Fig. 5
From: TrkB expression and dependence divides gustatory neurons into three subpopulations
In conditional TrkB knockouts, remaining neurons innervate fungiform papillae, but not taste buds, resulting in substantial taste bud loss by P20. a) Representative image of a taste bud (keratin-8) with Phox2b + fibers (tdTomato) from Phox2b-Cre::tdTomato::TrkBGFP/+ mice. b) Representative image of a taste bud from Phox2b-Cre::tdTomato::TrkBGFP/loxP lacking Phox2b-fibers. c) Phox2b + nerve fiber innervating a fungiform papillae (DAPI). D) Quantification of the number of taste buds remaining after TrkB removal from taste neurons (control, n = 3; conditional knockout, n = 5). e, g) Representative image of Phox2b-Cre::tdTomato::TrkBGFP/+ taste bud (keratin-8) with innervation (red) from Phox2b-Cre::tdTomato::TrkBGFP/+ mice, f, g) Car4+ (green) and PLCβ2+ taste receptor cells. H-J) Representative image of Phox2b-Cre::tdTomato::TrkBGFP/loxP taste bud (keratin-8) with no innervation from Phox2b-Cre::tdTomato::TrkBGFP/+ mice and I) PLCβ2+ taste receptor cells K) Quantification of percentage of taste buds with PLCβ2+ cells and Car4+ cells. Data represent the mean of percentage ± SEM. Scale bar = 10 μm. Scale bar on E applies to F and G. Scale bar on H applies to I and J. **p < 0.01