severity differences between symptoms in their genetic analyses. Therefore, the current study aimed to examine the genetic risk for individual AUD symptom criteria by using a polygenic risk score (PRS) approach to assess the relative severity of each AUD symptom and test for associates with AUD symptoms above and beyond a unidimensional AUD construct. An AUD PRS was created using summary statistics obtained from published genome-wide association studies (GWAS), and Multiple Indicators Multiple Causes (MIMIC) models were employed to examine the effect of the PRS on overall AUD severity as well as on individual symptoms after accounting for this overall effect. The phenotypic severity of AUD symptoms was highly correlated with the genetic severity of AUD symptoms (r = 0.78). Results of MIMIC models indicated that the AUD PRS significantly predicted the AUD factor. Regression paths testing the unique, direct effects of the PRS on individual AUD symptoms, independent of the latent AUD factor, were not significant. These results imply that PRSs derived from GWAS of AUD influence symptom expression through a single genetic factor that is highly correlated with the relative severity of individual symptoms when measured at the phenotypic level. Item-level GWAS of AUD symptoms are needed to further parse heterogeneous symptom expression and allow for more nuanced tests of these conclusions.

BackgroundContrary to previous findings, emerging studies support the increased likelihood of hazardous alcohol consumption in autistic adults when compared to neurotypical individuals. However, support services specifically for autistic people drinking hazardously are lacking. Examining the relationship of autistic features with alcohol consumption patterns longitudinally is essential to identify appropriate developmental points to offer support. MethodsWe investigated this using both phenotypic and genetic exposures measured in participants from the Avon Longitudinal Study of Parents and Children (ALSPAC). Our exposures included three measures of autistic traits (a broad autism phenotype measure, Social Communication Disorders Checklist score and polygenic score reflecting genetic liability for autism). Our outcome was alcohol consumption, measured across five timepoints between the ages of 17 to 28 years. We used multilevel piecewise linear spline analyses to model both the mean and 10th, 50th (median) and 90th quantiles of alcohol consumption longitudinally. ResultsThere was little evidence that genetic liability for autism influenced alcohol consumption. However, we found that individuals with higher autistic traits drank less at the mean and 10th, 50th (median) and 90th percentiles of alcohol consumption compared to those with lower autistic traits. We did not find evidence of a relationship between social communication differences and alcohol consumption at the mean, 10th and 50th (median) percentiles. Conversely, there was evidence to suggest that individuals with greater social communication differences drank more at the 90th percentile compared to those with fewer social communication differences. ConclusionOur findings indicate that social communication differences are associated with increased alcohol consumption in heavy drinkers, and that the relationship between autistic traits and alcohol consumption varies dependent on how traits are measured. This may explain the plurality of previous findings. Further research is needed to develop a more nuanced understanding of these associations across subpopulations of autistic traits and alcohol consumption.

BackgroundMethamphetamine addiction remains a significant public health concern, primarily affecting the central nervous system by disrupting dopamine and serotonin signaling. Epigenetic modifications, especially DNA methylation in the catechol-O-methyltransferase (COMT) and serotonin transporter (SLC6A4) genes, are implicated in addiction-related behavioral changes. While previous research has examined these genes, this study provides a novel perspective by analyzing methylation patterns in relation to aggression subtypes and methamphetamine use behaviors within a Middle Eastern cohort--an underrepresented population in addiction genetics. AimsTo investigate the genetic and epigenetic factors associated with methamphetamine addiction and aggression, with a specific focus on methylation profiles of the SLC6A4 and COMT genes. MethodsSixty male patients with methamphetamine addiction and aggression, and thirty age-matched healthy controls were enrolled. Peripheral blood samples were collected for RNA and DNA extraction. Methylation levels were assessed via bisulfite sequencing, and gene expression was evaluated using qRT-PCR. Behavioral data and substance use patterns were recorded through structured assessments. ResultsPatients showed significantly higher methylation levels in the SLC6A4 (63.29% vs. 7.84%, p = 0.0001) and COMT(50.98% vs. 19.77%, p = 0.0001) genes compared to controls. A strong correlation was observed between dopamine and methamphetamine levels (r = 0.846, p < 0.001). Methylation levels varied by aggression subtype and drug use frequency, suggesting epigenetic involvement in addiction severity and behavioral traits. ConclusionsThis study supports the role of SLC6A4 and COMT gene methylation in methamphetamine addiction and aggression. While causality cannot be inferred, the findings encourage further investigation into epigenetic biomarkers for behavioral risk profiling. Broader, longitudinal studies are needed to evaluate therapeutic potential and inform ethically sound applications in personalized addiction treatment.

