Ethanol Preference Research Articles

Microviridae bacteriophages influence behavioural hallmarks of food addiction via tryptophan and tyrosine signalling pathways.

Food addiction contributes to the obesity pandemic, but the connection between how the gut microbiome is linked to food addiction remains largely unclear. Here we show that Microviridae bacteriophages, particularly Gokushovirus WZ-2015a, are associated with food addiction and obesity across multiple human cohorts. Further analyses reveal that food addiction and Gokushovirus are linked to serotonin and dopamine metabolism. Mice receiving faecal microbiota and viral transplantation from human donors with the highest Gokushovirus load exhibit increased food addiction along with changes in tryptophan, serotonin and dopamine metabolism in different regions of the brain, together with alterations in dopamine receptors. Mechanistically, targeted tryptophan analysis shows lower anthranilic acid (AA) concentrations associated with Gokushovirus. AA supplementation in mice decreases food addiction and alters pathways related to the cycle of neurotransmitter synthesis release. In Drosophila, AA regulates feeding behaviour and addiction-like ethanol preference. In summary, this study proposes that bacteriophages in the gut microbiome contribute to regulating food addiction by modulating tryptophan and tyrosine metabolism.

Purmorphamine Alters Anxiety-Like Behavior and Expression of Hedgehog Cascade Components in Rat Brain after Alcohol Withdrawal.

Disturbances in the Hedgehog(Hh) signaling play an important role in dysmorphogenesis of bone tissue and central nervous system during prenatal alcohol exposure, which underlies development of fetal alcohol syndrome. The involvement of Hh proteins in the mechanisms of alcohol intake in adults remains obscure. We investigated the role of the Hh cascade in voluntary ethanol drinking and development of anxiety-like behavior (ALB) during early abstinence and assessed changes in the expression of Hh pathway components in different brain regions of male Wistar rats in a model of voluntary alcohol drinking using the intermittent access to 20% ethanol in a two-bottle choice procedure. Purmorphamine (Hh cascade activator and Smoothened receptor agonist) was administered intraperitoneally at a dose of 5mg/kg body weight prior to 16-20 sessions of alcohol access. Purmorphamine had no effect on the ethanol preference; however, rats exposed to ethanol and receiving purmorphamine demonstrated changes in the ALB during the early abstinence period. Alcohol drinking affected the content of the Sonic hedgehog(Shh) and Patched mRNAs only in the amygdala. In rats exposed to ethanol and receiving purmorphamine, the level of Shh mRNA in the amygdala correlated negatively with the time spent in the open arms of the elevated plus maze. Therefore, we demonstrated for the first time that alterations in the Hh cascade induced by administration of purmorphamine did not affect alcohol preference in voluntary alcohol drinking. It was suggested that Hh cascade is involved in the development of anxiety after alcohol withdrawal through specific changes in the Hh cascade components in the amygdala.

Adaptations in glutathione-based redox protein signaling pathways and alcohol drinking across species

Alcohol use disorder (AUD) is the most prevalent substance use disorder but there is incomplete knowledge of the underlying molecular etiology. Here, we examined the cytosolic proteome from the nucleus accumbens core (NAcC) of ethanol drinking rhesus macaques to identify ethanol-sensitive signaling proteins. The targets were subsequently investigated using bioinformatics, genetic, and pharmacological manipulations in mouse models of ethanol drinking. Of the 1000+ cytosolic proteins identified in our screen, 50 proteins differed significantly between control and ethanol drinking macaques. Gene Ontology analysis of the differentially expressed proteins identified enrichment in pathways regulating metabolic processes and proteasome activity. Because the family of Glutathione S-transferases (GSTs) was enriched in these pathways, validation studies targeted GSTs using bioinformatics and genetically diverse mouse models. Gstp1 and Gstm2 were identified in Quantitative Trait Loci and published gene sets for ethanol-related phenotypes (e.g., ethanol preference, conditioned taste aversion, differential expression), and recombinant inbred strains that inherited the C57BL/6J allele at the Gstp2 interval consumed higher amounts of ethanol than those that inherited the DBA/2J allele. Genetic deletion of Gstp1/2 led to increased ethanol consumption without altering ethanol metabolism or sucrose preference. Administration of the pharmacologic activator of Gstp1/2, carnosic acid, decreased voluntary ethanol drinking. Proteomic analysis of the NAcC cytosolic of heavy drinking macaques that were validated in mouse models indicate a role for glutathione-mediated redox regulation in ethanol-related neurobiology and the potential of pharmacological interventions targeting this system to modify excessive ethanol drinking.

