Abstract
The acetylcholine content of the frontal and temporal lobes, hippocampus, hypothalamus, cerebellum and spinal cord was estimated in 18 dogs 3 hr. after the intravenous administration of reserpine. Another group of 7 dogs served as control. After reserpine (0.5 mg./kg. body weight) there was an increase of acetylcholine in all the areas under study except in the hippocampus. The increase was specially marked in the hypothalamus. In the hippocampus, however, reserpine caused a significant decrease of acetylcholine.