AN IMMUNOHISTOCHEMICAL SCREENING OF NEUROCHEMICAL MARKERS IN FUNGIFORM PAPILLAE AND TASTE-BUDS OF THE ANTERIOR RAT TONGUE

The occurrence and distribution of several neurochemical markers were investigated. Numerous nerve fibres were shown, using antibodies to pr otein gene product (PGP) 9.5, neurone-specific enolase, calcitonin gen e-related peptide (CGRP), substance P, neurokinin A or protein S-100. The pre sence of vasoactive intestinal polypeptide (VIP), peptide hist idine isoleucine amide (PI-II), neuropeptide tyrosine, dopamine-beta-h ydroxylase (DBH), cholecystokinin/gastrin, glutamate and galanin was m ore scarce. Nerve fibres containing these above-mentioned markers were found at several locations, i.e. in the epithelium, connective tissue , and around blood vessels. In the taste buds, numerous PGP 9.5-, neur one-specific enolase-, CGRP-, substance P-, neurokinin A- and protein S-100-containing structures were found; but few VIP and galanin ones. No immunoreactivity was found with antibodies against somatostatin, bo mbesin, enkephalin or dynorphin. These findings extend knowledge about the general as well as the neurochemical messenger-based innervation of rat fungiform papillae, forming a firm basis for future functional investigations of normal, experimental and also clinical materials. (C ) 1997 Elsevier Science Ltd.