EtOH Intake Research Articles

Oxidative Stress-Induced Brain Damage Triggered by Voluntary Ethanol Consumption during Adolescence: A Potential Target for Neuroprotection?

Alcohol consumption, in particular ethanol (EtOH), typically begins in human adolescence, often in a "binge like" manner. However, although EtOH abuse has a high prevalence at this stage, the effects of exposure during adolescence have been less explored than prenatal or adult age exposure. Several authors have reported that EtOH intake during specific periods of development might induce brain damage. Although the mechanisms are poorly understood, it has been postulated that oxidative stress may play a role. In fact, some of these studies revealed a decrease in brain antioxidant enzymes' level and/or an increase in reactive oxygen species (ROS) production. Nevertheless, although existing literature shows a number of studies in which ROS were measured in developing animals, fewer reported the measurement of ROS levels after EtOH exposure in adolescence. Importantly, neuroprotective agents aimed to these potential targets may be relevant tools useful to reduce EtOH-induced neurodegeneration, restore cognitive function and improve treatment outcomes for alcohol use disorders (AUDs). The present paper reviews significant evidences about the mechanisms involved in EtOH-induced brain damage, as well as the effect of different potential neuroprotectants that have shown to be able to prevent EtOH-induced oxidative stress. A selective inhibitor of the endocannabinoid anandamide metabolism, a flavonol present in different fruits (quercetin), an antibiotic with known neuroprotective properties (minocycline), a SOD/catalase mimetic, a potent antioxidant and anti-inflammatory molecule (resveratrol), a powerful ROS scavenger (melatonin), an isoquinoline alkaloid (berberine), are some of the therapeutic strategies that could have some clinical relevance in the treatment of AUDs. As most of these works were performed in adult animal models and using EtOH-forced paradigms, the finding of neuroprotective tools that could be effective in adolescent animal models of voluntary EtOH intake should be encouraged.

Validity of Endoscopic Ultrasound Findings of Chronic Pancreatitis: Evaluation from the Viewpoint of Disease Risk Factors

Background: The diagnosis of chronic pancreatitis (CP) using endoscopic ultrasound (EUS) criteria, referred to as the Rosemont classification (RC), has been widely performed. However, the validity of the RC, which was based on expert opinion, is still controversial. If EUS findings are associated with CP, then they should be associated with risk factors for CP. In this study, to verify the appropriateness of the RC and each EUS finding, we performed a retrospective analysis from the viewpoint of risk factors for CP. Summary: Three hundred and forty-four patients were enrolled in this study. Clinical background characteristics that associate with CP were alcohol intake, smoking, history of acute pancreatitis (AP), and age. The correlation between EUS criteria for CP and clinical background was investigated. All EUS findings except the presence of cysts showed significant correlations with one or 2 of the 3 following factors: ethanol (EtOH) intake, smoking status, and history of AP. Results of the univariate and multivariate analyses showed that 3 factors (EtOH intake, smoking, and history of AP) other than age were positively correlated with the RC. Moreover, the risk of progression from normal to consistent CP to indeterminate and suggestive CP was found to increase with increasing EtOH intake. Key Messages: The RC and each EUS finding was validated from the viewpoint of risk factors for CP.

Social Interaction With an Alcohol-Intoxicated or Cocaine-Injected Peer Selectively Alters Social Behaviors and Drinking in Adolescent Male and Female Rats.

Drinking alcohol is facilitated by social interactions with peers, especially during adolescence. The importance of peer social influences during adolescence on alcohol and substance use has recently received more attention. We have shown that social interaction with an alcohol-intoxicated peer influences adolescent alcohol drinking differently in male and female rats using the demonstrator-observer paradigm. The present set of experiments analyzed the social interaction session to determine changes in social behaviors and subsequent alcohol drinking in adolescent male and female rats. Specifically, in Experiment 1, we determined whether specific social behaviors were altered during interaction with an alcohol-intoxicated demonstrator administered 1.5g/kg ethanol (EtOH) and assessed changes in EtOH intake in adolescent observers. Experiment 2 examined changes in voluntary saccharin consumption to determine whether social interaction with an alcohol-intoxicated demonstrator administered 1.5g/kg EtOH altered consumption of a palatable solution. In Experiment 3, we administered saline, and a low (5mg/kg) or high (20mg/kg) dose of cocaine to the demonstrator and assessed changes in the adolescent observers to determine whether social interaction with a "drugged" peer altered social behaviors and voluntary EtOH intake. We showed that social interaction with an alcohol-intoxicated demonstrator administered 1.5g/kg EtOH (i) decreased social play and increased social investigation and social contact in adolescent male and female observers, (ii) did not alter nonsocial behaviors, (iii) did not alter saccharin consumption, and (iv) increased voluntary EtOH intake in adolescent female but not male observers. When the peer was injected with cocaine, (i) social play was dose-dependently decreased, (ii) there were no changes in other social or nonsocial behaviors, and (iii) voluntary EtOH intake in adolescent male and female observers was unaffected. The present results are consistent and extend our previous work, showing that social interaction with an alcohol-intoxicated peer selectively alters social behaviors and alcohol drinking in adolescent rats. Females appear to be more sensitive to the elevating effects of social interaction on voluntary EtOH consumption.

