Skip to main content
SpringerLink
Log in

A cholinergic mechanism involved in the neuronal excitation by H+ in the respiratory chemosensitive structures of the ventral medulla oblongata of rats in vitro

  • Heart, Circulation, Respiration and Blood; Environmental and Exercise Physiology
  • Published:
Pflügers Archiv Aims and scope Submit manuscript

Abstract

The mechanism of neuronal excitation by H+ in the medullary chemosensitive structures was analyzed in brains slices of the rat in vitro. Responses of neurons to H+ in the ventral surface layer were compared with responses to various transmitter substances. Neurons excited by H+ were always also excited by acetylcholine (ACh). ACh increased the activity of 70% of superficial ventral medullary neurons. Effects of noradrenaline and serotonin on the activity of neurons were largely opposite to that of H+. Cholinergic blocking agents like atropine, hexamethonium and mecamylamine depressed the H+-elicited excitation of neurons. The cholinesterase inhibitor, eserine, increased the neuronal activity. In the presence of eserine, a solution of low pH caused further increase in discharge of most neurons. The low pH solution prolonged and augmented the excitatory action of ACh on the ventral medullary neurons.

It is concluded that the H+-elicited excitation of neurons in the ‘chemosensitive’ structures is dependent upon intact cholinergic transmission in the surface layer. This may be interpreted as resulting from facilitation and/or prolongation of such a chemical transmission by H+.

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

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Beleslin, D., Polak, R. L.: Depression by morphine and chloralose of acetylcholine release from the cat brain. J. Physiol. (Lond.)177, 411–419 (1965)

    Google Scholar 

  2. Bradley, P. B., Dhawan, B. N., Wolstencroft, J. H.: Pharmacological properties of cholinoceptive neurones in the medulla and pons of the cat. J. Physiol. (Lond.)183, 658–673 (1966)

    Google Scholar 

  3. Brimblecombe, R. W.: Drugs acting on central cholinergic mechanisms and affecting respiration. Pharmacol. Ther. Bull.3, 65–74 (1977)

    Google Scholar 

  4. Carpenter, D. O., Hubbard, J. H., Humphrey, D. R., Thompson, H. K., Marshall, W. H.: Carbon dioxide effects on nerve cell function. In: Carbon dioxide and metabolic regulations. Nahas, G., Schaefer, K. E. (eds.), pp. 49–62. Berlin-Heidelberg-New York: Springer 1974

    Google Scholar 

  5. Caspers, H.: Cortical DC shifts associated with changes of gas tension in blood and tissue. In: Handbook of electroencephalography and clinical neurophysiology. Vol. 10, part A. DC potentials recorded directly from the cortex. Remond, A. (ed.), pp. 10A 41–65. Amsterdam: Elsevier 1974

    Google Scholar 

  6. Cohen, J. A., Oosterbaan, R. A.: The interaction of acetylcholinesterase with substrates. In: Handbuch der Experimentellen Pharmakologie. XV. Cholinesterase and Anticholinesterase Agents (Chapter 7, The active site of acetylcholinesterase and related esterases and its reactivity towards substrates and inhibitors). Koelle, G. B. (ed.), pp. 300–316. Berlin, Göttingen, Heidelberg: Springer 1963

    Google Scholar 

  7. Cooper, J. R., Bloom, F. E., Roth, R. H.: The biochemical basis of neuropharmacology (2nd ed.). New York: Oxford University Press 1974

    Google Scholar 

  8. Cragg, P., Patterson, L., Purves, M. J.: The pH of brain extracellular fluid in the cat. J. Physiol. (Lond.)272, 137–166 (1977)

    Google Scholar 

  9. Davies, R. O., Loeschcke, H. H.: Neural activity evoked by electrical stimulation on the chemosensitive areas on the ventral medullary surface. Proc. Int. Un. Physiol. Sc.XIII, 164 (1977)

    Google Scholar 

  10. Dev, N. B., Loeschcke, H. H.: Effects on respiration and circulation of nicotine and acetylcholine applied to the ventral surface of the medulla oblongata of the cat. Pflügers Arch.365, R39 (1976)

    Google Scholar 

  11. Dev, N. B.: Wirkung neurotroper Substanzen auf die an der Regulation von Atmung und Vasomotorik beteiligten Gebiete der ventralen Oberfläche der Medulla oblongata der Katze. Ph. D. Thesis, Ruhr-University Bochum (1977)

  12. Eyzaguirre, C., Zapata, P.: Pharmacology of pH effects on carotid body chemoreceptors in vitro. J. Physiol. (Lond.)195, 557–588 (1968)

    Google Scholar 

  13. Fukuda, Y., Honda, Y.: pH-sensitive cells at ventro-lateral surface of rat medulla oblongata. Nature New Biol.256, 317–318 (1975)

    Google Scholar 

  14. Fukuda, Y., Honda, Y.: pH sensitivity of cells located at the ventro-lateral surface of the cat medulla oblongata in vitro. Pflügers Arch.364, 243–247 (1976)

    Google Scholar 

  15. Fukuda, Y., Loeschcke, H. H.: Effect of H+ on spontaneous neuronal activity in the surface layer of the rat medulla oblongata in vitro. Pflügers Arch.371, 125–134 (1977)

