ABSTRACT
The stomach, upper small intestine, lower small intestine, the liver and the colon, have all been suggested as exercising control over food intake. This chapter focuses on vagal participation in the control of food intake by the stomach and small intestine. Recordings from gastric mechanoresponsive fibers in the vagus were among the first data supporting the vagal role in gastrointestinal sensation. Clearly, gastrointestinal vagal innervation detects and responds to mechanical and chemical properties of ingesta during each meal. It would be surprising, however, if changes in food intake were mediated exclusively by signals from this innervation. In fact we can say with certainty that they are not. Nevertheless, sensory neurons of the vagus nerve respond to a variety of stimuli appropriate as putative satiety signals and it is probable that vagal sensory mechanisms make an important contribution to the process of satiation by relaying information to the brain on chemical and mechanical qualities of ingesta.