Intermittent ethanol exposure during adolescence impairs cannabinoid type 1 receptor-dependent long-term depression and recognition memory in adult mice.

Binge drinking is a significant problem in adolescent populations, and because of the reciprocal interactions between ethanol (EtOH) consumption and the endocannabinoid (eCB) system, we sought to determine if adolescent EtOH intake altered the localization and function of the cannabinoid 1 (CB1) receptors in the adult brain. Adolescent mice were exposed to a 4-day-per week drinking in the dark (DID) procedure for a total of 4 weeks and then tested after a 2-week withdrawal period. Field excitatory postsynaptic potentials (fEPSPs), evoked by medial perforant path (MPP) stimulation in the dentate gyrus molecular layer (DGML), were significantly smaller. Furthermore, unlike control animals, CB1 receptor activation did not depress fEPSPs in the EtOH-exposed animals. We also examined a form of excitatory long-term depression that is dependent on CB1 receptors (eCB-eLTD) and found that it was completely lacking in the animals that consumed EtOH during adolescence. Histological analyses indicated that adolescent EtOH intake significantly reduced the CB1 receptor distribution and proportion of immunopositive excitatory synaptic terminals in the medial DGML. Furthermore, there was decreased binding of [35S]guanosine-5*-O-(3-thiotriphosphate) ([35S] GTPγS) and the guanine nucleotide-binding (G) protein Gαi2 subunit in the EtOH-exposed animals. Associated with this, there was a significant increase in monoacylglycerol lipase (MAGL) mRNA and protein in the hippocampus of EtOH-exposed animals. Conversely, deficits in eCB-eLTD and recognition memory could be rescued by inhibiting MAGL with JZL184. These findings indicate that repeated exposure to EtOH during adolescence leads to long-term deficits in CB1 receptor expression, eCB-eLTD, and reduced recognition memory, but that these functional deficits can be restored by treatments that increase endogenous 2-arachidonoylglycerol.

Assessment of Acute Motor Effects and Tolerance Following Self‐Administration of Alcohol and Edible ∆9‐Tetrahydrocannabinol in Adolescent Male Mice

Cannabinoids and their principle psychoactive target, the cannabinoid type 1 receptor (CB1R), impact a number of alcohol-related properties, and although alcohol and cannabis are often co-used, particularly in adolescence, few animal models of this phenomenon exist. We modeled the co-use of alcohol and ∆9 -tetrahydrocannabinol (THC) in adolescent mice using ingestive methods popular during this developmental period in humans, namely binge-drinking and edible THC. With this model, we assessed levels of use, acute effects, and tolerance to each substance. Adolescent male C57BL/6J mice had daily, limited access to 1 of 2 edible doughs (THC or control), to 1 of 2 fluids (ethanol (EtOH) or water), and in 1 of 2 orders (dough-fluid or fluid-dough). Home cage locomotor activity was recorded both during access and after access. On the day following the final access session, a subset of mice were assessed for functional and metabolic tolerance to alcohol using accelerating rotarod and blood EtOH concentrations, respectively. The remaining mice were assessed for tolerance to THC-induced hypothermia, and whole-brain CB1R expression was assessed in all mice. EtOH intake was on par with levels previously reported in adolescent mice. Edible THC was well-consumed, but consumption decreased at the highest dose provided. Locomotor activity increased following EtOH intake and decreased following edible THC consumption, and edible THC increased fluid intake in general. The use of alcohol produced neither functional nor metabolic tolerance to an alcohol challenge. However, the use of edible THC impaired subsequent drug-free rotarod performance and was associated with a reduction in THC's hypothermic effect. Adolescent mice self-administered both alcohol and edible THC to a degree sufficient to acutely impact locomotor activity. However, only edible THC consumption had lasting effects during short-term abstinence. Thus, this adolescent co-use model could be used to explore sex differences in self-administration and the impact substance co-use might have on other domains such as mood and cognition.

Changes in brain kynurenine levels via gut microbiota and gut-barrier disruption induced by chronic ethanol exposure in mice.

