Alcohol seeking during abstinence is mediated in part by strong associations between the pharmacological effects of alcohol and the environment within which alcohol is administered. The amygdala, particularly the basolateral amygdala (BLA), is a key neural substrate of environmental cue and reward associations since it is involved in associative learning and memory recall. However, we still lack a clear understanding of how alcohol affects the activity of BLA neurons, which may encode information that drives environmental cue-dependent, alcohol-related behaviors. We previously demonstrated that a subset of BLA neurons which express the calcium/calmodulin-dependent protein kinase II (CaMKII) and thymus cell antigen 1 (Thy1) markers project preferentially to the nucleus accumbens (NAcc), rather than the central amygdala; and these neurons mediate fear inhibition rather than fear acquisition or expression, suggesting a specific role in positive valence processing. We now demonstrate that Pavlovian conditioning with alcohol administration increases the activity of these Thy1-expressing (Thy1+) excitatory neurons in mouse BLA, which is necessary for the conditioned appetitive response. In vivo calcium imaging indicates that the temporal activity profile of these neurons is also correlated with alcohol-induced motivated behavior in response to environmental cues. Optogenetic inhibition of BLA Thy1+ neuronal activity at cell body disrupts both the formation and expression of alcohol-induced conditioned place preference. Furthermore, selective axonal inhibition of BLA-Thy1+ efferents reveals that the activity of their NAcc and prefrontal cortex (PFC) projections are differentially necessary for alcohol cue association vs. recall, respectively. Together, these findings provide insights into a molecularly distinct subset of BLA neurons that regulates environmental cue-reward associations and drives alcohol-induced motivated behaviors in a projection-specific manner.

Objective Investigate the demographic, psychosocial, and Reasoned Action Approach (RAA) factors influencing sexual minority undergraduate college students’ intentions to seek alcohol-related help. Participants A non-probability sample of sexual minority college students throughout the U.S. (N = 253). Methods Participants completed an online cross-sectional survey of psychosocial and RAA scales. A hierarchical linear regression tested associations with intentions to seek alcohol related-help. Results Racial/ethnic minority students reported lower intentions to seek help than Non-Hispanic White students. Greater childhood adversity was associated with higher help-seeking intentions, whereas more hazardous drinking was associated with lower intentions. Regarding the RAA, more favorable attitudes, stronger norms, and greater autonomy were associated with higher intentions. Conclusions There is a need for alcohol screening and brief interventions that integrate racial and sexual minority cultural competency. Universities should implement behavioral health screenings to identify hazardous drinking and incorporate RAA constructs into social marketing campaigns to promote alcohol and other behavioral health help seeking.

Evaluation of suvorexant effects on alcohol seeking and self-administration in baboons.

Testing the effect of the non-selective opioid PPL-138 in a model of alcohol relapse in the context of PTSD.

A conceptual framework for the intersection of hyperalgesia and hyperkatifeia in alcohol addiction.

The cannabinoid receptor 1 (CB1R) in the hippocampus has been involved in impulsivity and alcohol consumption in adolescent rats. However, the role of CB1R in the cerebellum, despite that structure's exceptionally high CB1R density, remains unexplored. We therefore tested the hypothesis that cerebellar CB1R contributes to regulating impulsive behaviour, alcohol consumption and seeking. Male Wistar rats, adolescent (PND25), adult (PND90) and aged (PND365), were assessed on the delay discounting task (DDT) and for voluntary alcohol intake-conditioned place preference (ACPP). CB1R levels were quantified via immunofluorescence in the CRUS II and interposed nucleus. Separate cohorts were used for voluntary alcohol consumption and alcohol-conditioned place preference (ACPP). Results showed that adolescent rats displayed significantly greater impulsivity and alcohol consumption than adults and aged rats, and only adolescents developed ACPP. CB1R expression peaked in adolescents across both cerebellar regions, but only Crus II levels correlated positively with impulsivity (k value), indicating a region- and age-specific contribution. These data reveal, for the first time, that CB1R in cerebellar Crus II selectively underpins adolescent impulsive choice and alcohol consumption and seeking, highlighting both a novel brain locus and a critical developmental window for endocannabinoid modulation.

