应用溃变法对大鼠皮质脊髓束在脊髓内投射的研究

本研究为在单侧损毁大脑皮质的不同部位后,用铜银法、Fink-HeimerⅡ法和 Fink-HeimerⅡ后漂白复染法顺行追踪大鼠皮质脊髓束的投射。溃变纤维见于对侧脊髓后索的腹侧部和同侧脊髓前索的内侧部。位于后索的溃变纤维一直延伸到骶段,位于前索的仅限于颈段。溃变终末广布于脊髓的Ⅰ～Ⅶ层,并存在定位关系:来自运动区的纤维投射到脊髓的Ⅳ—Ⅶ层,来自体感区的纤维投射到脊髓的Ⅰ—Ⅴ层。对结果的讨论提示,动物皮质脊髓束的走行反映了某种种系进化关系;而该束在动物中枢神经系的运动和感觉机能调节中起重要作用。

The Investigation of the Corticospinal Tract in Rat Spinal Cord Studied with Degeneration

Auterograde degeneration of the corticospinal tract has been studied with the cupric silver method,the Fink-Heimer method procedure Ⅱ and bleaching of Fink-Heimer method in adult rat after lestions of different cortical areas.Degenerating fibers were found in the ventral part of the contralateral dorsal funiculus and the medial part of the ipsilateral ventral funiculus.The degenerating fibers located in the dorsal funiculus could be traced down to the sacral segment while those in the ventral funiculus were only observed in the cervical area.Degenerating terminals were widely distributed in laminaeⅠ-Ⅶ of the spinal cord.A somatotopic organization of degenerating terminals could be found:terminals from motor cortex are projected mainly to laminale Ⅳ-Ⅶ of the spinal cord and those from somotosensory cortex to laminaleⅠ-Ⅴ.The results suggest that the location of the corticospinal tract may reflect an aspect of mammalian evolution and the corticospinal tract must take an important part in regulation of sensory and motor functions in the central nervous system.