Ultrastructural and histochemical studies on the taste buds in some reptiles.

Publisher Website
Google Scholar
Abstract
The taste buds in tortoises (Clemmys japonica and Geoclemys reevesii), lizards (Takydromus tachydromoides) and snakes (Elaphe quadrivirgata) were examined by ultrastructural and histochemical methods. The taste buds consisted of at least 3 types of cells: type I, II and III cells. The type I cells were characterized by the presence of secretory dense granules containing polysaccharides. The granules were demonstrated by periodic acid-chromic acid-silver methenamine technique. The type II cells contained numerous tubular, vesicular and lamellated structures. The type III cells were characterized by dense cored vesicles and afferent synaptic contacts. Besides these cells, basally located cells, which resembled the basal cells of other lower vertebrates, were sometimes found in the tortoises. After administration of L-dopa following nialamide, some taste bud cells of the tortoises, C. japonica, showed weak yellowish green fluorescence by monoamine fluorescence histochemistry, and the dense-cored vesicles in the type III cells increased in number. Acetylcholine esterase activity was not observed in tortoise taste buds. The 3 types of cells which compose the taste buds of the reptiles may correspond to the 3 types of cells in mammals. The type III cells represent the gustatory cells which potentially produce biogenic monamines. The taste buds of the reptiles may hold an intermediate position between those of mammals and amphibia or fishes.