Adaptation and Ca ²⁺ dynamics as examined in the absence of EGTA in the recording pipette. (A) Photomicrograph of a single ORC. The ROI scan area is indicated by a white square. Scan speed, 0.12 s/scan with bleach mode. (B) Positions of ROIs on the single cilium (circles, 0.9 µm in diameter). Stimulus ROIs were ROIs 1 and 3. Analyses ROIs, ROIs 1–4. (C) Single current responses of ROIs 1 and 3. UV bleach duration: 0.62 s for each. Scaling Y, 0.09 µm. Line sum, 1. (D) Cross-adaptation. Current responses to double-pulse stimuli. (E) Fluorescence intensity changes during the double-pulse stimulus. The first bleach was applied to ROI 1 (red circle in B); the second bleach, to ROI 3 (blue circle in B). Data represented by black squares were obtained as averages from the four analysis ROIs shown in B (red, blue, and two white ROIs, error bars show SD from those data), whereas data represented by green circles were obtained after the adjacent-averaging (moving average) procedure in Origin program. The number of adjacent averaging points of the window was five. (F) Comparison of time courses between the current response and fluorescence intensity.