RESPONSE OF SINGLE VAGAL AFFERENT FIBRES TO MECHANICAL AND CHEMICAL STIMULATION OF THE GASTRIC AND DUODENAL MUCOSA IN CATS

Abstract

Single afferent fibres were dissected from the cervical vagus of adult cats and their response to mechanical and chemical stimulation of the gastroduodenal mucosa studied. All the units responded to light phasic mechanical stimulation of the mucosa but two different types of unit could be distinguished on the basis of their response to chemical stimulation. One type of unit responded to acidification of the mucosa while the other responded to application of high pH solutions to the mucosa. Each unit responded to one or other of these two forms of stimulation but not to both. Nor did any unit respond to any other form of chemical stimulation. Other functional characteristics, the location of the mucosal endings and the pathways of the units between the abdomen and neck are described. The possible role of these afferent units is discussed.