Modulations in the oscillatory activity of the Globus Pallidus internus neurons during a behavioral task-A point process analysis

The behavioral state of a subject is hypothesized to be reflected in the oscillatory modulations of the spiking activity of certain groups of neurons. In particular, the beta- and gamma-bands have been experimentally shown to be related to movement in the motor cortex and parts of the basal ganglia. Here, we analyze the relationship between directional tuning and oscillations in the beta- and gamma-bands of the neurons in the Globus Pallidus internus (GPi) of two healthy nonhuman primates during a radial center-out motor task. We find that, during the planning stages of the movement, the percentage of directionally tuned neurons displaying gamma oscillations increases when compared to the percentage of directionally tuned neurons displaying beta oscillations. A similar trend is not seen in non-directionally tuned neurons. This suggests that the GPi neurons involved in the planning of movement communicate information using an emergence of oscillations in the gamma-band.