Morphological studies of the neuromuscular mechanism shifting from sucking to biting of mice.
Morphological studies of the neuromuscular mechanism shifting from sucking to biting of mice.
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小鼠从吸吮到咬合转变的神经肌肉机制的形态学研究。
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
Tetsu Kawamoto
中科院分区：
文献类型：
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作者：
Kinziro Kubota;Noriyuki Narita;Kenichi Ohkubo;Shunji Shibanai;Kazuki Nagae;Miyuki Kubota;Noriko Odagiri;Tetsu Kawamoto
为了从神经解剖学的角度探讨由吸吮向咬咬转变的机制，我们利用HRP标记技术和电镜观察了产前、新生儿和产后小鼠的吸咬相关神经元的神经发生和周围效应器官的组织发生是否存在时间差。所得结果如下：(1)出生时面部运动神经元在细胞面积和发育上都超过三叉神经运动神经元。(2)出生后，三叉神经运动神经元生长迅速，6天时超过面部运动神经元的生长。(3)此后，两种神经元的细胞面积继续逐渐增大。(4) α -运动终板在17日龄胎儿面神经支配的口轮匝肌出现首发征象，而在18日龄胎儿咬肌出现三叉神经终板的征象较晚。(5)肌纺锤体的初步迹象出现在17日龄胎儿的咬肌感觉末梢，4日龄幼崽形成肌纺锤体的基本结构。(6)面神经髓鞘形成在3天大的婴儿开始，而三叉神经髓鞘形成在4或5天大的婴儿开始显现。由此可见，与吮吸有关的面神经成分在出生时首先发育，而与咬咬有关的三叉神经成分在出生后分化迅速加快。
In order to give a neuroanatomical evidence to the mechanism of shifting from sucking to biting, we investigated in prenatal, newborn and postnatal mice whether there is a time difference in the neurogenesis of the neurons relative to sucking and biting or in the histogenesis of their peripheral effector organs by the HRP labeling technique and electron microscopy. The results obtained are as follows. (1) At birth the facial motoneurons exceed the trigeminal motoneurons in cell area and development. (2) After birth, the trigeminal motoneurons grow rapidly and outstrip the growth of the facial motoneurons at the age of 6 days. (3) Thereafter, the cell area of both neuron types continues to increase gradually. (4) The initial sign of the alpha motor end plates is found in the orbicularis oris muscle innervated by the facial nerve in 17-day-old fetuses, while that of the trigeminal nerve is delayed in the masseter muscle of 18-day-old fetuses. (5) The initial sign of the muscle spindle appears with the sensory terminals in the masseter muscle of 17-day-old fetuses and the fundamental structure of the muscle spindle is formed in 4-day-old youngs. (6) Myelination of the facial nerve begins in 3-day-old youngs, while that of the trigeminal nerve becomes apparent in 4- or 5-day-old youngs. From these bases, it is obvious that the facial nerve elements related to sucking are firstly developed at birth and that the differentiation of the trigeminal nerve elements related to biting is rapidly accelerated after birth.