Representative Ca²⁺ responses elicited by TSCs during stimulation with 4 different stimuli.

Abstract

<p>Cells were stimulated with 4 different stimuli, L-amino acid MIX (AA-MIX) (MPG (10mM), Ser (20mM), Arg (10mM), and Gln (10 mM)), sweet (SC45647 (100μM)), bitter (denatonium (2mM) or cycloheximide (20μM)+denatonium (2mM)), and high-K⁺ (65mM) solution. The bar above each stimulus trace represents the 30 s stimulus application period. [A] A TSC that responded only to AA-MIX. [B] A TSC that responded to bitter and sweet stimuli. [C] A TSC that responded to AA-MIX, sweet, and high-K⁺ solution. AA-MIX elicited a very small increase in cytosolic Ca²⁺ compared to sweet stimulus. The high-K⁺ solution elicited very large increase in cytosolic Ca²⁺, suggesting the presence to voltage-gated calcium channels. Note: A different Y axis scale was used for the high-K⁺ response as the high-K⁺ elicited response was much larger compared to AA-MIX or sweet responses. [D] This TSC responded to both AA-MIX and bitter stimuli. AA-MIX elicited a very small increase in cytosolic Ca²⁺ compared to bitter stimulus. [E] This TSC responded only to bitter stimuli. [F] This TSC responded only to sweet stimuli.</p