Neuroscience and Behavioral Physiology

, Volume 30, Issue 4, pp 449–453

The effects of the mediodorsal nucleus of the thalamus on respiratory neurons of the medulla oblongata and respiration in rats in conditions of hypoxia

Authors

  • N. S. Akopyan
  • O. G. Baklavadzhyan
  • V. V. Sarkisyan
    • Department of Human and Animal PhysiologyErevan State University
Article

DOI: 10.1007/BF02463100

Cite this article as:
Akopyan, N.S., Baklavadzhyan, O.G. & Sarkisyan, V.V. Neurosci Behav Physiol (2000) 30: 449. doi:10.1007/BF02463100

Abstract

The effects of the associated mediodorsal nucleus of the thalamus on spike activity of respiratory neurons in the medulla oblongata and on respiration were studied in normal conditions and in oxygen insufficiency. At normal atmospheric pressure, before animals were elevated to low pressures, electrical stimulation of the mediodorsal nucleus of the thalamus had predominantly inhibitory effects. At the initial phase of hypoxia, at a “height” of 4000–5000 m, hypoxic activation of neuron discharge frequency occurred, with an increase in the frequency of respiration. In these conditions, the inhibitory effect of stimulation of the mediodorsal nucleus of the thalamus was less marked than in normoxic conditions. The opposite effect occurred at the second phase of hypoxia (7500–8000 m)— inhibition of activity in the medulla oblongata and thalamic center. In severe hypoxia, there was inhibition of neuron spike activity and a decrease in the frequency of respiration, which became superficial; in these conditions, the inhibitory effect of the thalamus was insignificant.

Key words

Normoxiamediodorsal nucleus of the thalamusexpiratory and inspiratory neurons

Copyright information

© Kluwer Academic/Plenum Publishers 2000