Chorda tympani nerve fibers remain and are functional after taste bud elimination in Hedgehog (HH) pathway inhibition. A. Chorda tympani fibers (red) in fungiform papillae (FP) in Phox2b-tdTomato mice after treatment with Vehicle or the HH pathway pharmacologic inhibitor Sonidegib for 28 days. Dashed lines outline the papillae. Chorda tympani fibers are in the FP connective tissue core, in the taste bud (TB, Vehicle) and extend into the epithelium outside of the taste bud. After Sonidegib treatment, and HH pathway inhibition, taste buds are eliminated in all FP. (Images are from work in progress and AChemS 2019.) B. Recordings from the chorda tympani nerve in Vehicle- (with taste buds) and Sonidegib-treated (with no taste buds) mice demonstrate loss of responses to chemical stimuli and retained robust responses to tactile and cold stimuli after treatment. At various times after drug removal, Recovery of responses to chemical stimuli is demonstrated. (Data from Figure 8, Ref. 6.)