Discharge patterns of pallidal neurons with input from various cortical areas during movement in the monkey

Activities of pallidal neurons were studied in awake monkeys which were implanted with stimulating electrodes in the various cortical areas in the frontal lobe. Cortical inputs to each pallidal neuron were examined by inhibitory responses to stimulation through these electrodes. Discharge patterns of pallidal neurons were observed during performance of the reaction-time, delayed go/no-go discrimination and self-paced movement tasks. Most of the pallidal neurons with input from the arm of the motor cortex changed their firing rate in close relation to the arm movement (movement-related activity). Many of the neurons with input from the supplementary motor and cingulate areas showed sustained changes in discharge rate during the delay period in addition to movement-related activity. Most of the neurons with input from prefrontal cortex responded to light stimulus.