Inflammatory processes have been shown to modify tryptophan (Trp) metabolism. Gut microbiota appears to play a significant role in the induction of peripheral and central inflammation. Ethanol (EtOH) exposure alters gut permeability, but its effects on Trp metabolism and the involvement of gut microbiota have not been studied. We analyzed several parameters of gut-barrier and of peripheral and central Trp metabolism following 2 different EtOH consumption patterns in mice, the binge model, drinking in the dark (DID), and the chronic intermittent (CI) consumption paradigm. Antibiotic treatment was used to evaluate gut microbiota involvement in the CI model. Mice exposed to CI EtOH intake, but not DID, show bacterial translocation and increased plasma LPS immediately after EtOH removal. Gut-barrier permeability to FITC-dextran is increased by CI, and, furthermore, intestinal epithelial tight-junction (TJ) disruption is observed (decreased expression of zonula occludens 1 and occludin) associated with increased matrix metalloproteinase (MMP)-9 activity and iNOS expression. CI EtOH, but not DID, increases kynurenine (Kyn) levels in plasma and limbic forebrain. Intestinal bacterial decontamination prevents the LPS increase but not the permeability to FITC-dextran, TJ disruption, or the increase in MMP-9 activity and iNOS expression. Although plasma Kyn levels are not affected by antibiotic treatment, the elevation of Kyn in brain is prevented, pointing to an involvement of microbiota in CI EtOH-induced changes in brain Trp metabolism. Additionally, CI EtOH produces depressive-like symptoms of anhedonia, which are prevented by the antibiotic treatment thus pointing to an association between anhedonia and the increase in brain Kyn and to the involvement of gut microbiota.-Giménez-Gómez, P., Pérez-Hernández, M., O'Shea, E., Caso, J. R., Martín-Hernández, D., Cervera, L. A., Centelles. M. L. G.-L., Gutiérrez-Lopez, M. D., Colado, M. I. Changes in brain kynurenine levels via gut microbiota and gut-barrier disruption induced by chronic ethanol exposure in mice.

Cross‐Sensitization to Binge Alcohol Intake Following Binge Intake of Palatable Diets

Obesity and alcoholism, two of the most common chronic conditions in the United States, may be behaviorally linked as binge intake of palatable diets, such as diets high in fat (HFD), and binge alcohol (EtOH) intake may utilize similar neurocircuitry. We hypothesized that binge intake of one modality (i.e. HFD) may sensitize the shared neurocircuitry to further activation by another modality (i.e. EtOH). Therefore, we combined a binge HFD intake model in mice where HFD access is limited to one 24hr session per week (Limited Access HFD: LAH) with a patterned EtOH access schedule that also promotes binge‐like intake in a two‐bottle choice model (Limited Access EtOH: LAE; 4hrs/day, 4days/wk). Control mice were given the same EtOH access schedule but were given continuous ad libitum access to HFD (60% calories from fat) or control Chow diet (10% calories from fat). Six‐week old male C57Bl/6J mice were weight matched, individually housed, and assigned to HFD+LAE, Chow+LAE, or LAH+LAE groups (n=10 per group). All groups of mice were given increasing EtOH concentrations over the course of the study (10% EtOH for three weeks, 15% EtOH for two weeks, and 20% EtOH for two weeks). Body mass was measured daily while EtOH/water intake and EtOH preference were assessed after every drinking session. Over the course of the study, HFD+LAE mice gained significantly more weight than Chow+LAE or LAH+LAE mice (p=0.001; one‐way ANOVA). While weight gain was predominantly linear in HFD+LAE and Chow+LAE mice, LAH+LAE mice showed weight cycling indicating a binge‐like eating pattern. LAH+LAE mice consumed significantly more EtOH than Chow+LAE or HFD+LAE mice (p=0.001, repeated measures two‐way ANOVA), suggesting that binge intake of HFD led to increased binge EtOH intake patterns in LAH mice. LAH+LAE and Chow+LAE mice showed higher preference towards EtOH than HFD+LAE mice (p=0.001, repeated measures two‐way ANOVA). Together, these results suggest limited access to palatable diets induce binge‐like eating patterns that further cross‐sensitize to binge alcohol intake and mitigates the loss of alcohol preference in mice given continuous HFD.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Bupropion, Alone and in Combination with Naltrexone, Blunts Binge‐Like Ethanol Drinking and Intake Following Chronic Intermittent Access to Ethanol in Male C57BL/6J Mice

