Figure 4

(a) Schematic diagram of the in vitro experiment. The image of the three-dimensionally cultured cells on the sensor was taken using a stereo microscope. (b) Bright-field, (c,d) fluorescence images. (e) Fluorescence image taken using the sensor. (f) After photostimulation, the change in fluorescence intensity is indicated as a pseudo-colored image. (g) Time-lapse images of the area indicated by the black square in (f). The numbers at the top of each time-lapse image indicate the number of frame. (h) Graph indicating the mean of the fluorescence intensity in the region of interest (red bars and arrows = photostimulation). (i–l) Experiment involving local photostimulation. The cells were stimulated locally by LEDs in different locations, as shown in (i). The cells were transfected with ChR2 and R-GECO1 (j) and R-GECO1 (k) and were stained with PKH26 (l). After photostimulation, the change in fluorescence intensity is indicated as a pseudo-colored image.