Fig. 2. [Mg] _i increased when mitochondrial activity was inhibited. Double stained PC12 cells were treated by mitochondrial inhibitor, FCCP. Bath application of 3 µM FCCP induced both [Mg] _i (triangles) and [Ca] _i (circles) increase. Excitation wavelengths are 490 nm for KMG-104 and 380 nm for fura-2. Decrease of fura-2 fluorescence implies [Ca] _i increase. Bar indicates FCCP application.