Abstract
BACKGROUND: Adolescent alcohol abuse remains a serious public health concern, with nearly a third of high school seniors reporting heavy drinking in the previous month. METHODS: Using the high ethanol-consuming C57BL/6J mouse strain, we examined the effects of ethanol (3.75 g/kg, IP, daily for 45 days) on body weight and brain region mass (cerebral cortex, cerebellum, corpus callosum) during peri-adolescence (postnatal day [P]25 to 70) or adulthood (P180 to 225) of both males and females. RESULTS: In control peri-adolescent animals, body weight gain was greater in males compared with females. In the peri-adolescent exposure group, ethanol significantly reduced body weight gain to a similar extent in both male and female mice (82 and 84% of controls, respectively). In adult animals, body weight gain was much less than that of the peri-adolescent mice, with ethanol having a small but significant effect in males but not females. Between the control peri-adolescent and adult cohorts (measurements taken at P70 and 225, respectively), there were no significant differences in the mass of the cerebral cortex or the cerebellum from either male or female mice, although the rostro-caudal length of the corpus callosum increased slightly but significantly (6.1%) between these time points. CONCLUSIONS: Ethanol treatment significantly reduced the mass of the cerebral cortex in peri-adolescent (-3.1%), but not adult, treated mice. By contrast, ethanol significantly reduced the length of the corpus callosum in adult (-5.4%), but not peri-adolescent, treated mice. Future studies at the histological level may yield additional details concerning ethanol and the peri-adolescent brain.