Taste Bud Development in Rat Vallate and Foliate Papillae

Abstract

Numerous studies have evaluated the neurotrophic capacity of axons to support adult mammalian taste buds. The present evidence indicates that degenerated taste buds are only regenerated by chemosensory axons and only re-formed or maintained in gustatory epithelium (reviewed in Oakley, 1985). The neurotrophic maintenance of taste buds is mediated by axonal transport (Sloan et al., 1983). The molecular mechanisms of neurotrophic support remain to be elucidated. The present paper provides an overview of a series of six recent studies from our laboratory on the development of taste buds of the vallate and foliate papillae on the posterior portion of the rat tongue. Our analyses emphasized the postnatal role that taste axons might play in the development of taste buds. The development of rat lingual taste buds is largely a postnatal process. Among mammalian mechanoreceptors with secondary sensory tissue, both muscle spindles (Zelena, 1957) and Pacinian corpuscles (Zelena, 1980) are neurally induced in development, but will survive without neurotrophic support in adults.