Transient focal cerebral ischemia-induced neurogenesis in dentate gyrus of adult rats

Objective To study the neurogenesis after focal cerebral ischemia in the dentate gyrus of adult rats and the mechanisms responsible for stroke-induced neurogenesis.Methods Animal models of middle cerebral artery occlusion(MCAO) were established in 16 adult rats,and four of another 8 rats served as normal control and four underwent sham operation.Doublecortin was used to label neuron precursors.The proliferation rate of neuron precursors in the dentate gyrus on day 1,7,14,21 after reperfusion was examined.Results The doublecortin-positive cells in the ipsilateral dentate gyrus and contralateral dentate gyrus reached the highest level on day 7 after reperfusion,up to 2.4-fold higher than that of sham-operated rats(P0.05),then down near to the normal level on day 21 after reperfusion.There was a significant increase of doublecortin-positive cells in ipsilateral dentate gyrus on each time point as compared with contralateral dentate gyrus (P0.05).Conclusion Neurogenesis in the dentate gyrus of the adult rat brain can be initiated after focal cerebral ischemia,which may be crucial in brain repair after ischemia.