Differentiation of Taste Buds in Organ Culture

It is well established that the structural integrity of mammalian taste buds is dependent on an intact innervation . This is based on the following lines of evidence . Experiments in which gustatory nerves were severed resulted in degeneration of taste buds (5, 8, 9, 14, 17) . If gustatory nerves were allowed to regenerate into the areas they previously innervated, taste buds reappeared (8, 10, 18) ; usually this occurred only under the influence of gustatory nerves, and not in response to other sensory or motor nerves (10, 18) . During development, taste bud cells begin to differentiate only after nerves have grown into the epithelium (4) . In transplant experiments fragments of embryonic tongue grafted into the anterior chamber of the eye grew and differentiated in essentially the same way as the normal tongue in situ, but taste buds did not appear because there was no innervation (6, 15) . The nature of the interaction between the developing or regenerating nerve and the presumptive taste bud epithelium is not known . The preliminary experiments described in this report were begun in order to develop a model system in which taste bud development could be manipulated and studied in more detail, with the ultimate aim of characterizing, on a molecular basis, the factors responsible for the differentiation of oral epithelial cells into gustatory receptors .