SIMILARITY OF EFFECTS OF BARBITURATE ANESTHESIA AND SPINAL TRANSECTION

Abstract

The striking similarity of the effects of low spinal transection and barbiturate anesthesia upon the flexion reflex of the cat''s leg is reported. Isotonic and isometric muscle studies with muscle action currents are used to demonstrate that under ether anesthesia a relatively sustained, cumulative reflex contraction of the leg flexors is regularly found upon repeated central stimulation of the sciatic nerve or its popliteal division; whereas, under barbiturate anesthesia ("evipal") larger isolated noncumu-lative twitches of the muscle occur in response to stimulation. The difference appears to be a matter of after-discharge, great in the case of ether, but little under barbiturate anesthesia. From this it is inferred that the "long-circuiting" of sensory impulses is much more seriously curtailed under barbiturate anesthesia than under ether. The behavior of the flexion reflex of the leg under 15 other anesthetic agents is reported.