Steroid-sensitive GABAA receptors in the fetal sheep brain

Abstract

Neuroactive steroids such as allopregnanolone (3α-hydroxy-5α-pregnan-20-one) influence central nervous system (CNS) excitability by increasing GABA (gamma aminobutyric acid) inhibitory activity. Allopregnanolone concentrations are higher in the fetal compared to the adult ovine brain, suggesting that this neurosteroid may have a role in regulating fetal CNS activity during gestation. We examined the localisation of allopregnanolone-sensitive GABAA receptors in the fetal brain to determine if their sensitivity to allopregnanolone changed during late gestation. The binding of [35S] tert-butylbicyclophosothionate (TBPS) was used to identify the GABA-chloride ion receptor complex in fetal sheep ..