光化学损伤单侧运动皮质致大鼠后肢痉挛性偏瘫模型的建立

Unilateral photothrombotic motor cortex lesion-induced hindlimb spastic hemiplegia model in rats

目的观察光化学损伤大鼠单侧运动皮质建立后肢痉挛性偏瘫模型的可行性。方法 20只大鼠随机分为A、B两组。A组大鼠注射光敏性化学物质赤藓红B后,激光照射损伤左侧大脑运动皮质,B组大鼠不损伤皮质。分别以术前及术后3、7、14、28d的H反射频率依赖性抑制(RDD)来判断两组大鼠双侧后肢肌肉痉挛情况。术后28d以霍乱毒素行脊髓前角运动神经元逆行示踪及囊泡型谷氨酸转运体1(VGLUT1)免疫荧光染色。同时取大脑组织切片行H-E染色观察脑损伤部位的组织病理学改变。结果在术后3、7、14和28d,A组大鼠右后肢跖肌H反射RDD较B组右后肢减弱(P<0.01),A、B两组左后肢跖肌H反射RDD差异无统计学意义(P>0.05)。A组脊髓前角运动神经元胞体及突起上VGLUT1的数量较B组增加(P<0.01)。脑组织H-E染色可见A组大鼠左侧大脑皮质缺损,而B组无明显损伤。结论损伤大鼠单侧运动皮质,可造成对侧后肢痉挛性偏瘫。

Objective To examine the feasibility of using photothrombotic unilateral motor cortex lesion for establishing hindlimb spastic hemiplegia model in rats. Methods Twenty SD rats were randomized into 2 groups： rats in group A received erythrosine B injection followed by laser irradiation, and those in group B received sham operation. Then the rate dependent depression （RDD） of H reflex was employed to measure the spasticity of the plantaris before and 3, 7, 14, 28 days post-operation. H-E staining was used to observed the lesions in the motor cortex. Cholera toxin B subunit was used to retrogradely label motoneurons in the spinal cord. The number of vesicular glutamine transporter 1 （VGLUT1） boutons on motoneuron soma and dendrite was quantified by immunofluorescence staining and laser confocal microscope scanning. Results H reflex RDD in the right plantaris muscle was significantly decreased in group A compared with that in group B at 3, 7 ,14, and 28 days post-operation （P 〈 0.01）. However, the H reflex RDD was not significantly different between groups in the left hindlimd at different time points after operation （P 〉 0.05）. The number of VGLUT1 boutons on soma and dendrite in group A was significantly increased compared with that in group B （P 〈 0.01）. H-E staining showed specific lesion in the motor cortex of the brain tissue in group A, but not in group B. Conclusion Unilateral photothrombotic motor cortex lesion is feasible to generate contralateral hindlimb spastic hemiplegia in rats.