Cuprizone-Induced Demyelination in Transgenic Mice

Wild type C57/BL6, Cx3cr1^+/CreER [56 (link)], Grn^flox/flox, and Grn^−/− mice [88 (link)] were obtained from the Jackson Laboratory. Cx3cr1^+/CreERGrn^flox/flox mice were fed Tamoxifen at 3 weeks of age to delete PGRN in microglia[56 (link)]. Cx3cr1^+/CreER mice were also fed Tamoxifen to be used as controls. Tamoxifen (Sigma T5648, 10mg/ml) was dissolved in filter-sterilized corn oil by incubating overnight at 37°C. The solution was protected from light and was administered to mice (75 mg /kg) via oral gavage every other day 7 times total. CNS demyelination was induced by supplementing the diet of 10-week-old mice with 0.2% (w/w) cuprizone (bis [cyclohexanone] oxaldihydrazone) in powdered rodent chow [72 (link)]). The rodent chow (5 g/mouse/day) was replaced every other day for 5 weeks. For the remyelination period, mice were returned to normal chow for 3 weeks. Untreated control mice were fed normal crushed chow for 5 weeks or 8 weeks. All the mice were housed in the Weill Hall animal facility at Cornell. All animal procedures have been approved by the Institutional Animal Care and Use Committee (IACUC) at Cornell.