Evidence that CCKB receptors mediate the regulation of exploratory behaviour in the rat

Peripheral administration of cholecystokinin tetrapeptide (CCK-4) at non-sedative doses (25-50 micrograms/kg) decreased the exploratory activity of rats in an elevated plus-maze. This effect was antagonized by treatment with CCK receptor antagonists proglumide (1 and 10 mg/kg), lorglumide (0.1 and 1 mg/kg), L 365,260 (10 micrograms/kg) and devazepide (1 mg/kg). The results suggest that the exploratory behaviour of rats can be altered by pharmacological manipulations at CCK-B receptors.