Effect of 6-OHDA injection on the AMPA glutamate receptor subunits in the substantia nigra of Sprague-Dawley rats

Abstract

Parkinson's disease (PD) is characterized by the destruction of dopaminergic cells in the substantia nigra (SN). The cause of the cell death and the development of Parkinsonism is however unknown. There are increasing evidences to suggest the involvement of glutamate mediated by its receptors. Using immunohistochemistry and cell counting, the present study investigated whether the numbers of neurons immunostained with glutamate α-amino-3- hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor subunits GluR1, GluR2/3 and GluR4 in the SN of rats would change after the injection of 6- hydroxydopamine (6-OHDA) into the SN. The results showed that the numbers of GluR1 positive cells were significantly decreased in the substantia nigra pars compacta (SNc), pars reticulata (SNr) and pars lateralis (SNI) from 3 days (13.7%) to 3 months (40.3%) and of GluR2/3 cells, from 1 week (17.6%) to 3 months (19.1%) after 6-OHDA injection, compared to those in the contralateral non-injected side. There was, however, no significant difference in the number of GluR4 positive cells between the injected and non-injected SN. The results were discussed.