Characteristics of A-type voltage-gated K currents expressed on sour-sensing type III taste receptor cells in mice.

Sour taste is detected by type III taste receptor cells that generate membrane depolarization with action potentials in response to HCl applied to the apical membranes. The shape of action potentials in type III cells exhibits larger afterhyperpolarization due to activation of transient A-type voltage-gated K currents. Although action potentials play an important role in neurotransmitter release, the electrophysiological features of A-type K currents in taste buds remain unclear.