Sex and age differences of neurons expressing GABA-immunoreactivity in therat bed nucleus of the stria terminalis

Neurons, containing GABA were visualised immunohistochemically in the bed n ucleus of the stria terminalis. Young prepubertal (20 days of age) and post pubertal (3 months and 1 year of age) Sprague Dawley rats were used. Quanti tative studies revealed greater density of GABA-immunoreactive perikarya in female than in male bed nucleus of the stria terminalis. This difference w as not due to distribution in different volumes, since the volumes of the b ed nucleus of the stria terminalis in the three ages studied did not differ by gender. Castration of new-born male rats caused elevation of the densit y of GABA-immunoreactive neurons in the bed nucleus of the stria terminalis to female levels on the third month of life. The percentage of nerve cells , expressing detectable amounts of GABA increased with age in the rat bed n ucleus of the stria terminalis. The sexual dimorphism of GABA-immunoreactiv e neurons in the bed nucleus of the stria terminalis may contribute to the formation of reproductive behavior. The elevation of GABA expression with a ge might reflect change of the cellular activity in this part of the limbic circuitry. (C) 1998 ISDN. Published by Elsevier Science Ltd.