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.

Four week old C57BL6/J mice were inoculated with 50% LD50 doses of RSA59 or RSMHV2 by intranasal administration or by intracranial injection, or mock transfected by intranasal administration of solution without virus. Pathology was assessed from LFB stained cross-sections of spinal cord isolated from mice at day 26 (peak of demyelination) p.i. RSA59, when injected intracranially, induced significant myelin loss within formed demyelinating plaques, [average demyelination score 1.33 ± 0.2357; (mean ± SE); n = 3 mice (9 sections/group); p < 0.0001 vs. control] as in prior studies (Figures 1J-L) . As expected, mice infected intracranially with RSMHV2 did not show any significant myelin loss (data not shown). Interestingly, no demyelination plaques were observed in any level of spinal cord sections of RSA59 infected mice when given via the intranasal route (Figures 1D-F) . Similarly, as expected, no myelin loss was observed in intranasally mockinfected (Figures 1A-C) or RSMHV2-infected mouse spinal cord (Figures 1 G-I) .