Immunocytochemical localizations of neuron-specific proteins in the taste bud of the guinea pig.

The taste buds and their nerves in the guinea pig were immunocytochemically investigated with regard to the localization of spot 35 protein, neuron-specific enolase (NSE), neurofilament protein (NFP), and S-100 protein. The spot 35 protein-like immunoreactivity was confined to slender cells comprising half the number of taste bud cells. NSE-like immunoreactivity was recognized in some taste bud cells as well as nerve fibers both within the taste bud and in the subepithelial connective tissue. The NSE-immunoreactive cells were divided into two cell populations: one weakly and the other intensely immunoreactive. The former cells proved to be spot 35 protein-immunoreactive. Moreover, the cells immunoreactive for both spot 35 protein and NSE were frequently associated with nerve fibers immunostained intensely for NSE. The NFP- and S-100 protein-like immunoreactivities were found in none of cells in the taste bud, but exclusively in the subepithelial neural elements.