Lesion of the substantia nigra pars compacta downregulates striatal glutamate receptor subunit mRNA expression

This is a study of the effect of the unilateral administration of dopamine (DA) in the pars compacta of the substantia nigra (SN) of the rat on striat al glutamate receptor subunit (GluR1, GluR2 and NMDAR1) gene expression det ermined by in situ hybridization. The location of the nigral lesion was det ermined by tyrosine hydroxylase (TH) immunohistochemistry and its extent by the striatal DA and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations. The DA-induced lesions produce significant bilateral reductions in the exp ression of GluR1 and NMDAR1 subunit mRNA in the medio-lateral striatum, whe reas the expression of striatal GluR2 receptors was not changed. The reduct ion in GluR1 and NMDAR1 subunit mRNA may be the consequence of glutamatergi c hyperactivity developed in the presence of a damaged nigro-striatal syste m and these may be associated with the genesis of some neurodegenerative di seases. (C) 1999 Elsevier Science B.V. All rights reserved.