The electroencephalogram and neurohumoral mechanisms of satiety

Summary

An electroencephalographic analysis was made of neurohumoral mechanisms associated with satiety. The experiments were performed on cats under urethane anaesthesia. Specific ascending activation of the anterior parts of the cortex of hungry animals disappeared after the introduction of food into the mouth or stomach. The effect was only temporary, and within one to two hours after introduction of food into the stomach “hunger” activation of the cortex regularly disappeared. A similar effect was obtained when food was introduced into the stomach at the same time that a glucose injection was given into the blood stream. These experiments showed that the mechanism of satiety was neurohumoral in origin. The nervous mechanism of satiety operated as a trigger, while the main effect in diminishing “hunger” activation was due to absorption of food from the intestine. The most remote effect was observed when food was introduced into the body by natural means, i.e. when it first came in contact with the oral and gastric receptors and was subsequently absorbed into the blood stream.