Figure 7. Mg²⁺-dependence of TRPM7 current block by NS8593.

TRPM7 currents were recorded in MLS-9 microglial cells in the whole-cell configuration with differing free Mg²⁺ concentrations in the pipette solution. The voltage protocol throughout was a 120 ms-long ramp from −100 to +115 mV, from a holding potential of −10 mV. Graphical data are presented as mean ± SEM for the number of cells indicated on each bar, and were compared using a one-way ANOVA. A–D. Effect of 75 µM and 300 µM intracellular free Mg²⁺ on TRPM7 currents and their inhibition by NS8593. In panels A and B, upper traces are representative currents with and without 7 µM NS8593, and the lower panels (time course of current at +115 mV) show the rapid onset and reversibility of inhibition by NS8593. TRPM7 current amplitude (at +115 mV; panel C), and percent inhibition by 7 µM NS8593 (panel D) are compared for 75 µM and 300 µM intracellular free Mg²⁺.