Trem2 Knockout Cuprizone Mouse Model

Eight-week-old C57BL/6 J, Trem2^em1Aduci (i.e. Trem2^{R47H NSS}), Trem2^em1Adiuj (i.e. Trem2^{R47H CSS}), and Trem2^em2Adiuj (i.e. Trem2-KO) mice (Jackson Laboratory stock number: 000664, 034,036, 027,918, 027,197 respectively) were used. Each mouse model consisted of 2 groups of 4 male mice. Control mice were supplied standard chow for 6 weeks while the CPZ groups were fed 0.3% cuprizone chow also for 6 weeks (Envigo, Indianapolis, IN). Mice within the same experiment group (i.e., same genotype and diet) were housed together for the duration of feeding. Weights of individual mouse and chow consumptions of each cage were recorded, and chow was changed every 3 or 4 days to monitor expected weight loss as well as ensuring freshness of cuprizone chow. Brains were collected and fixed in 4% paraformaldehyde for 24 h followed by cryoprotection by immersion in 5% sucrose for 24 h then 30% sucrose for 5 days, all at 4 °C.