Abstract
D and the nociceptive nature of the stimulus was ascertained by reflex increases in blood pressure. Levels of biliary pressure that did not evoke changes in blood pressure were considered innocuous. Using this approach electrical activity has been recorded from biliary afferents. Thirty-two recordings were obtained. Twenty-one were of afferents that could be excited by innocuous levels of biliary pressure (low threshold afferents) and 10 recordings were of afferents excited only by noxious stimulation of the biliary system (high threshold afferents). One fibre could not be activated by changes in biliary pressure. Twenty-seven receptive fields were located: 12 in the galllbladder and 15 in the biliary ducts. The relevance of high threshold biliary receptors to visceral nociception is discussed. (Received 30 April 1981, accepted 4 November 1981) © Lippincott-Raven Publishers....