Central allopregnanolone is increased in rat pups in response to repeated,short episodes of neonatal isolation

This experiment investigated whether neonatal isolation stress alters centr al concentrations of progestins. Whole brain progesterone (P). dihydroproge sterone (DHP), and allopregnanolone (3 alpha, 50 alpha -THP) were measured in pups that were isolated from the nest, dam, and siblings for 1 h on post natal days (PND) 2-9 and were compared to control litters of pups that were not isolated. isolated 2-day-old pups had significantly lower central P an d higher P to DHP and 3 alpha, 5 alpha -THP metabolism ratios. On PND 9, pu ps that had been repeatedly isolated (PND 2-8), had significantly lower who le brain DHP and significantly greater whole brain 3 alpha, 5 alpha -THP co mpared to controls. Thus, the biosocial stress of isolation in neonatal rat s alters central pregnane steroids. (C) 2000 Elsevier Science B.V. All righ ts reserved.