Fig. 4

Time-dependent changes in optical signals after staining. The preparations were stained with an absorption dye and three fluorescence dyes. a Optical signals related to the depolarization wave detected with a magnification of ×10 ×1.67 in single sweeps at 1, 2, 3, 4, and 5 h after staining. b, c Amplitudes (b) and durations (c) of the optical signal normalized to the values at 1 h after staining are plotted against time. The signal duration was measured at 50 % of the maximum signal amplitude. Modified from Ref. [24]