Figure 4
Quantitative analysis of signal-to-background ratios for in vivo imaging of neurons in the live mouse brain.
(a) A cross-sectional- (xy-) image obtained at 600-μm depth in a young adult mouse. The left white or left yellow box indicates the “soma” (upper right) or “apical dendrite” (lower right) region, respectively. In the upper and lower right panels, the averages of “signal” and “background” were calculated from fluorescence intensities in a circle (20 μm diameter) around an individual neural process (“signal”: red circle) and the background area (“background”: green circle), respectively. Ratio R at the each process was obtained from the average signal divided by the background (see Experimental procedure). Depth dependence of the average and SEM of signal-to-background ratios (R) obtained in the young adult (b) and the adult mouse (c). Red and black circles indicate averages with the 1030-nm picosecond and 910-nm femto-second lasers, respectively (n = 7 processes, ±: SEM).