A Novel Mouse Home Cage Lickometer System Reveals Sex- and Housing-Based Influences on Alcohol Drinking.

Alcohol use disorder (AUD) is a significant global health issue. Despite historically higher rates among men, AUD prevalence and negative alcohol-related outcomes in women are rising. Loneliness in humans has been associated with increased alcohol use, and traditional rodent drinking models involve single housing, presenting challenges for studying social enrichment. We developed LIQ PARTI (Lick Instance Quantifier with Poly-Animal RFID Tracking Integration), an open-source tool to examine home cage continuous access two-bottle choice drinking behavior in a group-housed setting, investigating the influence of sex and social isolation on ethanol consumption and bout microstructure in C57Bl/6J mice. LIQ PARTI, based on our previously developed single-housed LIQ HD system, accurately tracks drinking behavior using capacitive-based sensors and RFID technology. Group-housed female mice exhibited higher ethanol preference than males, while males displayed a unique undulating pattern of ethanol preference linked to cage changes, suggesting a potential stress or novelty-related response. Chronic ethanol intake distinctly altered bout microstructure between male and female mice, highlighting sex and social environmental influences on drinking behavior. Social isolation with the LIQ HD system amplified fluid intake and ethanol preference in both sexes, accompanied by sex- and fluid-dependent changes in bout microstructure. However, these effects largely reversed upon resocialization, indicating the plasticity of these behaviors in response to social context. Utilizing a novel group-housed home cage lickometer device, our findings illustrate the critical interplay of sex and housing conditions in voluntary alcohol drinking behaviors in C57Bl/6J mice, facilitating nuanced insights into the potential contributions to AUD etiology.

Neuromedin U Neurons in the Edinger–Westphal Nucleus Respond to Alcohol Without Interfering with the Urocortin 1 Response

The Edinger–Westphal nucleus (EW) is a midbrain nucleus composed of a preganglionic, cholinergic subpopulation and a densely clustered peptidergic subpopulation (EWcp). The EWcp is one of the few brain regions that show consistent induction of FOS following voluntary alcohol intake. Previous results in rodents point to urocortin 1 (UCN1) as one of the peptides most involved in the control of ethanol intake and preference. Notably, the functions described for UCN1, such as reward processing, stress coping or the regulation of feeding behavior are similar to those described for the neuropeptide neuromedin U (NMU). Interestingly, NMU has been recently associated with the modulation of alcohol-related behaviors. However, little is known about the expression and functionality of NMU neurons in alcohol-responsive areas. In this study, we used the recently developed Nmu-Cre knock-in mouse model to examine the expression of NMU in the subaqueductal paramedian zone comprising the EWcp. We delved into the characterization and co-expression of NMU with other markers already described in the EWcp. Moreover, using FOS as a marker of neuronal activity, we tested whether NMU neurons were sensitive to acute alcohol administration. Overall, we provided novel insights on NMU expression and functionality in the EW region. We showed the presence of NMU within a subpopulation of UCN1 neurons in the EWcp and demonstrated that this partial co-expression does not interfere with the responsivity of UCN1-containing cells to alcohol. Moreover, we proposed that the UCN1 content in these neurons may be influenced by sex.

