DESTRUCTION OF THE HYPOTHALAMUS IN CATS

Abstract

In the initial paper of this series it was shown that sodium amytal, when injected parenterally into a cat in a dose of from 20 to 50 mg. per kilogram of body weight, caused a fall in the mean blood pressure of the animal, a decrease in the rate and excursion of respiration and marked diminution or total abolition of the vegetative and emotional mimetic reactions to faradic stimulation of the hypothalamus. These observations indicated that sodium amytal definitely affects the reactivity of this region of the diencephalon; the probability remained, however, that the drug also acts on other portions of the nervous system. It is my purpose in this communication to report the methods and results of experiments designed to investigate the latter hypothesis. METHODS Acute Preparations. —A cat was anesthetized with ether, the head fixed in the Horsley-Clarke apparatus and the calvarium exposed through a dorsal incision in