Fig. 2

Noninvasive NIR-II fluorescence imaging of CSF distribution in the brain under ISO or ISO supplemented with Dex anesthesia. a Schematic representation of the NIR-II fluorescence imaging to investigate the effect of different anesthesia regimens on CSF influx in the brain. Dex dose is 0.2 mg/kg. The schematic diagram was created by using the online software https://biorender.com. b Brain imaging to record CSF distribution within 30 min after CM injection initiation. White scale bar: 2 mm. The schematic diagram was created by using the online software https://biorender.com. c The schematic shows the outline of three regions of interest (ROIs) at the dorsal brain position to quantify CSF distribution. The schematic diagram was created by using the online software https://biorender.com. The mean intensity variation of d Brain (ROI1), e right MCA (ROI2), and f left MCA (ROI3) over 30 min after CM injection initiation. Solid lines: means, shading: SEM. n = 7 mice per group. The region of mean intensity quantification was manually outlined according to the cartoon pattern in c. The mean intensity of MCA region represents the influx of NIR-II tracer along PVS surrounding the MCA. g Comparison of mean intensity at the 30 min time point. Two-Way ANOVA with Sidak’s multiple comparisons test, Brain: P = 0.0187, Right MCA: P = 0.0004, Left MCA: P = 0.0002, n = 7 mice per group. h Brain tissue imaging shows the distribution of the NIR-II tracer at the dorsal and ventral brain surfaces. Comparison of mean intensity in the two anesthetic mice at the dorsal i and ventral j positions, n = 7 mice per group, t test, Dorsal: P = 0.0733, Ventral: P = 0.2081. White scale bar: 2 mm. The quantified region was shown in Fig. S7a. Colored dot represents the intensity of individual animal. Center is median and quartiles shown by box and whiskers. k Schematic illustration represents the CM injection of BSA@IR-780 and analysis of coronal slice distribution. The schematic diagram was created by using the online software https://biorender.com. l The representative images reveal the distribution of the BSA@IR-780 within slices. m Comparison of mean slice intensity across all anesthetic mice, n = 6 mice per group, t test, P = 0.029. Colored dot represents the intensity of individual animal. Center is median and quartiles is shown by box and whiskers