This study was designed to examine the role of calcium in the amphetamine-induced turning behavior of mice lesioned with 6-hydroxydopamine. Intrastriatal administration of either saline or calcium had no effect on amphetamine-induced circling in lesioned mice. In contrast, intrastriatal administration of either EGTA, which chelates extracellular calcium, or verapamil, which inhibits calcium entry into cells, blocked the amphetamine-induced circling. The effect of EGTA was reveresd by the administration of calcium to the EGTA solution. At a dose that blocked amphetamine-induced circling, EGTA did not inhibit the circling produced by apomorphine. These results suggest that EGTA may exert its inhibitory effect on amphetamine-induced circling via a presynaptic mechanism.
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience