Alcohol-related cognitive impairments in patients with and without cirrhosis.

AIMS: up to 80% of patients with alcohol use disorder display cognitive impairments. Some studies have suggested that alcohol-related cognitive impairments could be worsened by hepatic damage. The primary objective of this study was to compare mean scores on the Brief Evaluation of Alcohol-Related Neurocognitive Impairments measure between alcohol use disorder patients with (CIR+) or without cirrhosis (CIR-). METHODS: we conducted a prospective case-control study in a hepatology department of a university hospital. All patients were assessed using the Evaluation of Alcohol-Related Neuropsychological Impairments test. RESULTS: a total of 82 patients (50 CIR+, 32 CIR-) were included in this study. CIR- patients were significantly younger than CIR+ patients (respectively, 45.5 ± 6.8 vs 60.1 ± 9.0; P < .0001). After adjusting for age and educational level, the mean Evaluation of Alcohol-Related Neuropsychological Impairments total scores in the CIR+ group were significantly lower than in the group of CIR- patients (14.1 ± 0.7 vs 7.8 ± 0.4, respectively, P < .0001). The mean subscores on delayed verbal memory, alphabetical ordination, alternating verbal fluency, visuospatial abilities, and ataxia subtests were also significantly lower in the CIR+ than in the CIR- group (respectively, 1.9 ± 0.2 vs 2.8 ± 0.2; 1.8 ± 0.2 vs 2.7 ± 0.2; 2.2 ± 0.2 vs 3.6 ± 0.2; 0.7 ± 0.2 vs 1.6 ± 0.2; 0.7 ± 0.2 vs 3.1 ± 0.2; P < .0001 for all comparisons). CONCLUSIONS: in the present study, alcohol use disorder patients with cirrhosis presented more severe cognitive impairments than those without cirrhosis. Longitudinal studies are needed to investigate how cirrhosis can influence cognitive impairments.

Alcohol demand in college students: The roles of athletic involvement and gender.

College student-athletes represent a high-risk group for heavy alcohol consumption and negative alcohol-related consequences. Although college drinking correlates with access to low-cost alcohol, no study has examined demand, or the relationship between price and consumption, in student-athletes. Furthermore, the prevalence of anxiety, depression, and drinking to cope motives in student-athletes suggest athlete-specific risks of alcohol consumption that have not yet been examined in conjunction with demand. Therefore, the present study examined gender differences in alcohol demand, alcohol consumption, and anxiety and depressive symptoms in student-athletes (n = 118) and nonathletes (n = 78) at three colleges/universities. Participants completed the Alcohol Purchase Task and measures of alcohol-related behaviors and mental health. Observed demand indices including intensity (i.e., consumption at zero price), Omax (i.e., maximum expenditure), Pmax (i.e., price associated with Omax), and breakpoint-1, or BP1 (i.e., highest price of nonzero consumption) were calculated at the individual level. The rate of change in demand elasticity (i.e., decrease in consumption relative to price increases) was calculated at the group level. Overall, students reported lower alcohol consumption at higher alcohol prices, but men reported higher alcohol consumption and demand intensity than women, student-athletes reported higher Omax than nonathletes, and student-athletes reported lower depressive symptoms than nonathletes. These findings support reducing access to low-cost alcohol in college drinking environments as a harm-reduction strategy, particularly for high-risk student populations, such as men and those involved in athletics. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A new statistical model for binge drinking pattern classification in college-student populations.

Background: Binge drinking (BD) among students is a frequent alcohol consumption pattern that produces adverse consequences. A widely discussed difficulty in the scientific community is defining and characterizing BD patterns. This study aimed to find homogenous drinking groups and then provide a new tool, based on a model that includes several key factors of BD, to assess the severity of BD regardless of the individual's gender. Methods: Using the learning sample (N1 = 1,271), a K-means clustering algorithm and a partial proportional odds model (PPOM) were used to isolate drinking and behavioral key factors, create homogenous groups of drinkers, and estimate the probability of belonging to these groups. Robustness of our findings were evaluated with Two validations samples (N2 = 2,310, N3 = 120) of French university students (aged 18-25 years) were anonymously investigated via demographic and alcohol consumption questionnaires (AUDIT, AUQ, Alcohol Purchase Task for behavioral economic indices). Results: The K-means revealed four homogeneous groups, based on drinking profiles: low-risk, hazardous, binge, and high-intensity BD. The PPOM generated the probability of each participant, self-identified as either male or female, to belong to one of these groups. Our results were confirmed in two validation samples, and we observed differences between the 4 drinking groups in terms of consumption consequences and behavioral economic demand indices. Conclusion: Our model reveals a progressive severity in the drinking pattern and its consequences and may better characterize binge drinking among university student samples. This model provides a new tool for assessing the severity of binge drinking and illustrates that frequency of drinking behavior and particularly drunkenness are central features of a binge drinking model.

