Skip to main content
SpringerLink
Log in

The localization of the first synapse in the carotid sinus baroreceptor reflex pathway and its alteration of the afferent input

  • Published:
Pflügers Archiv Aims and scope Submit manuscript

Summary

In 78 anaesthetized cats the lower brain stem was explored with microelectrodes for localization of the secondary neurones of the carotid sinus primary afferents. By means of recording single unit activities and evoked potentials (E.P.) by stimulation of the carotid sinus nerve (CSN) these neurones were located exclusively in the nucleus tractus solitarius (NTS) at the level of the obex.

The E. P. was recorded with both ipsilateral and contralateral CSN stimulation.

During repetitive stimulation of the CSN the frequency transmission across the synapse showed a sharp frequency limitation. With 10 Imp/sec the amplitude of the E.P. was only 50% of the maximal amplitude obtained with 1 Imp/sec. This frequency limitation is also manifested in the frequency effectiveness of the whole baroreceptor reflex measured as blood pressure reduction. It showed a maximum with frequencies of 20–30 Imp/sec, while stimulation of the secondary neurones in the NTS showed an increase in blood pressure reduction up to the tested frequencies of 120 Imp/sec.

The E.P. was tested in the different phases of the respiratory cycle. No difference in amplitude or latency between the E.P. was noted.

The relevance of these findings to the arrangement of the central neural substrates for the cardiovascular control is discussed.

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. Achari, N. K., C. B. B. Dowman, andW. V. Weber: A cardio-inhibitory pathway in the brainstem of the cat. J. Physiol. (Lond.)197, 35 P (1968).

  2. Adrian, E. D., D. W. Bronk, andG. Phillips: Discharges in mammalian sympathetic nerves. J. Physiol. (Lond.)74, 115–133 (1932).

    Google Scholar 

  3. Batsel, H. L.: Localization of bulbar respiratory center by microelectrode sounding. Exp. Neurol.9, 410–426 (1964).

    Google Scholar 

  4. —: Activity of bulbar respiratory neurons during passive hyperventilation. Exp. Neurol.19, 357–374 (1967).

    Google Scholar 

  5. Baumgarten, R. v., K. Balthasar u.H. P. Koepchen: Über ein Substrat atmungsrhythmischer Erregungsbildung im Rautenhirn der Katze. Pflügers Arch. ges. Physiol.270, 504–528 (1960).

    Google Scholar 

  6. — u.K. P. Schaefer: Beitrag zur Lokalisationsfrage bulboreticulärer respiratorischer Neurone der Katze. Pflügers Arch. ges. Physiol.264, 217–227 (1957).

    Google Scholar 

  7. — u.F. Timm: Beitrag zur Technik der extra-und intrazellulären, sowie der stereotaktischen Mikroableitung im Gehirn. Pflügers Arch. ges. Physiol.271, 245–256 (1968).

    Google Scholar 

  8. — u.L. Aranda: Untersuchungen zur Lokalisation der bulbären Kreislaufzentren. I. Mitteilung: Funktionelle Organisation der Vagus-Wurzeln. Verh. dtsch. Ges. Kreisl.-Forsch.25, 170–172 (1959).

    Google Scholar 

  9. Bonvallet, M., etB. Sigg: Étude électrophysiologique des afférences vagales au niveau de leur pénétration dans le bulbe. J. Physiol. (Paris)50, 63–74 (1958).

    Google Scholar 

  10. Calaresu, F. R., andJ. W. Pearce: Effects on heart rate of electrical stimulation of medullary vagal structures in the cat. J. Physiol. (Lond.)176, 241–251 (1965).

    Google Scholar 

  11. Cottle, M. K.: Degeneration studies of primary afferents of IXth and Xth cranial nerves in the cat. J. comp. Neurol.122, 329–345 (1964).

    Google Scholar 

  12. Downman, C. B. B., andM. H. Evans: The distribution of splanchnic afferents in the spinal cord of the cat. J. Physiol. (Lond.)137, 66–79 (1957).

    Google Scholar 

  13. Fallert, M. u.V. M. Bucher: Lokalisation eines blutdruckaktiven Substrates in der Medulla oblongata des Kaninchens. Helv. physiol. pharmacol. Acta24, 139–163 (1966).

