A decrease of cell proliferation by hypothermia in the hippocampus of the neonatal rat.
Hypothermia is a potential therapy for cerebral hypoxic ischemic injury of not only adults but also neonates. However, the side effects of hypothermia in the developing brain, where a massive amount of neurogenesis occurs, remain unclear. We investigated the proliferation of neural progenitor cells by systemic application of the thymidine analog 5-bromodeoxyuridine (BrdU) in neonatal rats in a severe hypothermic environment. The rat pups were divided into two groups, a hypothermia group (30 degrees C: n=10) and a normothermia group (37 degrees C: n=10). After the pups were placed for 21 h in each environment, 100 mg/kg/day of BrdU was injected intraperitoneally to label dividing cells, and then the pups were sacrificed at 24 h. We examined the number of BrdU-labeled cells in the subventricular zone of the periventricle and the subgranular zone of the dentate gyrus. In the hypothermic environment, BrdU-labeled cells significantly decreased in number in the dentate gyrus, but not in the periventricular region. Thus, the severe hypothermic environment induced a decrease of neurogenesis in the neonatal rat. These observations are noteworthy regarding clinical hypothermia therapy following cerebral hypoxic ischemic injury during the perinatal period.
Kanagawa
Takeshi
T
Department of Obstetrics and Gynecology, Osaka University, Faculty of Medicine, 2-2 Yamadaoaka, Suita, Osaka 565-0871, Japan. kanagawa@gyne.med.osaka-u.ac.jp
Fukuda
Hiromitsu
H
Tsubouchi
Hiroaki
H
Komoto
Yoshiko
Y
Hayashi
Shusaku
S
Fukui
On
O
Shimoya
Koichiro
K
Murata
Yuji
Y
D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001238:Asphyxia Neonatorum / Q000503:physiopathology / Q000628:therapy; D015415:Biomarkers / Q000378:metabolism; D001831:Body Temperature / Q000502:physiology; D001973:Bromodeoxyuridine; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D018891:Dentate Gyrus / Q000254:growth & development / Q000503:physiopathology; D004195:Disease Models, Animal; D000089622:Doublecortin Domain Proteins; D015536:Down-Regulation / Q000502:physiology*; D006624:Hippocampus / Q000254:growth & development / Q000503:physiopathology*; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects*; D020925:Hypoxia-Ischemia, Brain / Q000503:physiopathology / Q000628:therapy; D007231:Infant, Newborn; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
D015415:Biomarkers; D000089622:Doublecortin Domain Proteins; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides; D001973:Bromodeoxyuridine