Figure 3. Photomicrographs of Fitzroy River virus (FRV)–induced meningoencephalitis in weanling mice inoculated with 1,000 infectious units of FRV. Panels show multifocal mild to severe perivascular and neuropil infiltration of lymphocytes and monocytes (blue arrows in A–C); meningitis in a sulcus (black arrow in A); glial cell activation with notable astrocytosis, neuron degeneration, and neuronophagia (arrowhead in B); occasional hemorrhage (blue arrow in D); mild periventricular spongiosis (blue arrows in C); and meningitis (black arrow in C). Hematoxylin and eosin staining. Original magnifications: A) ×40, B) ×400, C) ×100, D) ×400.