PRIMING ENHANCES THE RELATIONSHIP OF STRIATAL L-DOPA CONCENTRATION TOBEHAVIOR

RATS with unilateral 6-hydroxydopamine (6-OHDA) lesions were exposed t o L-DOPA treatments, 25 mg kg(-1) L-DOPA methyl ester/2 mg kg(-1) carb idopa, or to saline. Fourteen days later, both sets of animals were te sted with the L-DOPA/carbidopa treatment. The L-DOPA preexposed animal s exhibited behavioral sensitization as indexed by a higher frequency of contralateral rotations. Although striatal L-DOPA and HVA concentra tions were equivalent in the two groups, the L-DOPA treatment induced a 10 fold variation in the range of L-DOPA concentrations in the 6-OHD A striatum in both sets of animals. Importantly, significant correlati ons between striatal L-DOPA concentration and behavior were obtained o nly for the L-DOPA pre-exposed animals.