Demyelination shown in the brain of mice infected with the Japanese encephalitis virus. (A) Severely demyelinating axons extensively distributed in the brain, primarily the cerebrum, of symptomatic mice. (B) Demyelinated axons present a loose composition of myelin. (C) Normal axons were surrounded by a myelin sheath that was condensed with intraperiodic lines. Scale bar = 5 μm for A, 500 nm for B, and 100 nm for C.