The Afferent and Efferent Pathways of the Recto-colonic Reflex in the Dog

Hiroyuki Fukuda, Kiyoko Fukai

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

The nature of the afferent and efferent pathways of the recto-colonic reflex was studied electrophysiologically in the dog. A compound action potential consisting of many peaks was evoked on a sacral dorsal rootlet by a stimulus to the ipsilateral rectal strands of the pelvic nerve. Conduction velocities of the peaks indicate that Aδ and C afferent fibers innervate the colon and rectum. When the stimuli were subthreshold for C fibers, the reflex discharges of contralateral parasympathetic post-ganglionic fibers in the rectal strands and the reflex contraction of the colon were smaller than those caused by stronger stimuli. As the intensity of the stimulus to the sacral ventral roots was weakened, response peaks of preganglionic B fibers in the rectal branch, post-ganglionic C fibers in the rectal strands and a bladder branch of the pelvic nerve disappeared in the order of slow to fast conduction velocities. Contraction of the colon also decreased. The number of peaks arising from each nerve correlated well with the strength of the contraction. These results indicate that the peripheral limbs of the recto-colonic reflex arc consist of afferent Aδ and C fibers, preganglionic B fibers and post-ganglionic C fibers.

Original languageEnglish
Pages (from-to)795-801
Number of pages7
JournalThe Japanese Journal of Physiology
Volume35
Issue number5
DOIs
Publication statusPublished - 1985
Externally publishedYes

Fingerprint

Afferent Pathways
Efferent Pathways
Unmyelinated Nerve Fibers
Myelinated Nerve Fibers
Reflex
Dogs
Colon
Spinal Nerve Roots
Rectum
Action Potentials
Urinary Bladder
Extremities

Keywords

  • defecation
  • parasympathetic nerve
  • pelvic nerve
  • recto-colonic reflex

ASJC Scopus subject areas

  • Physiology

Cite this

The Afferent and Efferent Pathways of the Recto-colonic Reflex in the Dog. / Fukuda, Hiroyuki; Fukai, Kiyoko.

In: The Japanese Journal of Physiology, Vol. 35, No. 5, 1985, p. 795-801.

Research output: Contribution to journalArticle

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