Sex-Specific Impacts of Early Life Sleep Disruption: Ethanol Seeking, Social Interaction, and Anxiety Are Differentially Altered in Adolescent Prairie Voles.

Early life sleep is important for neuronal development. Using the highly social prairie vole rodent model, we have previously reported that early life sleep disruption (ELSD) during the preweaning period results in interference with social bonding and increases ethanol consumption following a stressor in adulthood. Furthermore, ELSD increases parvalbumin expression and reduces glutamatergic neurotransmission in cortical regions in adult prairie voles. To understand the impact of ELSD on the lifespan, an examination of an earlier time in life is necessary. The aim of the present study was to examine behavioral outcomes of ELSD on adolescent prairie voles. Given the known effects of ELSD on development of neuronal systems involved in mood and social motivation, we hypothesized that anxiety, risk, and reward-related behaviors would be impacted by ELSD in adolescent prairie voles. We report that both male and female adolescent prairie voles that experienced ELSD showed heightened anxiety-like behavior compared to age-matched controls (CONs) as measured by a light-dark box. Additionally, both male and female ELSD voles showed reductions in both ethanol preference and consumption, and affiliative behavior compared to CONs. These results suggest that adolescent prairie voles of both sexes experience heightened anxiety-like behavior and reduced reward-seeking behaviors after ELSD. These results further suggest that early life sleep is critically important for neurotypical behaviors in adolescence.

Anxiety and risk-taking behavior maps onto opioid and alcohol polysubstance consumption patterns in male and female mice.

Polysubstance use is prevalent in the population but remains understudied in preclinical models. Alcohol and opioid polysubstance use is associated with negative outcomes, worse treatment prognosis, and higher overdose risk; but underlying mechanisms are still being uncovered. Examining factors that motivate use of one substance over another in different contexts in preclinical models will better our understanding of polysubstance use and improve translational value. Here we assessed baseline anxiety-like and locomotive behavior and then measured voluntary consumption of multiple doses of alcohol and fentanyl in group housed male and female mice using our novel Socially Integrated Polysubstance (SIP) system. Fifty-six male (n=32) and female (n=24) adult mice were housed in groups of 4 for one week with continuous access to food, water, two doses of ethanol (5% and 10%) and two doses of fentanyl (5 ug/ml and 20 ug/ml). Our analyses revealed sex differences across multiple domains - female mice consumed more liquid in the dark cycle, had higher activity, a higher preference for both ethanol and fentanyl over water, and their fentanyl preference increased over the seven days. We then used machine-learning techniques to reveal underlying relationships between baseline behavioral phenotypes and subsequent polysubstance consumption patterns, where anxiety-and risk-taking-like behavioral phenotypes mapped onto discrete patterns of polysubstance use, preference, and escalation. By simulating more translationally relevant substance use and improving our understanding of the motivations for different patterns of consumption, this study contributes to the developing preclinical literature on polysubstance use with the goal of facilitating better treatment outcomes and novel therapeutic strategies.

Effects of voluntary chronic intermittent access to ethanol on the behavioral performance in adult C57BL/6 J mice

BackgroundChronic alcohol drinking increases the risk of alcohol use disorders, causing various neurological disorders. However, the impact of different ethanol levels on a spectrum of behaviors during chronic drinking remains unclear. In this study, we established an intermittent access to ethanol in a two-bottle choice (IA2BC) procedure to explore the dose-dependent effects of ethanol on the behavioral performance of C57BL/6 J mice. MethodsAdult male C57BL/6 J mice were provided voluntary access to different ethanol concentrations (0 %, 5 %, 10 %, and 20 % ethanol) under a 12-week IA2BC paradigm. A battery of behavioral tests was administered to assess alterations in pain threshold, anxiety-like behaviors, locomotor activity, motor coordination, and cognition. Ethanol consumption and preference were monitored during each session. Moreover, the liver, heart, and lung tissues were examined using pathological microscopy. ResultsThe average (standard deviation) ethanol consumption of mice under the IA2BC paradigm increased dose-dependently to 5.1 (0.2), 8.7 (0.7), and 15.9 (0.8) g/kg/24 h with 5 %, 10 %, and 20 % ethanol, respectively. However, there is no significant difference in ethanol preference among all the ethanol groups. Chronic ethanol drinking caused hyperalgesia, cognitive impairment, and motor incoordination, but caused no changes in body temperature, locomotor activity, or anxiety-like behaviors. Minor histopathological alterations in the liver were detected; however, no major abnormal pathology was observed in the heart or lungs. ConclusionThese findings clarify the link between ethanol dosage and behavioral changes in mice over a 12-week IA2BC paradigm, thereby bridging the knowledge gap regarding the effects of chronic ethanol drinking on neurological disorders.