Alcohol abuse and dependence have a substantial heritable component. Although the genome has been considered the sole vehicle of heritable phenotypes, recent studies suggest that drug or alcohol exposure may induce alterations in gene expression that are transmitted across generations. Still, the transgenerational impact of alcohol use (and abuse) remains largely unexplored in part because multigenerational studies using rodent models present challenges for time, sample size, and genetic heterogeneity. Here, we took advantage of the extremely short generation time, large broods, and clonal form of reproduction of the nematode Caenorhabditis elegans. We developed a model of preconception parental alcohol exposure to test alterations in behavioral responses to acute alcohol treatment (intoxication) in subsequent F1, F2 and F3 generations. We found that a chronic alcohol-treatment paradigm in the parental generation resulted in alcohol-naive F3 progeny displaying moderate resistance to intoxication. To compare the treatment duration and timing on this transgenerational effect, we repeated the study using an intermittent treatment paradigm. We found that intermittent treatment resulted in alcohol-naive F3 progeny displaying moderate hypersensitivity to intoxication. Further study of this phenomena using this new C. elegans model may yield mechanistic insights into how transgenerational effects may occur in other animals.

BackgroundAlcohol consumption may impact and shape brain development through perturbed biological pathways and impaired molecular functions. We investigated the relationship between alcohol consumption rates and neuron-enriched exosomal microRNA (miRNA) expression to better understand the impact of alcohol use on early life brain biology. MethodsNeuron-enriched exosomal miRNA expression was measured from plasma samples collected from young people using a commercially available microarray platform while alcohol consumption was measured using the Alcohol Use Disorders Identification Test. Linear regression and network analyses were used to identify significantly differentially expressed miRNAs and to characterize the implicated biological pathways, respectively. ResultsCompared to alcohol naive controls, young people reporting high alcohol consumption exhibited significantly higher expression of four neuron-enriched exosomal miRNAs including miR-30a-5p, miR-194-5p, and miR-339-3p, although only miR-30a-5p and miR-194-5p survived multiple test correction. The miRNA-miRNA interaction network inferred by a network inference algorithm did not detect any differentially expressed miRNAs with a high cutoff on edge scores. However, when the cutoff of the algorithm was reduced, five miRNAs were identified as interacting with miR-194-5p and miR-30a-5p. These seven miRNAs were associated with 25 biological functions; miR-194-5p was the most highly connected node and was highly correlated with the other miRNAs in this cluster. ConclusionsOur observed association between neuron-enriched exosomal miRNAs and alcohol consumption concurs with results from experimental animal models of alcohol use and suggests that high rates of alcohol consumption during the adolescent/young adult years may impact brain functioning and development by modulating miRNA expression.

RationaleIn humans, alcohol drinking is a significant driver of violent behaviors such as assaults and homicides. While acute intoxication is known to produce heightened aggression, little is known about alcohols long-term effects. Emerging evidence, however, suggests that chronic alcohol intake can promote heightened aggression, including during abstinence and may also sensitize individuals to alcohols acute aggression-heightening effects. ObjectivesThe goal of this study was to test the effects of chronic binge-like ethanol drinking on both alcohol-involved and alcohol-uninvolved aggression in male CFW mice. We aimed to model individual differences in binge drinking and assess changes in aggression during both acute and protracted abstinence. ResultsAfter 5 weeks of Drinking in the Dark (DID), CFW mice that showed higher levels of EtOH drinking ( high drinkers, 1.33 g/kg/h) became more aggressive than low drinkers (0.45 g/kg/h) and H2O controls, as measured via frequency of attack bites during resident-intruder fighting. In the first aggressive encounter following 1 week of abstinence, animals with an alcohol drinking history initiate a fight more rapidly and with greater consistency than H2O controls. We also found that a single session of binge-like alcohol drinking acutely heightened aggression regardless of drinking history. ConclusionsThese results suggest that repeated binge-like alcohol drinking causes escalations in alcohol-uninvolved aggression during acute (in high drinkers) and protracted abstinence (in all alcohol drinkers). However, chronic alcohol intake does not appear to sensitize animals to alcohol-involved aggression. These findings support the utility of genetically heterogeneous CFW mice for modeling individual variability in alcohol-related aggression.

