Taste receptor cells (within taste buds) are constantly replaced through adulthood. This raises
the question of whether this continuous cell turnover causes remodeling in the taste nerve
terminal arbors, which innervate taste receptor cells. More specifically, how does taste receptor
cell entry and cell exit within the taste bud influence arbor structure? To answer these
questions, I propose to develop an in vivo two-photon imaging method to repeatedly sample the
same terminal arbors over time. Aim 1 will examine terminal arbor structure over the average
lifespan of a taste receptor cell (10 days). I hypothesize that terminal arbor structure in the
epithelium will remodel in this period, while structure beneath the epithelium will remain stable.
Aim 2 will examine arbor structure when taste cell turnover is manipulated to elucidate the
effects of cell entry and cell exit. I hypothesize that taste cell exit from the bud will promote
branch retraction and taste cell entry into the bud will promote branch formation/growth. These
experiments are the first to investigate changes in taste neuron anatomy over time using a intra
vital imaging approach and will provide direct evidence of extent of nerve fiber remodeling in the
taste bud. Future studies will use this approach to investigate the specific molecular
mechanisms, in both neurons and taste cells, used to orchestrate plasticity in the taste bud.