Advertisement

Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Comparison of activity in pontine versus medullary neurones during swallowing

Summary

  1. 1.

    On decerebellectomized sheep lightly anaesthetized with fluothane, the activity of 49 neurones in the pontine relay (see Car et al., 1975) was recorded with microelectrodes following stimulation of afferents in the superior laryngeal nerve (SLN).

  2. 2.

    These pontine neurones (PN) exhibited an “initial activity” (one or a few spikes) for stimulation either of the homolateral SLN (35 PN) or glossopharyngeal nerve (14 PN). This initial activity had a latency between 1.5 and 4 msec. When swallowing was induced by SLN stimulation, a later discharge appeared. This “swallowing activity” consisted of a variable burst of spikes.

  3. 3.

    The effect of curarization was tested for 13 PN. It always eliminated the “swallowing activity”.

  4. 4.

    A clear antidromic response of 16 PN (26 tested PN) was induced by stimulating the thalamic VPM nucleus. This stimulation failed to elicit an antidromic response in medullary neurones (14 tested) located in the nucleus of the tractus solitarius.

  5. 5.

    It is concluded that PN are probably sensory relay neurones which inform higher nervous centres of the state of oropharyngeal receptors; whereas medullary swallowing neurones are really interneurones involved in the programming of the wallowing motor sequence.

This is a preview of subscription content, log in to check access.

References

  1. Bernard, R.A., Nord, S.G.: A first-order synaptic relay for taste fibers in the pontine brain stem of the cat. Brain Res. 30, 349–356 (1971)

  2. Biscoe, T.J., Sampson, S.R.: Field potentials evoked in the brain stem of the cat by stimulation of the carotid sinus, glossopharyngeal, aortic and superior laryngeal nerves. J. Physiol. (Lond.) 209, 341–358 (1970)

  3. Car, A.: La commande corticale de la déglutition. II. Point d'impact bulbaire de la voie corticifuge déglutitrice. J. Physiol. (Paris) 66, 553–576 (1973)

  4. Car, A., Jean, A.: Potentiels évoqués dans le rhombencéphale du mouton par la stimulation du nerf laryngé supérieur. J. Physiol. (Paris) 63, 715–730 (1971)

  5. Car, A., Jean, A., Roman, C.: A pontine primary relay for ascending projections of the superior laryngeal nerve. Exp. Brain Res. 22, 197–210 (1975)

  6. Dell, P., Olson, R.: Projections thalamiques, corticales et cérébelleuses des afférences viscérales vagales. C.R. Soc. Biol. (Paris) 145, 1084–1088 (1951)

  7. Doty, R.W.: Neural organization of deglutition. In: Handbook of Physiology. Section VI, Alimentary canal, Vol. IV, p. 1861–1902. Washington: American Physiological Society 1968

  8. Doty, R.W., Bosma, J.F.: An eleotromyographic analysis of reflex deglutition. J. Neurophysiol. 19, 44–60 (1956)

  9. Jean, A.: Localisation et activité des neurones déglutiteurs bulbaires. J. Physiol. (Paris) 64, 227–268 (1972a)

  10. Jean, A.: Effet de lésions localisées du bulbe rachidien sur le stade oesophagien de la déglutition. J. Physiol. (Paris) 64, 507–516 (1972b)

  11. Jean, A., Car, A.: Activité comparée de certains neurones bulbaires et pontiques déchargeant lors de la déglutition. J. Physiol. (Paris) 67, 283A (1973)

  12. Morest, D.K.: Experimental study of the projections of the nucleus of the tractus solitarius and the area postrema in the cat. J. comp. Neurol. 130, 277–300 (1967)

  13. Porter, R.: Unit responses evoked in the medulla oblongata by vagus nerve stimulation. J. Physiol. (Lond.) 168, 717–735 (1963)

  14. Ramón y Cajal, S.: Histologie du système nerveux de l'Homme et des Vertébrés. Tome I, 986 p. Madrid: Consejo Sup. Invest. Cient. 1909

  15. Rhoton, A.L., Jr.: Afferent connections of the facial nerve. J. comp. Neurol. 133, 89–100 (1968)

  16. Sessle, B. J.: Excitatory and inhibitory inputs to single neurones in the solitary tract nucleus and adjacent reticular formation. Brain Res. 53, 319–331 (1973)

  17. Torvik, A.: Afferent connections to the sensory trigeminal nuclei, the nucleus of the solitary tract and adjacent structures. An experimental study in the rat. J. comp. Neurol. 106, 51–141 (1956)

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Jean, A., Car, A. & Roman, C. Comparison of activity in pontine versus medullary neurones during swallowing. Exp Brain Res 22, 211–220 (1975). https://doi.org/10.1007/BF00237690

Download citation

Key words

  • Swallowing
  • Pons
  • Neuronal activity
  • Superior laryngeal nerve