Regular binge drinking is associated with numerous adverse consequences, yet the U.S. Food and Drug Administration (FDA) has approved only 4 medications for the treatment of alcohol use disorders, and none have been specifically targeted for treating binge drinking. Here, we assessed the effectiveness of the dopamine/norepinephrine re-uptake inhibitor, bupropion (BUP), alone and in combination with naltrexone (NAL), to reduce binge-like and chronic ethanol (EtOH) intake in mice. While BUP is an FDA-approved drug that is currently used to treat depression and nicotine dependence, there has been only limited investigation to assess the ability of BUP to reduce EtOH intake. Male C57BL/6J mice were tested with 20% (v/v) EtOH using "drinking in the dark" (DID) procedures to model binge-like EtOH intake and following intermittent access to EtOH (IAE). In Experiment 1, mice were given intraperitoneal (i.p.) injection of 0, 20, or 40mg/kg BUP 30minutes before DID testing; in Experiment 2, mice were given i.p. injection of vehicle, BUP (20mg/kg), NAL (3mg/kg), or BUP+NAL (20 and 3mg/kg, respectively) 30minutes before DID testing; and in Experiment 3, mice were given i.p. injection of 0, 20, 40, or 60mg/kg BUP 30minutes before EtOH access after mice had 16weeks of IAE. BUP dose dependently blunted EtOH intake with DID procedures and after 16weeks of IAE. Administration of subthreshold doses of BUP+NAL also reduced binge-like EtOH intake. Finally, BUP failed to reduce consumption of a 3% (w/v) sucrose solution. BUP, alone and in combination with NAL, may represent a novel approach to treating binge EtOH intake. We are currently assessing the efficacy of BUP to curb binge drinking in a phase II clinical trial experiment.

Physical Exercise Attenuates Oxidative Stress and Morphofunctional Cerebellar Damages Induced by the Ethanol Binge Drinking Paradigm from Adolescence to Adulthood in Rats.

Ethanol (EtOH) binge drinking is characterized by high EtOH intake during few hours followed by withdrawal. Protection strategies against the damages generated by this binge are poorly explored. Thus, this study is aimed at investigating the protective role of treadmill physical exercise (PE) on the damage caused after repeated cycles of binge-like EtOH exposure in the oxidative biochemistry, morphology, and cerebellar function of rats from adolescence to adulthood. For this, animals were divided into four groups: control group (sedentary animals with doses of distilled water), exercised group (exercised animals with doses of distilled water), EtOH group (sedentary animals with doses of 3 g/kg/day of EtOH, 20% w/v), and exercised+EtOH group (exercised animals with previous mentioned doses of EtOH). The PE occurred on a running treadmill for 5 days a week for 4 weeks, and all doses of EtOH were administered through intragastric gavage in four repeated cycles of EtOH in a binge-like manner. After the EtOH protocol and PE, animals were submitted to open field and beam walking tests. In sequence, the cerebellums were collected for the biochemical and morphological analyses. Biochemical changes were analyzed by measurement of Trolox equivalent antioxidant capacity (TEAC), reduced glutathione content measurements (GSH), and measurement of nitrite and lipid peroxidation (LPO). In morphological analyses, Purkinje cell density evaluation and immunohistochemistry evaluation were measured by antimyelin basic protein (MBP) and antisynaptophysin (SYP). The present findings demonstrate that the binge drinking protocol induced oxidative biochemistry misbalance, from the decrease of TEAC levels and higher LPO related to tissue damage and motor impairment. In addition, we have shown for the first time that treadmill physical exercise reduced tissue and functional alterations displayed by EtOH exposure.

The Toll-Like Receptor 3 Agonist Poly(I:C) Induces Rapid and Lasting Changes in Gene Expression Related to Glutamatergic Function and Increases Ethanol Self-Administration in Rats.

Growing evidence suggests that neuroimmune signaling via Toll-like receptors (TLRs) alters brain circuitry related to alcohol use disorders. Both ethanol (EtOH) exposure and the TLR3 agonist, poly(I:C), increase brain TLR3 expression in neurons and glia. Furthermore, previous studies have shown that cortical TLR3 expression is correlated with lifetime EtOH intake in humans. The current experiments investigated the consequences of poly(I:C) treatment on gene expression in 2 brain regions contributing to alcohol reinforcement, the insular cortex (IC) and nucleus accumbens (Acb) and on operant EtOH self-administration, in Long Evans rats. TLR3 activation increased mRNA levels of neuroimmune genes (TLR3, COX2), glutamatergic genes (mGluR2, mGluR3, GLT1), and the trophic factor BDNF in Acb and IC. Furthermore, increases in each of these genes were correlated with increases in TLR3 mRNA, suggesting that TLR3 induction of these genes may impact excitatory transmission in IC and Acb. TLR3 activation also increased EtOH self-administration 18days postinjection and enhanced the effects of the mGluR2/3 agonist LY379268 to reduce EtOH self-administration following poly(I:C). Together, these findings suggest lasting consequences of TLR3 activation on gene expression including increases in Group II mGluRs in the Acb. Furthermore, we show an important role for TLR3 signaling in EtOH intake, and a functional involvement of Group II mGluRs.

Assessment of ventral tegmental area-projecting GABAergic neurons from the bed nucleus of the stria terminalis in modulating binge-like ethanol intake.

