Fig. 1

CSF-tracer intensity 3h after systemic LPS-injection (n = 14), compared with vehicle (n = 13). a Color coded areas used for mean fluorescence intensity measurements in ImageJ. Left (grey) cerebellum. Middle (magenta), MCA area (ROI confined to the perivascular space of the MCA). Middle (cyan), cortex. Right (grey), olfactory bulb. Scale bar 6 mm. b Representative tracer (BSA Alexa 647 and FITC dextran) images for Vehicle and LPS-groups. c–j Statistical analyses of mean pixel intensity in arbitrary units, MPI (a.u.). c MPI (a.u.) in area corresponding to cerebellum, BSA Alexa 647. Unpaired t test, 95% CI of difference = − 26 to 25. d MPI (a.u.) in area corresponding to cerebellum, FITC dextran. Unpaired t test, 95% CI of difference = − 19 to 18. e MPI (a.u.) in whole cortical brain area, BSA Alexa 647. 24% lower in LPS-mice, albeit not significantly so. Unpaired t test, 95% CI of difference = − 48 to 0.57. f MPI (a.u.) in cortical brain area, FITC dextran is 19% lower in LPS-treated animals. Unpaired t test, 95% CI of difference = − 35 to − 2.6. G: MPI (a.u.) in MCA area, BSA Alexa 647 was 31% lower on average in LPS-mice. Unpaired t test, 95% CI of difference = − 57 to − 5.8. h MPI (a.u.) in MCA area, FITC dextran. LPS 26% lower on average. Unpaired t-test, 95% CI of difference = − 43 to − 8.9. i MPI (a.u.) in area corresponding to olfactory bulb, BSA Alexa 647. Unpaired t test, 95% CI of difference = − 57 to 16. j MPI (a.u.) in area corresponding to olfactory bulb, FITC dextran. Unpaired t test, 95% CI of difference = − 37 to 14. Mean pixel intensity in arbitrary units, MPI (a.u.). Data are shown as mean and plotted individual samples, with P values above comparative brackets. Scale bars 6 mm