Evidence of the involvement of D1 dopamine receptors in PCP-induced stereotypy and ataxia in rabbits

Abstract

A behavioural study on the effects of D1 and D2 dopamine receptor antagonists (SCH 23390 and sulpiride respectively) and of an Al adenosine receptor agonist ( N 6- l-phenylisopropyladenosine, l-PIA) against phencyclidine (PCP)-induced effects was assessed in adult male rabbits. SCH 23390 (0·003–0·01 mg/kg i.v.) and sulpiride (12 · 5 mg/kg i.v.) were able to significantly prevent PCP induced stereotypy. Ataxia was reduced by SCH 23390 (0·003 mg/kg i.v.), while it was potentiated by sulpiride (12 · 5 mg/kg i.v. ). Given alone at 12 · 5 mg/kg, sulpiride induced some EEG and behavioural effects in rabbits, while SCH 23390 (0·003 and 0·01 mg/kg) did not. l-PIA prevented both PCP-induced stereotypy and ataxia at the dose (0 · 1 mg/kg i.v.) devoid of behavioural or EEG effects by itself. Our results suggest that Dl dopamine receptors might play a more important role than D2 receptors in the expression of PCP-induced behaviour. They also propose that Al adenosine receptors might be involved (e.g. via an influence on the dopamine release) in the behavioural effects of PCP.