Skip to main content
NCBI home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1985 Nov;368:471–480. doi: 10.1113/jphysiol.1985.sp015869

Discharge patterns of pudendal efferent fibres innervating the external anal sphincter of the cat.

J Krier
PMCID: PMC1192608  PMID: 4078747

Abstract

Segmental somatic reflexes to pudendal motor axons which innervate the skeletal muscle of the external anal sphincter were studied in cats with an intact spinal cord and in acutely spinalized cats (T13-L2 spinal cord transection level) during electrical stimulation of afferent fibres in the pudendal nerve, during distension of the anal canal and reproductive organs, and during tactile (light touch and pressure) and nociceptive stimuli (pinch) applied to the mucosa of the anal canal, anal-perianal skin region, and the skin surrounding reproductive organs. Forty single pudendal motor axons recorded from nerve filaments in the pudendal nerve branch to the external anal sphincter which responded reflexly to electrical stimulation of afferent fibres in the contralateral pudendal nerve were studied. Only one motor axon was spontaneously active. 70% of these motor axons were also activated by distension of the anal canal and reproductive organs and by mechanical stimulation of the skin. 61% of motor axons which were activated by distension of the anal canal were also activated by mechanical stimulation of the mucosa of the anal canal, anal-perianal skin region. 29% of motor axons were activated by convergent afferent inputs (during distension and mechanical stimulation) from both reproductive organs and from the external anal sphincter region. Motor axons exhibited bursts of action potentials during reflexes initiated during distension of the anal canal and vagina. Motor axons exhibited phasic discharges of action potentials during reflexes initiated by tactile or nociceptive stimuli applied to the mucosa of the anal canal, anal-perianal skin region and the skin surrounding reproductive organs. The peak firing frequencies of action potentials during mechanical stimulation of the skin ranged from 8 to 35 Hz. The average firing frequencies of action potentials during continuous distension of the anal canal ranged from 4 to 16 Hz.

Full text

PDF
471

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bradley W. E., Teague C. T. Synaptic events in pudendal motoneurons of the cat. Exp Neurol. 1977 Jul;56(1):237–240. doi: 10.1016/0014-4886(77)90153-4. [DOI] [PubMed] [Google Scholar]
  2. Burke R. E. Group Ia synaptic input to fast and slow twitch motor units of cat triceps surae. J Physiol. 1968 Jun;196(3):605–630. doi: 10.1113/jphysiol.1968.sp008526. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Evans J. P. Observations on the nerves of supply to the bladder and urethra of the cat, with a study of their action potentials. J Physiol. 1936 May 4;86(4):396–414. doi: 10.1113/jphysiol.1936.sp003375. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. FLOYD W. F., WALLS E. W. Electromyography of the sphincter ani externus in man. J Physiol. 1953 Dec 29;122(3):599–609. doi: 10.1113/jphysiol.1953.sp005024. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. GARRY R. C., ROBERTS T. D., TODD J. K. Reflexes involving the external urethral sphincter in the cat. J Physiol. 1959 Dec;149:653–665. doi: 10.1113/jphysiol.1959.sp006366. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. GASTON E. A. Physiological basis for preservation of fecal continence after resection of rectum. J Am Med Assoc. 1951 Aug 18;146(16):1486–1489. doi: 10.1001/jama.1951.03670160028008. [DOI] [PubMed] [Google Scholar]
  7. MCPHEDRAN A. M., WUERKER R. B., HENNEMAN E. PROPERTIES OF MOTOR UNITS IN A HOMOGENEOUS RED MUSCLE (SOLEUS) OF THE CAT. J Neurophysiol. 1965 Jan;28:71–84. doi: 10.1152/jn.1965.28.1.71. [DOI] [PubMed] [Google Scholar]
  8. Mackel R. Segmental and descending control of the external urethral and anal sphincters in the cat. J Physiol. 1979 Sep;294:105–122. doi: 10.1113/jphysiol.1979.sp012918. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. McMahon S. B., Morrison J. F., Spillane K. An electrophysiological study of somatic and visceral convergence in the reflex control of the external sphincters. J Physiol. 1982 Jul;328:379–387. doi: 10.1113/jphysiol.1982.sp014271. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. REID G. The rate of discharge of the extraocular motoneurones. J Physiol. 1949 Dec 15;110(1-2):217–225. doi: 10.1113/jphysiol.1949.sp004434. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Rampal G., Mignard P. Organization of the nervous control of urethral sphincter. A study in the anaesthetized cat with intact central nervous system. Pflugers Arch. 1975;353(1):21–31. doi: 10.1007/BF00584508. [DOI] [PubMed] [Google Scholar]
  12. SCHUSTER M. M., HOOKMAN P., HENDRIX T. R., MENDELOFF A. I. SIMULTANEOUS MANOMETRIC RECORDING OF INTERNAL AND EXTERNAL ANAL SPHINCTERIC REFLEXES. Bull Johns Hopkins Hosp. 1965 Feb;116:79–88. [PubMed] [Google Scholar]
  13. Schuster M. M. The riddle of the sphincters. Gastroenterology. 1975 Jul;69(1):249–262. [PubMed] [Google Scholar]
  14. TODD J. K. AFFERENT IMPULSES IN THE PUDENDAL NERVES OF THE CAT. Q J Exp Physiol Cogn Med Sci. 1964 Jul;49:258–267. doi: 10.1113/expphysiol.1964.sp001730. [DOI] [PubMed] [Google Scholar]
  15. Ueyama T., Mizuno N., Nomura S., Konishi A., Itoh K., Arakawa H. Central distribution of afferent and efferent components of the pudendal nerve in cat. J Comp Neurol. 1984 Jan 1;222(1):38–46. doi: 10.1002/cne.902220104. [DOI] [PubMed] [Google Scholar]
  16. Zajac F. E., Young J. L. Discharge properties of hindlimb motoneurons in decerebrate cats during locomotion induced by mesencephalic stimulation. J Neurophysiol. 1980 May;43(5):1221–1235. doi: 10.1152/jn.1980.43.5.1221. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES