Figure 1.

Ca²⁺-permeability of ChRGR. (A) Light-evoked whole cell currents from a ND 7/23 cell expressing ChRGR in a extracellular solution (pH 8.4) containing 0.1 mM [Ca²⁺]_o (Low, top traces; whole cell capacitance = 37 pF), or from another cell with 10 mM [Ca²⁺]_o (High, bottom traces; 39 pF), both at holding potentials of −80, −60, −40, −20, 0, and 20 mV. Each cyan line shows the timing of the irradiation (475 ± 28 nm, 1.3 mWmm⁻²). (B) The current-voltage (I-V) relationship of the steady-state photocurrent (I_ss). Mean ± SEM (Low: n = 6, High: n = 7) after standardized by the cell capacitance and expressed as pA/pF. (C) Box-and-whisker plots comparing the reversal potential between Low (n = 6) and High (n = 7) [Ca²⁺]_o. ^*P < 0.05 and ^**P < 0.005, Mann-Whitney U-test.