Dopamine uptake inhibition is positively correlated with cocaine-induced stereotyped behavior

Fast-scan cyclic voltammetry on freely moving rats was used to determine whether a correlation exists between the increase in stereotyped behavior and dopamine (DA) uptake inhibition following cocaine (20 mg/kg, i.p.) administration. Voltammetric recordings were performed every 100 ms at a carbon fiber microelectrode, positioned in the nucleus accumbens. The present experiments revealed that the time course of the changes in K_m strictly parallels the time course of the increase in stereotypy after cocaine. More importantly, the magnitudes of cocaine-stimulated stereotypy were positively and significantly correlated with the K_m increases. Therefore, these data closely link the DA transporter inhibition with cocaine-induced stereotypy.