Extended Data Fig. 2: Dissociation between light response rates and amplitudes.
From: Mapping light distribution in tissue by using MRI-detectable photosensitive liposomes
a, Top: Light-LisNR response amplitudes to blue and UV light are highly correlated over a 25 ×25 voxel region around fibre optic tips in six animals (R = 0.89, p < 10−5). Bottom: in contrast, blue light response amplitudes and response rates are statistically independent over the same voxels (R = –0.013, p = 0.66), indicating that the LisNR response rates are not strongly affected by variations in probe concentration, which largely determine the signal change amplitude distribution. b, Response amplitudes and rates can also be dissociated from one another as a function of distance from the fibre tip: amplitudes decrease monotonically (top), while response rates peak and then diminish (bottom). Error bars denote SEM over 6 (top) or 3 to 6 (bottom) biological replicates. c, Histograms of blue light response amplitudes (top) and response rates (bottom) over three cycles of illumination (B1-B3), showing stability over time (n = 2 animals). d, Box plots corresponding to the distributions in panel c. Central line = median, box limits = first and third quartiles, whiskers = limiting values. Consistency of the distributions indicates that diffusion and convection over the ~1 hour experimental time period do not strongly affect the results.
