Whole-cell voltage-gated currents in unlabeled fungiform taste cells of the TRPM5-GFP mice. A: Some unlabeled cells (53%) exhibit only an outward current in response to depolarizing voltage steps. The Barium-TEA-TTX solution decreased the outward current indicating the involvement of voltage-dependent K+ channels. The I-V plot is represented (n = 52 cells; mean ± sem). B: Other cells (46%) exhibit outward K+ and inward Na+ currents, but lack a voltage-dependent Ca2+ (Ba2+) current. The I-V plot is represented for inward and outward currents (n = 45 cells; mean ± sem).