Effects of prior cocaine exposure on subsequent neuronal responsiveness

In vivo electrophysiological experiments were conducted to examine the responses of single, spontaneously-active neostriatal neurons to repeated cocaine exposure. The second of two administrations in a 30 min interval, attenuated the magnitude and duration of cocaine-induced depression in discharge rate, and enhanced the same variables for cocaine-evoked excitation. These findings indicate that the responsiveness of striatal neurons to cocaine may vary predictably as a function of previous exposure.