MODULATION OF STRIATAL ADENOSINE A(1) AND A(2) RECEPTORS INDUCES ROTATIONAL BEHAVIOR IN RESPONSE TO DOPAMINERGIC STIMULATION IN INTACT RATS

The intraperitoneal injection of d-amphetamine (5 mg/kg i.p.), preceded (10 min before) by intrastriatal injection of an adenosine A(2) receptor agonist (CGS 21680, 5-10 mu g) or followed (5 min later) by an intrastriatal adenosine A(1) receptor agonist (N-6-cyclopentyladenosine, CPA, 30 mu g), induced ipsilateral rotations in rats. The opposite effect (contralateral rotations) was observed with adenosine receptor antagonists (A(2) antagonist, 3,7-dimethyl-1-propargylxanthine, DMPX, 10 mu g; A(1) antagonist, 8-cycropentyl-1,3-dimethylxanthine, CPT, 2.5 mu g). These results confirm that both adenosine A(2) and A(1) receptors modulate striatal dopaminergic neurotransmission.