A number of studies suggest that Parkinson's disease (PD) is associated with alterations of neuronal activity patterns in the basal-ganglia-thalamocortical circuit. There are limited electrophysiological data, however, describing how premotor cortex, which is involved in movement and decision making, is likely impacted in PD. In this study, spontaneous local field potential (LFP) and single unit neuronal activity were recorded in the dorsal premotor area of non-human primates in both the naïve and parkinsonian state using the MPTP model of parkinsonism. In both animals we observed a shift of power in LFP power spectral densities (1−350Hz) from higher to lower frequency bands; Parkinsonism resulted in increased power in frequencies below 8Hz and decreased power at frequencies above 30Hz. A comparable but not identical trend was observed in the power spectral analysis of single unit spike trains: alpha power increased in both animals and gamma power decreased in one; power in other frequency bands remaining unchanged. Although not consistent across animals we also observed changes in discharge rates and bursting activity. Overall, the LFP and single unit analysis suggest that abnormalities in premotor neural activity are a feature of parkinsonism, though specific details of those abnormalities may differ between subjects. This study further supports the concept that PD is a network disorder that induces abnormal spontaneous neural activities across the basal-ganglia-thalamocortical circuit including the premotor cortex, and provides foundational knowledge for future studies regarding the relationship between changes in neuronal activity in this region and the development of motor deficits in PD.
- local field potential
- single unit activity
- premotor cortex
- non-human primate
- Copyright © 2017, Journal of Neurophysiology