METHAMPHETAMINE-INDUCED FOS EXPRESSION IN THE SUBSTANTIA-NIGRA PARS RETICULATA IN RATS WITH A UNILATERAL 6-OHDA LESION OF THE NIGROSTRIATALFIBERS

In rats with a unilateral 6-hydroxydopamine (6-OHDA)-induced lesion in the nigrostriatal fibers, methamphetamine (3 mg/kg, i.p.) induced Fos -like immunoreactivity (FLI), which was inhibited by pretreatment with N-methyl-D-aspartate antagonist MK-801 (1 mg/kg, i.p.), not only in t he medial striatum contraiateral to the lesion but also in the substan tia nigra pars reticulata (SNr) ipsilateral to the lesion. Thus, hemis pheric asymmetries in FLI were induced by methamphetamine in the media l striatum and the SNr in the 6-OHDA model of turning which may be rel ated to the altered function of glutamatergic transmission. (C) 1998 E lsevier Science Ireland Ltd. All rights reserved.