Abstract: 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.

Key words: cerebral corkex, Corticospinal tract, spinal cord, anterograde degeneration methods, rat