The effects of transplanted peripheral nerve segment of the axonal regeneration of damaged pyramidal neurons in hamsters

Abstract

Segment of peripheral nerve(PN)was transplanted either into the motor cortex (proximal axotomy)or into the medulla pyramidal decussation(distal axotomy) which were verified by retrogra- de and anterograde HRP labelling respectively.Eight weeks after implantation,the presence of rege- nerated motoneurons was visualized by HRP histochemistry following the injection of the tracer into the distal end of the PN graft.An average of 8(n=10) labelled cells were detected in the motor cortex of animals with cortical PN graft while an average of 2116(n=5)labelled cells were found in the brainstem of animals with medullary PN graft.However,no labelled cells was observed in the motor cortex in the latter group of animals,Thus,it is concluded that the pyramidal neurons are capable of regenerating axons into a implanted PN graft but its potentiaI to regenerate depends partly on the distance of the lesion from the cell body.

將截取的金黃地鼠坐骨神經移植段分別植于運動皮質（第一組）和延髓錐體交叉處（第二組），同時造成植入處錐體束的損傷。８周后，用ＨＲＰ逆行追蹤法觀察運動皮質的標記細胞。結果，第一組（ｎ＝１０）平均每只動物皮質內出現８個標記細胞，第二組（ｎ＝５）的皮質內未見標記細胞，但在腦干中出現較多標記細胞（平均２１１６個）。提示：周圍神經移植法可誘導金黃地鼠錐體束再生，但此再生與移植神經植入和錐體細胞軸突損傷部位與錐體細胞體之間的距離密切相關。