Early Improvement of Neuropsychological Impairments During Detoxification in Patients with Alcohol Use Disorder.

AIMS: To assess recovery of alcohol-related neuropsychological deficits in a group of patients with pure severe alcohol use disorder (AUD) during a detoxification program using the Brief Evaluation of Alcohol-Related Neuropsychological Impairment (BEARNI) test. METHODS: Thirty-two patients with severe AUD using DSM-IV criteria (24 men, mean age = 45.5 ± 6.8 years old) were assessed using the BEARNI 8 ± 2 days after alcohol cessation (T1) and then were reassessed within 18 ± 2 days after alcohol cessation (T2). The primary study endpoint was the number of patients initially impaired at T1 who recovered cognitive functions at T2 assessment. RESULTS: At T1, 59% (n = 19) patients with pure severe AUD had at least one impaired cognitive function assessed by the BEARNI. At T2, 63% of the patients with AUD with deficits at T1 had normal BEARNI cognitive scores (χ2 = 7.7, P = 0.005); specifically, the percentages of participants with normal subtest scores were 63% on memory (χ2 = 12.4, P = 0.0004), 100% on verbal fluency (χ2 = 16; P = <0.0001), 60% on alphabetical span (χ2 = 12.8; P = 0.0003) and 67% on visuospatial (χ2 = 15, P = 0.0001). CONCLUSIONS: The cognitive impairments of two-thirds of patients with pure AUD included in the present study recovered within 18 days of abstinence, earlier than reported in previous studies.

Changes in Alcohol Consumption among Users of an Internet Drug Forum during a COVID-19 Lockdown.

BACKGROUND: The aim of the present study was to assess the frequency and clinical correlates of users of an Internet drug forum who changed their alcohol use during the March-May 2020 COVID-19 lockdown in France. METHODS: An anonymous Internet-based cross-sectional survey during the COVID-19 lockdown was used via messages on a French Internet drug forum. Participants reported any increase in their alcohol consumption during the lockdown. Alcohol craving and depressive/anxiety symptoms were assessed using the Obsessive and Compulsive Drinking scale (OCDS) and Hospital Anxiety and Depression scale (HADS). RESULTS: Of 1310 respondents, 974 (79% of 1270) participants reported alcohol use before lockdown. During the lockdown, 405 participants (41.6%; IC95 (38.5-44.7)) reported an increase. Odds of an increase in alcohol consumption was higher for those with HADS scores higher than 7 (aOR: 2.19; p = 0.00002), OCDS scores greater than 7 (aOR: 3.50; p < 0.001), and daily psychostimulant use (aOR: 1.85; p = 0.002). CONCLUSIONS: Users of an Internet drug forum who reported high levels of depressive symptoms, high levels of alcohol craving, and the use of psychostimulants were more likely to increase alcohol consumption during a COVID-19 lockdown.

The behavioral economics of alcohol demand in Greek-affiliated college students.

