Shiverer x Rag2-null and Rag1-null neonatal mice were transplanted on postnatal day 1 or 2. Half of the litter was removed from the dam and placed in a humidified warming chamber. For this we used a sterilized plastic box, lined with sterile gauze dampened with Hanks balanced salt solution, and warmed on a heating block. The pups to be injected were then wiped with Povidone-Iodine and wrapped in sterile gauze to prevent direct contact with ice, then cryo-anesthetized for 2 to 6 minutes, depending on size. The pups were then removed from ice and cleaned with an alcohol prep pad, then laid in a customized neonatal mouse holder made of baked molded clay. The pups were injected directly through the skin and skull osteoid into both the rostral (at Bregma, ML ± 1.0 mm, ventral 1.0 mm) and caudal (AP −1.0, ML ± 1.0 mm, ventral 0.9 mm) corpus callosum. Following injections, pups were cleaned with alcohol prep pads and returned to the warming chamber for recovery. Upon recovery, the first half of the litter was returned to the dam, and the second half put in the humidified chamber. Pups were weaned between 21 and 28 days, then group housed.
