| Objective: To explore the effect of high cervical Spinal cord electrical stimulation(c SCS)on the recovery of neurological function in rats with Traumatic brain injury(TBI)and to study its possible mechanism by blocking PI3K/AKT signal pathway.Methods: 72 SD Rats were randomly divided into 4 groups: sham operation group(sham group),Traumatic brain injury model group(TBI group),model + high cervical Spinal cord electrical stimulation group(TBI+c SCS group),occlusion + model + high cervical Spinal cord electrical stimulation group(LY294002+TBI+c SCS group),with18 rats in each group.Except for sham group,TBI models were made in other groups.c SCS group was given electrical stimulation with frequency of 50 Hz,pulse width of100 μs and current of 0.4-0.6m A every other day after TBI model.The SCS,of 2min was carried out every 10 min for a total of 30 minutes once a day for 7 consecutive days.In the inhibitor group,10 ul LY294002 inhibitor was injected into the lateral ventricle0.5 h before TBI.The degree of Neurological dysfunction was evaluated by modified Neurological severity score(m NSS).The pathological changes of brain tissue in the injured area were observed by HE staining,and the changes of apoptosis were observed by TUNEL staining.The expression of BDNF and VEGFm RNA was detected by RTPCR,and the expression of p-AKT,AKT,Bcl-2,Bax and caspase-3 protein was detected by Westernblot.Results: 1.In the experiment of neurological dysfunction,the m NSS score of TBI group was significantly higher than that of sham group on the 3rd and 7th day(P< 0.01),and the m NSS score of spinal cord electrical stimulation group was significantly lower than that of TBI group and inhibitor group on the 3rd and 7th day(F=5.516、21.000,P< 0.01).2.HE staining showed that in the TBI group,there were different lesions in the pericerebral cortex,serious damage to the brain tissue structure,infiltration of a large number of inflammatory cells,light staining of the cytoplasm,vacuolation of the nucleus,shrinkage of some nuclei and neuronal necrosis.The electrical stimulation group showed that the above pathological phenomena were improved,the inflammatory cells decreased,the degree of brain tissue damage was low,and the number of neurons increased.Compared with the electrical stimulation group,the PI3 K inhibitor group was aggravated,the hyperemia and bleeding focus were more obvious,and the neuron necrosis was increased.3.TUNEL staining showed that the apoptosis of nerve cells in the injured area of brain tissue in TBI group was significantly higher than that in sham group(P< 0.01),and decreased significantly in c SCS group compared with TBI group(P< 0.01),and increased in PI3 K inhibitor LY294002 group compared with c SCS group(P< 0.01).4.The results of RT-PCR showed that the expression of BDNF and VEGF m RNA in TBI group was higher than that in sham group(P< 0.01),and that the expression of BDNF and VEGF m RNA in electrical stimulation group was higher than that in TBI group and inhibitor group(F=12.813、49.15,P<0.01).5.The results of Westernblot showed that compared with sham group,the expression of Bcl-2 protein decreased(P< 0.01)and the expression of Bax and Caspase-3 increased(P< 0.01)in TBI group.Compared with TBI group and inhibitor group,the expression level of Bcl-2 protein increased(F=47.520,P<0.01)and the expression level of Bax and Caspase-3 decreased(F=144.268、175.784,P< 0.01)in electrical stimulation group.At the same time,compared with sham group,the expression of p-Akt/Akt in TBI group was lower than that in TBI group(P<0.01),while the expression of pAkt/Akt in electrical stimulation group was higher than that in TBI group and inhibitor group(F=84.505,P<0.01).Conclusion: c SCS may affect apoptosis and the expression of BDNF and VEGF after TBI by regulating PI3K/AKT signal pathway,so as to improve the recovery of neurological function in rats. |
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