The vertebrate taste bud is a good model for studying cellular aging in the nervous system. Taste cells possess many characteristics shared by neurons, such as excitability, chemosensitivity, and synapses (Roper, 1983a; Kinnamon, Taylor, Delay and Roper, 1985; Kinnamon and Roper, 1986). Taste cells have the added advantage that their lifespan is short (only a few days) compared to neurons, and thus age-related changes can be measured with reliability and confidence: complicating factors such as metabolic or hormonal differences between young and old animals are avoided. Furthermore, detailed analyses of age- related changes in the biophysical properties of taste cells and in their membrane chemosensitivity can be conducted on taste cells. Taste cells from the mudpuppy (Necturus maculosus) will be impaled with microelectrodes in situ, using a new isolated preparation developed in this laboratory (Roper, 1983). In depth analyses of the membrane conductances, particularly potassium conductance, will shed light on how ionic channels change over the lifespan of an excitable cell. Chemical stimuli will be applied focally onto the apical surface of taste cells to sutdy what age- related changes in chemosensitivity occur. Cells will be impaled with dye-filled micropipettes to identify the cells in subsequent light and electron micrographs in order to correlate the functional properites of the cell with its age: recent observations have indicated that taste cell aging can be determined by ultrastructural features (Kinnamon, et al. 1985; Delay, Kinnamon and Roper, 1986). These findings will provide information on cellular aging in excitable tissues and will also lead to a better understanding of taste transduction mechanisms.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG006557-04
Application #
3117626
Study Section
Neurology B Subcommittee 1 (NEUB)
Project Start
1986-01-01
Project End
1992-03-31
Budget Start
1989-04-01
Budget End
1990-03-31
Support Year
4
Fiscal Year
1989
Total Cost
Indirect Cost
Name
Colorado State University-Fort Collins
Department
Type
Schools of Veterinary Medicine
DUNS #
112617480
City
Fort Collins
State
CO
Country
United States
Zip Code
80523
Liang, Huiyun; Bai, Yidong; Li, Youfen et al. (2007) PGC-1alpha-induced mitochondrial alterations in 3T3 fibroblast cells. Ann N Y Acad Sci 1100:264-79
Mackay-Sim, A; Delay, R J; Roper, S D et al. (1996) Development of voltage-dependent currents in taste receptor cells. J Comp Neurol 365:278-88
Delay, R J; Mackay-Sim, A; Roper, S D (1994) Membrane properties of two types of basal cells in Necturus taste buds. J Neurosci 14:6132-43
Bigiani, A; Roper, S D (1994) Reduction of electrical coupling between Necturus taste receptor cells, a possible role in acid taste. Neurosci Lett 176:212-6
Delay, R J; Taylor, R; Roper, S D (1993) Merkel-like basal cells in Necturus taste buds contain serotonin. J Comp Neurol 335:606-13
Bigiani, A; Roper, S D (1993) Identification of electrophysiologically distinct cell subpopulations in Necturus taste buds. J Gen Physiol 102:143-70
Welton, J; Taylor, R; Porter, A J et al. (1992) Immunocytochemical survey of putative neurotransmitters in taste buds from Necturus maculosus. J Comp Neurol 324:509-21
Ewald, D A; Roper, S D (1992) Intercellular signaling in Necturus taste buds: chemical excitation of receptor cells elicits responses in basal cells. J Neurophysiol 67:1316-24
Jain, S; Roper, S D (1991) Immunocytochemistry of gamma-aminobutyric acid, glutamate, serotonin, and histamine in Necturus taste buds. J Comp Neurol 307:675-82
Bigiani, A R; Roper, S D (1991) Mediation of responses to calcium in taste cells by modulation of a potassium conductance. Science 252:126-8

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