Functional properties of neurones in the parietal retroinsular cortex in awake monkey.

The parietal retroinsular cortex of three, awake, behaving macaque monkeys was investigated using transdural microelectrode recording technique. All 73 cells identified responded to somatosensory stimuli. Most of the neurones (51) were activated by compression of the skin in an on, off or on-off fashion; these cells were unresponsive to light touching or stroking of the skin. The rest of the cells responded to light touching, rotation of a joint or palpation of a muscle belly. All body parts were represented in this area. Of the cells 30% responded to stimulation of both sides of the body. The results indicate that the parietal retroinsular cortex participates in the analysis of skin compression. This information is used, i.e. in the control of manipulative movements and in discrimination of supported weights. It is possible that ablation of the area examined would impair these functions.