Effects of H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH on passive and active avoidance behavior and on open-field activity of rats.

The action of H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH on the passive and active avoidance behavior and open-field activity of rats was studied after peripheral and intracerebroventricular administration. When applied before the test session, intracerebroventricular administration increased the avoidance latency of passive avoidance behavior. Subcutaneous, intraperitoneal and intracerebroventricular administration of the peptide delayed the extinction of active avoidance behavior. Both subcutaneous and intracerebroventricular administration increased the grooming activity of the rats. The data suggest that H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH is able to influence memory, acting mainly on the retrieval processes, and to modify open-field activity.