Fig. 3: Bessel TPLSM signal is correlated with vessel size and captures distributed dynamics of vasodilation and vasoconstriction in 3D.

a A 1.4 mm × 1.4 mm × 0.1 mm volume of vasculature imaged at 15 Hz using Bessel TPLSM, visualized in grayscale on the normalized square root of fluorescence signal. Insets: zoomed-in views of the white-boxed region at two time points, showing changes in vessel size. b Gaussian (single plane at Z = 50 µm) and Bessel images of the red-boxed region in a captured at different times, visualized in grayscale on the normalized fluorescence signal. Red arrows point to three vessels (large, medium, small) to highlight the differences in their fluorescence signal strength between Gaussian and Bessel TPLSM. c Fluorescence vs. vessel diameter for 60 vessel segments in a (see Supplementary Fig. 1) imaged with Gaussian or Bessel TPLSM. d Time traces of fluorescence signal changes of the magenta regions of interest (ROIs) and blood vessel diameter measured along the green lines in a for four vessel segments. e Scatter plot of the data in d. f, g Maps of cross-correlation coefficients between ROIs tiling the FOV in a, and a reference ROI (indicated by arrows and black squares). Representative data from four mice. Scale bars: 200 µm for a, f, g; 20 µm for insets in a; 100 µm for b. Post-objective power: Gaussian: 45 mW; Bessel: 217 mW.