AMPHETAMINE INFUSIONS INTO THE PREFRONTAL CORTEX ATTENUATE THE SENSITIZATION TO AMPHETAMINE

1. Adult male rats were implanted with chronic medial prefrontal corte x cannulae. 2. On each of 5 consecutive days, rats received bilateral 0.5 mi intra-prefrontal cortex injections of either 5 mg d-amphetamine or saline, followed by a subcutaneous injection of either 1 mg/kg d-a mphetamine 3. Immediately after the drug treatments each rat was place d into a photocell equipped locomotor activity chamber for 60 min. 4. Administration of d-amphetamine into the prefrontal cortex did not blo ck the acute locomotor response to subcutaneous d-amphetamine nor did it in itself produce an increase in locomotor activity. However, prefr ontal cortex amphetamine treatments did attenuate the sensitized locom otor effects of subcutaneous amphetamine that developed over trials/da ys. 5. Dopamine in the prefrontal cortex may be involved in the develo pment of amphetamine-induced behavioral sensitization.