An in vitro model for the study of taste papillae morphogenesis using branchial arch explants.

It is generally accepted that innervation is required for the maintenance of taste papillae and taste buds, but it is not entirely clear what role, if any, innervation plays in papillae and taste bud formation. Events in taste papillae formation and differentiation take place almost entirely in utero and, therefore, the study of the role of innervation in these events requires a suitable in vitro model. In the past, investigators have made use of various culture techniques to study mammalian taste papillae development in vitro and the role of innervation in this process with varying success. All of these models examined papillae development in isolated tongue or tongue fragments and have lacked the ability to manipulate the innervation of developing taste papillae in these explants. We have established a protocol for an in vitro model of taste papillae morphogenesis using branchial arch explants and roller tube culture methodology. Our results demonstrate that this model supports the morphogenesis of the circumvallate papilla with an integrated nerve. In addition, the use of branchial arch explants allows the inclusion or exclusion of geniculate and petrosal ganglia to examine directly the effects of the presence or absence of innervation on papillae formation and maintenance.