Intracranial Inoculation Is More Potent Than Intranasal Inoculation for Inducing Optic Neuritis in the Mouse Hepatitis Virus-Induced Model of Multiple Sclerosis

Singh, Manmeet; Khan, Reas S.; Dine, Kimberly; Das Sarma, Jayasri; Shindler, Kenneth S.

At 1 and 26 days p.i., tissues, including whole eyes, optic nerves, brains, spinal cords, and livers, were isolated from both mock-and virus-infected mice. For paraffin sectioning, eyes and optic nerves were fixed for 15 min after dissecton in 4% paraformaldehyde (PFA) while brains, spinal cords, and livers were fixed in 4% PFA overnight. Five micrometer sections were cut for routine CNS pathology staining following fixation and tissue processing. Sections were stained with Luxol Fast Blue (LFB) to detect myelin loss in spinal cord and optic nerve as in prior studies (Shindler et al., 2008) . Demyelination was scored based on detection of focal white matter areas lacking LFB staining using a relative three-point scale. Areas of demyelination were quantified using a 0-3 point scale, where 0-no demyelination; 1-rare foci of demyelination; 2a few foci of demyelination; and 3-large (confluent) areas of demyelination. All slides were coded and read in a blinded manner.