Fixation and occurrence of dark and light cells in taste buds of fungiform papillae

The fine structure of taste buds of the fungiform papillae of the Old World monkey Cynomolgus (Macaca fascicularis) was found to vary with the primary fixative solution used. Standard primary fixative solutions of glutaraldehyde as well as fixatives containing both formaldehyde and glutaraldehyde gave non-reproducible and usually poor results. Osmium tetroxide in distilled water gave reproducible fixation of acceptable quality. Further, when fixed in osmium tetroxide in distilled water, taste buds of the fungiform papillae did not show the dark and light cells well known from other studies. It is therefore suggested that the terms dark and light cells not be used as synonyms for receptor or support cells, since the appearance of taste bud cells is affected by fixation.