Alcohol consumption continues to cause a significant health burden globally. The advent of genome-wide association studies has unraveled many genetic loci associated with alcohol consumption. However, the biological effect of these loci and the pathways involved in alcohol consumption and its health consequences such as alcohol liver disease (ALD) remain to be elucidated. We combined human studies with model organisms Drosophila melanogaster and Caenorhabditis elegans to shed light on the molecular mechanisms underlying alcohol consumption and the health outcomes caused by alcohol intake. Using genetics and metabolite data within the Airwave study, a sample of police forces in the UK, we performed several analyses to identify changes in circulating metabolites that are triggered by alcohol consumption. We selected a set of genes annotated to genetic variants that are (1) known to be implicated in alcohol consumption, (2) are linked to liver function, and (3) are associated with expression (cis-eQTL) of their annotated genes. We used mutations and/or RNA interference (RNAi) to suppress the expression of these genes in C. elegans and Drosophila. We examined the effect of this suppression on ethanol consumption and on the sedative effects of ethanol. We also investigated the alcohol-induced changes in triacylglycerol (TGA) levels in Drosophila and tested differences in locomotion of C. elegans after acute exposure to ethanol. In human population, we found an enrichment of the alcohol-associated metabolites within the linoleic acid (LNA) and alpha linolenic acid (ALA) metabolism pathway. We further showed the effect of ACTR1B and MAPT on locomotion in C. elegans after exposure to ethanol. We demonstrated that three genes namely WDPCP, TENM2 and GPN1 modify TAG levels in Drosophila. Finally, we showed that gene expression of WDPCP in human population is linked to liver fibrosis and liver cirrhosis. Our results underline the impact of alcohol consumption on metabolism of lipids and pinpoints WDPCP as a gene with potential impact on fat accumulation upon exposure to ethanol suggesting a possible pathway to ALD.

BackgroundVariation in genes involved in ethanol metabolism has been shown to influence risk for alcohol dependence (AD) including protective loss of function alleles in ethanol metabolizing genes. We therefore hypothesized that people with severe AD would exhibit different patterns of rare functional variation in genes with strong prior evidence for influencing ethanol metabolism and response when compared to genes not meeting these criteria. ObjectiveLeverage a novel case only design and Whole Exome Sequencing (WES) of severe AD cases from the island of Ireland to quantify differences in functional variation between genes associated with ethanol metabolism and/or response and their matched control genes. MethodsFirst, three sets of ethanol related genes were identified including those a) involved in alcohol metabolism in humans b) showing altered expression in mouse brain after alcohol exposure, and altering ethanol behavioral responses in invertebrate models. These genes of interest (GOI) sets were matched to control gene sets using multivariate hierarchical clustering of gene-level summary features from gnomAD. Using WES data from 190 individuals with severe AD, GOI were compared to matched control genes using logistic regression to detect aggregate differences in abundance of loss of function, missense, and synonymous variants, respectively. ResultsThree non-independent sets of 10, 117, and 359 genes were queried against control gene sets of 139, 1522, and 3360 matched genes, respectively. Significant differences were not detected in the number of functional variants in the primary set of ethanol-metabolizing genes. In both the mouse expression and invertebrate sets, we observed an increased number of synonymous variants in GOI over matched control genes. Post-hoc simulations showed the estimated effects sizes observed are unlikely to be under-estimated. ConclusionThe proposed method demonstrates a computationally viable and statistically appropriate approach for genetic analysis of case-only data for hypothesized gene sets supported by empirical evidence.

Ethanols anxiolytic actions contribute to increased consumption and the development of Alcohol Use Disorder (AUD). Our laboratory previously identified genetic loci contributing to the anxiolytic-like properties of ethanol in BXD recombinant inbred mice, derived from C57BL/6J (B6) and DBA/2J (D2) progenitor strains. That work identified Ninein (Nin) as a candidate gene underlying ethanols acute anxiolytic-like properties in BXD mice. Nin has a complex exonic content with known alternative splicing events that alter cellular distribution of the NIN protein. We hypothesize that strain-specific differences in Nin alternative splicing contribute to changes in Nin gene expression and B6/D2 strain differences in ethanol anxiolysis. Using quantitative reverse-transcriptase PCR to target Nin alternative splicing, we identified isoform-specific exon expression differences between B6 and D2 mice in prefrontal cortex, nucleus accumbens and amygdala. We extended this analysis using deep RNA sequencing in B6 and D2 nucleus accumbens samples and that Nin expression was significantly higher in D2 mice. Furthermore, exon utilization and alternative splicing analyses identified 8 differentially utilized exons and significant exon-skipping events between the strains, including 3 novel splicing events in the 3 end of the Nin gene that were specific to the D2 strain. Our studies provide the first in-depth analysis of Nin alternative splicing in brain and identify a potential genetic mechanism altering Nin expression between B6 and D2 mice, thus contributing to differences in the anxiolytic-like properties of ethanol between these strains. This work contributes to our understanding of genetic differences modulating ethanol actions on anxiety that may contribute to the risk for alcohol use disorder.