JNK Signaling Positively Regulates Acute Ethanol Tolerance in C. elegans.

Alcohol use disorder (AUD) is a chronic neurobehavioral condition characterized by a cycle of tolerance development, increased consumption, and reinstated craving and seeking behaviors during withdrawal. Understanding the intricate mechanisms of AUD necessitates reliable animal models reflecting its key features. Caenorhabditis elegans (C. elegans), with its conserved nervous system and genetic tractability, has emerged as a valuable model organism to study AUD. Here, we employ an ethanol vapor exposure model in Caenorhabditis elegans, recapitulating AUD features while maintaining high-throughput scalability. We demonstrate that ethanol vapor exposure induces intoxication-like behaviors, acute tolerance, and ethanol preference, akin to mammalian AUD traits. Leveraging this model, we elucidate the conserved role of c-jun N-terminal kinase (JNK) signaling in mediating acute ethanol tolerance. Mutants lacking JNK signaling components exhibit impaired tolerance development, highlighting JNK's positive regulation. Furthermore, we detect ethanol-induced JNK activation in C. elegans. Our findings underscore the utility of C. elegans with ethanol vapor exposure for studying AUD and offer novel insights into the molecular mechanisms underlying acute ethanol tolerance through JNK signaling.

Effects of social housing on alcohol intake in mice depend on the non-social environment.

Excessive alcohol consumption leads to serious health problems. Mechanisms regulating the consumption of alcohol are insufficiently understood. Previous preclinical studies suggested that non-social environmental and social environmental complexities can regulate alcohol consumption in opposite directions. However, previous studies did not include all conditions and/or did not include female rodents. Therefore, in this study, we examined the effects of social versus single housing in standard versus non-standard housing conditions in male and female mice. Adult C57BL/6 J mice were housed in either standard shoebox cages or in automated Herdsman 2 (HM2) cages and exposed to a two-bottle choice procedure with 3% or 6% ethanol versus water for 5 days. The HM2 cages use radiotracking devices to measure the fluid consumption of individual mice in an undisturbed and automated manner. In both housing conditions, mice were housed either at one or at four per cage. In standard cages, group housing of animals decreased alcohol consumption and water consumption. In HM2 cages, group housing significantly increased ethanol preference and decreased water intake. There were no significant differences in these effects between male and female animals. These observations were similar for 3 and 6% ethanol solutions but were more pronounced for the latter. The effects of social environment on ethanol preference in HM2 cages were accompanied by an increase in the number of approaches to the ethanol solution and a decrease in the number of approaches to water. The differences in ethanol intake could not be explained by differences in locomotor or exploratory activity as socially housed mice showed fewer non-consummatory visits to the ethanol solutions than single-housed animals. In addition, we observed that significant changes in behaviors measuring the approach to the fluid were not always accompanied by significant changes in fluid consumption, and vice versa, suggesting that it is important to assess both measures of motivation to consume alcohol. Our results indicate that the direction of the effects of social environment on alcohol intake in mice depends on the non-social housing environment. Understanding mechanisms by which social and non-social housing conditions modulate alcohol intake could suggest approaches to counteract environmental factors enhancing hazardous alcohol consumption.

