Somatosensory properties of globus pallidus neurons in awake cats.

The somatosensory properties of globus pallidus (GP) neurons were assessed in awake restrained cats. Forty-two percent of GP units responded to stimulation of the face. Receptive fields were typically bilateral (49%) or contralateral and 75% included perioral tissues. Responsive units showed little ability to encode force. In contrast, cells were sensitive to changes in stimulus location within the receptive zone. The majority of cells so tested showed enhanced responding to stimuli applied within the perioral zone. Many (42%) of the cells which responded to brushing of the guard hairs or vibrissa were directionally sensitive. Of those, 89% showed enhanced responding to stimuli which moved toward the front of the mouth. These data were discussed in relation to a role of the GP in feedback regulated head positioning movements.