The Antinociceptive Role Of The Anterior Interposed Nucleus Of The Cerebellum

Abstract

The cerebellum has been extensively studied for its role in pain. It is safe to say that the cerebellum has a modulatory role in pain. It is active during various types of pain, but it also plays a role in inhibiting pain. An overall contribution to pain has yet to be defined. This study was performed to contribute to knowledge pertaining to the cerebellum's role in pain. Specifically, the role of the interposed nucleus in descending inhibition was of interest.To test the role of the interposed nucleus in descending inhibition, single-unit extracellular electrophysiological recordings were collected to observe dorsal horn neuronal responses to mechanical stimuli (brush, pressure, pinch) with and without electrical stimulation first in the left and then in the right hemisphere of the intermediate cerebellar cortex. This area inhibits nociceptive spinal neuronal responses to mechanical stimuli; therefore, recordings of neuronal responses were taken before and after 1 of 4 drugs was microinjected into the left interposed nucleus. Drugs used in the study were lidocaine, GABA, bicucilline, and ACSF. The results suggest that the interposed nucleus has a nociceptive contribution to pain modulation.