Alteration of Neonatal Allopregnanolone Levels Affects Exploration, Anxiety, Aversive Learning, and Adult Behavioral Response to Intrahippocampal Neurosteroids

The study investigated the impact of altering neonatal Allopregnanolone (Allop) levels on adult behavior and hippocampal response to neurosteroids (NS). Using 187 male Wistar rats, researchers administered Allop, Finasteride, or a vehicle to pups from postnatal day 5 to 9. Results showed that neonatal Allop level alterations affected adult exploratory behavior, anxiety, and aversive learning. Specifically, neonatal Allop or pregnenolone level changes suppressed the anxiolytic effect of intrahippocampal Allop in the elevated plus maze (EPM). The findings highlighted the critical role of neonatal Allop in hippocampal development and adult behavior, marking the first demonstration of these effects.