The study on the sciatic nerve graft inducing axonal regeneration of the neurons in motor cortex and brainstem in adult hamsters

Abstract

A segment of the right sciatic nerve was transplanted into medulla pyramidal decussation and concurrently sev-eral short segments of the left sciatic nerve were inserted into the motor cortex.Eight weeks later,1μl of 20% so-lution of HRP was injected into the sciatic nerve graft placed in the medulla.The HRP Iabelled cells were found inthe brainstem and diencephalon,but none was present in the motor cortex. Most of labelled cells were concentrat-ed around the grafting site.The number of labelled cells decreased rapidiy with increasing distance from the site ofgraft insertion。Thus,the results suggest that the insertion of the short sciatic nerve grafts near the pyramidal cellbodies do not enhance regeneration of the neurons in the motor cortex,and the ability of the damaged axons togrow into the graft partly depends on the location of the cell bodies from the site of axotomy and the sciatic nervegraft.

將右側坐骨神經植入金黃地鼠的延髓錐體交叉處，同時，又將左側坐骨神經切成數個短段后全段植入運動皮質。８周后用辣根過氧化物酶（ＨＲＰ）軸突逆行追蹤法觀察ＨＲＰ標記的軸突再生中樞神經元。結果，各組的運動皮質內均未發現標記細胞，在腦干和間腦可見標記細胞，呈距移植神經越遠標記細胞越少的分布趨勢。提示：植入錐體細胞胞體周圍的坐骨神經短段對遠距胞體的軸突損傷后再生無明顯促進作用，腦干神經元的軸突再生與移植神經插入及軸突損傷部位距神經元胞體之間的距離密切相關。