The Journal of Neurophysiology Vol. 85 No. 6 June 2001, pp. 2359-2363
Copyright ©2001 by the American Physiological Society

Cerebellar Cortical Stimulation Increases Spinal Visceral Nociceptive Responses

 ¹Department of Anatomy and Neurosciences and  ²Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas 77555

Saab, Carl Y., Motohiro Kawasaki, Elie D. Al-Chaer, and William D. Willis. Cerebellar Cortical Stimulation Increases Spinal Visceral Nociceptive Responses. J. Neurophysiol. 85: 2359-2363, 2001. The role of the cerebellum in modulating nociceptive phenomena is unclear. In this study, we focus on the effects of cerebellar cortical stimulation on the responses of midline neurons of the lumbosacral spinal cord to graded nonnoxious and noxious visceral (colorectal distension) as well as somatic (brush, pressure, pinch) stimuli. Extracellular recording was used for the isolation and recording of spinal nociceptive neurons, while electrical current pulses and chemical injection of D, L-homocysteic acid were used to stimulate the cortex of the posterior cerebellar vermis. Cerebellar cortical stimulation increased the responses of all isolated cells to colorectal distension, whereas the effect on the responses to somatic stimuli was variable. These findings indicate that the posterior cerebellar vermis may exert a pro-nociceptive effect on spinal visceroceptive neurons.