The experimental research on cognitive function recovery of electrical stimulation pre-conditioned rats after brain trauma

Abstract

Objective To investigate the cognitive change in electrical stimulation (ECS) pre-conditioned rats after traumatic brain injury (TBI) and the role of endothelial progenitor cells in brain trauma. Methods Adult male Wistar rats were divided into 4 groups randomly: Sham group (n = 61), TBI group (n = 61), ECS pre-conditioned and TBI group (ECS-TBI group, n = 61), ECS group (n = 61). At 3 h, 6 h, 24 h, 48 h, 72 h after fluid percussion injury (FPI), 6 rats were randomly selected from each group and the number of circulating endothelial progenitor cells was counted by flow cytometry. At the same time, 3 rats from each group were chosen randomly and brain tissue was taken out. Microvascular density (MVD) of injured hippocampus was measured by vWF immunohistochemical staining. Ten rats of each group were subjected to Morris Water Maze Test and escaping latencies were recorded separately at 7-11 days after FPI. Results Compared with TBI group, the number of endothelial progenitor cells in peripheral circulation increased significantly in ECS-TBI group at 3 hours and 6 hours after brain trauma (P = 0.000, for all), and reduced to baseline gradually afterwards. The vWF+ MVD on the injured side of hippocampus in ECS-TBI group was higher than those of other groups 1d after FPI, and reached to a peak at 7 d (P < 0.01). In Morris Water Maze Test, the escaping latency of ECS-TBI rats were reduced significantly compared to that of the TBI group from 3 d to 5 d after brain trauma (P < 0.01). Conclusion Compared to TBI group, there was less cognitive defect in ECS-TBI group after traumatic brain injury. This protective effect may partially due to enhanced angiogenesis induced by increasing circulating endothelial progenitor cells after ECS. Endothelial progenitor cells accumulated in the injured brain may promote post-traumatic angiogenesis and recovery of neurological function.

DOI：10.3969/j.issn.1672-6731.2011.06.005