{"title":"Age- and sex-driven alterations in alcohol consumption patterns: Role of brain ethanol metabolism and the opioidergic system in the nucleus accumbens","authors":"","doi":"10.1016/j.pbb.2024.173845","DOIUrl":null,"url":null,"abstract":"<div><p>Alcohol consumption leads to significant neurochemical and neurobiological changes, contributing to the development of alcohol use disorders (AUDs), which exhibit sex- and age-dependent variations according to clinical data. However, preclinical studies often neglect these factors when investigating alcohol consumption patterns. In this study, we present data on male and female rats continuously exposed to a 20 % ethanol solution for one month. The animals were divided into two groups based on their age at the onset of drinking (8 and 12 weeks old). Interestingly, 12-week-old males consumed significantly less alcohol than both 12-week-old females and 8-week-old animals, indicating that alcohol consumption patterns vary with sex and age in our model. Additionally, to advance in the study of the neurobiological alterations induced by ethanol intake in the mesocorticolimbic system (MCLS) that may participate in its reinforcing properties and the maintenance of alcohol drinking behavior, we measured catalase activity—an enzyme involved in alcohol metabolism and related to ethanol reinforcement—in the nucleus accumbens (NAc) of these animals. Furthermore, we measured the levels of mu (MOR), kappa (KOR), delta (DOR), and nociceptin (NOP) opioid receptors in the NAc, as the endogenous opioidergic system plays a pivotal role in regulating the MCLS and alcohol reinforcement. MOR levels were lower in high alcohol-consuming groups (8-week-old males and all females). Both DOR and NOP levels decreased with age, whereas KOR levels remained unchanged. Our findings suggest that the age at onset of alcohol consumption critically influences alcohol intake, particularly in males. Additionally, females consistently showed higher alcohol intake regardless of age, highlighting inherent sex-specific differences. The dynamic changes in catalase activity and opioid receptor expression suggest the involvement of these factors in modulating alcohol consumption.</p></div>","PeriodicalId":19893,"journal":{"name":"Pharmacology Biochemistry and Behavior","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0091305724001394/pdfft?md5=eafd9709425dba6cfbb4b770ee7ade21&pid=1-s2.0-S0091305724001394-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Pharmacology Biochemistry and Behavior","FirstCategoryId":"102","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0091305724001394","RegionNum":3,"RegionCategory":"心理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BEHAVIORAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Alcohol consumption leads to significant neurochemical and neurobiological changes, contributing to the development of alcohol use disorders (AUDs), which exhibit sex- and age-dependent variations according to clinical data. However, preclinical studies often neglect these factors when investigating alcohol consumption patterns. In this study, we present data on male and female rats continuously exposed to a 20 % ethanol solution for one month. The animals were divided into two groups based on their age at the onset of drinking (8 and 12 weeks old). Interestingly, 12-week-old males consumed significantly less alcohol than both 12-week-old females and 8-week-old animals, indicating that alcohol consumption patterns vary with sex and age in our model. Additionally, to advance in the study of the neurobiological alterations induced by ethanol intake in the mesocorticolimbic system (MCLS) that may participate in its reinforcing properties and the maintenance of alcohol drinking behavior, we measured catalase activity—an enzyme involved in alcohol metabolism and related to ethanol reinforcement—in the nucleus accumbens (NAc) of these animals. Furthermore, we measured the levels of mu (MOR), kappa (KOR), delta (DOR), and nociceptin (NOP) opioid receptors in the NAc, as the endogenous opioidergic system plays a pivotal role in regulating the MCLS and alcohol reinforcement. MOR levels were lower in high alcohol-consuming groups (8-week-old males and all females). Both DOR and NOP levels decreased with age, whereas KOR levels remained unchanged. Our findings suggest that the age at onset of alcohol consumption critically influences alcohol intake, particularly in males. Additionally, females consistently showed higher alcohol intake regardless of age, highlighting inherent sex-specific differences. The dynamic changes in catalase activity and opioid receptor expression suggest the involvement of these factors in modulating alcohol consumption.
期刊介绍:
Pharmacology Biochemistry & Behavior publishes original reports in the areas of pharmacology and biochemistry in which the primary emphasis and theoretical context are behavioral. Contributions may involve clinical, preclinical, or basic research. Purely biochemical or toxicology studies will not be published. Papers describing the behavioral effects of novel drugs in models of psychiatric, neurological and cognitive disorders, and central pain must include a positive control unless the paper is on a disease where such a drug is not available yet. Papers focusing on physiological processes (e.g., peripheral pain mechanisms, body temperature regulation, seizure activity) are not accepted as we would like to retain the focus of Pharmacology Biochemistry & Behavior on behavior and its interaction with the biochemistry and neurochemistry of the central nervous system. Papers describing the effects of plant materials are generally not considered, unless the active ingredients are studied, the extraction method is well described, the doses tested are known, and clear and definite experimental evidence on the mechanism of action of the active ingredients is provided.