Fig. 2.

Two-photon Ca²⁺ imaging reveals that neurons in the inner nuclear layer (INL) participate in glutamatergic retinal waves. A: example of wave propagation in the INL (top) and ganglion cell layer (GCL; bottom) observed with two-photon Ca²⁺ imaging at a frame rate of 1 Hz. Leftmost images are the retinal sample loaded with Oregon green BAPTA-1 AM (OGB). Circles are identified cells; black indicates cells with ΔF/F of >15% for the first time in that frame, and gray indicates cells with persisting ΔF/F above threshold. B: sample ΔF/F traces from averaged regions within cells. Each trace represents a different cell. C: raster plots of neuronal Ca²⁺ transients of >15% ΔF/F for all cells in the field of view. The total imaging duration was 5 min. D: histogram of interwave intervals for glutamate and Ca²⁺ imaging from both the GCL and INL (Ca²⁺ imaging: N = 150 wave intervals and FRET: N = 47 wave intervals).