Environmental enrichment enhances ethanol preference over social reward in male swiss mice: Involvement of oxytocin-dopamine interactions

The impact of environmental enrichment (EE) on natural rewards, including social and appetitive rewards, was investigated in male Swiss mice. EE, known for providing animals with various stimuli, was assessed for its effects on conditioned place preference (CPP) associated with ethanol and social stimuli. We previously demonstrated that EE increased the levels of the prosocial neuropeptide oxytocin (OT) in the hypothalamus and enhanced ethanol rewarding effects via an oxytocinergic mechanism. This study also investigated the impact of EE on social dominance and motivation for rewards, measured OT-mediated phospholipase C (PLC) activity in striatal membranes, and assessed OT expression in the hypothalamus. The role of dopamine in motivating rewards was considered, along with the interaction between OT and D1 receptors (DR) in the nucleus accumbens (NAc). Results showed that EE mice exhibited a preference for ethanol reward over social reward, a pattern replicated by the OT analogue Carbetocin. EE mice demonstrated increased social dominance and reduced motivation for appetitive taste stimuli. Higher OT mRNA levels in the hypothalamus were followed by diminished OT receptor (OTR) signaling activity in the striatum of EE mice. Additionally, EE mice displayed elevated D1R expression, which was attenuated by the OTR antagonist (L-368-889). The findings underscore the reinforcing effect of EE on ethanol and social rewards through an oxytocinergic mechanism. Nonetheless, they suggest that mechanisms other than the prosocial effect of EE may contribute to the ethanol pro-rewarding effect of EE and Carbetocin. They also point towards an OT-dopamine interaction potentially underlying some of these effects.

Sugar consumption induces the consummatory suppression of sugary ethanol: Differential effects of sugar restriction according to sex and age

Sweet foods activate the reward system that is essential in processing natural reinforcers. Maturation changes in this system during adolescence are linked to heightened impulsivity and risk-seeking behavior, including the use of drugs like ethanol. This usually starts with the consumption of sugary mixtures. However, the influence of sugar exposure on ethanol consumption remains inconclusive. The present research examines the effect of long-term sugar exposure on sugary ethanol (S-EtOH) preference and net intake, exploring the implications of sex, age, accessor restriction of sugar, and its effect during the transition into adulthood. Wistar rats of both sexes were given 24-hour access to a sugar solution for 21 days during adolescence or adulthood. Subsequently, four preference tests of S-EtOH vs. water were carried out every other day, with or without sugar access between each preference test. Our results demonstrate that continuous acute and long-term sugar access induces a consummatory suppression effect on S-EtOH intake, particularly in adult rats, irrespective of sex. This effect becomes more pronounced with more extended periods of exposure to sugar, leading to a higher prevalence of low consumers. Notably, when sugar access was restricted after high familiarization, the suppression effect in adolescent male rats was reduced. Under these conditions, the rats appeared to be more susceptible to developing a preference for S-EtOH consumption. Furthermore, our longitudinal observations reveal that sugar access or restriction conditions during the transition from adolescence to adulthood play a crucial role in shaping S-EtOH consumption patterns in adulthood.

