树鼩红核的细胞构筑和红核脊髓束的起源

AN HRP STUDY ON CYTO ARCHITECTURE OF RED NUCLEUS AND ORIGIN OF RUBROSPINAL TRACTS IN TREE SHREW

用Nissl法染色和HRP注入树鼩脊髓的不同节段,观察了红核的细胞构筑和红核脊髓束的起源.结果表明:与其它动物相比,树鼩红核的细胞构筑、红核脊髓束的组成、起源和行程有明显的差异.树鼩红核和上丘高度向吻侧延伸至乳头体内侧核尾端,细胞柱呈梭状,长约3.7mm,最大处直径2mm.它由大(60～100μm)、中(30～50μm)和小型(10～25μm)细胞构成.红核吻段大细胞较多,占60.7%,中尾段中小型细胞多,占71.7%,中、小细胞散 在分布于大细胞之间.树鼩的红核-脊髓束主要由对侧红核大、中和小型细胞发出的纤维组成;红核吻段背侧部,中尾段的腹部、腹中部和腹中背部细胞发出的纤维交叉投射到颈吻段;红核吻、中、尾段的腹部、腹中部和腹中背部细 胞发出的纤维还投射到对侧颈尾段;红核中尾段的腹部、腹中部、腹中背部细胞也有纤维交叉投射到腰段;只有红核吻段和尾段少量细胞发出的纤维投射到同侧颈段.

The cytoarchitecture of the red nucleus and the origin of the rubrospinal tracts were studied in tree shrew using HRP method. The results showed that the red nucleus in tree shrew was of shuttling form, its length was 3. 7 mm and width 2 mm. At light microscopic level, large (60-100μm), medium (30-50μm) and small (10-25 μm) neurons were observed in the red nucleus. The medium and small nurons scattered among the large ones. The rubrospinal tracts from different parts of the red nucleus were crossly terminated at different parts of the opposite side of the spinal cord, mainly at the cervical lumber. Those characteristics suggested that the cytoarchitecture of the red nucleus, the origin and distribution of the rubrospinal tracts in tree shrew were significantly different from those of the other mammals.