Changes in the Morphology of Tongue Tissue Resulting from Lingual Nerve Transection

The sense of taste is a means through which our nervous system interacts with food and fluid. Taste buds transmit taste information to the brain along the chorda tympani nerve. These taste buds are located in structures called fungiform papillae, which can be found on the anterior surface of the tongue. This papilla structure transmits somatosensory information (hot, cold, etc.) to the brain along the lingual nerve. The lingual and chorda tympani nerves have no known connections or overlap in the papillae or taste buds. It has previously been observed in rats that cutting the chorda tympani nerve early in development causes the fungiform papillae structures to either change in shape or disappear entirely, despite the fact that there is no known relation between this specific nerve and the papilla structure itself. The purpose of this study was to further investigate these two nerves and the papillae and taste buds they innervate. In this study, the lingual nerve was severed in rats of different age groups, and then the tongue tissue from these animals was sectioned on a cryostat to a thickness of m. The tissue was then stained and analyzed using a research microscope to determine differing taste bud volumes. These volumes were calculated using the computer program Neurolucida. By observing the changes to the tongue tissue that were caused by severing the lingual nerve, we are able to better understand the relationship between the chorda tympani and lingual nerves and how they interact within the peripheral nervous system