Pflügers Archiv

, Volume 335, Issue 4, pp 323–334 | Cite as

Temperature-sensitive neurons in the brain stem: Their responses to brain temperature at different ambient temperatures

  • R. F. Hellon
Article

Summary

Unit recordings have been made in the hypothalamus of cats and rabbits under urethane anaesthesia. The final position of each electrode penetration was marked by the ejection of a dye. Techniques used enabled brain temperature and ambient temperature to be controlled.

Neurons were found whose mean firing rate was positively or negatively correlated with changes of brain temperature over a range of 4°C. Some of these neurons also responded when ambient temperature over a range of 4°C. Some of these neurons also responded when ambient temperature was raised to 40°C or lowered to 10°C. In four cases, lowering, but not raising, ambient temperature was found to modify the neuron's responses to brain temperature changes. Two forms of modulation were found. In one, the curve relating brain temperature and firing rate was shifted without showing a change in slope (sensitivity). In the other, the slope of curve changed, so that the sensitivity of the neuron to brain temperature was altered. Both types of modulation are consistent with current models of temperature regulation involving receptors in the hypothalamus and in the skin.

Key words

Temperature Neurons Hypothalamus Ambient Temperature 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Cabanac, M., Stolwijk, J. A. J., Hardy, J. D.: Effect of temperature and pyrogens on single-unit activity in the rabbit's brain stem. J. appl. Physiol.24, 645–652 (1968).Google Scholar
  2. Edinger, H. M., Eisenman, J. S.: Thermosensitive neurons in tuberal and posterior hypothalamus of cats. Amer. J. Physiol.219, 1098–1103 (1970).Google Scholar
  3. Eisenman, J. S.: Unit activity studies of thermoresponsive neurons. In: Essays on temperature regulation. J. Bligh and R. Moore, ed. London: North-Holland 1972.Google Scholar
  4. Eisenman, J. S., Jackson, D. C.: Thermal response patterns of septal and preoptic neurons in cats. Exp. Neurol.19, 33–45 (1967).Google Scholar
  5. Forster, R. E., Ferguson, T. B.: Relationship between hypothalamic temperature and thermoregulatory effectors in unanesthetized cat. Amer. J. Physiol.169, 255–269 (1952).Google Scholar
  6. Guieu, J.-D., Hardy, J. D.: Effects of heating and cooling of the spinal cord on preoptic unit activity. J. appl. Physiol.29, 675–683 (1970).Google Scholar
  7. Hammel, H. T.: Neurones and temperature regulation. In: Physiological Controls and Regulations. W. S. Yamamoto and J. R. Brobeck, ed. London: W. B. Saunders 1965.Google Scholar
  8. Hammel, H. T.: Regulation of internal body temperature. Ann. Rev. Physiol.30, 641–710 (1968).Google Scholar
  9. Hammel, H. T., Jackson, D. C., Stolwijk, J. A. J., Hardy, J. D., Strømme, S. B.: Temperature regulation by hypothalamic proportional control with adjustable set temperature. J. appl. Physiol.18, 1146–1154 (1963).Google Scholar
  10. Hardy, J. D., Hellon, R. F., Sutherland, K.: Temperature sensitive neurones in the dog's hypothalamus. J. Physiol. (Lond.)175, 242–253 (1964).Google Scholar
  11. Hellon, R. F.: Thermal stimulation of hypothalamic neurones in unanaesthetized rabbits. J. Physiol. (Lond.)193, 381–395 (1967).Google Scholar
  12. Hellon, R. F.: The stimulation of hypothalamic neurones by changes in ambient temperature. Pflügers Arch.321, 56–66 (1970a).Google Scholar
  13. Hellon, R. F.: Interaction between peripheral temperature receptors and central neurones responding to brain temperature. J. Physiol. (Lond.)210, 161 P (1970b).Google Scholar
  14. Hellon, R. F.: The marking of electrode tip positions in nervous tissue. J. Physiol. (Lond.)214, 12P (1971).Google Scholar
  15. Hellon, R. F., Misra, N. K.: Thalamic neurones responding to scrotal skin temperature in rats. J. Physiol. (Lond.) (in press). (1972).Google Scholar
  16. Hellon, R. F., Provins, K. A.: Unit responses in the somatosensory cerebral cortex of the rat following temperature changes in scrotal skin. J. Physiol. (Lond.)222, 151–152P (1972).Google Scholar
  17. Hensel, H., Iggo, A., Witt, I.: A quantitative study of sensitive cutaneous thermoreceptors with C afferent fibres. J. Physiol. (Lond.)153, 113–126 (1960).Google Scholar
  18. Hensel, H., Kenshalo, D. R.: Warm receptors in the nasal region of cats. J. Physiol. (Lond.)204, 99–112 (1969).Google Scholar
  19. Iggo, A.: Cutaneous thermoreceptors in primates and sub-primates. J. Physiol. (Lond.)200, 403–430 (1969).Google Scholar
  20. Jacobson, F. H., Squires, R. D.: Thermoregulatory responses of the cat to preoptic and environmental temperatures. Amer. J. Physiol.218, 1575–1582 (1970).Google Scholar
  21. Jasper, H. H., Ajmone-Marsan, C.: A stereotaxic atlas of the diencephalon of the cat. Ottawa: National Research Council of Canada 1954.Google Scholar
  22. Nakayama, T., Hammel, H. T., Hardy, J. D., Eisenman, J. S.: Thermal stimulation of electrical activity of single units of the preoptic region. Amer. J. Physiol.204, 1122–1126 (1963).Google Scholar
  23. Nakayama, T., Hardy, J. D.: Unit responses in the rabbit's brain stem to changes in brain and cutaneous temperature. J. appl. Physiol.27, 848–857 (1969).Google Scholar
  24. Nutik, S. L.: Effect of temperature change of the preoptic region and skin on posterior hypothalamic neurons. J. Physiol. (Paris)63, 368 (1971).Google Scholar
  25. Sawyer, C. H., Everett, J. W., Green, J. D.: The rabbit diencephalon in stereotaxic co-ordinates. J. comp. Neurol.101, 801–824 (1954).Google Scholar
  26. Simon, E., Iriki, M.: Sensory transmission of spinal heat and cold sensitivity in ascending spinal neurons. Pflügers Arch.328, 103–120 (1971).Google Scholar
  27. Stolwijk, J. A. J., Hardy, J. D.: Temperature regulation in man — a theoretical study. Pflügers Arch. ges. physiol.291, 129–162 (1966).Google Scholar
  28. Wit, A., Wang, S. C.: Temperature-sensitive neurons in the preoptic/anterior hypothalamic region: effects of increasing ambient temperature. Amer. J. Physiol.215, 1151–1159 (1968).Google Scholar
  29. Wünnenberg, W., Brück, K.: Single unit activity evoked by thermal stimulation of the cervical spinal cord in the guinea pig. Nature (Lond.)218,1268–1269 (1968).Google Scholar

Copyright information

© Springer-Verlag 1972

Authors and Affiliations

  • R. F. Hellon
    • 1
  1. 1.National Institute for Medical ResearchLondonEngland

Personalised recommendations