Three-dimensional reconstructions of mouse circumvallate taste buds using serial blockface scanning electron microscopy: I. Cell types and the apical region of the taste bud |
| |
Authors: | Ruibiao Yang Yannick K Dzowo Courtney E Wilson Rae L Russell Grahame J Kidd Ernesto Salcedo Robert S Lasher John C Kinnamon Thomas E Finger |
| |
Institution: | 1. Department of Cell and Developmental Biology, Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Denver, Colorado;2. Department of Cell and Developmental Biology, Rocky Mountain Taste and Smell Center, University of Colorado School of Medicine, Denver, Colorado
Modern Human Anatomy Program, University of Colorado School of Medicine, Denver, Colorado;3. Department of Neuroscience, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
3D-Electron Microscopy, Renovo Neural Inc., Cleveland, Ohio;4. Department of Biological Sciences, University of Denver, Denver, Colorado |
| |
Abstract: | Taste buds comprise four types of taste cells: three mature, elongate types, Types I–III; and basally situated, immature postmitotic type, Type IV cells. We employed serial blockface scanning electron microscopy to delineate the characteristics and interrelationships of the taste cells in the circumvallate papillae of adult mice. Type I cells have an indented, elongate nucleus with invaginations, folded plasma membrane, and multiple apical microvilli in the taste pore. Type I microvilli may be either restricted to the bottom of the pore or extend outward reaching midway up into the taste pore. Type II cells (aka receptor cells) possess a large round or oval nucleus, a single apical microvillus extending through the taste pore, and specialized “atypical” mitochondria at functional points of contact with nerve fibers. Type III cells (aka “synaptic cells”) are elongate with an indented nucleus, possess a single, apical microvillus extending through the taste pore, and are characterized by a small accumulation of synaptic vesicles at points of contact with nerve fibers. About one-quarter of Type III cells also exhibit an atypical mitochondrion near the presynaptic vesicle clusters at the synapse. Type IV cells (nonproliferative “basal cells”) have a nucleus in the lower quarter of the taste bud and a foot process extending to the basement membrane often contacting nerve processes along the way. In murine circumvallate taste buds, Type I cells represent just over 50% of the population, whereas Types II, III, and IV (basal cells) represent 19, 15, and 14%, respectively. |
| |
Keywords: | microvilli mitochondria nerve fibers RRID: SCR_001622 RRID: SCR_002716 RRID:SCR_014199 RRID: SCR_008606 synaptic vesicles taste taste buds |
|
|