Fig. 1: Analysis of SARS-CoV-2 brain infection in K18-hACE2 mice.
a, Brain coronal sections of control (uninfected) and SARS-CoV-2-infected K18-hACE2 mice (6 dpi) after immunohistochemistry against the SARS-CoV-2 N protein. b, Qualitative analysis of SARS-CoV-2 level of infection in different cerebral regions of infected K18-hACE2 mice at 2, 4 and 6 dpi. Between brackets, the number of mice showing SARS-CoV-2+ cells among the total number of mice studied is indicated for each brain region analyzed. c, High-magnification images, after SARS-CoV-2 N immunohistochemistry, illustrating the time course of SARS-CoV-2 infection in the cortex, hypothalamus and mesencephalon of control and infected K18-hACE2 mice. SARS-CoV-2 N immunostaining was performed in six independent experiments obtaining similar results. d, Quantitative analysis of SARS-CoV-2 RNA, detected by RT–qPCR targeting the viral E gene, in the olfactory bulb, cortex, hypothalamus and brain stem. Data are presented as the mean ± s.e.m. SARS-CoV-2-infected mice: 2 dpi, n = 8 (3 females and 5 males); 4 dpi, n = 8 (3 females and 5 males); and 6 dpi, n = 10 (5 females and 5 males) mice. Kruskal–Wallis test, post hoc Dunn’s test. *P < 0.05; ***P < 0.001; ****P < 0.0001 with regard to the RT–qPCR values obtained, in each respective brain region, of uninfected controls.
