THE ULTRASTRUCTURE OF TASTE-BUDS IN THE NEWBORN PIG

Taste buds localized on circumvallate papillae of the porcine tongue w ere investigated for the occurrence of dark, light and receptor cells and the stage of their differentiation, the morphology of the taste po re area, the occurrence and distribution of intragemmal nerve endings and the way in which these are connected with each cell type. It was o bserved that, as early as two days after birth, the porcine taste buds included all three cell types. These were elongated towards the taste pore. Their apical parts, however, did not come up to level with the epithelial surface nor were they shaped into microvilli typical of the bud ultrastructure described in adult animals of other mammalian spec ies. The cytoplasm of the dark cells had only a low amount of dark sec retory granules and the receptor cells showed only occasional occurren ce of dark vesicles. The dark, light and receptor cells were connected with nerve fibres and the way of contact was different in each cell t ype.