Serotonergic Agonists Inhibit Calcium-Activated Potassium and Voltage-Dependent Sodium Currents in Rat Taste Receptor Cells

2000 ◽  
Vol 173 (2) ◽  
pp. 127-138 ◽  
Author(s):  
M.S. Herness ◽  
Y. Chen
Keyword(s):  
Taste Receptor ◽  
Sodium Currents ◽  
Receptor Cells ◽  
Voltage Dependent ◽  
Taste Receptor Cells

Dual actions of caffeine on voltage-dependent currents and intracellular calcium in taste receptor cells

2002 ◽  
Vol 283 (1) ◽  
pp. R115-R129 ◽  
Author(s):  
Fang-Li Zhao ◽  
Shao-Gang Lu ◽  
Scott Herness
Keyword(s):  
Intracellular Calcium ◽  
Imaging Techniques ◽  
Sodium Current ◽  
Taste Receptor ◽  
Input Resistance ◽  
Ionic Currents ◽  
Receptor Cells ◽  
Voltage Dependent ◽  
Transduction Mechanisms ◽  
Taste Receptor Cells

Although the numerous stimuli representing the taste quality of bitterness are known to be transduced through multiple mechanisms, recent studies have suggested an unpredicted complexity of the transduction pathways for individual bitter stimuli. To investigate this notion more thoroughly, a single prototypic bitter stimulus, caffeine, was studied by using patch-clamp and ratiometric imaging techniques on dissociated rat taste receptor cells. At behaviorally relevant concentrations, caffeine produced strong inhibition of outwardly and inwardly rectifying potassium currents. Caffeine additionally inhibited calcium current, produced a weaker inhibition of sodium current, and was without effect on chloride current. Consistent with its effects on voltage-dependent currents, caffeine caused a broadening of the action potential and an increase of the input resistance. Caffeine was an effective stimulus for elevation of intracellular calcium. This elevation was concentration dependent, independent of extracellular calcium or ryanodine, and dependent on intracellular stores as evidenced by thapsigargin treatment. These dual actions on voltage-activated ionic currents and intracellular calcium levels suggest that a single taste stimulus, caffeine, utilizes multiple transduction mechanisms.

Development of voltage-dependent currents in taste receptor cells

1996 ◽  
Vol 365 (2) ◽  
pp. 278-288 ◽  
Author(s):  
Alan Mackay-Sim ◽  
Rona J. Delay ◽  
Stephen D. Roper ◽  
Sue C. Kinnamon
Keyword(s):  
Taste Receptor ◽  
Receptor Cells ◽  
Voltage Dependent ◽  
Taste Receptor Cells

Serotonin Modulates Voltage-Dependent Calcium Current in Necturus Taste Cells

1997 ◽  
Vol 77 (5) ◽  
pp. 2515-2524 ◽  
Author(s):  
Rona J. Delay ◽  
Sue C. Kinnamon ◽  
Stephen D. Roper
Keyword(s):  
Calcium Current ◽  
Taste Receptor ◽  
Cell Voltage ◽  
Nerve Fibers ◽  
Receptor Subtype ◽  
Basal Cells ◽  
Receptor Cells ◽  
Taste Cells ◽  
Voltage Dependent ◽  
Taste Receptor Cells

Delay, Rona J., Sue C. Kinnamon, and Stephen D. Roper. Serotonin modulates voltage-dependent calcium current in Necturus taste cells. J. Neurophysiol. 77: 2515–2524, 1997. Necturus taste buds contain two primary cell types: taste receptor cells and basal cells. Merkel-like basal cells are a subset of basal cells that form chemical synapses with taste receptor cells and with innervating nerve fibers. Although Merkel-like basal cells cannot interact directly with taste stimuli, recent studies have shown that Merkel-like basal cells contain serotonin (5-HT), which may be released onto taste receptor cells in response to taste stimulation. With the use of whole cell voltage clamp, we examined whether focal applications of 5-HT to isolated taste receptor cells affected voltage-activated calcium current ( I Ca). Two different effects were observed. 5-HT at 100 μM increased I Ca in 33% of taste receptor cells, whereas it decreased I Ca in 67%. Both responses used a 5-HT receptor subtype with a pharmacological profile similar to that of the 5-HT1A receptor, but the potentiation and inhibition of I Ca by 5-HT were mediated by two different second-messenger cascades. The results indicate that functional subtypes of taste receptor cells, earlier defined only by their sensitivity to taste stimuli, may also be defined by their response to the neurotransmitter 5-HT and suggest that 5-HT released by Merkel-like basal cells could modulate taste receptor function.

Taste Transductions in Taste Receptor Cells: Basic Tastes and Moreover

2014 ◽  
Vol 20 (16) ◽  
pp. 2684-2692 ◽  
Author(s):  
Shusuke Iwata ◽  
Ryusuke Yoshida ◽  
Yuzo Ninomiya
Keyword(s):  
Taste Receptor ◽  
Receptor Cells ◽  
Taste Receptor Cells
Sign in / Sign up

Export Citation Format

Share Document