用麦芽凝集素-辣根过氧化物酶逆行示踪法研究大鼠C_7神经根运动皮层的定位  

Locating corticospinal neurons of C_7 nerve root by retrograde axonal transport ation method of WGA-HRP: a preliminary report

作　　者：李文军[1] 顾玉东[1] 徐文东[1] 刘含秋[2] 孙贵新[1] 郑宪友[1] 李继峰[1] 

机构地区：[1]复旦大学附属华山医院手外科,上海200040 [2]复旦大学附属华山医院放射科,上海200040

出　　处：《中华手外科杂志》2004年第1期47-50,共4页Chinese Journal of Hand Surgery

基　　金：国家自然科学基金资助项目 ( 30 2 4 0 0 0 9);复旦大学Med-X基金资助项目 (EXF0 0 0 30 1 );复旦大学研究生创新基金资助项目(CQF1 51 80 3);上海市青年科技启明星计划资助项目 ( 0 3QD1 40 0 7);国家973创伤基础研究基金资助项目 (G1 9990 542 0 2 )

摘　　要：目的　研究大鼠C7神经根运动皮层定位域 ,为C7神经根移位后皮层变化的研究奠定基础。方法　SD大鼠 48只 ,按手术先后随机分为 6组 :C5 节段组、C6 节段组、C7节段组、C8节段组、T1节段组和C5～ 8、T1节段组 ,每组 8只。在左侧皮质脊髓束 (CST)中注射 0 .5μl麦牙凝集素 辣根过氧化物酶 (Wheatgermagglutinin HRP ,WGA HRP) ,成活 60～ 72h ,灌注后 ,取脑和相应节段脊髓做冰冻切片 ,TMB显色、中性红复染 ,观察臂丛神经节段锥体神经元的分布规律及C7神经根锥体细胞的形态学特征。结果　C7神经根锥体细胞胞体呈三角形或圆锥形 ,主要分布在前囟前 [(2 .5± 0 .0 1)mm～ (1.5± 0 .0 1)mm , x±s下同 ]约 1mm的皮层区域范围内 ,集中在第Ⅴ层 (2 5%≤Z≤ 51% ) ,Z =3 8.5± 5.6) ,胞体平均截面积为 (12 78±2 13 ) μm2 ,以中型细胞为主。基树突分支以一级分支为主 ,平均为 (446± 68)个。顶树突走向与皮层切线位的θ角 ,平均为 (6.8± 8.3 )°。结论　C7神经根运动皮层定位域的初步确立 。ObjectiveTo study the distribution of the corticospinal neuron s of C 7 nerve root in the rat motor cortex, and provide foundation for further research about cortex plasticity after C 7 nerve transfer.Methods48 adult Sprague Dawley rats were randomly divided into 6 groups: T 1 segm ent, C 8 segment, C 7 segment, C 6 segment, C 5 segment and T 1-C 5 segme nt group. Animals were anesthetized with intraperitoneal injection of pentobarbital sodium (40 mg/kg) and laminect o my was performed at the fifth, sixth, seventh, eighth cervical spinal cord segme nts. The tip of a 1μl Hamilton syringe held in a stereotaxic manipulator was po sitioned 1.0mm left of the middle of the dorsal surface of the spinal cord, poin ting medially at an angle of 45° from vertical, and advancing 1.7mm under micro s cope guide. A total of 0.5μl of 4% WGA-HRP (wheat germ agglutinin-horseradish p eroxidase) was injected over a period of 10～30 minutes. The animals survived for 48～72 hours, and were then perfused with 1.25% glutaraldehyde and 1.0% par aformaldehyde in phosphate buffer (pH=7.4). The brain and spinal cord were secti oned coronally at 50 μm thickness on a freezing microtome. The sections were re acted for presence of HRP by using TMB kit, and counterstained with 1% neutral r ed. The sections were observed under microscope for the distribution range and the morphological properties of corticospinal neurons of C 7 nerve root in th e motor cortex. ResultsThe neurons of C 7 nerve root were conif orm or triangular and were distributed at rostral of bregma from (2.5±0.01) mm to (1.5±0.01) mm, that are situated in layer Ⅴ of motor cortex (25%≤Z≤51%, Z = 38.5±5 .6). The mean soma cross sectional area was (1 278±213) μm 2. The majority of cells was medium-sized (from 1 000 to 1 500 μm 2). They had a principal apica l dendrite with the angle of θ as (6.8±8.3)°,and several basal dendrites tha t we re mainly first grade bifurcations. ConclusionOur findings pro vided the cortex distribution of C 7 nerve root.

关 键 词：麦芽凝集素-辣根过氧化物酶 逆行示踪法 大鼠 C7神经根根移 运动皮层 定位 臂丛神经根性撕脱伤 

分 类 号：R651.3[医药卫生—外科学]