Corticotropin-releasing factor (CRF) circuitry is a key component in plasticity underlying the transition to ethanol (EtOH) dependence. We have previously shown that chemogenetic silencing of CRF neurons stemming from the dorsolateral bed nucleus of the stria terminalis (dlBNST) and projecting to the ventral tegmental area (VTA) significantly blunts binge-like EtOH consumption. While CRF neurons in the BNST are thought to entail primarily a GABA phenotype, glutamatergic neurons within the BNST also innervate the VTA and influence consummatory behaviors. Here, we combined the well-validated Vgat-ires-Cre transgenic mice with chemogenetic tools to extend our previous findings and corroborate the contribution of the VTA-projecting dlBNST GABAergic circuitry in modulating binge-like EtOH consumption using "drinking-in-the-dark" procedures. Mice were given bilateral injection of Gi-coupled chemogenetic viral vector (or control virus) into the dlBNST and bilateral cannulae into the VTA. On test day, clozapine-N-oxide (CNO; or vehicle) was infused directly into the VTA to silence VTA-projecting dlBNST neurons and subsequent binge-like EtOH consumption was assessed. We then used immunohistochemistry (IHC) to determine the co-expression of CRF and viral vector. Our results showed that relative to vehicle treatment or CNO treatment in mice expressing the control virus, silencing VTA-projecting dlBNST GABAergic neurons by CNO treatment in mice expressing Gi-coupled chemogenetic virus significantly reduced binge-like EtOH intake. This effect was not seen with sucrose consumption. Our IHC results confirm a population of CRF-expressing GABAergic neurons within the dlBNST. This study directly establishes that VTA-projecting GABAergic neurons of the dlBNST modulate binge-like EtOH consumption.

Effect of menstrual cycle on ethanol drinking in rhesus monkeys

BackgroundSex differences in the abuse-related effects of alcohol have been demonstrated in the clinic and in preclinical animal models. Less is known about the influence of menstrual cycle phase on drinking. MethodsIn this study, we examined the relationship between menstrual cycle phase and intake of ethanol (EtOH) in five adult female rhesus monkeys. Subjects consumed a 4% EtOH solution in their home cage 6 h per day, 5 days per week and pressed a lever to receive food pellets during the drinking session. Menstrual cycle was determined with vaginal swabs 5–7 days per week. To facilitate comparison with previous studies, the cycle was divided three different ways for analysis. ResultsFirst, no significant difference was observed when EtOH intake was compared between phases defined as “follicular” (days 5–10) and “luteal” (19–24). Second, when the cycle was further divided into four phases [early follicular (days 1–7), late follicular (8–14), early luteal (15–21) and late luteal (22-next cycle)], significant differences were detected, with intake highest in phases that bracket menses and lowest in the late follicular phase. Finally, EtOH intake during “mid-cycle” (days 12–16) was significantly lower than during “menses” (days 1–5) and “late luteal” (last 5 days). Effect sizes were small to moderate, although absolute differences in EtOH intake (g/kg) were <15%. Food-maintained responding was not different across phases. ConclusionsMenstrual cycle has modest but statistically significant and selective effects on EtOH drinking, with higher EtOH intake observed in the peri-menstrual period compared to the middle of the cycle.

Exploring Sex Differences in the Attenuation of Ethanol Drinking by Naltrexone in Dependent Rats During Early and Protracted Abstinence.

Despite considerable efforts, few drugs are available for the treatment of alcohol (ethanol [EtOH]) use disorder (AUD). EtOH directly or indirectly modulates several aspects of the central nervous system, including neurotransmitter/neuromodulator systems. Relapse vulnerability is a challenge for the treatment of EtOH addiction. EtOH withdrawal symptoms create motivational states that lead to compulsive EtOH drinking and relapse even after long periods of abstinence. Among the therapeutics to treat AUD, naltrexone (NTX) is a pharmacological treatment for relapse. The present study evaluated the effect of NTX on EtOH drinking in male and female EtOH-dependent rats during abstinence. Wistar rats (males and females) were first trained to orally self-administer 10% EtOH. Half of the rats were then made dependent by chronic intermittent EtOH (CIE) vapor exposure, and the other half were exposed to air. Using this model, rats exhibit somatic and motivational signs of withdrawal. At the end of EtOH vapor (or air) exposure, the rats were tested for the effects of NTX (10mg/kg, oral) on EtOH self-administration at 3 abstinence time points: acute abstinence (A-Abst, 8hours), late abstinence (L-Abst, 2weeks), and protracted abstinence (P-Abst, 6weeks). NTX decreased EtOH intake in nondependent rats, regardless of sex and abstinence time point. In postdependent rats, NTX decreased EtOH intake only at a delayed abstinence time point (P-Abst) in males, whereas it similarly reduced EtOH drinking in females at all abstinence time points. The therapeutic efficacy of NTX depends on the time of intervention during abstinence and is different between males and females. The data further suggest that EtOH dependence causes different neuroadaptations in male and female rats, reflected by differential effects of NTX. The results underscore the significance of considering the duration of EtOH abstinence and sex as a biological variable as important factors when developing pharmacotherapies for AUD.

