The susceptibility of rat strains to experimental allergic encephalomyelitis.

Nine rat strains were immunized with guinea-pig spinal cord emulsified with Freund's complete adjuvant. Five strains were relatively resistant to experimental allergic encephalomyelitis (EAE). In particular outbred Wistar rats did not produce more than a 25 per cent incidence of clinical disease although rats from four separate colonies were tried. Four strains were highly susceptible. An immunization schedule for producing a 95 per cent incidence of clinical and histological disease in one of these, inbred AS, is described. The importance of the dose of guinea-pig spinal cord in controlling the incidence of EAE and the production of antibodies to galactocerebroside was defined. The results do not support the previous suggestion that these antibodies might protect animals from EAE. There was no clear correlation, either positive or negative, between the titre of antibodies to galactocerebroside and the incidence of EAE in different strains.