Facilitation of arginine-vasopressin analogs on learning and memory in rats

Adult rats were trained in a maze for brightness discrimination (BD) or in a shuttle box for active avoidance. It was found that the pretreatment of 1-desamino-8-D-arginine-vasopressin (DDAVP) enhanced the retention of brightness discrimination and retarted the extinction of avoidance response. Neonatal daily administration for 14 d of both 9-desglycylamide-DDAVP (DGDDAVP) or 2-destyrosyl-3-desphenylalanyl-9-desglycylamide-AVP (AVP4-8), but not D-arginine-AVP4-8 (DAVP4-8) showed significant facilitation on acquisition and subsequent maintenance of BD in adult rats. The results indicate that some of synthetic arginine-vasopressin analogs may directly act on CNS and consequently affect learning behaviors in rats.