Usually people use 2-3 months old B6 mice for induction of EAE with pMOG35-55. I used elder B 6 mice (up to 6-8 months) for induction active EAE with standard protocol, which also worked wells (I did not intend to compare the age's effect(s) on the outcome of EAE, just to use and save the mice which for some reasons were not used at younger).