title: Impact of social isolation and enriched environment during adolescence on voluntary ethanol intake and anxiety in C57BL/6J mice.
abstract: This study was designed to determine the impact of an enriched environment in a previously established stress model of isolation during early development that induces high alcohol (ethanol) self-administration. The study was conducted with male and female C57BL/6J mice housed in isolation or in groups that were either provided or withheld enrichment during adolescence. The impact of these housing conditions was assessed during adulthood by measuring weight gain, quantifying voluntary ethanol intake, measuring plasma corticosterone levels, and assessing anxiety-like behavior. Results showed that, regardless of sex, mice that were single-housed during adolescence showed a significant increase in voluntary ethanol intake, which was not observed in isolated mice that were provided with nesting material during adolescence (compared to group-housed non-enriched control group). Basal corticosterone was not affected by housing, enrichment conditions, or sex. Corticosterone levels did not relate to levels of voluntary ethanol intake. However, corticosterone levels were higher after three weeks of ethanol intake. Surprisingly, mice that were group-housed during adolescence showed higher levels of anxiety-like behavior in the light/dark test. Overall, these results indicate that housing conditions during a critical developmental period can significantly modulate voluntary ethanol intake later in life.
authors.affiliation: Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 29425, United States. Electronic address: lopezm@musc.edu.
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Lopez
authors.affiliation: VA Medical Center, 114 Doughty Street, Charleston, SC 29425, United States; Comparative Medicine Branch, NIEHS, PO Box 12333, MD-C1-05, Research Triangle Park, NC 27709, United States.
authors.forename: Kathy
authors.initials: K
authors.lastname: Laber
mesh_terms: D000367:Age Factors; D000428:Alcohol Drinking / Q000503:physiopathology*; D000704:Analysis of Variance; D000818:Animals; D001007:Anxiety / Q000097:blood / Q000451:nursing* / Q000523:psychology*; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D003345:Corticosterone / Q000097:blood; D003623:Dark Adaptation / Q000502:physiology; D004195:Disease Models, Animal; D004777:Environment; D000431:Ethanol / Q000008:administration & dosage*; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012737:Sex Factors; D012934:Social Isolation / Q000523:psychology*
chemical_list: D000431:Ethanol; D003345:Corticosterone
keywords: Adolescence; Alcohol; Enriched environment; Isolation