Microglia adopt longitudinal transcriptional changes after traumatic brain injury

Traumatic brain injury (TBI) is an under-recognizedpublic healththreat. Even mild brain injuries can lead to long-term neurologic impairment.Microgliaplay a fundamental role in the development and progression of this ensuing neurologic impairment. Despite this, a microglia-specific injury signature has yet to be identified. We hypothesized that TBI would lead to long-term changes in the transcriptional profile of microglial pathways associated with the development of subsequent neurologic impairment. Bone marrow chimeras (BMC) were generated by transplanting male B6.CD45.1 donor bone marrow into male B6.CD45.2 recipient mice irradiated with head shielding. BMC then underwent TBI via a controlled cortical impact and were followed longitudinally. CD45.2 microglia were sorted and subjected to bulk RNA-seqat 7, 30, and 90d after TBI.