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.

The objective of this study was to compare the efficacy of a shorter (8 sessions) and longer (16 sessions) Dog-Assisted Therapy (DAT) program for children and adolescents with Fetal Alcohol Spectrum Disorder (FASD). We evaluated the impact of DAT on social skills, internalizing and externalizing problems, quality of life, severity of the disorder, and parental emotional well-being. A randomized controlled trial was conducted with 55 FASD patients, assigned to either the short (n = 24) or long (n = 31) DAT program. The longer DAT group showed significant reductions in externalizing symptoms (CBCL inattention; F = 4.676; p = 0.035; ES = 0.083) and greater improvements in social skills (SSIS-P Problem Behavior: F = 7.803, p = 0.007, ES = 0.13), lower FASD severity scores (CGI-S Clinician; F = 6.54, p = 0.014, ES = 0.014; CGI-S Parents: F = 4.938, p = 0.031; ES = 0.087), and enhanced quality of life (K-Screen Peers and Social: F = 4.38, p = 0.04, ES = 0.78) compared to the shorter program. Parents in the long DAT group also reported significant reductions in depressive symptoms (BDI-II; F = 14.03, p = 0.000, ES = 2.12). These findings suggest that both short- and long-duration DAT programs are effective, with longer programs offering additional benefits in specific domains. Clinical Trial RegistrationNCT06763614.

Prenatal alcohol exposure (PAE) affects embryonic development, leading to a variable fetal alcohol spectrum disorder (FASD) phenotype with neuronal and dysmorphological defects. To understand the etiology of FASD, we have established a cohort consisting of biological samples at birth and developmental information of prenatally alcohol-exposed and unexposed control children. To explore the phenotypic effects of PAE, we performed neuropsychological, neuropediatric, and dysmorphological assessments on the first 28 PAE children and 52 control children at the age of six. In the PAE group, 76% (19/25) of the children, who attended a full evaluation, met the criteria for FASD at this age. These diagnoses included five children with fetal alcohol syndrome (FAS), six with partial FAS, seven with alcohol-related neurodevelopmental disorder (ARND), and one with alcohol-related birth defect. In addition to characteristic features of FAS, including short palpebral fissure length, smooth philtrum, and thin vermilion (P<0.0001 for each), numerous other anomalies, such as mild midface hypoplasia (P<0.0001), were associated significantly with PAE. Unexpectedly, PAE was associated not only with underweight but also with an increased risk of overweight among six-year-olds, prominently among boys. Neurocognitive assessments indicated lower performance scores and a high prevalence of ADHD symptoms in PAE children compared to controls. Furthermore, additional PAE-associated phenotypic features, such as perturbations in adaptive and social functioning, somatic health issues, as well as reduced postural stability and lower performance in static balance tasks, were observed, which are not included in the diagnostic criteria of FASD. These findings underscore the complexity of FASD diagnosis and the importance of comprehensive phenotypic characterization to improve identification of FASD. This emphasizes the significance of the chosen diagnostic method and may leave some of the tested children without a diagnosis needed for developmental support. Interestingly, early alcohol exposure, up to the seventh gestational week, resulted in similar rates of dysmorphic features and cognitive scores compared to the longer exposure group. These results, along with several ARND diagnoses in the early PAE group, emphasize the vulnerability of early pregnancy to alcohol exposure, particularly the sensitivity of the nervous system. This is also consistent with the guidelines recommending the use of contraception when consuming alcohol and advising individuals to stop drinking alcohol when planning a pregnancy.

