title: Long-term upregulation of inflammation and suppression of cell proliferation in the brain of adult rats exposed to traumatic brain injury using the controlled cortical impact model.
abstract: The long-term consequences of traumatic brain injury (TBI), specifically the detrimental effects of inflammation on the neurogenic niches, are not very well understood. In the present in vivo study, we examined the prolonged pathological outcomes of experimental TBI in different parts of the rat brain with special emphasis on inflammation and neurogenesis. Sixty days after moderate controlled cortical impact injury, adult Sprague-Dawley male rats were euthanized and brain tissues harvested. Antibodies against the activated microglial marker, OX6, the cell cycle-regulating protein marker, Ki67, and the immature neuronal marker, doublecortin, DCX, were used to estimate microglial activation, cell proliferation, and neuronal differentiation, respectively, in the subventricular zone (SVZ), subgranular zone (SGZ), striatum, thalamus, and cerebral peduncle. Stereology-based analyses revealed significant exacerbation of OX6-positive activated microglial cells in the striatum, thalamus, and cerebral peduncle. In parallel, significant decrements in Ki67-positive proliferating cells in SVZ and SGZ, but only trends of reduced DCX-positive immature neuronal cells in SVZ and SGZ were detected relative to sham control group. These results indicate a progressive deterioration of the TBI brain over time characterized by elevated inflammation and suppressed neurogenesis. Therapeutic intervention at the chronic stage of TBI may confer abrogation of these deleterious cell death processes.
authors.affiliation: Center of Excellence for Aging and Brain Repair, Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, Tampa, Florida, United States of America.
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Acosta
authors.forename: Naoki
authors.initials: N
authors.lastname: Tajiri
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Shinozuka
authors.forename: Hiroto
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Bethany
authors.initials: B
authors.lastname: Grimmig
authors.forename: David M
authors.initials: DM
authors.lastname: Diamond
authors.forename: David
authors.initials: D
authors.lastname: Diamond
authors.forename: Paul R
authors.initials: PR
authors.lastname: Sanberg
authors.forename: Paula C
authors.initials: PC
authors.lastname: Bickford
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Cesar V
authors.initials: CV
authors.lastname: Borlongan
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D001930:Brain Injuries / Q000378:metabolism*; D001931:Brain Mapping / Q000379:methods; D016923:Cell Death; D002454:Cell Differentiation; D049109:Cell Proliferation; D004195:Disease Models, Animal; D000089662:Doublecortin Protein; D005786:Gene Expression Regulation; D005802:Genes, MHC Class II; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism*; D008297:Male; D017628:Microglia / Q000378:metabolism; D055495:Neurogenesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation