BEHAVIOURAL PROFILE IN CHICKEN OF CQ 32-084 AND CQP 201-403, TWO DOPAMINE AGONISTS

CQ 32-084 and CQP 201-403, two ergot derivatives that previous behavioural studies in rats had suggested to be differently active on dopamine (DA) receptors, were IP injected into male chickens. Both compounds strongly modified the animals' behaviour. CQ 32-084 led to sedation, increased 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 diminished sedation and yawning, enhanced preening, and pecking. The sedation, increased yawning, and decreased preening induced by the two DA agonists were reversed by the D2-selective antagonist, sulpiride. The present studies indicate that, from a behavioural point of view, chickens respond similarly to rats to the DA agonists CQ 32-084 and CQP 201-403, which differ in their selectivity of action on the various DA receptor subtypes.