Proliferation and migration of endogenous neural progenitor cells in the adult rat brain after focal ischemia

Objective To investigate the proliferation and migration of endogenous neural precur- sor cells in the adult rat brain after ischemia in different time and the maximum cumulation of the progen- itor cells. Methods The ischemic models of rat brain were made by Longa's way. The expression of BrdU in different time window and the maximum cumulating expression of BrdU were determined by im- munocytochemistry Results As compared with the controls, numbers of BrdU immunoreactive cells were significantly increased in the ipsilateral subventricular zone (SVZ), olfactory bulb (OB) and rostral migratory stream 1 day, reached the peak at 3rd to 7th day, then decreased at 14th day after ischemia. There was a positive correlation between the numbers of immunoreactive cells in the ipsilateral SVZ and OB. The numbers of BrdU immunoreactive cells were not significantly increased in the dentate gyrus. In cumulative test, the numbers of BrdU positive cells were most at the 3rd week after ischemia, then de- creased at the 4th week. Conclusion It was at the 3rd to 7th day that endogenous neural progenitor cells proliferated to the peak after focal ischemia in the adult rat brain and it was probably more effective to transplant exogenous neural progenitor cells into the ischemic zone in this period.