经颅交流电刺激对缺血性脑卒中大鼠rs-fMRI的影响

Effects of transcranial alternating current stimulation on resting-state functional magnetic resonance of MCAO rats

目的:建立缺血性脑卒中大鼠右侧大脑中动脉阻塞(middle cerebral artery occlusion,MCAO)模型,观察经颅交流电刺激(transcranial alternating current stimulation,tACS)干预对缺血性脑卒中大鼠行为学及静息态功能性磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)的影响。方法:24只雄性SD大鼠随机分为假手术组(S组)、模型组(M组)和tACS组(T组),记录体重,神经缺损评分(neurological deficit scores,NDS)及造模前(B)、造模后1天(D1)、造模后10天(D10)的rs-fMRI,对比观察tACS干预对MCAO模型大鼠rs-fMRI的影响。结果:NDS评分:M组、T组2h、D1、D3、D5、D7与S组相比显著升高(P<0.05);T组D3、D5、D7与M组相比显著降低(P<0.05)。体重:M组、T组D1与其他各时间相比显著下降;S组D5、D7与其他各时间相比显著上升;S组D3与B、D1相比显著上升(P<0.05);而M组在D1、D3、D5、D7与S组相比均显著下降(P<0.05)。脑成像:D10时,T组在健侧前额叶皮质、患侧前额叶皮质、健侧前扣带皮质的脑区局部一致性(regional homogeneity,ReHo)显著高于S组(P<0.05);T组D10在患侧前额叶皮质、患侧海马的ReHo显著高于D1(P<0.05)。D1时,T组在健侧下丘脑、患侧脑脚间核、健侧嗅球的基于体素的形态学分析(voxel-based morphometry,VBM)显著高于S组(P<0.05);T组D10在患侧海马、上丘脑、纹状体的VBM显著低于D1(P<0.05)。此外,T组D10时灰质体积显著大于S组(P<0.05)。D1时,T组在嗅球的双侧血管小球层、纹状体的低频振荡振幅(amplitude of low-frequency fluctuation,ALFF)显著高于S组(P<0.05);D10时,T组在双侧小脑、纹状体、前额叶皮质、嗅球的ALFF显著高于S组(P<0.05)。结论:tACS早期干预对MCAO大鼠的脑功能有影响,可能与其增强神经元活动及增大灰质体积有关。除了对学习记忆相关脑区,tACS可能还对运动相关脑区有影响从而促进运动功能康复。

Objective:A stroke rat model(MCAO)was established to dynamically observe the effects of transcranial alternating current stimulation(tACS)intervention on behavioral performance and resting state functional magnetic resonance imaging(rs-fMRI)in cerebral ischemia rats.Method:Twenty-four male SD rats were randomly divided into sham-operation group(S group),model group(M group)and tACS group(T group).Body weight at five time points,neurological deficit scores(NDS)at six time points and rs-fMRI before modeling,at D1 and D10 were recorded,The effects of tACS on the brain function of MCAO rats were observed.Result:NDS in M group and T group were increased compared with S group at 2h,D1,D3,D5 and D7(P<0.05).T group were decreased when compared with M group at 3D,5D,7D(P<0.05).Body Weight in M group and T group at D1 decreased significantly compared with other time points(P<0.05);S group at D5 and D7 increased significantly compared with other time points(P<0.05);S group at D3 increased significantly compared with B group at D1(P<0.05);M group at D1,D3,D5,D7 decreased significantly compared with S group(P<0.05).Brain Imageing:At D10,the ReHo in T group increased significantly compared with S group in left prefrontal cortex,right prefrontal cortex and left anterior cingulate cortex;the ReHo at D10 were increased significantly compared with that at D1 in T group in right prefrontal cortex,right hippocampus(P<0.05).At D1,the voxel-based morphometry(VBM)in T group increased significantly compared with S group in left of olfactory bulb,right interpeduncular nucleus,left hypothalamic region.The VBM at D10 were decreased significantly compared with that at D1 in T group in right hippocampus,right brachium of the superior colliculus,right striatum;and the volume of gray matter at D10 in T group in whole brain was increased significantly compared with that in S group(P<0.05).At D1,the ALFF in T group increased significantly compared with that in S group in right/left glomerular layer of the olfactory bulb,striatum;At D10,the ALFF in T group increased significantly compared with that in S group in Cerebellum,striatum,prefrontal cortex and olfactory bulb(P<0.05).Conclusion:The early intervention of tACS had effects on the brain function of MCAO rats,which may related to the enhancement of neuronal activity and the increase of gray matter volume.In addition to learning and memory-related brain regions,tACS may also affect the motor-related brain regions and promote motor rehabilitation.