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. Overall design: 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.