BACKGROUND: College students affiliated with fraternity and sorority, or "Greek" life represent a known high-risk group for alcohol consumption and related consequences, but little is known about demand for alcohol in this population. The current study examined behavioral economic demand for alcohol in a sample of Greek life-affiliated undergraduate students using the alcohol purchase task (APT) and a novel variation of the APT that included a fixed-price, nonalcoholic alternative (APT Choice). METHODS: Participants (n = 229) completed the APT, APT Choice, Alcohol Use Disorders Identification Test (AUDIT), and Daily Drinking Questionnaire (DDQ). Group demand indices were calculated for the entire sample and then separately for participants who met or did not meet the legal drinking age (21+ or underage, respectively). Independent-sample t tests assessed whether there were any significant differences between the two age cohorts in the percent change in each behavioral economic index from the APT to APT Choice. Tests of correlation evaluated the construct validity of the demand indices from both hypothetical purchase tasks. RESULTS: Descriptive statistics on alcohol use in this Greek-affiliated sample revealed "hazardous" drinking scores, with AUDIT-C scores exceeding the threshold of alcohol misuse. These measures were significantly correlated with demand indices from both APT conditions, and demand was inversely related to price; however, demand for alcohol was reduced when a nonalcoholic alternative was available. Both age cohorts reported a reduction in BP1 (highest price of nonzero consumption) and an increase in α (rate of change in elasticity), but these changes were significantly greater among underage participants. CONCLUSIONS: Although Greek life-affiliated students demonstrate high demand for alcohol, the concurrent availability of a nonalcoholic alternative reduces alcohol demand, particularly for underage students. These findings suggest that nonalcoholic options may enhance the effectiveness of increasing alcohol prices to reduce alcohol consumption among students at higher risk for alcohol use.

Sugar, a powerful substitute for ethanol in ethanol postdependent rats: Relevance for clinical consideration?

Sugar has been shown to be a powerful substitute for drugs in preclinical studies on addiction. However, the link between sugar intake and alcohol use disorder (AUD) is poorly understood. We assessed the influence of sucrose on ethanol drinking in both nondependent (ND) and dependent (D) Long-Evans rats during acute withdrawal using the postdependent state model. Ethanol (10%-40%) and sucrose (1%-4%) solutions were offered in an operant paradigm either independently or concurrently under ratio schedules of reinforcement. We showed that D rats displayed an enhanced motivation for both 10% ethanol solution (10E) and 4% sucrose solution (4S) as compared with ND rats, and a clear preference for 4S was observed in both groups. During acute withdrawal, D rats showed a strong motivation for 30% ethanol (30E), even when adulterated with quinine, but still preferred 4S despite the fact that a high level of negative reinforcement could be expected. However, when a premix solution (30E4S) was offered concurrently with 4S, the preference for 4S was lost in D animals, which consumed as much premix as 4S, whereas ND animals displayed preference for 4S. Altogether, those results suggest that reinforcing properties of sucrose surpass those of ethanol in D rats under acute withdrawal, which indicates that sugar is a powerful substitute for ethanol. Our results suggest that craving for sugar may be increased in AUD patients during withdrawal and raise the issue of dependence transfer from alcohol to sugar.

The behavioral economics of the bottomless cup: The effects of alcohol cup price on consumption in college students.

Heavy drinking among college students is a public health concern in part due to the accessibility of alcohol and promotions such as "happy hours," which discount the price of alcohol. In addition, consuming alcohol at unregulated off-campus parties may result in greater alcohol consumption, higher blood alcohol concentrations, and increased negative consequences. The purpose of the current study was to assess demand for a refillable red "Solo" cup using a new hypothetical purchase task, the Cup-Price Purchase Task (CPPT). The CPPT asked college student participants to read a description of an off-campus party drinking context and indicate the likelihood of purchasing a refillable cup at prices ranging from $0.00-$60.00. We found that at cup prices of $5.00 or below, the likelihood of purchase was 75% or higher; however, probability of purchase decreased to about 47% at a cup price of $10.00. In addition, several CPPT behavioral economic parameters were positively correlated with the Alcohol Purchase Task (APT) and other alcohol-related measures, providing support for the CPPT's construct validity. Finally, hierarchical regression analyses revealed that maximum expenditure on the CPPT was a unique predictor of both alcohol consumption and alcohol-related consequences, even after controlling for the APT metrics. These findings may inform future studies investigating the behavioral economics of high-risk drinking situations and potential strategies to reduce binge drinking. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Patch-Clamp Recording of Low Frequency Stimulation-induced Long-Term Synaptic Depression in Rat Hippocampus Slices During Early and Late Neurodevelopment.

