Binge ethanol consumption causes differential brain damage in young adolescent rats compared with adult rats

Background: Adolescents respond differently to alcohol than adults. Furthermore, binge drinking in young adolescents is becoming increasingly common. Methods: To determine if the effects of binge drinking on brain damage are different in juveniles compared with adults, the effects of a 4 day binge ethanol treatment (e.g., 4 days of 4 times per day 15% ethanol intragastrically, approximately 9-10 g/kg/day ethanol) were investigated in adolescent-juvenile rats (JVN) 35 days old and compared with adult (ADT) rats 80 to 90 days old. Brain damage was measured by using the amino cupric silver stain of de Olmos et al. (1994). Results: Significant brain damage was found in both groups. The olfactory bulbs were equally damaged in both groups; however, the associated frontal cortical olfactory regions were damaged only in JVN. The anterior portions of the piriform and perirhinal cortices also were damaged only in JVN rats. Quantitation of silver-stained frontal areas in binge ethanol-treated JVN rats ranged from 400% to 1260% of control values. For example, in anterior perirhinal cortex, silver stain increased from 48 +/- 14 to 444 +/- 114 (mm(2) x 10(3) argyrophilic area; p < 0.01) in JVN control and binge ethanol-treated animals, respectively. In contrast, posterior perirhinal cortex showed greater damage in adults, being 236 +/- 76 vs. 875 +/- 135 (mm(2) x 10(3) argyrophilic area; p < 0.005) in JVN and ADT, respectively. Conclusions: The young-adolescent brain shows differential sensitivity to alcohol-induced brain damage compared with adults.