Early-life inflammation increases ethanol consumption in adolescent male mice

Recent studies have demonstrated that stress during the critical windows of development can evoke a cascade of neurological changes that can result in neuropsychiatric disorders later in life. In this study, we examined the effect of early-life inflammation on ethanol consumption in adolescent mice. C57BL/6J mice were assigned to either the control or Lipopolysaccharide (LPS) group on postnatal day 14 (P14). In the latter group, LPS at a dose of 50 μg/kg was injected intraperitoneally. The mice were weaned at P21, and behavior tests were performed at P45. Ethanol consumption was assessed using a two-bottle choice drinking paradigm. Anxiety-like behaviors were assessed by marble burying test (MBT), open field (OF), and elevated plus maze (EPM). Ethanol-induced loss of righting reflex (LORR), hypothermia and ethanol metabolism were assessed to evaluate ethanol intoxication. P14 LPS-injected adolescent male mice exhibited significantly increased ethanol preference and consumption, with a similar taste preference for saccharin and avoidance of quinine. The adolescent male mice showed increased anxiety-like behaviors in the OF and EPM tests, and an increased duration of LORR, without affecting the hypothermic effects of ethanol and ethanol metabolism. Interestingly, these behavioral changes were not obvious in female mice. In conclusion, our data indicate that early-life inflammation may be a risk factor for ethanol consumption in adolescents with greater changes observed in male mice. Significance StatementOur study is the first preclinical model to report the enhancement effect of early-life inflammation on ethanol consumption in adolescent male mice and our findings provide a valuable mouse model to examine the neurobiological mechanisms mediating the long-lasting effects of early-life inflammation on alcohol use disorders vulnerability.

Bitter taste function-related genes are implicated in the behavioral association between taste preference and ethanol preference in male mice

Alcohol use disorder in humans is highly heritable, and as a term is synonymous with alcoholism, alcohol dependence, and alcohol addiction. Defined by the NIAAA as a medical condition characterized by an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences, the genetic basis of alcohol dependence is much studied. However, an intriguing component to alcohol acceptance exists outside of genetics or social factors. In fact, mice of identical genetic backgrounds without any prior experience of tasting ethanol display widely varying preferences to it, far beyond those seen for typical taste solutions. Here, we hypothesized that a preference for ethanol, which tastes both bitter and sweet to humans, would be influenced by taste function. Using a mouse model of taste behavior, we tested preferences for bitter and sweet in mice that, without training or previous experience, either preferred or avoided ethanol solutions in consumption trials. Data showed clear sex differences, in which male mice that preferred ethanol also preferred a bitter quinine solution, whereas female mice that preferred ethanol also preferred a sweet sucralose solution. Male mice preferring ethanol also exhibited lower expression levels of mRNA for genes encoding the bitter taste receptors T2R26 and T2R37, and the bitter transducing G-protein subunit GNAT3, suggesting that the higher ethanol preference observed in the male mice may be due to bitter signaling, including that arising from ethanol, being weaker in this group. Results further support links between ethanol consumption and taste response, and may be relevant to substance abuse issues in human populations.

Sex-dependent effects of chronic intermittent ethanol treatment in Wistar rats

Multiple behavioral parameters are associated with vulnerability to alcohol dependence, but the contribution of such factors as cognitive flexibility and sex differences still require further clarification. Our goal was to assess how sex differences mediate relationships between cognitive flexibility, affective state, hierarchy and ethanol preference before and after chronic intermittent ethanol (CIE) exposure in Wistar rats. The results of our study revealed sex-dependent changes in ethanol preference and locomotor activity throughout the time. Anxiety levels were sex-dependently affected by ethanol exposure with a dramatic decrease in ethanol-exposed females. Similarly, striatal tyrosine hydroxylase expression was affected by CIE in a sex-dependent manner, with ethanol-exposed females having higher expression than males. Baseline cognitive flexibility was better in rats with higher locomotor activity and lower anxiety levels but did not correlate with ethanol preference in rats. Taken together, these results are important for understanding sex-dependent alterations in brain and behavior induced by alcohol. This provides important insights into understanding sex differences in the risk for mental disorders.