Stress is a major contributor to the chronic nature of alcohol use disorder (AUD). Orexin (OX) neurons project to the paraventricular nucleus of the thalamus (PVT)—particularly the posterior part (pPVT)— a structure that plays a key role in stress regulation. The blockade of OX receptors in the pPVT was shown to prevent the stress-induced reinstatement of alcohol seeking in alcohol-dependent rats. Accumulating evidence indicates interactions among OX and dynorphin (DYN) in the pPVT, but unclear is the role of OX and DYN transmission in the pPVT in the stress-induced alcohol seeking during alcohol abstinence. Male Wistar rats were trained to self-administer 10% alcohol for 3 weeks. They then underwent 6 weeks of chronic intermittent alcohol vapor exposure to induce dependence. After 12 extinction sessions (∼3 weeks of abstinence), the rats received intra-pPVT infusions of the dual OX receptor antagonist TCS1102 (15 µg/0.5 µL), the κ-opioid receptor (KOP) antagonist nor-binaltorphimine (norBNI; 4 µg/0.5 µL), or their combination, and they were assessed for their reactivity to the stress (footshock)-induced reinstatement of alcohol-seeking behavior. In dependent rats, TCS1102 and norBNI reduced reinstatement but, when co-administered, their individual effects were modulated. At the time of testing, increases in Hcrt and Pdyn mRNA expression in the hypothalamus and a decrease in Hcrtr1 expression and an increase in Oprk1 expression in the pPVT were observed. These findings reveal a functional interaction among OX receptor and KOP signaling in the pPVT that underlies relapse that is precipitated by stress post-dependence, underscoring the value of multi-target interventions to restore pPVT function and prevent relapse.

The current study measured the extent to which different neurobehavioral indices of incentive-motivational salience attribution to alcohol cues predict alcohol craving and consumption in the natural environment. Laboratory study at a university in Missouri, USA, followed by a smartphone-based 21-day ecological momentary assessment (EMA) protocol. Participants were emerging adults (N = 218-268 [52-56% female], age 18-20). Participants completed an alcohol cue approach-avoidance task while their electroencephalogram (EEG) was recorded. Behavioral measures (response time) indexed the strength of cue-activated approach vs. avoidance tendency. Cue-locked event-related potentials provided EEG-based neural measures of motivated attention (P3 amplitude) and approach-avoidance conflict (N450 amplitude). From EMA, measures of alcohol consumption dynamics (as indexed by estimated blood alcohol concentration [eBAC], g/dL) during real-world drinking episodes were obtained, as were measures of alcohol craving (7-point visual analogue scale) dynamics during and outside these episodes. Different approach-avoidance task-derived behavioral and neural measures rank-ordered participants differently. Participants who approached alcohol cues more rapidly in lab subsequently showed steeper increases in craving (∆B ± standard error [SE] = 1.042 ± 0.499 point/hr), and eBAC (∆B ± SE = 0.046 ± 0.017 g/dl/hr), during real-world drinking episodes. Participants who avoided alcohol cues more slowly in lab also showed steeper increases in eBAC (∆B ± SE = 0.056 ± 0.017 g/dl/hr). Participants with larger P3 during alcohol cue approach in lab subsequently showed steeper increases in eBAC (∆B ± SE = 0.048 ± 0.017 g/dl/hr), as did those with smaller P3 during alcohol cue avoidance (∆B ± SE = 0.025 ± 0.017 g/dl/hr). Participants with smaller N450 during alcohol cue approach in lab subsequently showed steeper increases in craving during drinking episodes (∆B ± SE = 1.465 ± 0.607 point/hr). Tests examining lab-based neurobehavioral measures as predictors of craving dynamics during nondrinking moments, such as following incidental cue exposure, generally were inconclusive. Incentive salience toward alcohol may influence alcohol seeking (including craving) and alcohol consumption through distinct behavioral risk pathways in different people.

