ASCORBATE POTENTIATES AMPHETAMINE-INDUCED CONDITIONED PLACE PREFERENCE AND FOREBRAIN DOPAMINE RELEASE IN RATS

In order to evaluate the effects of ascorbate, which is known to modul ate dopamine neurotransmission, on the reinforcing effects of amphetam ine, we coadministered ascorbate and amphetamine during the acquisitio n of conditioned place preference (CPP) in rats. Our results indicate that 100 mg/kg ascorbate potentiates the CPP induced by 0.5 mg/kg, but not 1.0 mg/kg, amphetamine. A higher dose of ascorbate (500 mg/kg) di d not influence the CPP induced by either dose of amphetamine. In vitr o release assays revealed that, whereas ascorbate alone (0.01-1.0 mM) did not influence striatal dopamine levels, this vitamin potentiated a mphetamine-induced dopamine release in both the nucleus accumbens and neostriatum. Collectively, these results raise the possibility that as corbate potentiates amphetamine-induced CPP by increasing the ability of this psychostimulant to release dopamine.