Amphetamine enhances extracellular concentrations of dopamine and acetylcholine in dorsolateral striatum and nucleus accumbens of freely moving rats.

The effect of two consecutive administrations of amphetamine (1.5 mg/kg, s.c.; 2 h apart) on dopamine (DA) and acetylcholine (ACh) efflux in dorsolateral striatum and nucleus accumbens was studied with in vivo microdialysis in freely moving rats. Amphetamine was found to cause a more persistent increase of extracellular DA in the dorsolateral striatum than in the nucleus accumbens. The increase in DA overflow by amphetamine was accompanied by an increase of extracellular ACh in both brain areas. The results are inconsistent with the hypothesis of an amphetamine-induced inhibitory regulation by DA on ACh overflow.