ROLE OF GABA(A) RECEPTORS IN THE ORGANIZATION OF BRAIN AND BEHAVIORALSEX-DIFFERENCES

SEX differences in GABA neurotransmitter have been described. We have studied the involvement of the GABA(A) receptor in sex differences in the brain and reproductive behaviour. Neonatal administration of the G ABA(A) agonist diazepam to male rats facilitated the induction of mate rnal behaviour in adults, while the antagonist picrotoxin disrupted it in females. Sex differences in the accessory olfactory bulb were also reversed, but gonadal function remained unaltered in both sexes. This suggests that neonatal changes in neuronal membrane permeability to C l- ions may play a role in the organization of sex differences. Our st udy constitutes a new model for understanding the early neurobiologica l organization of sex differences.