BEHAVIORAL PROFILE IN THE CHICKEN OF CQ 32-084 AND CQP 201-403, 2 DOPAMINE AGONISTS

CQ 32-084 and CQP 201-403, two ergot derivatives that previous behavio ural studies in rats had suggested to be differently active on dopamin e (DA) receptors, were IP injected into male chickens. Both compounds strongly modified the animals' behaviour. CQ 32-084 led to sedation, i ncreased yawning, and decreased preening, while CQP 201-403 exerted a biphasic activity: At a low dose, it elicited sedation and yawning; at high doses, however, it induced a state of excitation manifested by d iminished sedation and yawning, enhanced preening, and pecking. The se dation, increased yawning, and decreased preening induced by the two D A agonists were reversed by the D2-selective antagonist, sulpiride. Th e present studies indicate that, from a behavioural point of view, chi ckens respond similarly to rats to the DA agonists CQ 32-084 and CQP 2 01-403, which differ in their selectivity of action on the various DA receptor subtypes.