Effects of H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH on different behavioral tests of rats.

H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH inhibited the extinction of active avoidance behavior 3 h and 6 h after administration and facilitated the learning of a T-discrimination task. The peptide antagonized ECS-induced amnesia, if the treatment was performed 1 h before the test session. These results suggest that H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH can facilitate learning and memory processes.