CHANGES OF GDNF mRNA EXPRESSION IN RAT BRAIN FOLLOWING CEREBRAL ISCHEMIA REPERFUSION

The effect of ischemia reperfusion on the expression of GDNF mRNA in the hippocampus and cortex in rat brain was observed and the NMDA receptor antagonist and Ca 2+ channel blocker were used for studying whether they regulate the expression of GDNF mRNA under the condition of cerebral ischemia. A transient forebrain ischemia and reperfusion model was established in rat according to Smith et al method. The expression of GDNF mRNA was examined by in situ hybridization using oligonucleotides probe for GDNF mRNA in samples of rat brain. The expression of GDNF mRNA was increased in the dentate gyrus at 2 h after 10 min ischemic insult, in hippocampus CA1, CA3 and cortical PAR region at 6 h. The maximum expression of GDNF mRNA was found at 24 h following reperfusion. The increase of GDNF mRNA expression induced by ischemia was reversed by treatment with ketamine. After transient ischemia the expression of GDNF mRNA was increased and probably prevented the neurons from ischemic injury. Up regulation of GDNF mRNA expression after ischemia may be mediated by NMDA glutamate receptor.