Differential gene expression is often inadequate to predict the activity of transcription factors and their contribution to the phenotypes associated with specific gene expression states. Here we used a systems biology approach based on gene network inference and master regulator analysis (MRA) to identify candidate drivers of the gene network dysregulations in the prefrontal cortex (PFC) of human subjects with a history of alcohol dependence. The estrogen-related receptor gamma (ERRγ) gene ESRRG, an orphan nuclear receptor protein that acts as a transcription activator, emerged as a high-ranking Master Regulator (MR) based on the expression of its targets and was selected for functional validation due to its translational and druggability potential. The ERRγ agonist, GSK4716, reduced alcohol drinking in the mouse binge drinking paradigm of drinking in the dark (DID) and in both non-dependent mice as well as in mice made dependent by chronic intermittent vapor exposure (CIE). GSK4716 also prevented alcohol-conditioned place preference without affecting saccharin intake or mouse locomotion. Similarly, in rats, GSK4716 reduced operant oral alcohol self-administration in non-dependent and dependent (by CIE) rats under fixed and progressive ratio schedules of reinforcement. Overall, these results support the efficacy of transcriptome-wide gene regulatory network approaches for the identification of key druggable regulators of long-term transcriptional adaptations that sustain the molecular and behavioral pathology of alcohol dependence and identify ERRγ as a regulator of excessive alcohol drinking and seeking, and a therapeutic target for AUD.

Sphingosine-1-phosphate (S1P) is a lipid mediator signaling through broadly expressed G protein-coupled receptors. We found that S1P is regulated by alcohol and that S1P receptor agonists reduce alcohol drinking in rodent models. Specifically, we observed that two S1P receptor agonists FDA-approved for multiple sclerosis, fingolimod and ozanimod, and the more brain penetrant S1P 1 receptor agonist CYM5442, reduced binge alcohol drinking in the drinking in the dark (DID) paradigm in mice. CYM5442 also reduced drinking in dependent mice in the chronic intermittent ethanol vapor paradigm of dependence-induced increased drinking paired with 2 bottle-choice (CIE-2BC) as well as in non-dependent mice. CYM5442 reduced operant oral alcohol self-administration in both non-dependent and dependent rats made dependent by vapor exposure, and reduced motivation for alcohol in dependent rats tested in a progressive ratio schedule of reinforcement. CYM5442 significantly prevented cue-induced reinstatement in alcohol-dependent rats, a model of relapse to alcohol seeking. CYM5442 also reduced intake of non-drug reinforcers, including sucrose, food, water and, to a lesser extent, saccharine. Notably, CYM5442 was less aversive than naltrexone, an FDA-approved medication for the treatment of alcohol use disorder that shares a similar broad reducing action on alcohol intake and consummatory behavior. CYM5442 had no effect on loss of righting reflex, alcohol metabolism, motor coordination or spontaneous locomotor activity in rodents. Lastly, gene expression analysis by RNA-Seq revealed that S1P regulates a complex set of genes in the transition to alcohol dependence. Overall, our results establish S1P signaling as a novel therapeutic target for alcohol use disorder.

Abstinence and extinction drive opposing changes in striatal activity and dopamine signaling during alcohol relapse.

Alcohol use disorder (AUD) represents a significant medical challenge, with available therapeutic approaches having limited efficacy. Emerging data suggest that psychedelic compounds could represent an alternative treatment for AUD. Among this class of molecules, ketamine, a dissociative psychedelic, shows promising properties. It reduces alcohol drinking in rodents and in humans it is used to treat depression, a condition often comorbid with AUD. Unfortunately, the marked dissociative and anesthetic effects of this molecule severely limit its therapeutic application. Ketamine is a racemic mixture of (S, R)-enantiomers, and the R-enantiomer possesses lower dissociative and anesthetic properties compared to the racemic mixture. METHODS: Here, using male and female genetically selected Marchigian Sardinian alcohol-preferring (msP) rats, we evaluated the potential efficacy of (R)-ketamine, in alcohol-related behaviours including home cage voluntary drinking and alcohol self-administration. We also evaluated whether R ketamine may affect the reconsolidation process of alcohol-related memories. In the two-bottle free choice (free choice between 10% alcohol and water) 24-h drinking paradigm R-ketamine given orally (10, 20 and 40mg/kg) significantly reduced alcohol consumption in female but not in male rats. No effect was observed on alcohol self-administration. We subsequently tested (R)-ketamine on alcohol memory consolidation/ retrieval task and found a significant attenuation in the retrieval of alcohol-related memories in female but not in male msP rats. Taken together, our findings indicate that (R)-ketamine attenuates alcohol-related behaviors in a sex-dependent manner with females showing a higher sensitivity to its effects. Given its more favorable safety profile compared to the racemic mixture, these results support the clinical investigation of (R)-ketamine as a therapeutic intervention in patients with AUD. Particular attention should be paid to sex-specific effects observed with (R)-ketamine, as they may have important clinical implications.