    Google Scholar 

  14. Fussey, I. F., D. Kidd, andJ. G. Whitwam: Single unit activity, associated with cardiovascular events in the brain stem of the dog. J. Physiol. (Lond.)191, 57 P (1967).

  15. Gunn, C. G., G. Sevelius, M. J. Puiggari, andF. K. Myers: Vagal cardiomotor mechanisms in the midbrain of the dog and cat. Amer. J. Physiol.214, 258–262 (1968).

    Google Scholar 

  16. Haber, E., K. W. Kohn, S. H. Ngai, D. A. Holaday, andS. C. Wang: Localization of spontaneous respiratory neuronal activities in the medulla oblongata of the cat: A new location of the expiratory center. Amer. J. Physiol.190, 350–355 (1957).

    Google Scholar 

  17. Hellner, K., u.R. v. Baumgarten: Über ein Endigungsgebiet afferenter, kardiovaskulärer Fasern des Nervus vagus im Rautenhirn der Katze. Pflügers Arch. ges. Physiol.273, 223–243 (1961).

    Google Scholar 

  18. Heymans, C., andE. Neil: Reflexogenic areas of the cardiovascular system. London: Churchill 1958.

    Google Scholar 

  19. Humphrey, D. R.: Neuronal activity in the medulla oblongata of cat evoked by stimulation of the carotid sinus nerve. In: Baroreceptors and hypertension. Oxford: Pergamon Press 1967.

    Google Scholar 

  20. Illert, M.: Untersuchungen zur spinalen Lokalisation und zur Konvergenz hemmender und fördernder Efferenzen auf die sympathische Kreislauf-innervation. Inaug.-Diss., München 1969.

  21. — u.H. P. Koepchen: Zur Existenz und Lokalisation efferenter depressorischer Bahnen im Rückenmark der Katze. Pflügers Arch. ges. Physiol.297, R81 (1967).

    Google Scholar 

  22. Ingram, W. R., andE. A. Dawkins: The intramedullary course of afferent fibres of the vagus nerve in the cat. J. comp. Neurol.82, 157–168 (1945).

    Google Scholar 

  23. Iriuchijima, J., andM. Kumada: Activity of single vagal fibres efferent to the heart. Jap. J. Physiol.14, 479–487 (1964).

    Google Scholar 

  24. Jarausch, K. H., u.K. J. Ullrich: Zur Technik der Entnahme von Harnproben aus einzelnen Sammelrohren der Säugetierniere mittels Polyäthylen-Capillaren. Pflügers Arch. ges. Physiol.264, 88–94 (1957).

    Google Scholar 

  25. Jewett, D. L.: Activity of single efferent fibres in the cervical vagus nerve of the dog, with special reference to possible cardio-inhibitory fibres. J. Physiol. (Lond.)175, 321–357 (1964).

    Google Scholar 

  26. Kerr, F. W. L.: Facial, vagal and glossopharyngeal nerves in the cat. Arch. Neurol. (Chic.)6, 264–281 (1962).

    Google Scholar 

  27. Kezdi, P.: Baroreceptors and Hypertension. Oxford: Pergamon Press 1967.

    Google Scholar 

  28. Koch, E.: Die reflektorische Selbststeuerung des Kreislaufes. Dresden: Steinkopff 1931.

    Google Scholar 

  29. Koepchen, H. P., u.P. Langhorst: Verbessertes Verfahren zur Einführung “reitender” Mikroelektroden ins Gewebe. Pflügers Arch. ges. Physiol.294, 65–67 (1967).

    Google Scholar 

  30. —— u.P. H. Wagner: Neuronale Aktivität im unteren Hirnstamm mit Beziehung zum Kreislauf. Pflügers Arch. ges. Physiol.294, 40–64 (1967).

    Google Scholar 

  31. — u.H. D. Lux: Über die Zusammenhänge zwischen zentraler Erregbarkeit, reflektorischem Tonus und Atemrhythmus bei der nervösen Steuerung der Herzfrequenz. Pflügers Arch. ges Physiol.273, 443–465 (1961).

    Google Scholar 

  32. Lim, R. K. S., S. C. Wang, andC. L. Yi: On the question of a myelencephalic sympathetic centre. VII. The depressor area a sympatho-inhibitory centre. Chin. J. Physiol.13, 61–78 (1938).

    Google Scholar 

  33. Lindgren, P., andB. Uvnäs: Vasodilator responses in the skeletal muscles of the dog to electrical stimulation in the oblongate medulla. Acta physiol. scand.29, 137–144 (1953).

