Figure 1.

Current Recordings from NvNa_v2.1, NvNa_v2.2, and NvNa_v2.1^DEKA Channels Expressed in Xenopus Oocytes

Oocytes were clamped at −80 mV holding potential, and currents were elicited by 200 ms depolarizations from −75 mV to 50 mV.

(A) Ca²⁺-activated Cl⁻ currents recorded in ND96 bath solution from an oocyte expressing NvNa_v2.1.

(B–E) NvNa_v2.1 currents recorded in bath solution with Ba²⁺ substituting for Ca²⁺, and in addition with choline substituting for Na⁺ (C) and also without Ba²⁺ as control (see inset). See Figure S1 for further characterization of NvNa_v2.1. (D) Current-voltage relations of NvNa_v2.1 (circles: E_rev = 16.2 ± 0.8 mV; n = 14) and with choline substituting for Na⁺ (triangles: E_rev = 13.3 ± 0.9 mV; n = 7). (E) Inward currents elicited by 200 ms depolarizing pulse to −30 mV in the presence of increasing concentrations of lidocaine. The inhibitory effect of lidocaine was removable by washes with bath solution (gray).

(F) Outward and tail currents elicited by 1 s depolarizations from −75 mV to 50 mV, measured for an oocyte expressing NvNa_v2.2 in ND96 bath solution.

(G and H) Currents decreased in the presence of 5 mM lidocaine (G) and were eliminated when Ca²⁺ was substituted with Ba²⁺ ions in the bath solution (H).

(I and J) NvNa_v2.1^DEKA currents in ND96 bath solution (I) and with choline substituting for Na⁺ (J).

(K) Current-voltage relations of NvNa_v2.1^DEKA in ND96 bath solution (E_rev = 16.7 ± 1.1 mV; n = 14). Each point represents the mean ± SEM of n cells.

See also Figure S1.