Increased maternal corticosterone levels in rats: Effects on brain 5-HT1A receptors and behavioral coping with stress in adult offspring

This study examined the consequences of elevated corticosterone levels in l actating rats on their offspring's serotonergic 5-hydroxytryptamine (5-HT)( 1A) receptor system and behavioral coping with stress. The mothers received normal drinking water or water with corticosterone, which, via the milk, e nters the circulation and brains of the pups. In adulthood, the corticoster one-nursed offspring showed a consistently more passive way of coping with environmental challenges. However, they did not seem to be more anxious. Au toradiographic analysis of the 5-HT1A receptor system revealed a decrease i n the adult 5-HT1A receptor binding in the hippocampal CAI region. The resu lts support the hypothesis that differences in behavioral coping with stres s by adult rats are associated with differences in the serotonergic system. At the same time, it suggests that adult coping and its neuronal substrate s are not solely determined by genes but depend on subtle developmental fac tors as well.