title: Traumatic Brain Injury Severity Affects Neurogenesis in Adult Mouse Hippocampus.
abstract: Traumatic brain injury (TBI) has been proven to enhance neural stem cell (NSC) proliferation in the hippocampal dentate gyrus. However, various groups have reported contradictory results on whether TBI increases neurogenesis, partially due to a wide range in the severities of injuries seen with different TBI models. To address whether the severity of TBI affects neurogenesis in the injured brain, we assessed neurogenesis in mouse brains receiving different severities of controlled cortical impact (CCI) with the same injury device. The mice were subjected to mild, moderate, or severe TBI by a CCI device. The effects of TBI severity on neurogenesis were evaluated at three stages: NSC proliferation, immature neurons, and newly-generated mature neurons. The results showed that mild TBI did not affect neurogenesis at any of the three stages. Moderate TBI promoted NSC proliferation without increasing neurogenesis. Severe TBI increased neurogenesis at all three stages. Our data suggest that the severity of injury affects adult neurogenesis in the hippocampus, and thus it may partially explain the inconsistent results of different groups regarding neurogenesis following TBI. Further understanding the mechanism of TBI-induced neurogenesis may provide a potential approach for using endogenous NSCs to protect against neuronal loss after trauma.
authors.affiliation: 1 Spinal Cord and Brain Injury Research Group, Indiana University , Indianapolis, Indiana.|2 Stark Neuroscience Research Institute, Indiana University , Indianapolis, Indiana.|3 Department of Neurological Surgery, Indiana University , Indianapolis, Indiana.
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Wang
authors.affiliation: 1 Spinal Cord and Brain Injury Research Group, Indiana University , Indianapolis, Indiana.|2 Stark Neuroscience Research Institute, Indiana University , Indianapolis, Indiana.|3 Department of Neurological Surgery, Indiana University , Indianapolis, Indiana.
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.affiliation: 3 Department of Neurological Surgery, Indiana University , Indianapolis, Indiana.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Michalski
authors.affiliation: 1 Spinal Cord and Brain Injury Research Group, Indiana University , Indianapolis, Indiana.|2 Stark Neuroscience Research Institute, Indiana University , Indianapolis, Indiana.|3 Department of Neurological Surgery, Indiana University , Indianapolis, Indiana.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhao
authors.affiliation: 1 Spinal Cord and Brain Injury Research Group, Indiana University , Indianapolis, Indiana.|2 Stark Neuroscience Research Institute, Indiana University , Indianapolis, Indiana.|3 Department of Neurological Surgery, Indiana University , Indianapolis, Indiana.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Chen
mesh_terms: D000367:Age Factors; D000818:Animals; D000070642:Brain Injuries, Traumatic / Q000473:pathology*; D006624:Hippocampus / Q000473:pathology* / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D058953:Neural Stem Cells / Q000473:pathology* / Q000502:physiology; D055495:Neurogenesis / Q000502:physiology; D012720:Severity of Illness Index
keywords: injury severity; neural stem cell proliferation; neurogenesis; traumatic brain injury