Upregulation of GluR2 decreases intracellular Ca2+ following ischemia in developing gerbils.
Developing animals are known to be resistant to cerebral ischemia. To investigate the mechanisms by which developing animals exhibit ischemic resistance, we examined the changes in intracellular calcium ([Ca2+]i) after oxygen-glucose deprivation (OGD) using hippocampal slices from gerbils. We found that increases of [Ca2+]i in hippocampal CA1 neurons is significantly less after OGD in developing gerbils than in adults. Western blot analysis of AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid) receptors (AMPARs) showed that GluR2 expression, but not that of the other AMPARs is significantly higher in developing gerbils than in adults. Expression of the anti-apoptotic proteins such as HSP70, Bcl-XL, and plasma membrane Ca2+-ATPase type1 (PMCA1) are not higher in the developing gerbils than in adults. These results suggest that the higher expression of GluR2 is important for the smaller increases in [Ca2+]i and enhanced resistance to ischemia-induced neuronal damage in developing animals.
Oguro
Keiji
K
Department of Surgical Neurology, Jichi Medical School, Minamikawachi-machi, Tochigi 329-0498, Japan. oguro@jichi.ac.jp
Miyawaki
Takahiro
T
Yokota
Hidenori
H
Kato
Kengo
K
Kamiya
Tatsushi
T
Katayama
Yasuo
Y
Fukaya
Masahiro
M
Watanabe
Masahiko
M
Shimazaki
Kuniko
K
D000375:Aging / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D002545:Brain Ischemia / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000096:biosynthesis / Q000235:genetics; D017536:Carotid Artery, Common / Q000502:physiology; D005456:Fluorescent Dyes; D005849:Gerbillinae; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics; D006624:Hippocampus / Q000378:metabolism; D066298:In Vitro Techniques; D018091:Receptors, AMPA / Q000096:biosynthesis* / Q000235:genetics*; D015854:Up-Regulation / Q000502:physiology*
D005456:Fluorescent Dyes; D018840:HSP70 Heat-Shock Proteins; D018091:Receptors, AMPA; D000252:Calcium-Transporting ATPases; C104722:glutamate receptor ionotropic, AMPA 2; D002118:Calcium