Respiratory Depression following Acute Hypoxia in Vagotomized and Carotid Sinus Nerve Denervated Cats
Hypoxic depression of respiration has been observed in carotid chemo-denervated animals1, 2, 3. Although there seems to be general agreement that this is a direct inhibitive effect of hypoxia on central neurones, the exact nature of this mechanism is not well understood. Recently, we observed in carotid chemo-denervated cats that electrical stimulation of the carotid sinus nerve at the threshold Pco2 during moderate hypoxia produced phrenic nerve activity, the peak height of which was not significantly different from that in normoxia4. This suggests that the neural pathway from the carotid chemoreceptors through the central respiratory neurones remains unimpaired during hypoxia. Therefore, the present study was designed to examine the possibility that respiratory depression in hypoxia might be caused by inhibition of the central CO2 chemoreceptors.
KeywordsRespiratory Depression Basilar Artery Phrenic Nerve Anterior Inferior Cerebellar Artery Moderate Hypoxia
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