    Google Scholar 

  34. ——: Postulated vasodilator centre in the medulla oblongata. Amer. Physiol.176, 68–76 (1954).

    Google Scholar 

  35. Löfving, B.: Cardiovascular adjustments induced from the rostral cingulate gyrus. With special reference to sympatho-inhibitory mechanisms. Acta physiol. scand.53, Suppl. 184 (1961).

  36. Mollica, A., G. F. Rossi eE. Venturelli: Sopra un metodo di localizzatione di microelettrodi metallici nel tessuto nervoso (microelettrolisi). Boll. Soc. ital. Biol. sper.30, 272 (1954).

    Google Scholar 

  37. Morest, 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).

    Google Scholar 

  38. Oberholzer, R. J. H.: Lokalisation einer Schaltstelle für den Depressorreflex in der Medulla oblongata des Kaninchens. Helv. physiol. pharmacol. Acta13, 331–353 (1955).

    Google Scholar 

  39. Ranson, S. W., andP. R. Billingsley: Vasomotor reactions from stimulation of the floor of the fourth ventricle. Amer. J. Physiol.41, 85–90 (1916).

    Google Scholar 

  40. Richter, D., H. Seller u.H. P. Koepchen: Adaptation der durch Sinus-nervenreizung erzeugten Hemmung der Sympathicusaktivität in Abhängigkeit von Frequenz und Impulsmuster der Reizung. Pflügers Arch. ges. Physiol.297, R82 (1967).

    Google Scholar 

  41. Sagawa, K., andK. Watanabe: Summation of bilateral carotid sinus signals in the barostatic reflex. Amer. J. Physiol.209, 1278–1286 (1965).

    Google Scholar 

  42. Salmoiraghi, G. C.: “Cardiovascular” neurones in brain stem of cat. J. Neurophysiol.25, 182–197 (1962).

    Google Scholar 

  43. Scott, J. M. D.: The part played by the ala cinerea in vasomotor reflexes. J. Physiol. (Lond.)59, 443–454 (1925).

    Google Scholar 

  44. —, andF. Roberts: Localization of the vaso-motor centre. J. Physiol. (Lond.)58, 168–174 (1924).

    Google Scholar 

  45. Seller, H.: Untersuchungen zur funktionellen Organisation der Kreislaufzentren. Habilitationsschrift, München 1968.

  46. —, u.M. Illert: Lokalisation der ersten Umschaltstelle der Carotissinusafferenz und über ihre Funktion in der Reflexverarbeitung. Pflügers Arch. ges. Physiol.300, 72 (1968).

    Google Scholar 

  47. — u.H. P. Koepchen: Über die Abhängigkeit der pressoreceptorischen Hemmung des Sympathicus von der Atemphase und ihre Auswirkung in der Vasomotorik. Pflügers Arch.302, 300–314 (1968).

    Google Scholar 

  48. Smith, R. S., andJ. W. Pearce: Microelectrode recordings from the region of the nucleus solitarius in the cat. Canad. J. Biochem.39, 933–939 (1961).

    Google Scholar 

  49. Stegemann, J., u.H. Müller-Bütow: Zur regeltheoretischen Analyse des Blutkreislaufes. I. Die zentrale Verrechnung der Signale aus den einzelnen Pressoreceptorenfeldern. Pflügers Arch. ges. Physiol.287, 247–256 (1966).

    Google Scholar 

  50. Yamamoto, S., S. Sugihara, andM. Kuru: Microelectrode studies on sensory afferents in the posterior funiculus of cat. Jap. J. Physiol.6, 68–85 (1956).

    Google Scholar 

  51. Yi, C. L.: Further evidence for the existence of reflex sympatho-inhibitory centre in the medulla oblongata. Chin. J. Physiol.13, 411–416 (1938).

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Physiologisches Institut der Universität München, München, Germany

    H. Seller & M. Illert

Authors
  1. H. Seller
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. M. Illert
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

This work was supported by the Deutsche Forschungsgemeinschaft.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Seller, H., Illert, M. The localization of the first synapse in the carotid sinus baroreceptor reflex pathway and its alteration of the afferent input. Pflugers Arch. 306, 1–19 (1969). https://doi.org/10.1007/BF00586608

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00586608

Key-Words

Search

Navigation