An improved model of ethanol and nicotine co-use in female P rats: Effects of naltrexone, varenicline, and the selective nicotinic α6β2* antagonist r-bPiDI

Background Although pharmacotherapies are available for alcohol (EtOH) or tobacco use disorders individually, it may be possible to develop a single pharmacotherapy to treat heavy drinking tobacco smokers by capitalizing on the commonalities in their mechanisms of action.Methods Female alcohol-preferring (P) rats were trained for EtOH drinking and nicotine self-administration in two phases: (1) EtOH alone (0 vs. 15% EtOH, 2-bottle choice) and (2) concomitant access, during which EtOH access continued with access to nicotine (0.03 mg/kg/infusion, i.v.) using a 2-lever choice procedure (active vs. inactive lever) in which the fixed ratio (FR) requirement was gradually increased to FR30. When stable co-use was obtained, rats were pretreated with varying doses of naltrexone, varenicline, or r-bPiDI, an α6β2* subtype-selective nicotinic acetylcholine receptor antagonist shown previously to reduce nicotine self-administration.Results While EtOH intake was initially suppressed in phase 2 (co-use), pharmacologically relevant intake for both substances was achieved by raising the “price” of nicotine to FR30. In phase 2, naltrexone decreased EtOH and water consumption but not nicotine intake; in contrast, naltrexone in phase 1 (EtOH only) did not significantly alter EtOH intake. Varenicline and r-bPiDI in phase 2 both decreased nicotine self-administration and inactive lever pressing, but neither altered EtOH or water consumption.Conclusions These results indicate that increasing the “price” of nicotine increases EtOH intake during co-use. Additionally, the efficacy of naltrexone, varenicline, and r-bPiDI was specific to either EtOH or nicotine, with no efficacy for co-use. Nevertheless, future studies on combining these treatments may reveal synergistic efficacy.

A Predisposing Condition of Hemochromatosis Complicated by Alcoholic Liver Disease

Cirrhosis and chronic liver failure are common causes of morbidity and mortality in the United States. The majority of preventable cases of these are attributed to alcohol (ETOH) consumption, viral hepatitis, or nonalcoholic fatty liver disease. End-stage cirrhosis without hereditary hemochromatosis (HH) is often associated with a significant amount of hepatic iron overload especially in those with ETOH abuse and/or hepatitis C. We present a case of a 78 year old male admitted for cirrhosis secondary to alcoholic liver disease (ALD) but was found to have a preexisting condition that may have precipitated his symptoms. A 78 year—old male with history of ETOH abuse (12 beers/day) was admitted for altered mental status with fevers, hematuria, and disorientation for 1 week. On exam, he was altered and jaundiced with a distended abdomen. Initial lab results: Creatinine (3.18), Bilirubin (1.58), Albumin (2.14), AST (35), ALT (18.6), Ammonia (141), PT (16), INR (1.46), PTT (36), Iron Saturation (89%), negative viral hepatitis panel. His MELD score was calculated at 21. Abdominal imaging showed liver cirrhosis, esophageal/gastric varices, ascites, bilateral anasarca and pleural effusions. EGD revealed severe portal gastropathy, erosive antral gastritis, and gastric varices. He was found to be a carrier of a single mutation in the S65C gene. Diuretics, albumin and fluid hydration were administered prior to discharge. HH and ALD are known risk factors for the development of cirrhosis. S65C substitution has been associated with mild HH. Studies looking at the heterozygous genotype of S65C with C282Y or H63D show a similar risk to developing HH as with homozygous carriers of these genes. Both diseases have shown links between hepatic iron deposition and developing cirrhosis. However, together, these diseases increase the risk of cirrhosis by 9 fold. This is due to oxidative stress, stellate cell activation, and fibrosis caused by iron deposition and ETOH. In addition, up to 50% of patients with HH drink above the average amounts of ETOH. This can increase iron accumulation and phenotypic expression of HH. By contrast, other studies propose that heavy deposition of iron, regardless of ETOH intake, is an indication of HH. For this reason, it is important to assess for other causes when there are persistently elevated ALT levels. Workup should include viral/autoimmune hepatitis assays and transferrin saturation to guide treatment and prevent end stage liver disease.

Histone Deacetylase Inhibitor Suberanilohydroxamic Acid Treatment Reverses Hyposensitivity to γ-Aminobutyric Acid in the Ventral Tegmental Area During Ethanol Withdrawal.

