Courtney Wilson, PhD
University of Colorado School of Medicine
Dr. Courtney Wilson: As a member of Dr. Tom Finger’s laboratory and now as the PI of an R21, I’ve used serial blockface scanning electron microscopy (sbfSEM) as a tool to understand the detailed morphology of taste cells and their connections to nerves. Recently, we observed a population of taste cells that show morphological signs of cell death. Many dying cells do maintain synaptic structures at points of contact with nerve fibers, though we cannot determine whether or not these synapses are still capable of signal transmission. Interestingly, many of the post-synaptic nerve fibers do not connect to larger nerve trunks, indicating that nerve fragmentation may be a component of the nerve remodeling process in the taste bud.
Lindsey Macpherson, PhD
The University of Texas at San Antonio
Dr. Lindsey Macpherson: The Macpherson Lab has investigated the connectivity, loss, and re-emergence of synapses in the taste bud using a combination of immunohistochemistry and in vivo 2-phtoton imaging experiments in mice. We have discovered that the vast majority of taste receptor cell synaptic proteins (such as Calhm1 and Bassoon) are located directly adjacent to gustatory nerve fibers in normal conditions. However, after glossopharyngeal or chorda tympani nerve transection, expression of these proteins quickly diminishes. As soon as chorda tympani axons regenerate and reinnervate fungiform taste buds, the presynaptic proteins return, often without direct contact by an axon. This indicates that presynaptic sites in TRCS are dependent on gustatory axon proximity, but not direct contact, within the taste bud.