Effects of SCH23390 injection into the dorsal striatum and nucleus accumbens on methamphetamine-induced gnawing and hyperlocomotion in rats.

The effects of SCH23390, a selective D1 receptor antagonist, injected into either the dorsal striatum or nucleus accumbens on methamphetamine-induced stereotyped gnawing and hyperlocomotion in rats were investigated. SCH23390 injected into the dorsal striatum did not alter the gnawing induced by both methamphetamine and apomorphine. However, SCH23390 injected into the nucleus accumbens significantly reduced methamphetamine-induced gnawing without altering the effects of apomorphine. Injection of SCH23390 into the nucleus accumbens reduced the hyperlocomotion produced by methamphetamine more markedly than injection of SCH23390 into the dorsal striatum.