SPROUTING AND DEGENERATION OF MAMMALIAN MOTOR AXONS IN NORMAL AND DE-AFFERENTATED SKELETAL MUSCLE
SPROUTING AND DEGENERATION OF MAMMALIAN MOTOR AXONS IN NORMAL AND DE-AFFERENTATED SKELETAL MUSCLE
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DOI：
10.1098/rspb.1966.0008
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发表时间：
1966-01-01
期刊：
影响因子：
--
通讯作者：
IP, MC
中科院分区：
文献类型：
--
作者：
BARKER, D;IP, MC
在正常和去传入后肢骨骼肌的梳理、银制备物中描述了骨骼运动和梭动轴突的侧支和超末端发芽的发生。在12只猫和10只兔肌梭中，板状终末轴突出芽的比例分别为30.4%和34.0%。如果小终板，以前在文献中描述为“附属末梢”，被视为年轻的板新形成的侧枝芽，在两个纺锤体样品的发芽程度增加到33.9%和38.3%，分别。在取自正常肌肉的各种猫、兔和大鼠肌肉中观察到骨骼运动轴突的发芽。在这三种动物的肌肉中检查的567个终末分支的样品中，8.1%的人生芽，或19.4%，如果形成副末梢的侧枝被包括为芽。支配正常肌肉的骨骼运动轴突终末分支之间的逆行变性的一些证据进行了描述。有人建议，发芽影响更换旧终板退化后，有限的寿命，它是一个一般属性的脊椎动物运动神经元的外周终端进行循环更新，以这种方式。与skeletomotor轴突相比，fusimotor板末端轴突所示的更大程度的发芽归因于这样的事实，即由这样的轴突提供给纺锤体的神经支配是多神经元的。最后，一些替代假说的影响，例如，关于神经肌肉病理学，进行了讨论。
The occurrence of collateral and ultraterminal sprouting by skeletomotor and fusimotor axons is described in teased, silver preparations of normal and de-afferentated hindlimb skeletal muscles. In twelve cat and ten rabbit muscle spindles the proportions of plate-ending fusimotor axons showing sprouting were 30.4 and 34.0 % , respectively. If small end-plates, previously described in the literature as ‘accessory endings’, are regarded as young plates newly formed by collateral sprouts, the degree of sprouting in the two spindle samples is increased to 33.9 and 38.3 % , respectively. Sprouting by skeletomotor axons was observed in a variety of cat, rabbit, and rat muscles taken from normal muscles. In a sample of 567 terminal branches examined in muscles from the three animals, 8.1% bore sprouts, or 19.4% if the collaterals forming accessory endings are included as sprouts. Some evidence of retrograde degeneration among the terminal branches of skeletomotor axons innervating normal muscle is described. It is suggested that sprouting effects the replacement of old end-plates which degenerate after a limited life-span; and that it is a general property of the vertebrate motoneuron for its peripheral terminals to undergo cyclic renewal in this way. The greater degree of sprouting shown by fusimotor plate-ending axons as compared with skeletomotor ones is attributed to the fact that the innervation supplied to spindles by such axons is both multiple and polyneuronal. In conclusion, some of the implications of the replacement hypothesis, e.g. with regard to neuromuscular pathology, are discussed.