BDNF plays a crucial role in shaping the structure and function of neurons. In rodents, BDNF signaling in the dorsolateral striatum (DLS) is part of an endogenous pathway that protects against the development of phenotypes associated with alcohol use. Dysregulation of BDNF levels in the cortex or dysfunction of BDNF/TrkB signaling in the DLS of rodents results in the escalation of alcohol drinking and compulsive alcohol intake. The major source of BDNF in the striatum is the prefrontal cortex. We identified a small ensemble of BDNF-positive neurons in the mouse ventrolateral orbitofrontal cortex (vlOFC), a region implicated in alcohol use disorder (AUD), that extend axonal projections to the DLS, which is associated with alcohol drinking behaviors. We speculated that BDNF in vlOFC-to-DLS circuit may play a role in limiting alcohol drinking and that heavy alcohol intake disrupts this protective pathway. We found that BDNF expression is reduced in the vlOFC of male but not female mice after long-term cycles of binge alcohol drinking and withdrawal. We further discovered that overexpression of BDNF in vlOFC-to-DLS but not in vlOFC-to-dorsomedial striatum (DMS) or M2 motor cortex-to-DLS circuit reduces alcohol but not sucrose intake and preference. We further showed that BDNF in vlOFC-to DLS reduces alcohol self-administration, alcohol seeking, and relapse. Finally, we found that systemic administration of BDNF receptor TrkB agonist, LM22A-4, dampens habitual alcohol seeking. Together, our data suggest that BDNF in a small ensemble of vlOFC-to-DLS neurons may gate alcohol drinking behaviors by attenuating habitual alcohol seeking.

ABSTRACTAlcohol misuse remains a leading cause of preventable death worldwide, prompting research into novel pharmacotherapies for alcohol use disorder (AUD). This study investigated the therapeutic potential of full agonism or positive allosteric modulation of the serotonin 2C receptor (5‐HT2CR) in addressing alcohol binge drinking and seeking behaviours in mice. Using a drinking‐in‐the‐dark paradigm and a context‐induced reinstatement model following punishment‐imposed abstinence, we assessed the acute effects of 5‐HT2CR ligands lorcaserin, CYD‐1‐79, VA012 and CTW0415 on alcohol intake and seeking behaviours in mice. Results showed that while lorcaserin effectively reduced both alcohol consumption and seeking behaviours, the 5‐HT2CR positive allosteric modulators (PAMs) did not significantly alter these behaviours over the range of doses examined. These findings suggest that 5‐HT2CR PAMs, at the tested doses, may lack intrinsic efficacy in modulating alcohol use. However, our lorcaserin data demonstrate that targeting 5‐HT2CR remains a valid approach to reduce behaviours associated with AUD.

Sex-dependent role of Neuropeptide-S on anxiety, fear conditioning, and alcohol seeking in alcohol preferring rats.

Therapeutic potential of agmatine in alcohol use disorder: Preclinical insights and future directions.

Glycyrrhiza glabra L. (Fabaceae; licorice) is a widely used medicinal herb known to exert protective effects against multiple neurological diseases. The flavonoid, isoliquiritigenin (ISL), is a main constituent of roots of Glycyrrhiza glabra. ISL has been reported to behave as a GABAB receptor agonist and exert multiple pharmacological effects. Given the role of the GABAB receptor in the neurobiological and pharmacological bases of alcohol use disorder, the present study investigated the effect of ISL on a series of alcohol-related behaviors in selectively bred, female Sardinian alcohol-preferring rats. The collected results indicated that acute treatment with ISL (5-20 mg/kg, i.p.; 50-200 mg/kg, i.g.) decreased operant oral alcohol self-administration under both fixed and progressive ratio schedules of reinforcement and suppressed cue-induced reinstatement of alcohol seeking. ISL effect on alcohol self-administration was partially blocked by pretreatment with the GABAB receptor antagonist, SCH50911, and potentiated by co-administration of the positive allosteric modulator of the GABAB receptor, GS39783. Acute treatment with doses of ISL as high as 80 mg/kg (i.p.) did not alter spontaneous locomotor activity, suggestive of the specificity of ISL effects on alcohol-related behaviors. These results confirm the ability of ISL to behave in vivo as a GABAB receptor agonist; they also indicate that ISL reproduced the suppressing effects of the prototypic GABAB receptor agonist, baclofen, on multiple alcohol-related behaviors in rodents.

