Effect of the length of the distal stump of transected nerve upon the rate of degeneration of taste buds

Abstract

The present work was carried out to study the effect of the length of the distal stump of transected nerve upon the rate of degeneration and the time course of disappearance of mammalian taste buds. Twelve adult rabbits were anaesthetized and the glossopharyngeal nerves of both sides were exposed and transected so as to leave a long distal stump on the right and a short one on the left side. The animals were sacrificed at different post-operative periods ranging from 2 to 14 days and the circumvallate and foliate papillae of both sides were examined. The taste buds on the side of the short distal stump always showed a greater decrease in number, size and cell contents than those of the side of the long distal stump. The taste buds on the side of the short distal stump disappeared earlier than those of the side of the long distal stump. Vallate taste buds disappeared earlier than the foliate: possible reasons for this were put forwards. The validity of the neurohumoral theory to the mammalian taste buds was discussed.