LOCALIZATION OF SUBSTANCE-P NK-1 RECEPTORS IN RAT TONGUE

In rat tongue, neurons containing substance P terminate in connective tissue, in taste buds, and in lingual epithelium surrounding taste bud s in fungiform, foliate and circumvallate papillae. Although many func tions have been attributed to these neurons, virtually nothing is know n about their physiological function. As a step towards this end, immu nocytochemical methods were used to identify the NK-1 receptors (SPR) in rat tongue. SPR-IR was found in the basolateral membranes of taste cells in fungiform, circumvallate and foliate papillae. SPR-IR was not found in the dorsal epithelium or in any structure that could be clea rly identified as a neuron. SPR-IR was also found in von Ebner's gland s in circumvallate and foliate papillae and in blood vessels in connec tive tissue in all three papillae. These data suggest that substance P may play a role in taste and/or in oral pain.