Chonnam Med J.  2001 Sep;37(3):219-224.

Changes of Glutamate Receptor Subunit Gene Expression in the Rat Hippocampus following Global Cerebral Ischemia

• Lee SH
• Kim JK
• Bae CS
• Chung YY
• Cho KH

Abstract

It has been well known that transient global ischemia of the brain induces delayed neuronal death of hippicampal CA1 pyramidal cells. Calcium influx is thought to play a critical role in the neuronal death after ischemia. Changes in AMPA receptor subunit composition has been proposed to determine calcium permeability and the delayed neuronal death. The present study is undertaken to examine the involvement of changes of AMPA receptor subunit composition in the delayed neuronal death. Global ischemia was produced in rats using 20-min 4-vessel occlusion model, and in situ hybridization with oligoprobes for GluR1, 2 and NMDAR1 was performed on sections from the brain of sham operated and ischemic rat. In CA1 region, the expressions of all three receptor subtype mRNAs decreased at day 1 after the ischemic insults, and almost abolished at day 5. In CA3 region, the expression of three mRNA also decreased at day 1 and then it somehow recovered at day 5. In dentate gyrus, the expression of three mRNA showed weak decreases at day 1. The expression of GluR1 and GluR2 mRNA were comparable to control (sham operated) but NMDAR1 mRNA expression was higher than control at day 5. These findings suggest that the changes of AMPA receptor subunit composition might not be correlated with the delayed neuronal death in hippocampal CA1 region.

Keyword

Global cerebral ischemia; Delayed neuronal death; In situ hybridization; GluR1; GluR2

MeSH Terms

Animals
Brain
Brain Ischemia*
CA1 Region, Hippocampal
Calcium
Dentate Gyrus
Gene Expression*
Glutamic Acid*
Hippocampus*
In Situ Hybridization
Ischemia
Neurons
Permeability
Pyramidal Cells
Rats*
Receptors, AMPA
Receptors, Glutamate*
RNA, Messenger
Calcium
Glutamic Acid
RNA, Messenger
Receptors, AMPA
Receptors, Glutamate