运用HRP逆行追踪法对家兔脊髓小脑束起始细胞的研究

ORIGIN OF CELLS OF SPINOCEREBELLAR TRACTS IN THE RABBIT,STUDIED WITH THE METHOD OF RETROGRADE TRANSPORT OF HORSERADISH PEROXIDASE

本文在11只家兔小脑内,进行单侧或双侧辣根过氧化物酶注射,以研究脊髓各部标记神经元的分布。同时,为确定胸髓以下这些神经元轴突是否在脊髓内交叉上行,其中4只家兔在注射前,还作了下胸髓的一侧半断。标记的脊髓小脑束起始细胞在脊髓中分布甚广。位于颈髓的有:1.中央颈核(C_(1~4));2.Ⅵ层内侧部细胞(C_(2)~T_(1));3.Ⅶ层中央部细胞(C_(4~8));4.后角Ⅳ~V层细胞(C_(5~8))。胸髓以下的标记细胞可分两大类:1.具有不交叉上行轴突的细胞为:(1)背核(T_(2)~L_(4));(2)后角Ⅳ~Ⅵ层细胞(T_(2)~L_(6))。2.具有交叉越边上行轴突的细胞则包括:(1)脊髓前角边缘细胞(L_(3~6));(2)Ⅶ层内侧群细胞(L5以下骶尾髓);(3)后角V层细胞(骶尾髓);(4)前角Ⅶ~Ⅷ层细胞(骶尾髓)。家兔脊髓小脑束起始细胞的分布和轴突投射特点,与猫相类似。这对进一步用家兔研究脊髓小脑系统的解剖学和生理学打下一定基础。

Horseradish peroxidase(HRP)was injected unilaterally or bilaterally into the cerebellum of 11 rabbits in order to trace the distribution of labeled neurons in the whole length of the spinal cord.To investigate the ascending side of the axons,hemisections were made unilaterally in the lower thoracic cord of 4 rabbits before injection.The distribution of labeled spinocerebellar tract neurons was rather wide.Neurons in the cervical segments were located in(1)the central cervical nucleus(CCN)in C_(1-4),(2)the medial part of lamina VI in C_(2)-T_(1),(3)the central part of lamina VII in C_(4-8)and(4)lamina IV-V in C_(5-8).The labeled neurons located in segments caudal to thoracic cord could be divided into two groups.Neurons of the uncrossed tract were located in(1)Clarke's column in T_(2)-L_(4),(2)laminae IV-VI in T_2-L_6.Neurons of the crossed tract were found in(1)the spinal border cells(SBC)in L_(3-6),(2)the medial part of the lamina VII in segments caudal to L_(6),(3)lamina V in the sacrococcygeal cord and(4)laminae VII-VIII in the sacrococcygeal cord.The present study suggests that the location and fiber course of the spinocerebellar neurons in the rabbit are quite the same as those in the cat.These results should form a basis for further anatomical and physiological studies of spinocerebellar system in the rabbit.