The impulse activity of single neurons in substantia nigra pars compacta - SNc (242 neurons, n=11) and substantia nigra pars reticulate - SNr (289 neurons, n=12) under high frequency stimulation of primary motor cortex (M1) was analyzed on 23 white male rats in control and rotenone model of Parkinson’s disease (PD). In SNc neurons in PD model there was no stimulation-induced depression, however, the posttetatic potentiation and depression following the tetanic potentiation, were 1.65 and 2.02 times higher than in control. In control SNr neurons the tetanic potentiation followed by the posttetanic potentiation and depression was 2.37 times higher than the tetanic depression, whereas in the PD model both depression and potentiation levels were subnormal. In PD model, both SNc and SNr neurons exhibited significantly higher spike frequency before and during the stimulation in comparison with control. This indicates the presence of the excitotoxicity accompanied by the neurodegenerative damage followed by the apoptosis and the neuronal death. In SNr neurons both depression and potentiation after the stimulation were much more prominent than in SNc neurons, which indicates that the cortical projections on the SNr are more pronounced. Moreover, the SNc neurons demonstrated higher succeptibility to the pathological changes in the poststimulus depression, leading to the more pronounced potentiation in those neurons in comparison with the SNr neurons, which indicates the more prominent involvement of the former in the PD pathogenesis. In the PD model, with no stimulation-induced depression and more prominent potentiation in the SNc neurons, the SNr neurons maintain the depression and show relatively lowered potentiation, which indicates their lower succeptibility to the excitotoxicity, and the excessive excitability of the remaining neurons as a compensation for the dead ones.