| Objective Axonal regeneration after injury to the adult CNS is limited in part by the inhibitory factors in CNS myelin: Nogo-A,MAG,and OMgp. All these three of proteins bind to the neuronal glycosylphosphatidylinositol-anchored receptor (NgR) that tranduces inhibitory signal to the cell interior by a transmembrane co-receptor, p75, thus, blocks axonal regeneration and limits motorial recovery after adult CNS injury. Previous studies have found that electrostimulation of fastigial nucleus could protect the adult brain from ischemia lesion and improve axonal plasticity. The study focused on the expression changes of NgR mRNA and protein in the infracted cortex and hippocampus after cerebral ischemia-reperfusion in rat and the effect and significance of electrostimulation of fastigial nucleus on NgR expression and axonal regeneration.Method In the study the focal MCAO ischemia-reperfusion model was induced by ligation with nylon monofilament in rats. Ninety-six male SD rats were selected and randomly divided into 6 groups including the sham group and 12h,24h,1w,2w,3w group after cerebral ischemia-reperfusion. The histological features of nerve cells were identified by HE staining. RT-PCR was used to determine the changes of NgR mRNA expression. And immunohistochemistry was used to detect the expression of NgR protein and the state of axonal regeneration. In addition, forty-eight male SD rats were selected and randomly divided 3 groups including the sham group, the ischemia-reperfusion group and the ischemia-reperfusion group with a FNS treatment, in which rats suffering from ischemia for 2h were electrostimulated immediately in cerebellar fastigial nucleus lasted 1 h. At 24h and 2w the expression levels of NgR and axonal regeneration in the infracted cortex and hippocampus were detected by RT-PCR and immunohistochemistry analysis.Results In the first part the result demonstrated that the expression levels of NgR in the infracted cortex and hippocampus were significantly increased(p<0.01) and axons were grossly damaged at 24h after cerebral ischemia-reperfusion compared to the sham group(p<0.05). Secondly, the result showed the expression levels of NgR in the infracted cortex and hippocampus were significantly decreased and axons were obviously increased in FNS treatment group in contrast to single ischemia-reperfusion group.Conclusions Together, these results showed that the expression levels of NgR in the infracted cortex and hippocampus were downregulated after a FNS treatment, which suggested that electrostimulation of fastigial nucleus might be an effective target for a disinhibition strategy to promote CNS axonal regeneration.
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