title: Neurogenesis and glial proliferation are stimulated following diffuse traumatic brain injury in adult rats.
abstract: Although increased neurogenesis has been described in rodent models of focal traumatic brain injury (TBI), the neurogenic response occurring after diffuse TBI uncomplicated by focal injury has not been examined to date, despite the pervasiveness of this distinct type of brain injury in the TBI patient population. Here we characterize multiple stages of neurogenesis following a traumatic axonal injury (TAI) model of diffuse TBI as well as the proliferative response of glial cells. TAI was induced in adult rats using an impact-acceleration model, and 5-bromo-2'-deoxyuridine (BrdU) was administered on days 1-4 posttrauma or sham operation to label mitotic cells. Using immunohistochemistry for BrdU combined with phenotype-specific markers, we found that proliferation was increased following TAI in the subventricular zone of the lateral ventricles and in the hippocampal subgranular zone, although the ultimate production of new dentate granule neurons at 8 weeks was not significantly enhanced. Also, abundant proliferating and reactive astrocytes, microglia, and polydendrocytes were detected throughout the brain following TAI, indicating that a robust glial response occurs in this model, although very few new cells in the nonneurogenic brain regions became mature neurons. We conclude that diffuse brain injury stimulates early stages of a neurogenic response similar to that described for models of focal TBI.
authors.affiliation: National Trauma Research Institute, The Alfred Hospital, Melbourne, Victoria, Australia. nicole.bye@monash.edu
authors.forename: Nicole
authors.initials: N
authors.lastname: Bye
authors.forename: Sarah
authors.initials: S
authors.lastname: Carron
authors.forename: Xiaodi
authors.initials: X
authors.lastname: Han
authors.forename: Doreen
authors.initials: D
authors.lastname: Agyapomaa
authors.forename: Si Yun
authors.initials: SY
authors.lastname: Ng
authors.forename: Edwin
authors.initials: E
authors.lastname: Yan
authors.forename: Jeffrey V
authors.initials: JV
authors.lastname: Rosenfeld
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Morganti-Kossmann
mesh_terms: D000367:Age Factors; D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000473:pathology*; D001930:Brain Injuries / Q000473:pathology* / Q000503:physiopathology; D049109:Cell Proliferation; D004195:Disease Models, Animal; D005911:Gliosis / Q000209:etiology / Q000473:pathology; D008297:Male; D017628:Microglia / Q000166:cytology / Q000473:pathology*; D009416:Nerve Regeneration / Q000502:physiology; D055495:Neurogenesis / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley