Effects of RGH 2202 on cognitive and motor behavior of the rat.

The behavioral activity of the thyrotropin-releasing hormone (TRH) analogue, L-6-ketopiperidine-2-carbonyl-leucyl-L-prolinamide (RGH 2202), has been studied in animal models of central neurotransmission disruption. In 24-month-old rats, repeated administration of the peptide (5 or 10 mg/kg/day, injected IP for 20 days) was followed by a facilitated acquisition of active avoidance behavior in the shuttle-box test and retention of passive avoidance reaction in a step-through passive avoidance task. Also, ambulation in an open field was increased and motor performance and co-ordination in the rotorod test was facilitated by the treatment.