IntroductionThe ability of conditioned cues to evoke drug craving is considered a critical factor precipitating relapse of drug use. The nucleus accumbens shell (AcbSh) is a structure that mediates drug-seeking via the influence of associations formed between conditioned cues and drug reward. MethodsIn the present experiments, alcohol-preferring (P) rats were exposed to three conditioned odor cues; CS+ associated with alcohol self-administration, CS− associated with the absence of alcohol (extinction training), and a neutral stimulus (CS0) presented in neutral environment with no association to alcohol. The experiments examined the effects of the conditioned cues on extracellular levels of dopamine (DA), serotonin (5-HT), and glutamate (GLU), as well as the pattern of activation of D1 receptor-containing neurons in the AcbSh. The involvement of 5-HT7 receptors within the AcbSh in regulating context- and cue-induced alcohol-seeking was also determined. ResultsPresentation of the CS+ resulted in increased extracellular DA levels and reduced 5-HT levels in the AcbSh, as well as increased activation of D1 receptor-containing neurons. In contrast, presentation of the CS− decreased extracellular DA and GLU levels in the AcbSh. The conditioned cues did not affect DA levels in the Acb core. The intra-AcbSh administration of a 5-HT7 antagonist enhanced context- and cue-induced alcohol seeking, whereas a 5-HT7 agonist reduced these behaviors. DiscussionOverall, the data suggest that there are distinct neurocircuits within the AcbSh that mediating the effects of excitatory and inhibitory conditioned cues on motivated behavior. While this work highlights a complex interaction of several neurotransmitter systems, it may also suggest a potential role for behavioral therapies involving extinction training and 5-HT7 receptor activation as potential targets for the treatment of cue-induced drug-seeking behavior.

Background: Alcohol use disorder (AUD) is a chronic relapsing brain disorder characterized by compulsive alcohol seeking, loss of control over drinking, and negative emotional states when not using. It has significant psychological, physiological, and social consequences, often co-occurring with mental health disorders such as depression and anxiety. Psychological resilience is gaining more recognition. Sense of coherence (SOC) could be treated as a health factor, and individual predispositions play a crucial role in fighting disease and addiction. Our study examines whether SOC and its components—comprehensibility, manageability, and meaningfulness—predict life satisfaction in patients with AUD and whether perceived stress and health behaviors mediate these relationships. Methods: The study was conducted on a sample of 100 adult patients diagnosed with alcohol use disorder. Results: We found that the higher the manageability and meaningfulness, the lower the level of perceived stress and the higher the level of preventive behavior. Notably, perceived stress emerged as a significant mediator between SOC and satisfaction with life, while health behaviors did not show a mediating effect. Conclusions: The findings emphasize the protective role of SOC in enhancing psychological well-being among individuals with AUD and suggest that interventions aimed at strengthening SOC may reduce stress and improve overall life satisfaction in this population.

BackgroundStress is a key factor contributing to relapse, a major hurdle in the treatment of alcohol use disorders. A region key to brain stress systems and essential for emotional regulation is the central amygdala, and alcohol dependence has been shown to impact this brain region functioning. Muscarinic acetylcholine receptors (mAChRs) mediate alcohol consumption and seeking and are densely expressed in the central amygdala. Targeting M1 and M4 mAChRs have been highlighted as potential novel treatment targets for alcohol use disorders.Aims & ObjectivesTo probe the potential role of muscarinic receptors in the central amygdala in stress-induced relapse to alcohol seeking.MethodWe employed quantitative polymerase chain reaction (qPCR) of central amygdala following abstinence from chronic alcohol drinking in iP alcohol preferring rats. In a different cohort of rats, we pharmacologically activated M4 mAChR with the selective positive allosteric modulator, VU0467154 (VU154), both systemically (30 mg/kg, i.p) and intra-central amygdala (3μmol/hemisphere), during a stress-induced relapse behavioural paradigm.ResultsOur qPCR data show a downregulation of M1 and M4 mRNA in the central amygdala following abstinence from chronic alcohol drinking. Further, both systemic and intra-central amygdala VU154 administration reduced stress-induced alcohol-seeking.Discussion & ConclusionsCollectively, our data show alcohol-induced cholinergic dysregulation in the central amygdala and a role for M4 mAChR within this brain region in reducing relapse to alcohol seeking.