    Google Scholar 

  16. Fukuda, Y., Honda, Y., Schläfke, M. E., Loeschcke, H. H.: Effect of H+ on the membrane potential of silent cells in the ventral and dorsal surface layers of the rat medulla in vitro. Pflügers Arch.376, 229–235 (1978)

    Google Scholar 

  17. Hubbard, J. I., Jones, S. F., Landau, E. M.: On the mechanism by which calcium and magnesium affect the spontaneous release of transmitter from mammalian motor nerve terminals. J. Physiol. (Lond.)194, 355–380 (1968)

    Google Scholar 

  18. Leusen, I.: Chemosensitivity of respiratory center. Influence of CO2 in the cerebral ventricles on respiration. Am. J. Physiol.176, 39–44 (1954)

    Google Scholar 

  19. Leusen, I.: Chemosensitivity of the respiratory center. Influence of changes in the H+ and total buffer concentrations in the cerebral ventricles on respiration. Am. J. Physiol.176, 45–51 (1954)

    Google Scholar 

  20. Loeschcke, H. H., Koepchen, H. P., Gertz, K. H.: Über den Einfluß von Wasserstoffionenkonzentration und CO2-Druck im Liquor cerebrospinalis auf die Atmung. Pflügers Arch. Ges. Physiol.266, 569–585 (1958)

    Google Scholar 

  21. Loeschcke, H. H.: Central nervous chemoreceptors. In: Respiration physiology, Widdicombe, J. G. (ed.), pp. 167–196. London: Butterworths 1974

    Google Scholar 

  22. Marino, R. L., Lamb, T. W.: Effects of CO2 and extracellular H iontophoresis on single cell activity in the cat brainstem. J. Appl Physiol.38, 688–695 (1975)

    Google Scholar 

  23. Metz, B.: Correlation between respiratory reflex and acetylcholine content of pons and medulla. Am. J. Physiol.202, 80–82 (1962)

    Google Scholar 

  24. Metz, B.: Hypercapnia and acetylcholine release from the cerebral cortex and medulla. J. Physiol. (Lond.)186, 321–332 (1966)

    Google Scholar 

  25. Mitchell, R. A., Loeschcke, H. H., Massion, W. H., Severinghaus, J. W.: Respiratory response mediated through superficial chemosensitive areas on the medulla. J. Appl. Physiol.18, 523–533 (1963)

    Google Scholar 

  26. Mitchell, R. A., Herbert, D. A.: The effect of carbon dioxide on the membrane potential of medullary respiratory neurons. Brain Res.75, 345–349 (1974)

    Google Scholar 

  27. Mitchell, R. A., Berger, A. J.: Neural regulation of respiration. Am. Rev. Resp. Dis.3, 206–224 (1975)

    Google Scholar 

  28. Nunn, J. F.: Applied respiratory physiology (2nd ed.), pp. 48–51. London: Butterworths 1977

    Google Scholar 

  29. Pappenheimer, J. R.: The ionic composition of cerebral extracellular fluid and its relation to control of breathing. Harvey Lect.61, 71–94 (1967)

    Google Scholar 

  30. Pokorski, M.: Neurophysiological studies on central chemosensor in medullary ventrolateral areas. Am. J. Physiol.230, 1288–1295 (1976)

    Google Scholar 

  31. Salmoiraghi, G. C., Steiner, F. A.: Acetylcholine sensitivity of cat's medullary neurons. J. Neurophysiol.26, 581–597 (1963)

    Google Scholar 

  32. Schläfke, M. E., Pokorski, M., See, W. R., Prill, P. K., Loeschcke, H. H.: Chemosensitive neurons on the ventral medullary surface. Bull. Physio-path. Resp.11, 277–284 (1975)

    Google Scholar 

  33. Sparf, B.: On the turnover of acetylcholine in the brain. An experimental study using intravenously injected radioactive choline. Acta Physiol. Scand., Suppl.397 (1973)

  34. Speckmann, E. J., Caspers, H.: Responses of spinal and cortical neurons to changes ofP O 2 andP CO 2 in blood and tissue. In: The Peripheral Arterial Chemoreceptors, Purves, M. J. (ed.), pp. 163–174. London: Cambridge University Press 1975

    Google Scholar 

  35. Stewart, W. C., Anderson, E. A.: Effect of a cholinesterase inhibitor when injected into the medulla of the rabbit. J. Pharmacol. Exp. Ther.162, 309–318 (1968)

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Institut für Physiologie, Lehrstuhl I, Ruhr-Universität Bochum, Postfach 102148, D-4630, Bochum 1, Federal Republic of Germany

    Yasuichiro Fukuda & Hans H. Loeschcke

Authors
  1. Yasuichiro Fukuda
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Hans H. Loeschcke
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

Supported by the Deutsche Forschungsgemeinschaft (SFB 114)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Fukuda, Y., Loeschcke, H.H. A cholinergic mechanism involved in the neuronal excitation by H+ in the respiratory chemosensitive structures of the ventral medulla oblongata of rats in vitro. Pflugers Arch. 379, 125–135 (1979). https://doi.org/10.1007/BF00586938

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00586938

Key words

Search

Navigation