Calcium imaging of neurons expressing FGCaMP in zebrafish larva at 4 days post fertilization.

<p>(A) Overlay of confocal fluorescence images of neurons expressing FGCaMP, acquired with 488 and 405 nm excitation and 525/50BP emission. White box indicates area zoomed-in in panel B. Scale bar, 100 μm. FB, forebrain; MB, midbrain; HB, hindbrain. (B) High magnification images of the neurons highlighted in the white box in panel A acquired with 488 nm excitation and 525/50BP emission (<i>left</i>; green pseudocolor) and 405 nm excitation and 525/50BP emission (<i>middle</i>; blue pseudocolor), and overlay of the left and middle images (<i>right</i>). Scale bar, 50 μm. (C) Representative single cell recording of GCaMP6f (<i>top</i>; magenta) and FGCaMP green fluorescence responses (<i>bottom</i>; green) during 4-aminopyridine induced neuronal activity (Ex: 475/34BP, Em: 527/50BP). Population data for (D) maximum fluorescence changes ΔF/F and (E) SNR corresponding to the experiment in panel C (26 neurons in 3 fish and 43 neurons from 5 fish for GCaMP6f and FGCaMP, respectively). Box plots with notches are used (narrow part of notch, median; top and bottom of the notch, 95% confidence interval for the median; top and bottom horizontal lines, 25% and 75% percentiles for the data; whiskers extend to 5th and 95th percentile for the data; horizontal bar is mean). (F) Representative single cell recording of FGCaMP green fluorescence excited with 488 and 405 nm laser illumination during 4-aminopyridine induced neuronal activity. (G) Fluorescence ratio for the traces shown in panel F. (H) Population data for fluorescence ratio for experiment in panel C (107 neurons in 2 fish). Box plots with notches are used (see panel D for description).