EFFECTS OF SELECTIVE ADENOSINE A(1) AND A(2A) AGONISTS ON AMPHETAMINE-INDUCED LOCOMOTION AND C-FOS IN STRIATUM AND NUCLEUS-ACCUMBENS

Low to moderate doses of amphetamine produce locomotion which is depen dent on release of dopamine in the anteromedial striatum and nucleus a ccumbens. The effects of selective adenosine A(1) and A(2a) receptor a gonists on locomotion and c-Fos induction following a moderate dose of amphetamine was assessed in rats. Pretreatment with the adenosine A(1 ) receptor agonist N-6-cyclohexyladenosine (CHA) or the adenosine A(2a ) receptor agonist ylphenylethylamino]-5'-N-ethylcarboxamidoadenosine (APEC) inhibited locomotion following an injection of amphetamine (1.5 mg/kg). This dose of amphetamine induced Fos-like immunoreactivity in an antero-dorsomedial distribution in the caudate-putamen and uniform ly in the core and shell of the nucleus accumbens. Pretreatment with t he adenosine A(2a) receptor agonist APEC, but not the adenosine A(1) r eceptor agonist CHA, attenuated c-Fos induction in caudate-putamen and nucleus accumbens by amphetamine. These findings indicate that amphet amine-induced behavior is subject to modulation by adenosine receptors through mechanisms which are both related to and independent of c-Fos induction.