The effects of neurosteroids on acquisition and retention of a modified passive-avoidance learning task in mice

摘要: This study examined the effects of neurosteroids, pregnenolone sulfate (PS) and dehydroepiandrosterone (DHEAS), on learning memory processes in a modified passive-avoidance task mice. The two parameters measured are number step-down descents active escape latency to reach shock-free zone. Each neurosteroid was administered 60 min before or immediately after training session, retention test given 24 h acquisition. Pretraining injection PS (0.125-10 mg/kg, s.c.) DHEAS decreased mistakes committed day but had no effect measure. Both zone, dose-dependent bell-shaped manner, following pretraining posttraining administration schedules. Neurosteroids failed improve performance when testing. Injection (0.5 1 mg/kg) (1 5 both sessions, however, also significantly facilitated retention. In addition, memory-facilitating blocked by concurrent haloperidol (0.25 i.p.), prototype sigma receptor antagonist. These results confirm that facilitate either posttraining, not prior test. neurosteroid-induced modulation do involve state-dependent effects. suggest role for central memory-modulating neurosteroids.