Extended Data Fig. 5: Calculation of mouse-specific effective attenuation lengths in the posterior parietal cortex.
a) The mean intensity of the top 1% of the brightest pixels (experimental 3P signal) plotted with depth beneath the brain surface for an example mouse. b) Data from the mouse shown in (a) normalized to the cube of the pulse energy shows the decay of the 3P signal with depth in the mouse brain. c) Logarithm of the data in (b) shows a linear decrease with depth. The single mouse-specific effective attenuation length (EAL) can be calculated from the slope of the linear fit (gray = gray matter, blue = white matter). A steeper slope represents a shorter EAL due to increased scattering. d) Semilogarithmic plot showing gray matter and white matter EALs for n = 10 mice at the first time point of longitudinal imaging. Mean EAL (GM) = 249 ± 12.7 µm, Mean EAL (WM) = 169 ± 8.9 µm. e) Distributions of experimental mouse-specific EALs in the gray matter (gray) and white matter (blue). n = 10 mice. Linear fits (black line plots in c, d) were calculated separately by region. Box plots represent the median, interquartile ranges and minimum/maximum values.
