RESPONSES OF LATERAL HYPOTHALAMIC NEURONS TO ODOURS BEFORE AND DURING STOMACH DISTENSION IN UNANAESTHETIZED RABBITS

Abstract

Publisher Summary There is much evidence that the lateral hypothalamic (LH) neurons receive olfactory inputs. Recent neuro-anatomical experiments have demonstrated that the origins of the fibers projecting to the LH neurons exist in several parts of the basal brain, such as the anterior olfactory nucleus, the olfactory tubercle, the amygdale, and the prepyriform cortex. Electro-physiological data also indicate the existence of these olfactory projections. This chapter describes a relationship between the behavior of LH neurons and the condition of the stomach. It discusses the study of the responses to the odors of LH neurons in unanesthetized rabbits. This was done through a preliminary operation performed under anesthesia. After the response patterns of all neurons to eight odors were examined, the rabbit's stomach was inflated and any changes in their response patterns were sought. It is still entirely unknown where in the brain, the sensation of smell occurs. However, the finding that responses to odors of neurons in the feeding center become different, depending upon the condition of the stomach, indicates that the odors that are appetite-stimulating during the state of hunger become less and less attractive as the stomach is distended by food intake.