Changes of evoked potential and expression of nestin in subventricular zones in rats after focal cerebral ischemia

Abstract Objective To study the characteristics of latency of somatosensory evoked potential (SEP) and motor evoked potential (MEP) and the expression of nestin in subventricular zones (SVZ) after persistent focal cerebral ischemia in rats. Methods The model of cerebral ischemia in rats was made by middle cerebral artery occlusion (MCAO). All animals of ischemia were sacrificed after 12 h, 1 d, 3 d, 7 d, and 14 d to observe the changes of latency of SEP and MEP and to detect the expression of nestin, with an immunohistochernical approach. Results The latencies of P1 (positive wave 1), N1 (negative wave 1) and P2 (positive wave 2) in SEP were significantly prolonged after MCAO. The latencies of N1 and N2 waves in MEP were postponed gradually and no statistical difference of latency of N1 wave was found in rats at 7 d and 14 d after MCAO. The expression of nestin increased at 12 h, and showed a significant augmentation at 3 d and peaked at 7 d, then declined slightly at 14 d after MCAO. Conclusion The cerebral ischemia prolonged the latency of EP waves and the expression of nestin was up-regulated and reached the peak at 7 d, showing the ischemia induced the proliferation of nervous stem cells. The SEP and MEP may evaluate the proliferation in SVZ after brain ischemia.