FIGURE 5.
TRPM3 is potentially permeable to protons. (A) Schematic showing the protons permeation recording condition, where all intracellular and extracellular ions were replaced by NMDG and glutamic acid, respectively, except for protons. 50 µM PS was applied while holding hTRPM3-GFP transfected HEK cells at −100 mV. (B) Inward currents were elicited by the PS application. No PS activated current under the NMDG solution at pHo 7.40, while lowering down the pHo to 5.50 generated a small and transient inward current. Insert panel shows the inward current recorded during NMDG-PS (pH 5.5) application. (C) Mean current amplitude in response to PS at the indicated conditions (mean ± SEM, n = 8 cells). (D) Relative current amplitude in response to PS, comparing with Tyrode (pHo 7.4) solution response of the same cell (mean ± SEM, n = 8 cells).