Gestational environmental enrichment prevents chronic social stress induced anxiety- and ethanol-related behaviors in offspring

Epidemiological surveys have shown a strong relationship between maternal stress and offspring's mood disorders. Growing evidence suggested that environmental enrichment (EE) improves cognitive function in models of psychiatric and neurological disorders. However, the potential protective effects of gestational EE on social stress-elicited mood disorders in offspring have not been studied. Knowing that the undeveloped brain is more sensitive to gestational environmental stimuli, we hypothesized that initiating cognitive stimulation, during gestation, would protect against social stress-induced behavioral alterations in adulthood. Therefore, the present study aimed to investigate the effects of gestational EE on social stress-elicited anxiety- and ethanol-related behaviors in adult offspring. EE consisted of free access, of dams, to tubular devices of different shapes, colors, and sizes that were changed regularly. After birth and weaning, young adult offspring were exposed to 19 days of social stress and anxiety-like behavior was evaluated by elevated plus maze, open field, and marbles burying tests. The two-bottle choice (TBC) drinking paradigm was used to assess stress-induced ethanol intake. Results showed that gestational EE prevented social stress-elicited anxiogenic-like effects with no differences in spontaneous locomotor activity. Moreover, in the TBC paradigm, mice pre-exposed to EE consistently showed a significantly decreased consumption and preference for ethanol with no effects on tastants' intakes. Interestingly, gestational EE increased serum BDNF levels, which showed a correlation with measures of anxiety- and ethanol-related behaviors. These findings indicate that some neurodevelopmental changes associated with prenatal EE may counteract adult social stress-induced behavioral alterations through a BDNF mechanism. Therefore, we propose that gestational EE has significant protective and beneficial effects on social stress-induced cognitive impairment. It can also alleviate anxiety-like behavior and subsequent excessive alcohol consumption.

Sexually dimorphic effects of a modified adolescent social isolation paradigm on behavioral risk factors of alcohol use disorder in Long Evans Rats

Early life stress (ELS) is a major risk factor for alcohol use disorder (AUD) and comorbid neuropsychiatric conditions. We previously demonstrated that an adolescent social isolation (aSI) model of ELS significantly increased behavioral risk factors for these disorders (e.g. anxiety-like behaviors, alcohol drinking) in male, but not female rats. Since many neurodevelopmental milestones are accelerated in females, we investigated whether an earlier/shorter isolation window (PND 21-38) would yield comparable phenotypes in both sexes. In two experiments, Long Evans rats were socially isolated (SI) or group-housed (GH) on postnatal day (PND) 21 and locomotion was assessed in the open field test (OFT; PND 30). Experiment 1 also assessed behavior on the elevated plus-maze (EPM) (PND 32). In Experiment 2, all rats were single housed on PND 38 to assess home cage alcohol drinking. Experiment 1 revealed that SI females had increased locomotor activity in the OFT but did not differ from GH subjects on the EPM. The OFT results were replicated in both sexes in Experiment 2 and both male and female SI rats had significantly greater ethanol consumption during an eight day continuous access paradigm. In contrast, during subsequent intermittent two-bottle choice drinking, only SI females displayed greater ethanol intake and preference and increased consumption of a quinine-adulterated alcohol solution. These findings demonstrate that early life social isolation can promote AUD vulnerability-related phenotypes in female rats but that there are profound sex differences in the vulnerability window to this early life stressor. Uncovering the neural mechanisms responsible for these sexually dimorphic differences in sensitivity to ELS may shed light on the biological substrates associated with vulnerability to AUD and comorbid disorders of negative emotion in men and women.

Huntingtin Plays a Role in the Physiological Response to Ethanol in Drosophila.

Huntingtin (htt) protein is an essential regulator of nervous system function through its various neuroprotective and pro-survival functions, and loss of wild-type htt function is implicated in the etiology of Huntington's disease. While its pathological role is typically understood as a toxic gain-of-function, some neuronal phenotypes also result from htt loss. Therefore, it is important to understand possible roles for htt in other physiological circumstances. To elucidate the role of htt in the context of ethanol exposure, we investigated how loss of htt impacts behavioral and physiological responses to ethanol in Drosophila. We tested flies lacking htt for ethanol sensitivity and tolerance, preference for ethanol using capillary feeder assays, and recovery of mobility after intoxication. Levels of dopamine neurotransmitter and numbers of dopaminergic cells in brains lacking dhtt were also measured. We found that dhtt-null flies are both less sensitive and more tolerant to ethanol exposure in adulthood. Moreover, flies lacking dhtt are more averse to alcohol than controls, and they recover mobility faster following acute ethanol intoxication. We showed that dhtt mediates these effects at least in part through the dopaminergic system, as dhtt is required to maintain normal levels of dopamine in the brain and normal numbers of dopaminergic cells in the adult protocerebrum. Our results demonstrate that htt regulates the physiological response to ethanol and indicate a novel neuroprotective role for htt in the dopaminergic system, raising the possibility that it may be involved more generally in the response to toxic stimuli.

