Klueber K M
Anat Rec. 1987 Apr;217(4):402-6. doi: 10.1002/ar.1092170412.
Since the number of motor neurons supplying a muscle graft is reduced, the peripheral field for the surviving motor neurons would be enlarged. This possible change in motor unit size may result in morphologic changes in the size of motor neurons within the motor neuron pool of the graft. The extensor digitorum longus (EDL) muscle from 19 transplanted and 17 age-matched normal 129 ReJ female mice were injected with horseradish peroxidase in order to examine the cell size distributions of the motor neuron pools supplying these muscles. Computer-assisted morphometric analysis of cell sizes within the motor neuron pool to the transplants indicated a significant shift in cell size, with the largest areas ranging between 630 and 1250 micron2. A number of the alpha neurons supplying the grafts were twice the average cell size for the control population (means = 592 micron2). The increase in the number of large motor neurons indicates an hypertrophy of neurons reinnervating the grafts. The long-term graft is reinnervated by a decreased population of motor neurons (means = 7), which vary in size from small to very large, reflecting both changes in the possible source of the nerve reinnervating the graft as well as alteration in the size of the motor unit, respectively.
由于支配肌肉移植物的运动神经元数量减少，存活的运动神经元的外周区域会扩大。运动单位大小的这种可能变化可能导致移植物运动神经元池内运动神经元大小的形态学改变。为了检查支配这些肌肉的运动神经元池的细胞大小分布，对19只移植的和17只年龄匹配的正常129 ReJ雌性小鼠的趾长伸肌（EDL）注射了辣根过氧化物酶。对移植肌肉的运动神经元池内细胞大小进行计算机辅助形态测量分析表明，细胞大小有显著变化，最大面积在630至1250平方微米之间。一些支配移植物的α神经元的细胞大小是对照群体平均细胞大小的两倍（平均值 = 592平方微米）。大型运动神经元数量的增加表明再支配移植物的神经元发生了肥大。长期移植物由数量减少的运动神经元（平均值 = 7）再支配，这些运动神经元大小从小到非常大不等，分别反映了支配移植物的神经可能来源的变化以及运动单位大小的改变。
