Effects of visceral sensation on the dorsal horn cell activity. 3. Effects of thiamylal and changes of the rectal luminal pressure
Sato, I.; Nagasaka, H.; Aikawa, K.; Nakajima, T.; Arima, T.; Matsumoto, N.; Maruno, Y.; Hori, T.
Masui. Japanese Journal of Anesthesiology 31(5): 434-439
1982
ISSN/ISBN: 0021-4892 PMID: 7131719 Document Number: 189518
Effects of the intraluminal pressure of the rectum were studied on lumbar dorsal horn neurons responding to peripheral somatic sensation in nondecerebrated and decerebrated spinal cats. Effects of thiamylal sodium 3.0 mg/kg i.v. were tested on those neurons which changed their activity with increased intraluminal pressure of the rectum. Unit activity of lamina 4 decreased gradually after raising the intraluminal pressure of the rectum. Thiamylal sodium given in this neuronal state increased their firing rate significantly in nondecerebrated cats but decreased it in decerebrated spinal cats. Neuronal activities of lamina 5 were inhibited in 2/3 of neurons tested; the other 1/3 of them increased their activity after raising the intraluminal pressure of the rectum. In nondecerebrated cats, thiamylal increased their neuronal activity in neurons which showed facilitated activity and also in those with inhibited activity, while in decerebrated spinal cats, their firing rates decreased after the adminstration of thiamylal. Firing rates of neurons in lamina 6 increased after raising the intraluminal pressure of the rectum in nondecerebrated and decerebrated spinal cats but decreased their activity after thiamylal in both groups of cats.