兴奋作用的间歇性Theta节律爆发式刺激模式经颅磁刺激对大鼠全横断脊髓损伤早期脑内炎症及神经元凋亡的影响

关键词：脊髓损伤  经颅磁刺激  炎症微环境  凋亡

Keywords:spinal cord injury  transcranial magnetic stimulation  inflammatory microenvironment  apoptosis

摘要：

      摘要 目的：研究兴奋作用的间歇性Theta节律爆发式刺激（intermittent theta burst stimulation， iTBS）模式经颅磁刺激对大鼠T10全横断脊髓损伤早期脑内炎症及运动皮层神经元凋亡的影响。 方法：将40只SD雌性大鼠随机分为正常对照组（n=10）、SCI模型组（n=10）、假刺激组（n=10）和iTBS治疗组（n=10）。正常对照组不施加任何处理，其余3组做T10脊髓全横断手术。SCI模型组术后不施加任何干预，iTBS治疗组在术后72h开始对大鼠大脑皮层运动区进行iTBS模式刺激，每日1次，600个脉冲，每次3min 20s，假刺激组术后72h开始给予假磁刺激治疗，只将刺激线圈垂直放置于头部。各组分别于治疗1周和2周取材5只大鼠的大脑组织，一侧大脑半球用于Western Blot免疫印迹法检测CD68、CCR7和CD206蛋白的表达，另一侧大脑半球用于免疫荧光染色，检测CD68、IBA-1和cleaved caspase3在组织内的表达变化。 结果：大鼠T10全横断脊髓损伤经iTBS治疗1周后，iTBS组大鼠大脑皮层内CD68、CCR7蛋白表达量明显低于SCI模型组和假刺激组（P<0.01），而CD206蛋白含量显著高于SCI模型组和假刺激组（P<0.001）；经iTBS治疗2周后，大鼠大脑皮层IBA-1阳性细胞的数量显著低于SCI模型组和假刺激组（P<0.0001）；运动皮层cleaved caspase 3阳性神经元的数量也显著低于SCI模型组和假刺激组（P<0.05）；而SCI模型组和假刺激组无显著性差异（P>0.05）。 结论：脊髓损伤早期采取iTBS治疗可以有效抑制损伤导致的脑内炎症，防止小胶质细胞过度激活和运动皮层神经元凋亡，可为运动皮层神经元的存活和再生提供有利的微环境，为严重脊髓损伤后的脑神经保护和及早开展康复治疗提供实验依据。

Abstract:

      Abstract Objective： To investigate the effects of intermittent theta burst stimulation（iTBS） therapy on intracerebral inflammation and motor cortex neuronal apoptosis in rats with T10 total transected spinal cord injury at the early stage. Method： Forty SD female rats were randomly divided into normal control group （n=10）， SCI model group （n=10）， sham stimulation group （n=10） and iTBS group （n=10）. The normal control group received no intervention， and the remaining three groups underwent total T10 spinal cord transection. Since 72h after surgery, the iTBS group was received the iTBS on the motor area of the cerebral cortex once a day with 600 pulses for 3 minutes and 20 seconds each time, and the sham stimulation group was given ineffective magnetic stimulation with only the stimulation coil placed perpendicular to the head and the SCI model group without any intervention. The brain tissues of five rats in each group were collected at one-week and two-week after treatment. One side of the brain hemisphere was used to quantitate the expression of CD68， CCR7 and CD206 inflammatory factors by Western Blot， and the other side was used to detect the expression sites and levels of CD68， IBA-1 and cleaved caspase3 in brain tissues by immunofluorescence staining. Result： After one week of iTBS treatment， the expression level of CD68 and CCR7 protein in the cerebral cortex of iTBS group was significantly lower than SCI model group and sham stimulation group（P<0.01）， while the expression level of CD206 protein was significantly higher than SCI model group and sham stimulation group（P<0.001）. After 2 weeks of iTBS treatment， the number of IBA-1 positive cells in the cerebral cortex of iTBS group was significantly lower than that of SCI model group and sham stimulation group（P<0.0001） and the number of cleaved caspase3 positive neurons in the cerebral motor cortex of iTBS group was significantly lower than that of SCI model group and sham stimulation group（P<0.05）； there was no significant difference between SCI model group and sham stimulation group（P>0.05）. Conclusion： Early iTBS therapy can effectively inhibit intracerebral inflammation caused by spinal cord injury， prevent microglial overactivation and motor cortex neuron apoptosis， and provide a favorable microenvironment for the survival and regeneration of motor cortex neurons. It provides experimental basis for cerebral neuroprotection and early rehabilitation treatment after severe spinal cord injury.