Effects of vagus nerve stimulation on neuroprotective mechanism of cerebral ischemia in rats
WANG Wen-xin
XUE Zhe
SHU Xu-jun
XIANG Yao-xian
SUN Zheng-hui
XU Bai-nan
Abstract：Objectives To investigate the neuroprotective mechanism of vagus nerve stimulation ( VNS) by stimulating the vagus nerve in ischemic cerebral tissue in a rat model of transient focal cerebral ischemia. Methods Twenty-six adult male Sprague-Dawley ( SD ) rats were randomly divided into sham operation group (n=6),model group (n=10),and VNS-treated group (n=10) . The model of rat transient focal cerebral ischemia was induced by the intraluminal suture method. At 30 min after modeling,the right side neck VNS in the VNS-treated group was stimulated ( stimulus intensity 0. 5 mA, interval 0. 5 ms, frequency 20 Hz),once every 5 min within 1 h,and once for 30 s. The model group repeated the steps of the VNS-treated group,but did not stimulate. The sham operation group repeated the experimental steps,but it neither embolized the vessels nor stimulated nerves. The changes of cerebral blood flow were monitored with a laser Doppler flowmeter. The rats were sacrificed after 24 h. The expressions of interleukin 6(IL-6) and caspase-3 in brain tissue were determined by immunohistochemistry staining. The neuronal apoptosis was observed by the in situ end-labelling technique. Results ( 1 ) Compared with the sham operation group, the number of positive cells of IL-6,caspase-3,and the numbers of neuronal apoptosis in the model group were significantly increased (20. 7 ± 5. 0 cells/HP vs. 2. 3 ± 1. 0 cells/HP,44. 5 ± 9. 5 cells/HP vs. 0,30. 9 ± 9. 0 cells/HP vs.0).Thereweresignificantdifferences(P<0.05).(2)Comparedwiththemodelgroup,thenumber of positive cells of IL-6(10. 9 ± 3. 7 cells/HP),the caspase-3 (18. 9 ± 6. 7 cells/HP),and the numbers of neuronal apoptosis (14. 0 ± 5. 2 cells/HP) in the VNS-treated group decreased significantly. There were significant differences (P<0. 01). (3) Before and after modeling,there were no significant differences in cerebral blood flow in various periods between the model group and the VNS-treated group (P>0. 05). Conclusion The neuroprotective mechanism of VNS for cerebral ischemia may be associated with the inhibition of neuronal apoptosis and decreasing inflammatory response. It may not be associated with the changes of cortical cerebral blood flow.
Keywords：Brain ischemiaVagus nerveElectric stimulationRats
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 424-430 )