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.
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References
N. S. Akopyan, O. G. Baklavadzhyan, and N. V. Sarkisyan, “The role of the limbic cortex in controlling the spike activity of neurons in the respiratory center of the medulla oblongata in conditions of oxygen deficiency,”Zh. Vyssh. Nerv. Deyat.,44, No. 4–5, 777–785 (1994).
O. G. Baklavadzhyan, L. B. Nersesyan, and N. K. Manukyan, “Responses of neurons in the bulbar respiratory center to stimulation of the anterior ventral and mediodorsal thalamic nuclei,”Neirofiziologiya,25, No. 3, 218–225 (1993).
Ya. Buresh, M. Petran, and I. Zakhar,Electrophysiological Study Methods [Russian translation], Foreign Literature Press (Inostrannaya Literature), Moscow (1962).
R. A. Durinyan,Central Structures of Afferent Systems [in Russian], Meditsina, Moscow (1965).
V. N. Kazakov,Integrative Mechanisms of the Thalamus. A Partial Physiology of the Nervous System [in Russian], Nauka, Leningrad (1983).
A. G. Kartseva, N. Z. Vasil'eva, and V. V. Raevskii, “Studies of descending pathways of suprabulbar structures of the cat brain, involved in controlling the circulation,” in:Axonal Transport of Substances in Brain Systems [in Russian], Kiev (1981).
T. A. Leontovich,Neuronal Organization of Subcortical Formations of the Forebrain [Russian translation], Forergn Literature Press (Inostrannaya Literatura) Moscow (1962).
L. B. Nersesyan, “Effects of the limaic system and hypothalamus on the activity of medullary neurons,”Fiziol. Zh. SSSR,71, No. 3, 304–309 (1985).
I. Oivin, “Statistical processing of experimental data,”Zh. Patol. Éksper. Terapii,4, No. 4, 76–85 (1959).
F. N. Serkov and V. N. Kazakov,Neurophysiology of the Thalamus [in Russian], Naukova Dumka, Kiev (1980).
K. E. Livingston and A. Escobar, “Anatomical basis of the systems concept,”Arch. Neurol.,24, No. 1, 17–21 (1971).
R. R. Terreberry and E. J. Neafsey, “Rat medial frontal cortex visceral motor region with a direct projection to the solitary tract,”Brain Res.,178, No. 1, 245–249 (1983).
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Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 85, No. 2, pp. 283–289, February, 1999.
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Akopyan, N.S., Baklavadzhyan, O.G. & Sarkisyan, V.V. The effects of the mediodorsal nucleus of the thalamus on respiratory neurons of the medulla oblongata and respiration in rats in conditions of hypoxia. Neurosci Behav Physiol 30, 449–453 (2000). https://doi.org/10.1007/BF02463100
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DOI: https://doi.org/10.1007/BF02463100