Prenatal exposure to alcohol or cannabinoids can produce enduring neurobiological, cognitive, and behavioral changes in the offspring. Furthermore, prenatal co-exposure to alcohol and cannabinoids induces malformations in brain regions associated with reward and stress-related circuitry. This study examined the effects of co-exposure to alcohol and the synthetic cannabinoid (SCB) CP55,940 throughout gastrulation and neurulation in rats on basal corticosterone levels and a battery of behavioral tests during adolescence and alcohol self-administration in adulthood. Importantly, we find that prenatal alcohol exposure (PAE) caused lower baseline corticosterone levels in adolescent males and females. Co-exposure to alcohol + CP produced hyperactivity during open field test in males, but not females. During the two-bottle choice alcohol-drinking procedure, prenatal cannabinoid exposed male and female adolescent rats drank more alcohol than their vehicle-exposed controls. In adulthood, female rats treated with prenatal cannabinoid exposure (PCE), showed an overall total increase in alcohol intake during alcohol self-administration; but this was not found in males. When the reinforcer was changed to a 1% sucrose solution, male rats exposed to PCE, showed a reduced self-administration compared to vehicle-exposed males, potentially indicative of an anhedonic response. This lower self-administration persisted when 20% alcohol was reintroduced to the sucrose solution. Lastly, following an abstinence period, there were no changes due to prenatal drug exposure in either males or females. Overall, these data suggest lasting consequences of prenatal alcohol and cannabinoid exposure during adolescence and adulthood in male and female rats.

BackgroundSex differences in ethanol consumption have been reported in both humans and laboratory rodents, but the independent/dependent contributions of genetic and hormonal sex{square}biasing mechanisms to these phenotypes have not yet been fully explored. MethodsTo examine the contributions of sex-chromosome complement (SCC) and gonadal sex (GS) to ethanol consumption, we studied adolescent (28-32 days old) four core genotypes (FCG) mice (C57BL/6J background; FCG model allows for independent assortment of GS and SCC) using a modified drinking-in-the-dark (DID) procedure. Mice were offered concurrent access to 20%, 10% and 0% ethanol (in water) in four daily 2-hour sessions. Consumption at the level of individual bouts was recorded. ResultsAlthough all four genotype groups preferred the 20% ethanol over 10% and 0%, and showed similar consumption of the 10% and 0% solutions, the group rankings for consumption of the 20% ethanol solution were XX+testes > XY+testes > XY+ovaries > XX+ovaries. Thus, an interaction was observed between SCC and GS for which the simple effect of SCC was greatest in mice with ovaries (XY > XX) and the simple effect of GS was greatest in XX mice (testes > ovaries). Moreover, these effects varied in magnitude across and within drinking sessions. The behavioral microstructure of ethanol consumption (i.e., parameterization of within-session discriminable drinking bouts) support the validity of our 3-bottle modification of the DID procedure as a model of binge-like consumption as: (1) the consumption rate of the 20% ethanol solution was ~80 g EtOH/kg/h within a bout (~12 s/bout, ~3 bouts/session), (2) most of this ethanol consumption was completed in a single bout and (3) within-session ethanol consumption was greater earlier than later, indicating "front loading." ConclusionsThese results indicate that SCC and GS interact on ethanol consumption in adolescent FCG mice on a C57BL/6J background to affect binge-like consumption from the very initiation of access and that these effects are dynamic as they varied both across and within sessions. HighlightsO_LIGonadal sex and sex-chromosome complement interact on ethanol consumption in adolescent four core genotypes mice C_LIO_LIIn adolescent four core genotypes mice, mice with testes drink more ethanol than mice with ovaries, particularly in the presence of an XX karyotype C_LIO_LIIn adolescent four core genotypes mice, XY mice drink more ethanol than XX mice, but only in mice with ovaries C_LIO_LIThe effects of sex-biasing biological factors on the patterns of ethanol consumption by adolescent four core genotypes mice that we observed in our 3-bottle Drinking-in-the-Dark procedure showed face validity with some of the sex/gender differences observed in human adolescents C_LI

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.

