STEREOSPECIFIC BLOCKADE OF N-METHYL-D-ASPARTATE TRANSMISSION BY MK-801 PREVENTS PRIMING OF SKF 38393-INDUCED TURNING

In rats unilaterally lesioned with 6-hydroxydopamine, the D-1 agonist SKF 38393 (3 mg/kg SC) induced contralateral turning only after priming with a dopaminergic agonist such as apomorphine. Administration of the N-methyl-d-aspartate receptor antagonist (+) MK 801 (0.1 mg/kg IP) 15 min before apomorphine (0.1 mg/kg SC) prevented the ability of apomorphine to act as a primer while potentiating its acute contralateral turning effects. The inactive isomer (-) MK 801 was without effect. The results indicate that the N-methyl-d-aspartate receptor exerts a permissive role on priming. © 1990 Springer-Verlag.