Study of neurogenesis in dentate gyrus after global ischemia reperfusion in rats

AIM To investigate the tempo spatial characteristics of neurogenesis in dentate gyrus (DG) of rats after global ischemia reperfusion and to explore the possible mechanisms of neurogenesis. METHODS Male mature Spraque Dawley rats were subjected to a 4 vessel occlusion (4 VO) model. Bromodeoxyuridine (BrdU) labelling method was used to observe the neurogenesis in the DG of rats and double immunostaining with laser confocal microscopy was used to determine the cell phenotype. RESULTS Ischemia enhanced cell proliferation in DG of adult rats. The number of BrdU immunoreactive cells in DG did not significantly increase during the first 3 days after the global ischemia. Thereafter, cell proliferation increased markedly and reached the peak on the 14th day after ischemia. Compared with the control rats, the quantity of BrdU immunoreactive cells in the DG of rats after global ischemia had a 7 fold increase. The result obtained by observing the differentiation of newborn cells showed that many of the BrdU immunoreactive cells in DG had become neurons. CONCLUSION Neurogenesis in DG could be induced to increase at a certain time window after global ischemia reperfusion. The accommodational mechanisms of neurogenesis were possibly related to the changes of hormones, neurotransmitters, neurotrophic factors and the micro circumstances of the dentate gyrus after ischemia.