Cellular relations in mouse circumvallate taste buds

Abstract

The fine structure of the taste buds of circumvallate papillae of two strains of mice was studied by electron microscopy. Mice anesthetized with ketamine were perfused through the heart with a double aldehyde mixture in cacodylate buffer and the tissues embedded in Epon. Semi-serial sections were employed. The morphology and relationships of cell types are consistent with the majority of descriptions of mammalian taste buds served by the ninth cranial nerve. Cells of type II are particularly well documented, as the stages in their origin, maturation and degeneration could be followed. Significant differences, however, relate to cell type I. These cells contain large dense-cored granules, contrasted with the more irregular and somewhat larger dark granules of the type I cells in the rabbit. These granules do not produce a dense homogenous product for the pore, as seen in the rabbit. Rather the pore substance consists of small, empty vesicles in a diffuse dark matrix. These granules are only moderately larger than the dense-cored vesicles of the type III cells. All features of the type III cell were demonstrated, although no instance of a complete cell was seen in any section. No significant differences were noted between the two strains of mice. Intimate proximity of a nerve to a cell nucleolus, suggestive of a trophic pathway, is illustrated.

Immunoelectron microscopic studies on protein gene product 9.5 and calcitonin gene‐related peptide in vallate taste cells and related nerves in the guinea pig

“…Since PGP 9.5 is a widely distributed neuronal marker (Iwanaga et al, 1992;Kanazawa and Yoshie, 1996;Wang et al, 1990), it is reasonable to assume that PGP 9.5-immunoreactive cells may correspond to taste receptor cells for chemoreception. Type III taste cells have been found in taste buds in rabbit foliate papillae (Fujimoto and Murray, 1970), human fungiform papillae (Paran et al, 1975), monkey foliate papillae (Farbman et al, 1985), and vallate papillae in the mouse (Murray, 1993), rat (Yee et al, 2001), and guinea pig Lu, 1996a, 2001;Yoshie et al, 1990). Type III cells are regarded as taste receptor cells and form chemical synapses on nerve processes that convey primarily gustatory information from the peripheral sensory organ to the CNS.…”

“…Different types of taste cells are considered to be involved in gustatory or supportive functions (Farbman et al, 1985;Huang and Lu, 1996a;Yoshie et al, 1990). Type III taste cells have been found in taste buds in rabbit foliate papillae (Fujimoto and Murray, 1970), human fungiform papillae (Paran et al, 1975), monkey foliate papillae (Farbman et al, 1985), and vallate papillae in the mouse (Murray, 1993), rat (Yee et al, 2001), and guinea pig Lu, 1996a, 2001;Yoshie et al, 1990). Type III cells forming chemical synapses on nerve processes in the taste buds of rabbit foliate papillae (Murray, 1973;Royer and Kinnamon, 1991) and of vallate papillae in the mouse (Murray, 1993), guinea pig (Huang and Lu, 1996a;Yoshie et al, 1990), and rat (Yee et al, 2001) are regarded as taste receptor cells and convey primarily gustatory information from the peripheral sensory organ to the CNS.…”

“…Type III cells forming chemical synapses on nerve processes in the taste buds of rabbit foliate papillae (Murray, 1973;Royer and Kinnamon, 1991) and of vallate papillae in the mouse (Murray, 1993), guinea pig (Huang and Lu, 1996a;Yoshie et al, 1990), and rat (Yee et al, 2001) are regarded as taste receptor cells and convey primarily gustatory information from the peripheral sensory organ to the CNS. In addition to forming synapses with nerve terminals, type III cells have several distinct characteristics, including an elongated spindle shape, an invaginated nucleus, and dense-cored vesicles (Huang and Lu, 1996a;Murray, 1993;Royer and Kinnamon, 1991;Yee et al, 2001;Yoshie et al, 1990). Iwanaga et al (1992) have shown that the structure, metabolism, and functional characteristics of paraneurons, such as endocrine and sensory cells, are very similar to those of neurons.…”

“…Type III taste cells have been found in taste buds in rabbit foliate papillae (Fujimoto and Murray, 1970), human fungiform papillae (Paran et al, 1975), monkey foliate papillae (Farbman et al, 1985), and vallate papillae in the mouse (Murray, 1993), rat (Yee et al, 2001), and guinea pig Lu, 1996a, 2001;Yoshie et al, 1990). Type III cells forming chemical synapses on nerve processes in the taste buds of rabbit foliate papillae (Murray, 1973;Royer and Kinnamon, 1991) and of vallate papillae in the mouse (Murray, 1993), guinea pig (Huang and Lu, 1996a;Yoshie et al, 1990), and rat (Yee et al, 2001) are regarded as taste receptor cells and convey primarily gustatory information from the peripheral sensory organ to the CNS. In addition to forming synapses with nerve terminals, type III cells have several distinct characteristics, including an elongated spindle shape, an invaginated nucleus, and dense-cored vesicles (Huang and Lu, 1996a;Murray, 1993;Royer and Kinnamon, 1991;Yee et al, 2001;Yoshie et al, 1990).…”

Postnatal Development of the Mouse Volatile Papilla Taste Bud Cells

“…The taste bud has been reported to consist of three or four different cell types. These include the gustatory cells, suspentacular cells, and basal cells [4,12], or type I, type II, type III and basal cells [9]. The gustatory cells or type I and II cells have a spindle shape with a taste receptor.…”