Pflügers Archiv

, Volume 403, Issue 2, pp 164–169 | Cite as

Pelvic afferent reflex control of rectal motility and lumbar colonic efferent discharge mediated by the pontine sympatho-inhibitory region in guinea pigs

  • Miyako Takaki
  • Toshiaki Neya
  • Sosogu Nakayama
Excitable Tissues and Central Nervous Physiology


Rectal motility and the efferent discharge of lumbar colonic nerves (LCED) have previously been shown to be affected by reflex activity activated by rectal stimulation. The sensory limb of this reflex is represented by afferent fibers in pelvic nerves. The present study revealed that this reflex is modulated by supraspinal sympatho-inhibitory regions. Pelvic afferent stimulation led to rectal contraction through the withdrawal of a tonic inhibitory influence of lumbar colonic nerves. The supraspinal region responsible for this antagonism ofthe rectal-inhibitory colonic nerve activity was localized to the pons. Neither the intravenous administration of atropine nor that of guanethidine (and Eisai compound 865–123, another adrenergic neuron blocking agent) effected the ability of pelvic afferent stimulation to inhibit tonic discharge of lumbar colonic efferent nerves; nervertheless, both agents eliminated the mechanical response of the rectum to stimulation of pelvic afferents. These observations suggest that lumbar sympathetic nerves may tonically inhibit the release of acetylcholine from excitatory neurons in the rectal myenteric plexus. We conclude that descending fibers from the pons are activated as a result of pelvic afferent nerve stimulation. These descending pontine fibers in turn inhibit the firing of sympathetic lumbar colonic nerves. Removal of this tonic restraint leads to rectal contraction.

Key words

Defecation reflex Guinea pig Lumbar colonic nerve Pons Pelvic afferent stimulation Rectal motility Supraspinal center Sympathetic activity 


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  1. Beani L, Bianchi C, Crema A (1969) The effects of catecholamines and sympathetic stimulation on the release of acetylcholine from the guinea-pig colon. Brit J Pharmac 36:1–17Google Scholar
  2. Costa M, Furness JB (1973) The origins of the adrenergic fibres which innervate the internal anal sphincter, the rectum and other tissues of the pelvic region in the guinea pig. Z Anat Entwickl Gesch 140:129–142Google Scholar
  3. Gershon MD (1967) Inhibition of gastrointestinal movement by sympathetic nerve stimulation: the site of action. J Physiol 189:317–327Google Scholar
  4. de Groat WC, Krier J (1979) The central control of the lumbar sympathetic pathway to the large intestine of the cat. J Physiol 289:449–468Google Scholar
  5. de Groat WC, Lalley PM (1972) Reflex firing in the lumbar sympathetic outflow to activation of vesical afferent fibres. J Physiol 226:289–309Google Scholar
  6. Furness JB, Costa M (1973) The ramifications of adrenergic nerve terminals in the rectum, anal sphincter and anal accessory muscles of the guinea pig. Z Anat Entwickl Gesch 140:109–128Google Scholar
  7. Fukuda H, Fukai K, Yamane M, Okada H (1981) Pontine reticular unit responses to pelvic nerve and colonic mechanical stimulation in the dog. Brain Research 207:59–71Google Scholar
  8. Gagnon DJ, Belisle S (1970) Stimulatory effects of catecholamines on the isolated rat colon after beta-adrenergic blockade with oxprenolol and propranolol. Europ J Pharmacol 12:303–309Google Scholar
  9. Jansson G, Martinson J (1966) Studies on the ganglionic site of action of sympathetic outflow to the stomach. Acta Physiol Scand 68:184–192Google Scholar
  10. Johansson B, Johansson O, Ljung B (1968) Tonic supraspinal mechanisms influencing the intestino-intestinal inhibitory reflex. Acta Physiol Scand 72:200–204Google Scholar
  11. Kewenter J (1965) The vagal control of jejunal and ileal motility and blood flow. Acta Physiol Scand 45 [Suppl] 251:1–68Google Scholar
  12. Manber L, Gershon MD (1979) A reciprocal adrenergic-cholinergic axo-axonic synapse in the mammalian gut. Am J Physiol 236(6):E738-E745Google Scholar
  13. Misu Y, Nishio H, Hosotani T, Hamano S (1976) A new guanidine derivative: Dissociation of the adrenergic neuron blocking activity from local anesthetic activity. Jpn J Pharmacol 26:367–375Google Scholar
  14. Neya T, Takaki M, Nakayama S (1984) Mechanism for rectal contraction mediated by sympathetic efferents from rectoanal pelvic afferents in guinea pigs. Acta Med Okayama 38:21–27Google Scholar
  15. Okada H, Fukuda H, Yamane M (1976) On the localization of the pontine defecation reflex center of the dog. The Autonomic Nervous System 13:24–31 (in Japanese)Google Scholar
  16. Paton WDM, Vizi ES (1969) The inhibitory action of noradrenaline and adrenaline on acetylcholine output by guinea-pig ileum longitudinal muscle strip. Brit J Pharmac 35:10–28Google Scholar
  17. Rostad H (1973) Colonic motility in the cat. IV. Peripheral pathways mediating the effects induced by hypothalamic and mesencephalic stimulation. Acta Physiol Scand 89:154–168Google Scholar
  18. Schaumann W (1958) Zusammenhänge zwischen der Wirkung der Analgetica und Sympatheticomimetica im Meerschweinchen-dünndarm. Naunyn-Schmiedeberg's Arch Pharmacol 233: 112–124Google Scholar
  19. Takaki M, Neya T, Nakayama S (1980) Sympathetic activity in the recto-rectal reflex in the guinea pig. Pflügers Arch 338:45–52Google Scholar
  20. Takaki M, Neya T, Nakayama S (1983) Role and localization of a region in the pons which has a descending inhibitory influence on sympathetically mediated inhibition of the recto-rectal reflex of guinea pigs. Pflügers Arch 398:120–125Google Scholar

Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • Miyako Takaki
    • 1
  • Toshiaki Neya
    • 1
  • Sosogu Nakayama
    • 1
  1. 1.Department of PhysiologyOkayama University Medical SchoolOkayamaJapan

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