Fig. 3.
Light activates cha-lOLP and inhibits glu-lOLP. a, b Optical recordings using the voltage sensor Arclight together with the calcium sensor RCaMP reveal light-induced depolarization and fast calcium transients in cha-lOLP (magenta) as well as hyperpolarization and delayed calcium transients in glu-lOLP (blue). Representative frames from the recordings (left), averaged traces (middle), and the quantification of peak values of the changed intensity (ΔF/F) (right) are shown. Scale bars and time are as indicated. Somatic regions used for quantification are marked by dashed circles. The dashed green line represents a 100 ms light pulse. cha-lOLP, n = 7; glu-lOLP, n = 6. c cha-lOLP exhibits ON responses, while glu-lOLP exhibits OFF responses. A representative raw trace from the lOLP > RCaMP recording is shown (top). The sample was subjected to an extended (12.5 s) light stimulation (green bar). cha-lOLP responded to the light onset, but not to the light offset. In contrast, the light onset induced a small reduction of calcium signal in glu-lOLP, while the light offset produced a rapid calcium rise. Representative frames of the recording are shown (bottom). d ON and OFF signals generate calcium transients with different temporal profiles in glu-lOLP. Average traces of calcium transients generated by recordings of lOLPglu-Gal4 driving RCaMP are shown, demonstrating the slow calcium response to the light pulse (ON response, blue) and the fast calcium response to the dark pulse (OFF response, gray). The response amplitudes were not significantly different. The average traces (top) and the quantification of peak value and peak time of changed intensity (ΔF/F) (bottom) are as shown. n = 7 in both groups. ON: p = 0.1205; OFF: p < 0.001. Shaded areas on traces and error bars on quantifications represent SEM. The dashed line represents a 100 ms light or dark pulse. Statistical significance was determined by Student’s t test. p ≥ 0.05 was considered not significant, ***p < 0.001