COCAINE-INDUCED BEHAVIORAL SENSITIZATION IS ASSOCIATED WITH INCREASEDPROTEIN-KINASE-C ACTIVITY IN THE VENTRAL TEGMENTAL AREA

The studies outlined below examined the effects of repeated cocaine-ad ministration on protein kinase C activity within the mesocorticolimbic and nigrostriatal dopamine systems. Twenty-four hours after receiving daily injections of saline or cocaine animals were challenged with sa line or 15 mg/kg cocaine and motor activity was measured for 2 hours. Protein kinase C activity was determined in brain samples collected im mediately following acquisition of behavioral data. Animals receiving daily injections of 15.0 mg/kg cocaine demonstrated a behaviorally sen sitized response to cocaine, which was associated with enhanced protei n kinase C activity in the ventral tegmental area. These data suggest that increased protein kinase C activity in the ventral tegmental area may be important in the development of behavioral sensitization.