BACKGROUND: Studying synaptic plasticity in the rat hippocampus slice is a well-established way to analyze cellular mechanisms related to learning and memory. Different modes of recording can be used, such as extracellular field excitatory post-synaptic potential (EPSP) and diverse patch-clamp methods. However, most studies using these methods have examined only up to the juvenile stage of brain maturation, which is known to terminate during late adolescence/early adulthood. Moreover, several animal models of human diseases have been developed at this late stage of brain development. To study the vulnerability of adolescent rat to the cognitive impairment of alcohol, we developed a model of binge-like exposure in which ethanol selectively abolishes low frequency stimulation (LFS)-induced, field EPSP long-term depression (LTD) in the rat hippocampus slice. METHODS: In the present study, we sought to use whole-cell patch-clamp recording in the voltage-clamp mode to further investigate the mechanisms involved in the abolition of LFS-induced LTD in our model of binge-like exposure in adolescent rat hippocampus slices. In addition, we investigated LFS-induced NMDAR-LTD and mGluR-LTD at different ages and changed several parameters to improve the recordings. RESULTS: Using patch-clamp recording, LFS-induced NMDAR-LTD and mGluR-LTD could be measured until 4 weeks of age, but not in older animals. Similarly, chemical mGluR-LTD and a combined LFS-LTD involving both N-Methyl-D-Aspartate Receptor (NMDAR) and mGluR were not measured in older animals. The absence of LFS-LTD was not due to the loss of a diffusible intracellular agent nor the voltage mode of recording or intracellular blockade of either sodium or potassium currents. In contrast to voltage-clamp recordings, LFS-induced LTD tested with field recordings was measured at all ages and the effects of EtOH were visible in all cases. CONCLUSIONS: We concluded that whole-cell patch-clamp recordings are not suitable for studying synaptic LFS-induced LTD in rats older than 4 weeks of age and therefore cannot be used to explore electrophysiological disturbances, such as those induced by alcohol binge drinking during adolescence, which constitutes a late period of brain maturation.

Predicting adverse consequences of alcohol consumption in underage college students using a novel Fake ID Purchase Task.

Underage drinking is a significant public health concern, specifically among college students. The availability of fake IDs increases risks of college binge drinking as well as sexual victimization, providing a call for research on behavioral correlates. The purpose of the present experiment was to determine how much money an underage college sample (N = 98) at a large Midwestern university would be willing to pay to obtain a fake ID and to identify relations between demand for alcoholic drinks, demand for a fake ID, and adverse consequences of past alcohol consumption as measured by the Brief Young Adult Alcohol Consequences Questionnaire. Hierarchical negative binomial regression suggested demand intensity and Omax for alcoholic drinks as well as Omax for a fake ID were associated with a greater number of negative consequences of past alcohol consumption. The present experiment adds to the surmounting evidence implicating demand for fake IDs on college campuses as a serious public health concern. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The Behavioral Economics of Alcohol Demand in French and American University Students.

BACKGROUND: Behavioral economic approaches have revealed several characteristics of alcohol demand (e.g., intensity, elasticity, and essential value) in university students; however, these approaches have not yet examined alcohol demand among students outside of the United States. The current study examined alcohol demand among student samples in the United States and France using a hypothetical alcohol purchase task (APT) and a novel APT Choice task, in which nonalcoholic beverages were concurrently available at a fixed low price. METHODS: Participants at each site (United States, n = 132; France, n = 132) were asked to complete an Internet-based survey including the APT, APT Choice, Alcohol Use Disorders Identification Test, Daily Drinking Questionnaire, and Drinking Motives Questionnaire-Revised Short Form. Group demand functions were produced for each of the 2 samples in both country-specific and standardized drink units, and the exponential demand equation was fitted to each of the APT and APT Choice demand curves. Slope analyses were performed on the Non-Alcoholic Cross-Price demand to assess substitutability. RESULTS: APT data revealed that in both samples, alcohol price and consumption were inversely related and demand measures were significantly associated with other alcohol measures. In addition, the availability of a nonalcoholic alternative reduced alcohol demand in both samples, with evidence of substitutability revealed by increases in cross-price consumption. CONCLUSIONS: Low-cost alcohol is associated with increased alcohol consumption in both French and U.S. university students, and concurrent availability of a nonalcoholic beverage within the APT both reduces alcohol demand and demonstrates behavioral economic substitutability. These findings will inform future studies investigating behavioral and environmental factors underlying transcultural differences and specific prevention efforts.

Animal models of binge drinking, current challenges to improve face validity.