BackgroundThe ventral tegmental area (VTA) is important for alcohol‐related reward and reinforcement. Mouse VTA neurons are hyposensitive to γ‐aminobutyric acid (GABA) during ethanol (EtOH) withdrawal, and GABA responsiveness is normalized by in vitro treatment with histone deacetylase inhibitors (HDACi). The present study examined the effect of a systemically administered HDACi, suberanilohydroxamic acid (SAHA) on GABA sensitivity, and related molecular changes in VTA neurons during withdrawal after chronic EtOH intake in rats.MethodsSprague Dawley male adult rats were fed with Lieber‐DeCarli diet (9% EtOH or control diet) for 16 days. Experimental groups included control diet‐fed and EtOH diet‐fed (0‐ or 24‐hour withdrawal) rats treated with either SAHA or vehicle injection. Single‐unit recordings were used to measure the response of VTA neurons to GABA. Immunohistochemistry was performed to examine levels of HDAC2, acetylated histone H3 lysine 9 (acH3K9), and GABAA receptor α1 and α5 subunits in the VTA; quantitative polymerase chain reaction was performed to examine the mRNA levels of HDAC2 and GABAA receptor subunits.ResultsVTA neurons from the withdrawal group exhibited GABA hyposensitivity. In vivo SAHA treatment 2 hours before sacrifice normalized the sensitivity of VTA neurons to GABA. EtOH withdrawal was associated with increased HDAC2 and decreased acH3K9 protein levels; SAHA treatment normalized acH3K9 levels. Interestingly, no significant change was observed in the mRNA levels of HDAC2. The mRNA levels, but not protein levels, of GABAA receptor α1 and α5 subunits were increased during withdrawal.ConclusionsWithdrawal from chronic EtOH exposure results in a decrease in GABA‐mediated inhibition, and this GABA hyposensitivity is normalized by in vivo SAHA treatment. Disruption of signaling in the VTA produced by alteration of GABA neurotransmission could be 1 neuroadaptive physiological process leading to craving and relapse. These results suggest that HDACi pharmacotherapy with agents like SAHA might be an effective treatment for alcoholism.

Ethanol (EtOH)-Related Behaviors in α-Synuclein Mutant Mice and Association of SNCA SNPs with Anxiety in EtOH-Dependent Patients.

Data have shown a role of α-synuclein in anxiety and also in addiction, particularly in alcohol use disorders (AUD). Since the comorbidity between AUD and anxiety is very high and because anxiety is an important factor in ethanol (EtOH) relapse, the aim of the present study was to investigate the role of α-synuclein in moderating EtOH intake, the anxiolytic effects of EtOH, and EtOH withdrawal-induced anxiety and convulsions in mice. The study aimed to determine whether SNCA variants moderated anxiety in EtOH-dependent patients. We analyzed the moderator effect of 3 SNCA Tag-single nucleotide polymorphisms (Tag-SNPs) rs356200, rs356219, and rs2119787 on the anxiety symptoms in 128 EtOH-dependent patients. We used the C57BL/6JOlaHsd Snca mutant mice to assess EtOH intake; sensitivity to the anxiolytic effects of EtOH in a test battery comprising the open field, the light-dark box, and the elevated plus maze; and both anxiety and convulsions induced by EtOH withdrawal. Our results demonstrated a reduction in both EtOH intake and preference and also a lack of sensitivity to the anxiolytic effects of EtOH in α-synuclein mutant mice. Results on anxiety-like behavior were mixed, but mutant mice displayed increased anxiety when exposed to a low anxiogenic environment. Mutant mice also displayed an increase in handling-induced convulsion scores during withdrawal after EtOH inhalation, but did not differ in terms of EtOH withdrawal-induced anxiety. In humans, we found a significant association of the rs356219 SNP with a high level of anxiety (Beck Anxiety Inventory score >15) and the rs356200 SNP with a positive familial history of AUD. Our translational study highlights a significant role of α-synuclein in components of AUD.

COMT Inhibition Alters Cue-Evoked Oscillatory Dynamics during Alcohol Drinking in the Rat.

Alterations in the corticostriatal system have been implicated in numerous substance use disorders, including alcohol use disorder (AUD). Adaptations in this neural system are associated with enhanced drug-seeking behaviors following exposure to cues predicting drug availability. Therefore, understanding how potential treatments alter neural activity in this system could lead to more refined and effective approaches for AUD. Local field potentials (LFPs) were acquired simultaneously in the prefrontal cortex (PFC) and nucleus accumbens (NA) of both alcohol preferring (P) and Wistar rats engaged in a Pavlovian conditioning paradigm wherein a light cue signaled the availability of ethanol (EtOH). On test days, the catechol-o-methyl-transferase (COMT) inhibitor tolcapone was administered prior to conditioning. Stimulus-evoked voltage changes were observed following the presentation of the EtOH cue in both strains and were most pronounced in the PFC of P rats. Phase analyses of LFPs in the θ band (5–11 Hz) revealed that PFC-NA synchrony was reduced in P rats relative to Wistars but was robustly increased during drinking. Presentation of the cue resulted in a larger phase reset in the PFC of P rats but not Wistars, an effect that was attenuated by tolcapone. Additionally, tolcapone reduced cued EtOH intake in P rat but not Wistars. These results suggest a link between corticostriatal synchrony and genetic risk for excessive drinking. Moreover, inhibition of COMT within these systems may result in reduced attribution of salience to reward paired stimuli via modulation of stimulus-evoked changes to cortical oscillations in genetically susceptible populations.

