Fig. 5. In vivo viral distributions of infectious SARS-CoV-2-mCherry in IN-infected mice.

K18-hACE2 mice were IN-inoculated with 10⁴ PFU of SARS-CoV-2-mCherry (n = 6 for the mock-infected and infected mice, respectively). a, b Body weight (a) and survival (b) were monitored at the indicated dpi (Mock, grey; SARS-CoV-2-mCherry, red). Symbols represent means ± SEM. Statistically significant differences between the groups were determined using multiple two-tailed t-tests. c A brain-dissected dorsal view of the murine cranial cavity showing optic nerves, optic chiasma, trigeminal ganglia and trigeminal branches (1, ophthalmic; 2, maxillary; 3, mandibular). Created with BioRender.com. d Representative in vivo fluorescence images of organs, including the lungs, brain, eyes and spleen in mock- or SARS-CoV-2-mCherry-infected mice at 6 dpi (n = 5 for the mock-infected and infected mice, respectively; upper, mock; lower, SARS-CoV-2-mCherry) were acquired using sequential imaging. Colour bars indicate radiant efficiency [p/sec/cm²/sr]/[μW/cm²]. SARS-CoV-2 severe acute respiratory syndrome coronavirus 2, PFU plaque-forming unit; dpi: days post-infection.