Fine structure of the taste bud in the mud puppy, Necturus maculosus

This is the authors' abstract. We don't add key points for this paper.

The taste receptor of Necturus was studied because of its potential usefulness in electrophysiological intracellular recording. The taste bud has about twice the length and twice the diameter of buds in most other vertebrates. The large size can be attributed to both a greater number of cells and a greater size of the individual cells. The cells of Necturus taste buds appear to be homologous to those in other vertebrates. Three distinct cell types were found: dark cells (60%), light cells (30%), and basal cells (10%). Dark cells contained granular endoplasmic reticulum, Golgi bodies, and many clusters of characteristic granules that reacted positively when treated with the periodic acid‐silver methenamine technique. They are probably secretory cells. Light cells, found in the center of the taste bud, were virtually filled with agranular endoplasmic reticulum, mitochondria and Golgi bodies. Their morphology is similar to that of chloride cells in fish gills, and they may have an ion transport function important in the gustatory response. Basal cells, located at the periphery in the basal half of the bud, contained characteristic dense‐core vesicles about 70–90 mμ in diameter. The lower half of the taste bud contained many intraepithelial nerve processes adjacent to the cells.