Wild type male C57/BL6J and the immunodeficient NOD scid gamma (NSG) mice were purchased from the Jackson Laboratories. The following transgenic mice have been previously described and were obtained from the Jackson Laboratories: mGfap-Cre line 77.667 (link), Ng2-Cre36 (link), Rosa-tdTomato (tdT)37 (link), and Rosa-YFP68 (link). Adult male and female mice at 2–3 months of age were used unless otherwise stated. All mice were housed under a 12 h light/dark cycle and had ad libitum access to food and water in the UT Southwestern animal facility. No statistical method was used to predetermine sample size. The experiments were not randomized and the experimenters were not blinded to the allocation of animals during experiments and outcome assessment. All experimental procedures and protocols were approved by the Institutional Animal Care and Use Committee at UT Southwestern.