Environmental Enrichment During Adolescence Acts as a Protective and Therapeutic Tool for Ethanol Binge-Drinking, Anxiety-Like, Novelty Seeking and Compulsive-Like Behaviors in C57BL/6J Mice During Adulthood.

Repetitive drug/ethanol (EtOH) binge-like consumption during pre-addictive stages favors a transition to addiction in vulnerable organisms. Experimental evidence points to the therapeutic and preventive effects of environmental enrichment (EE) on drug and EtOH addiction; however, little is known regarding EE modulation of binge-like consumption in non-dependent organisms. Here, we explore the impact of early EE on binge-like EtOH consumption: (1) we test whether early EE exposure prevents binge-like EtOH intake (20% v/v) in adult mice under an intermittent drinking in the dark (iDID) schedule; (2) we evaluate the therapeutic effects of EE housing conditions on binge-like EtOH consumption in adult animals; and (3) we compare novelty-seeking and compulsive-like behaviors, and anxiety-like behavior, as measured by the Hole Board (HB) and Elevated Plus Maze (EPM) tests, respectively, in adult EE/standard environment (SE) animals. Adolescent (postnatal day 28; PND28) mice were randomly allocated to two housing conditions (4 animals/cage): EE or SE. At PND67 all the animals were exposed to a schedule of EtOH binge-like iDID. On PND92 half of the animals in each environmental condition (EE and SE) were randomly allocated to two subgroups in a crossover design, where environmental conditions were kept similar to those previously experienced or switched, finally leading to four experimental conditions: EE-EE, EE-SE, SE-SE, and SE-EE. EtOH binge-like consumption continued until PND140, when EPM and HB tests were finally conducted. The main observations were: (1) EE-reared mice showed lower EtOH binge-like intake than SE-reared mice during adulthood, which supports a protective role for EE. (2) when adult EtOH drinking SE-reared mice were switched to EE conditions, a reduction in EtOH binge-like consumption was observed, suggesting a therapeutic role for EE; however, losing EE during adulthood triggered a progressive increase in EtOH binge-like intake. Moreover, (3) EE-housed adult animals with long-term exposure to EtOH binge-drinking showed lower anxiety-like, compulsive-like, and novelty-seeking behaviors than SE-housed mice, irrespective of the specific housing conditions during adolescence. We discuss the primary impact of EE on anxiety-like neurobehavioral brain systems through which it secondarily modulates EtOH binge-like drinking.

Commonality of Ethanol and Nicotine Reinforcement and Relapse in Wistar-Derived UChB Rats: Inhibition by N-Acetylcysteine.

Life expectancy is greatly reduced in individuals presenting alcohol use disorders and chronic smoking. Literature studies suggest that common mechanisms may apply to the chronic use and relapse of both alcohol and nicotine. It is hypothesized that an increased brain oxidative stress and neuroinflammation are involved in perpetuating these conditions and that a common treatment may be considered for both. Rats bred as high ethanol (EtOH) drinkers (UChB) were allowed chronic access to EtOH solutions and water and were thereafter deprived of EtOH for a prolonged period, subsequently allowing reaccess to EtOH, which leads to marked relapse binge-like drinking. Separately, EtOH-naïve animals were chronically administered nicotine intraperitoneally and tested under either a conditioned place preference (CPP) reinstatement condition or allowed a free-choice drinking of nicotine solutions and water. Oral N-acetylcysteine (NAC) (100mg/kg) was administered daily to the animals to determine its effect on both chronic voluntary EtOH and nicotine intake, on EtOH relapse and nicotine-CPP reinstatement. Oxidative stress was evaluated in hippocampus as the oxidized/reduced glutathione ratio (GSSG/GSH), and neuroinflammation by glial fibrillary acidic protein (GFAP) immunohistochemistry. Marked increases in hippocampal oxidative stress (GSSG/GSH) and neuroinflammation (astrocyte reactivity, GFAP) were observed after both chronic EtOH and chronic nicotine treatment. Oral NAC administration (i) fully abolished the increased oxidative stress and the neuroinflammation induced by both drugs, (ii) greatly inhibited EtOH intake (70%) and EtOH relapse binge-like drinking (76%), and (iii) markedly inhibited (90%) voluntary nicotine intake and fully suppressed nicotine-CPP reinstatement. Data indicate that (i) oxidative stress and neuroinflammation are tightly associated with chronic EtOH and nicotine intake and drug relapse and (ii) NAC inhibits the relapse for both drugs, suggesting that the oral chronic administration of NAC may be of value in the concomitant treatment of alcohol and nicotine use disorders.