Binge drinking (BD), i.e., consuming a large amount of alcohol in a short period of time, is an increasing public health issue. Though no clear definition has been adopted worldwide the speed of drinking seems to be a keystone of this behavior. Developing relevant animal models of BD is a priority for gaining a better characterization of the neurobiological and psychobiological mechanisms underlying this dangerous and harmful behavior. Until recently, preclinical research on BD has been conducted mostly using forced administration of alcohol, but more recent studies used scheduled access to alcohol, to model more voluntary excessive intakes, and to achieve signs of intoxications that mimic the human behavior. The main challenges for future research are discussed regarding the need of good face validity, construct validity and predictive validity of animal models of BD.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Our translational study highlights a significant role of α-synuclein in components of AUD.

The effects of next-day class characteristics on alcohol demand in college students.

Behavioral economic principles have been useful for addressing strategies to reduce alcohol consumption among college students. For example, academic variables (such as class schedule or academic rigor) have been found to affect alcohol demand assessed with a hypothetical alcohol purchase task (APT). The present studies used the APT to address the effects of 2 academic variables: next-day course level (no class, introductory level or upper level) and class size (no class, 30-student or 12-student). In each of 2 experiments, undergraduate participants read a description of a drinking context (either a no-class control version or 1 of the academic constraint conditions) and were asked to indicate how many drinks they would purchase at a variety of prices. Hursh and Silberberg's (2008) exponential demand equation was used to determine intensity and elasticity of demand, and Hursh and Roma's (2015) essential value (EV) parameter was calculated to assess essential value. In both experiments, a next-day class reduced alcohol demand, and alcohol consumption decreased as drink price increased. The presence of a smaller next-day class reduced alcohol demand compared with a larger next-day class; however, course level did not differentially affect alcohol demand. These results suggest that smaller next-day classes may reduce alcohol demand among college students and also provide initial evidence for the reliability of EV across studies. (PsycINFO Database Record

Delay discounting for sucrose in alcohol-preferring and nonpreferring rats using a sipper tube within-sessions task.

BACKGROUND: Delay discounting (DD) is a measure of impulsivity that quantifies preference for a small reward delivered immediately over a large reward delivered after a delay. It has been hypothesized that impulsivity is an endophenotype associated with increased risk for development of alcohol use disorders (AUDs); however, a causal role of impulsivity is difficult to determine with human studies. We tested this hypothesis by assessing the degree of DD present in alcohol-naïve rats selectively bred for either high- or low-alcohol preference. METHODS: A novel adaptation of a within-sessions DD procedure was used to compare impulsivity differences between male alcohol-preferring (P) and nonpreferring (NP) rat lines (n = 6 per line) using a 5% sucrose reward. Animals chose between 2 options: 2-second sipper tube access delivered immediately (small reward) or 8-second access after a variable delay (large reward). Each 50-minute session consisted of 5 blocks of ten 60-second trials. Within each session, the delay to the large reward increased in each block of trials. Delays were gradually increased over 3 sets to attain a final delay set of 3, 8, 15, 18, and 25 seconds. RESULTS: Prior to starting delays, there were no significant differences between lines in sucrose consumption or percent choice for the large reward, and both lines exhibited a clear preference for the large reward. After delays were initiated, choice for the large reward decreased as the delay to its presentation increased. Although discounting of the large, delayed reward was observed for both lines, the degree of discounting, or "impulsivity," was greater for P rats compared with NP rats. CONCLUSIONS: P rats are more impulsive for sucrose rewards before exposure to alcohol compared with NP rats. Thus, individuals genetically predisposed toward developing AUDs may be more likely to engage in impulsive decision making prior to alcohol exposure.

Academic constraints on alcohol consumption in college students: a behavioral economic analysis.

