PRESENCE AND ACTION OF ACETYLCHOLINE IN EXPERIMENTAL BRAIN TRAUMA

Abstract

Following exptl. concussion to dogs and cats, the acetyl-choline (ACh) content of their uneserinized ecrebro-spinal-lluid was estimated to range from 2.7 9.0 [gamma] % and persisted for as long as 48 hrs. Patterned behavioral and EEG changes were also noted to persist for 5 days following trauma. These were partially abolished with appropriate subcut. doses of atropine. ACh, when perfused directly over the cortex, produced excitatory or synchronous EEG effects in low physiologic concn.[long dash]1 7 % or less and depressant effects in high physiologic concn.[long dash]2.0 7 % or more. Intracisternal ACh, 0.02[long dash]10.0 [gamma], produced similar EEG and behavioral patterns as observed following trauma. These also were abolished by atropine. It is suggested that "free ACh" may be a factor in early post-traumatic depressed and excitatory states.