Abstract
Neurosecretory neurons were identified in the rat supraoptic nucleus (SON) by the antidromic response to stimulation of the neurohypophysis. I investigated the effects of inhalation anesthetics (nitrous oxide, halothane, diethyl ether) on the unit activity of antidromically identified neurohypophysial neurosecretory neurons. As inhalation of anesthetic agents, 67% nitrous oxide-oxygen (GO), 0.3%-0.5% halothane-oxygen (OF), 0.3%-0.5% halothane-67% nitrous oxide-oxygen (GOF), 6%-12% diethyl ether-oxygen (OE), 6%-12% diethyl ether-67% nitrous oxide-oxygen (GOE) were studied in 5 identified units respectively.
Inhalation of GO showed no change in spontaneous firing rate of the units. OF and GOF showed variant changes of the unit activity.
As the case of OE and GOE, 4 out of 5 tested units exhibited inhibition of the unit firing after inhalation respectively.
From these results, it was concluded that the most of neurohypophysial neurosecretory neurons of the rat supraoptic area were inhibited by inhalation of diethyl ether.