Behavioral economic analyses recently have been extended to alcohol drinking among college students. The current study used a hypothetical alcohol purchase task (APT) to assess the effects of academic constraints (next-day class time and next-day class requirement) on alcohol demand among college students. Participants were asked to read a description of a drinking scenario and indicate how many standard drinks they would consume at a variety of prices. In Experiment 1, 164 participants (71% female) were randomly assigned to one of three "academic constraint" conditions, for which the scenario included a next-day class that differed by scheduled time (8:30 a.m., 10:00 a.m., or 12:30 p.m.), or a control condition (no next-day class). Exponential demand analyses revealed that participants in all three of the academic constraint conditions reported fewer drinks consumed and displayed lower "essential value" of alcohol, or greater sensitivity to price increases, compared with the no-constraint control. In Experiment 2, 66 participants (80.3% female) were randomly divided into four groups and received one of four versions of the APT, manipulated to examine class time and class requirement (8:30 a.m. class, 8:30 a.m. exam, 12:30 p.m. class, 12:30 p.m. exam). Exponential demand analyses revealed that the essential value of alcohol was lower for the two 8:30 a.m. conditions compared with the 12:30 p.m. conditions and was lowest for participants in the 8:30 a.m. exam condition compared with the other three. These results suggest that academic requirements may reduce alcohol demand among college students.

Matching law choice analyses of ethanol and sucrose consumption in alcohol-preferring (P), nonpreferring (NP), and Sprague-Dawley (SD) rats.

BACKGROUND: Quantitative models of choice, such as the matching law and behavioral economics, allow for the analysis of alcohol consumption within a choice context. Such models can provide further knowledge of phenotypic differences between selected lines of rats. The current study applied the generalized matching law to the ethanol (EtOH) and sucrose consumption of alcohol-preferring (P), nonpreferring (NP), and Sprague-Dawley (SD) rats. METHODS: Male P, NP, and SD rats were trained to consume increasing concentrations of EtOH and water in a limited access, 2-bottle choice procedure. The animals were then given concurrent access to pairs of differing EtOH solutions (2, 4, 6, and 10%, v/v) for 1 h/d. A subset of animals from each rat type was subsequently given access to 8% sucrose for 1 h/d for 5 days, and then concurrent access to pairs of differing sucrose solutions (3, 8, and 15%, w/v) for 1 h/d. The generalized matching law was used to assess the relationship between the relative EtOH and sucrose concentrations and the relative volumes of solutions consumed. RESULTS: The P rats consumed more EtOH and sucrose than the NP and SD rats overall. However, only the P rats consistently consumed disproportionately greater quantities of the higher EtOH concentration than the lower one, indicating overmatching. Additionally, all 3 types of rats displayed overmatching in the sucrose choice experiment. CONCLUSIONS: These data provide further evidence of phenotypic differences between the P rats and other types of rats, and suggest that the generalized matching law can be a useful tool for describing rats' EtOH or sucrose consumption in a 2-bottle choice, limited access paradigm.

Limited-access consumption of ascending ethanol concentrations in alcohol-preferring, nonpreferring, and Sprague-Dawley rats.

BACKGROUND: Ethanol intake and preference differences between the selectively bred alcohol-preferring (P) and nonpreferring (NP) rats have generally been studied in a continuous-access paradigm using 10% ethanol. Little is known about the consumption of lower concentrations of ethanol in these lines or consumption of a wide range of ethanol concentrations in limited-access paradigms. Recently, limited-access paradigms have been used to study the biological and pharmacological mechanisms of ethanol consumption in animal models. Such research would be informed by studies investigating ethanol oral self-administration within a limited-access context. Therefore, the current study addressed P, NP, and Sprague-Dawley (SD) rats' consumption of a wide range of ethanol concentrations in a 2-bottle-choice, limited-access procedure. METHODS: Male P, NP, and SD rats were given concurrent access to water and ethanol solutions for 1 h/d, 7 d/wk. Ethanol solutions were presented in an ascending series ranging from 0.01 to 20% (v/v) over 55 days. Ethanol intakes (g/kg), volumes of solutions consumed (mL/kg), and preference ratios were assessed for each rat line at each concentration. RESULTS: Clear differences among the 3 types of rats emerged at an ethanol concentration of 4%, although differences between P and NP rats emerged at concentrations as low as 1.8%. Alcohol-preferring rats almost exclusively preferred ethanol solutions over water at ethanol concentrations of 4% and above, whereas SD and NP rats' preference ratios were more variable. CONCLUSIONS: The results suggest that differences between P and NP rats exist at ethanol concentrations lower than those previously studied in continuous-access paradigms. They also provide a current description of the ranges of ethanol concentrations preferred by P, NP, and SD rats.