Anesthesia selectively reduces hypoglossal nerve activity by actions upon the brain stem.
Alcohol as well as anesthetic and sedative agents depress the respiratory activity of the hypoglossal-genioglossal system more than that of the phrenic-diaphragmatic system. The mechanisms for this selective depression remain unclear. To evaluate the contribution of pathways traversing the spinal cord, the response of phrenic and hypoglossal nerve activities to 0.5% halothane was obtained in decerebrate cats before and after transection of the spinal cord at T1 and again following transection at C1. Halothane produced a much greater decrease in hypoglossal than phrenic activity before and after spinal cord section at T1. Following cord section at C1, which eliminates phrenic activity, 0.5% halothane still produced a marked depression of hypoglossal activity. Therefore, the selective depression of the hypoglossal-genioglossal system does not depend on spinal mechanisms and appears to be mediated in the brain stem.
D000768:Anesthesia, General; D000818:Animals; D001933:Brain Stem / Q000502:physiology*; D002415:Cats; D003655:Decerebrate State; D006221:Halothane / Q000494:pharmacology; D007002:Hypoglossal Nerve / Q000187:drug effects / Q000502:physiology*; D010791:Phrenic Nerve / Q000187:drug effects / Q000502:physiology
D006221:Halothane