[The effect of neurohypophyseal peptides on the formation of conditioned active avoidance behavior].

An injection of vasopressin and its analog into ventral hippocampus facilitated the formation of avoidance response and inhibited the behavioural habit in the process of extinction. Opposite effects occurred after administration of oxytocin and its fragment. The changes observed in the avoidance paradigms motivated by fear seem to be related to effects of the peptides under study on the processes of learning and memory.