Intestinal Pain: An Electrophysiological Investigation on Mesenteric Nerves

Abstract

Summary. Afferent impulses from the abdominal viscera have been recorded from the splanchnic nerve and from fine strands of mesenteric nerves of the cat. The Pacinian corpuscles of the exposed mesentery were found to be extremely sensitive to the most gentle pressure, such as faint puff of air. The small intestine very rarely receives any large medullated fibres, and light mechanical stimuli such as slight pressure or touch do not give rise to any inflow of impulses. Fast impulses can be elicited only from those parts of the mesentery possessing Pacinian corpuscles. Injurious stimuli such as pinching applied to the intestinal wall as well as to the mesentery produce δ‐ and C‐potentials. In addition to this, intense stimulation gives rise to large potentials waves apparently built up by slow C‐potentials. It is thus concluded that nociceptive reactions from the intestine are not produced by afferent fibers belonging to the α‐or β‐group but by δ‐ and C‐fibers only. Support is given for the view that the intestinal wall is supplied by afferent fibers able to produce nociceptive reactions in response to such mechanical stimuli which if applied to the skin, would elicit nociceptive reflexes. The sensibility of the intestine itself is thus to be looked upon as very much the same as that of the skin deprived of its fast‐conducting afferent fibers, which respond to vibratory and light mechanical stimuli as well as to stronger pressure.