Structured abstractO_ST_ABSBackgroundC_ST_ABSEven at lower doses, ethanol exposure impacts both the brain and behavior. Emerging work has shown that chronic exposure to lower doses of ethanol may lead to inflexible behaviors and promote aberrant reward seeking. This study investigated the impact of chronic, low-dose ethanol exposure on neural substrates of reward and on motivated behavior. MethodsAdult C57BL/6J mice were trained to self-administer sucrose. Throughout training, mice received an injection of low-dose ethanol (0.5g/kg) or saline, 1 hour after each session. Mice did not receive ethanol during testing. Mice were then tested in a PR task in which the reward magnitude of reinforcer was reduced (small or large) or increased (small or large). A subset of mice expressed a retrograde tracer in the nucleus accumbens (NAc), and cFos expression within NAc circuits was analyzed following a sucrose self-administration session. ResultsChronic low-dose ethanol exposure altered behavioral responding in female mice following small changes in reward magnitude. Female mice showed divergent response patterns when there was a small reduction in reward magnitude, with greater proportions of ethanol-exposed female mice either increasing or decreasing responding versus controls. Following a small increase, low-dose ethanol female mice significantly increased responding versus controls. Female - but not male - mice exposed to chronic low-dose ethanol shifted behavioral strategy with a reduction in magazine checking behavior. Low-dose ethanol exposure altered cFos expression within the prelimbic cortex and its projections to the NAc during reward seeking. ConclusionsChronic, low-dose ethanol altered behavioral responding and strategy in female mice in response to changes in reward value. Low-dose ethanol exposure impacted cFos induction in prelimbic cortex and its projections to NAc in both female and male mice. Future studies should investigate the consequences of chronic, low-dose ethanol on the brain and behavior to understand what underlying processes drive aberrant reward-seeking behaviors.

Alcohol use disorder (AUD) commonly co-occurs with posttraumatic stress disorder (PTSD), and comorbid PTSD and AUD is associated with poorer outcomes including worse treatment outcomes and significant physical health consequences. Both PTSD and AUD are polygenic in nature and genetically overlap. Previous work showed negative or non-significant associations between PTSD and alcohol consumption but positive genetic associations between PTSD and AUD. This work highlights the need for more nuanced examination of the similarities and distinctions in the associations between PTSD and alcohol consumption versus AUD. We leveraged the latest large-scale GWAS data to perform a multivariate GWAS of alcohol consumption (ALCC), problematic alcohol use (ALCP), and PTSD using GenomicSEM. Partial genetic correlations revealed that ALCP and PTSD were associated with each other (rG=0.39, p = 4.38x10-60) and with other psychiatric problems, medical conditions, and pain, while ALCC was generally only weakly correlated with PTSD (rG=-0.08, p = 2.03x10-4) and uncorrelated with most traits after accounting for its genetic overlap with ALCP and PTSD. We examined associations between GenomicSEM-derived polygenic scores (PGS) and their corresponding phenotypes in participants from the Collaborative Study on the Genetics of Alcoholism (COGA). PGS for ALCC were unrelated to PTSD diagnosis and PGS for PTSD were unrelated to drinks in a typical week. PTSD is more strongly related to alcohol problems, and much of the overlap in PTSD and consumption is accounted for by its overlap with alcohol problems. These results help demonstrate the complex partial overlaps of PTSD, AUD, and alcohol consumption.

Background & AimsEthanol affects lipid metabolism through multiple pathways, leading to fatty liver development in most ALD patients. Recent studies have highlighted the role of calpain, a calcium-dependent protease, in liver inflammation and fibrosis. Calpain activity is regulated by its essential subunit, Capns1, (calpain-4, Capn4), which stabilizes and modulates the activity of its catalytic isoforms, calpain-1 and calpain-2. This study investigated calpains impact on lipid metabolism in ALD. Approach & ResultsSix-week-old C57Bl6/J mice were injected with rAAV8 vectors encoding Capn4 shRNA or control vectors. After four weeks, mice underwent a 10-day period of ad libitum ethanol consumption, followed by a single gavaged ethanol administration on day 11. Following Capn4 knockdown, microvesicular steatosis was attenuated. While triglycerides and free fatty acids levels showed no significant changes, cholesterol levels were significantly reduced in the ethanol (EtOH) group with Capn4 knockdown. Cpt1a expression increased significantly in the EtOH group with Capn4 knockdown. Western blot analysis revealed increased Cleaved-HMGCR to Pro-HMGCR ratio in Capn4 knockdown mice, suggesting reduced HMGCR activity and suppressed cholesterol biosynthesis. LXR expression was mainly increased in the cytoplasm in the EtOH group, and following Capn4 knockdown, it was relocalized to the nucleus via its activation. In addition, RNA sequencing analysis suggests that Capn4 knockdown contributes to the reprogramming of ethanol-induced disruptions in metabolic and homeostatic pathways, primarily those involving cholesterol metabolism. ConclusionsFurther investigation into the relationship between Capn4 and cholesterol biosynthesis proteins may provide insights into using calpain inhibitors as a therapeutic approach for alcohol-related hepatitis.