Age features of the correction of alcohol motivation and voluntary alcohol consumption by intranasal administration of dehydroepiandrosterone under long-term preventive alcoholization (experimental study)

We studied the effect of exogenous DHEA on the severity of alcohol motivation in animals of mature and adolescent-pubertal periods of ontogenesis using a model of voluntary ad libitum consumption of ethanol with determination of its level and preference index in a 2-bottle test. Course intranasal administration of DHEA under conditions of long-term preventive alcoholization, has a normalizing effect on emotional-motor activity and weakens anxiety-phobic reactions, which leads to the predominance of the sociocentric type in the structure of zoosocial behavior of animals. At the same time, there is a significant (by 74 %, p ≤ 0.001) decrease in the ethanol preference index in the situation of alcohol free choice, which reflects the suppression of alcohol motivation in mature adult male rats. Such effects of DHEA may indicate its certain therapeutic potential under psychoemotional disorders due to long-term alcohol consumption on the background of age-related peripheral neurosteroid hormone deficiency. In comparison, there were no found such properties during puberty, which is characterized by the highest intensity of endogenous DHEA production. Key words: periods of ontogenesis, disorders due to ethanol consumption, zoosocial behavior, intranasal administration of DHEA, correction of alcohol motivation

Striatonigral direct pathway 2-arachidonoylglycerol contributes to ethanol effects on synaptic transmission and behavior

Endocannabinoids (eCB) and cannabinoid receptor 1 (CB1) play important roles in mediating short- and long-term synaptic plasticity in many brain regions involved in learning and memory, as well as the reinforcing effects of misused substances. Ethanol-induced plasticity and neuroadaptations predominantly occur in striatal direct pathway projecting medium spiny neurons (dMSNs). It is hypothesized that alterations in eCB neuromodulation may be involved. Recent work has implicated a role of eCB 2-arachidonoylglycerol (2-AG) in the rewarding effects of ethanol. However, there is insufficient research to answer which cellular subtype is responsible for mediating the 2-AG eCB signal that might be involved in the rewarding properties of ethanol and the mechanisms by which that occurs. To examine the role of dMSN mediated 2-AG signaling in ethanol related synaptic transmission and behaviors, we used conditional knockout mice in which the 2-AG-synthesizing enzyme diacylglycerol lipase α (DGLα) was deleted in dMSNs, DGLαD1-Cre+. Using acute brain slice photometry and a genetically encoded fluorescent eCB sensor, GRABeCB2.0, to assess real-time eCB mediated activity of sensorimotor inputs from primary motor cortices (M1/M2) to the dorsolateral striatum, we showed that DGLαD1-Cre+ mice had blunted evoked eCB-mediated presynaptic eCB signaling compared to littermate controls. Furthermore, ethanol induced eCB inhibition was significantly reduced in DGLαD1-Cre+ deficient mice. Additionally, there was a reduction in the duration of loss of righting reflex (LORR) to a high dose of ethanol in the DGLαD1-Cre+ mice compared to controls. These mice also showed a male-specific decrease in ethanol preference accompanied by an increase in ethanol-induced water consumption in a voluntary drinking paradigm. There were no significant differences observed in sucrose and quinine consumption between the genotypes. These findings reveal a novel role for dMSN mediated 2-AG signaling in modulating ethanol effects on presynaptic function and behavior.