title: Chronic Drinking During Adolescence Predisposes the Adult Rat for Continued Heavy Drinking: Neurotrophin and Behavioral Adaptation after Long-Term, Continuous Ethanol Exposure.
abstract: Previous research has found that adolescent ethanol (EtOH) exposure alters drug seeking behaviors, cognition and neuroplasticity. Using male Sprague Dawley rats, differences in spatial working memory, non-spatial discrimination learning and behavioral flexibility were explored as a function of age at the onset (mid-adolescent vs. adult) of chronic EtOH exposure (CET). Concentrations of mature brain-derived neurotrophic factor (mBDNF) and beta-nerve growth factor (β-NGF) in the prefrontal cortex and hippocampus were also assessed at different time-points: during CET, following acute abstinence (48-hrs), and after protracted abstinence (6-8 wks). Our results revealed that an adolescent onset of CET leads to increased EtOH consumption that persisted into adulthood. In both adult and adolescent onset CET groups, there were significant long-term reductions in prefrontal cortical mBDNF and β-NGF levels. However, only adult onset CET rats displayed decreased hippocampal BDNF levels. Spatial memory, assessed by spontaneous alternation and delayed alternation, was not significantly affected by CET as a function of age of drinking onset, but higher blood-EtOH levels were correlated with lower spontaneous alternation scores. Regardless of the age of onset, EtOH exposed rats were impaired on non-spatial discrimination learning and displayed inflexible behavioral patterns upon reversal learning. Our results indicate that adolescent EtOH exposure changes long-term consumption patterns producing behavioral and neural dysfunctions that persist across the lifespan.
authors.affiliation: Department of Psychology, Binghamton University, State University of New York, Binghamton, New York, United States of America.
authors.forename: Gina M
authors.initials: GM
authors.lastname: Fernandez
authors.affiliation: Department of Psychology, Binghamton University, State University of New York, Binghamton, New York, United States of America.
authors.forename: William N
authors.initials: WN
authors.lastname: Stewart
authors.affiliation: Department of Psychology, Binghamton University, State University of New York, Binghamton, New York, United States of America.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Savage
mesh_terms: D000367:Age Factors; D000428:Alcohol Drinking; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D002492:Central Nervous System Depressants / Q000494:pharmacology; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009414:Nerve Growth Factors / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D065853:Spatial Learning / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D015430:Weight Gain / Q000187:drug effects / Q000502:physiology
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D002492:Central Nervous System Depressants; D009414:Nerve Growth Factors; D000431:Ethanol