NAN-190 potentiates the impairment of retention produced by swim stress.

Exposing rats to stress in the form of forced swim immediately after passive-avoidance training impaired retention. In contrast, exposure to the same stressor 2 h after training failed to impair retention. Systemic administration of the 5-HT1A receptor antagonist NAN-190 (1 mg/kg) immediately after forced swim markedly potentiated the stress-induced impairment of retention. In contrast, NAN-190 failed to affect retention when administered 2 h after forced swim or in forced swim's absence. These findings provide evidence for a NAN-190-sensitive system modulating retention that is 1) activated during a critical period shortly after exposure to swim stress, and 2) protective of memory, thereby limiting the extent to which retention is impaired by experiential stress.