title: Long-term observation of neuronal degeneration and microgliosis in the gerbil dentate gyrus after transient cerebral ischemia.
abstract: Ischemic insults in the central nervous system evoke activation of microglia. In this study, we investigated long-term changes of neuronal damage and microglial activation in the gerbil dentate gyrus for 60 days after transient cerebral ischemia using immunohistochemistry and western blot. Neuronal damage or death was hardly found in the dentate gyrus after transient ischemia using cresyl violet staining and NeuN immunohistochemistry; however, neuronal degeneration was detected in the polymorphic layer of the dentate gyrus using Fluoro-Jade (F-J) B staining. F-J B-positive cells were significantly increased after ischemia-reperfusion (I-R) and peaked at 3 days post-ischemia, thereafter, F-J B-positive cells were decreased in a time-dependent manner and shown until 30 days post-ischemia; no F-J B-positive cells were observed 60 days after I-R. On the other hand, Iba-1-immunoreactive microglia were hypertrophied after I-R, and numbers of Iba-1-immunoreactive microglia were significantly increased along with the neuronal degeneration and highest 7 days after I-R, thereafter, numbers of Iba-1-immunoreactive microglia were decreased with time, although microglia activation lasted up to 60 days after I-R. In addition, Iba-1 protein level in the dentate gyrus after I-R was changed like immunohistochemical change. Our results, in brief, indicate that transient ischemia-induced neuronal degeneration in the dentate gyrus is maintained for about 30 days after I-R and that microglial activation lasts up to, at least, 60 days after I-R in the gerbil dentate gyrus after transient cerebral ischemia.
authors.affiliation: Department of Biomedical Science, Research Institute for Bioscience and Biotechnology, Hallym University, Chuncheon 24252, South Korea.
authors.forename: Ji Hyeon
authors.initials: JH
authors.lastname: Ahn
authors.affiliation: Department of Physiology, College of Medicine, Hallym University, Chuncheon 24252, South Korea.
authors.forename: Bich Na
authors.initials: BN
authors.lastname: Shin
authors.affiliation: Department of Neurobiology, Institute of Medical Sciences, School of Medicine, Kangwon National University, Chuncheon 24341, South Korea.
authors.forename: Joon Ha
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Neurobiology, Institute of Medical Sciences, School of Medicine, Kangwon National University, Chuncheon 24341, South Korea.
authors.forename: In Hye
authors.initials: IH
authors.lastname: Kim
authors.affiliation: Department of Neurobiology, Institute of Medical Sciences, School of Medicine, Kangwon National University, Chuncheon 24341, South Korea.
authors.forename: Jeong Hwi
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Department of Physiology, College of Medicine, Hallym University, Chuncheon 24252, South Korea.
authors.forename: BaiHui
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Neurobiology, Institute of Medical Sciences, School of Medicine, Kangwon National University, Chuncheon 24341, South Korea.
authors.forename: Tae-Kyeong
authors.initials: TK
authors.lastname: Lee
authors.affiliation: Department of Biomedical Science, Research Institute for Bioscience and Biotechnology, Hallym University, Chuncheon 24252, South Korea.
authors.forename: Hyun-Jin
authors.initials: HJ
authors.lastname: Tae
authors.affiliation: Department of Neurobiology, Institute of Medical Sciences, School of Medicine, Kangwon National University, Chuncheon 24341, South Korea.
authors.forename: Jae-Chul
authors.initials: JC
authors.lastname: Lee
authors.affiliation: Department of Emergency Medicine, School of Medicine, Kangwon National University, Chuncheon 24341, South Korea.
authors.forename: Jun Hwi
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Department of Food Science and Nutrition, Hallym University, Chuncheon 24252, South Korea.
authors.forename: Il Jun
authors.initials: IJ
authors.lastname: Kang
authors.affiliation: Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon 24341, South Korea.
authors.forename: Young-Myeong
authors.initials: YM
authors.lastname: Kim
authors.affiliation: Department of Physiology, College of Medicine, Hallym University, Chuncheon 24252, South Korea.
authors.forename: Yun Lyul
authors.initials: YL
authors.lastname: Lee
authors.affiliation: Department of Neurobiology, Institute of Medical Sciences, School of Medicine, Kangwon National University, Chuncheon 24341, South Korea. Electronic address: mhwon@kangwon.ac.kr.
authors.forename: Moo-Ho
authors.initials: MH
authors.lastname: Won
authors.affiliation: Department of Emergency Medicine, Chuncheon Sacred Heart Hospital, College of Medicine, Hallym University, Chuncheon 200-702, South Korea. Electronic address: siris94@hanmail.net.
authors.forename: Jeong Yeol
authors.initials: JY
authors.lastname: Seo
mesh_terms: D000818:Animals; D018891:Dentate Gyrus / Q000473:pathology*; D005849:Gerbillinae; D005911:Gliosis / Q000473:pathology*; D002546:Ischemic Attack, Transient / Q000150:complications / Q000473:pathology*; D008297:Male; D017628:Microglia / Q000473:pathology*; D009410:Nerve Degeneration / Q000209:etiology / Q000473:pathology*; D009474:Neurons / Q000473:pathology*; D013997:Time Factors
keywords: Dentate gyrus; Gerbil; Ischemia-reperfusion; Microglia activation; Neuronal degeneration; Polymorphic cells