Figure 4.

Viral tropism analysis via immunofluorescence of SARS-CoV-2 antigen in the brain. FFPE serial sections of the brain harvested at 4 dpi were analyzed via dual-labeling immunofluorescence (IF) for the expression of the SARS-2 spike (S) protein (red) and different cell identity markers (green). (A–D) Neurons (Tuj1⁺, frontal cortex); (E–L) Astrocytes (GFAP⁺, frontal cortex), white arrowheads indicate selected points of colocalization, (E–H) SARS-CoV-2-infected mice, (I–L) mock-infected mice; (M–P) Microglia (IBA1⁺, frontal cortex). Magnifications: (A–L), 10X; (M–P), 40X. DAPI counterstaining (blue).