The influence of cerebral infarction on neurogenesis in the subventricular zone of adult mice

Objective To investigate the influence of cerebral infarction on neurogenesis in the subventricular zone (SVZ) of adult mice. Methods Forty-eight mice were randomly assigned to a cerebral infarction group (n=24) and a sham-operation group (n=24). A model of focal middle cerebral artery occlusion (MCAO) was established. Neural stem cells were labeled by 5-bromo- 2′-deoxyuridine 5′-monophosphate (BrdU). The SVZ, striatum and number of cortical BrdU-positive cells on the affected sides at day 7, 14, 21 and 28 after MCAO, as well as BrdU and the changes of the number of amphophilic cells in doublecortin (DCX), glial fibrillary acidic protein (GFAP) and neural nuclear protein (NeuN) were detected by immunohistochemistry. Results Compared with the sham operation group, the SVZ, striatum and number of cortical BrdU- positive cells on the affected sides increased significantly 7 days after MCAO in the cerebral infarction group, and they were 45.0±5.6 vs 245.0±26.1, 0 vs 201.9±21.3 and 0 vs 159.3±16.4, respectively. They began to decrease 14 days later (P0.05). BrdU and DCX positive cells were observed in SVZ and striatum on the affected sides 7 and 14 days after MCAO procedure in the cerebral infarction group. BrdU and NeuN positive cells were observed in striatum on the affected sides 28 days after MCAO procedure; and the numbers were significantly higher than the control group. Conclusion Cerebral infarction may promote the increase of the SVZ, striatum and cortical BrdU-positive cells on the affected sides in adult mice, and induce stem cells of SVZ to migrate to striatum and differentiate into neurons, thus enhance neurogenesis in SVZ.