The Journal of Neurophysiology Vol. 79 No. 6 June 1998, pp. 3143-3150
Copyright ©1998 The American Physiological Society

A Role for the Dorsal Column in Nociceptive Visceral Input Into the Thalamus of Primates

Elie D. Al-Chaer^{1, 2}, Yi Feng², and William D. Willis²

¹ Department of Internal Medicine and Division of Gastroenterology; ² Department of Anatomy and Neurosciences and the Marine Biomedical Institute, University of Texas Medical Branch, Galveston, Texas 77555-1069

Al-Chaer, Elie D., Yi Feng, and William D. Willis. A role for the dorsal column in nociceptive visceral input into the thalamus of primates. J. Neurophysiol. 79: 3143-3150, 1998. A possible role of the dorsal column (DC) in the processing of visceral pain has gained attention after studies in the rat have revealed that the DC transmits a major part of the pelvic visceral nociceptive input from the colon into the thalamus. Furthermore, clinical interventions aimed at interrupting ascending DC axons near the midline were successful in relieving the pain suffered by patients with cancer of the pelvic organs. The purpose of this study was to check whether a DC lesion in monkeys would reduce the responses of thalamic neurons to graded colorectal distension (CRD) as in rats. Experiments were done on anesthetized male monkeys (Macaca fascicularis). Extracellular single cell recordings were made in the ventrolateral complex of the thalamus, mainly the ventral posterolateral (VPL) nucleus, in response to visceral and cutaneous stimulation. Of 80 VPL cells isolated, CRD activated 25, inhibited 25, and had no effect on 30 neurons. The responses of six viscerosensitive VPL neurons were recorded before and after a lesion of the DC at or above the T10 spinal segment. Lesions of other spinal tracts were made after the DC lesion. The results show that the DC lesion significantly reduced the responses of the thalamic neurons tested with CRD by >50%. Lesions of other tracts did not have a consistent effect. These results corroborate findings in the rat and support the proposal that the DC plays an important role in transmitting nociceptive visceral input into the thalamus and subsequently in visceral pain.

This article has been cited by other articles:

				J. Gao, X. Wu, C. Owyang, and Y. Li Enhanced responses of the anterior cingulate cortex neurones to colonic distension in viscerally hypersensitive rats J. Physiol., January 1, 2006; 570(1): 169 - 183. [Abstract] [Full Text] [PDF]

				P J Matthews and Q Aziz Functional abdominal pain Postgrad. Med. J., July 1, 2005; 81(957): 448 - 455. [Abstract] [Full Text] [PDF]

				H.-Q. Zhang, E. D. Al-Chaer, and W. D. Willis Effect of Tactile Inputs on Thalamic Responses to Noxious Colorectal Distension in Rat J Neurophysiol, September 1, 2002; 88(3): 1185 - 1196. [Abstract] [Full Text] [PDF]

				Y. Ji and R. J. Traub Spinal NMDA Receptors Contribute to Neuronal Processing of Acute Noxious and Nonnoxious Colorectal Stimulation in the Rat J Neurophysiol, October 1, 2001; 86(4): 1783 - 1791. [Abstract] [Full Text] [PDF]

				C. Y. Saab, M. Kawasaki, E. D. Al-Chaer, and W. D. Willis Cerebellar Cortical Stimulation Increases Spinal Visceral Nociceptive Responses J Neurophysiol, June 1, 2001; 85(6): 2359 - 2363. [Abstract] [Full Text] [PDF]

				D. I. Hobday, Q. Aziz, N. Thacker, I. Hollander, A. Jackson, and D. G. Thompson A study of the cortical processing of ano-rectal sensation using functional MRI Brain, February 1, 2001; 124(2): 361 - 368. [Abstract] [Full Text] [PDF]

				E. D. Al-Chaer, Y. Feng, and W. D. Willis Comparative Study of Viscerosomatic Input Onto Postsynaptic Dorsal Column and Spinothalamic Tract Neurons in the Primate J Neurophysiol, October 1, 1999; 82(4): 1876 - 1882. [Abstract] [Full Text] [PDF]

				W. D. Willis, E. D. Al-Chaer, M. J. Quast, and K. N. Westlund A visceral pain pathway in the dorsal column of the spinal cord PNAS, July 6, 1999; 96(14): 7675 - 7679. [Abstract] [Full Text] [PDF]