The experimental research on endogenous neural progenitor cells proliferation and migration in the adult rat brain after focal ischemia

Objective To investigate the proliferation and migration of endogenous neural precursor cells in the adult rat brain in different time after ischemia and the maximum cumulation of the progenitor cells. Methods The ischemic models of rat brain were made by Longa's method, the expression of Brdu in different time and the maximum cumulating expression of Brdu were determined by immunocytochemistry. Results Compared with the controls, significant increases in numbers of proliferating cells in the ipsilateral subventricular zone, olfactory bulb and rostral migratory stream were observed 1 day and with a peak at 3-7 day after ischemia, the number of Brdu immunoreactive cells decreased at 14 day after ischemia. There were a positive relevance between the number of immunoreactive cells in the ipsilateral SVZ and OB. The number of Brdu immunoreactive cells did not significantly increase in the dentate gyrus. In cumulative test, the number of Brdu positive cells were mostly increased in the 3rd week after ischemia, and decreased in the 4th week. Conclusion It was at the 3-7 day that endogenous neural progenitor cells proliferate 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.