QUANTITATIVE-ANALYSIS OF CERVICAL MUSCULATURE IN RATS - HISTOCHEMICAL COMPOSITION AND MOTOR POOL ORGANIZATION .2. DEEP DORSAL MUSCLES
QUANTITATIVE-ANALYSIS OF CERVICAL MUSCULATURE IN RATS - HISTOCHEMICAL COMPOSITION AND MOTOR POOL ORGANIZATION .2. DEEP DORSAL MUSCLES
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DOI：
10.1002/cne.902550305
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发表时间：
1987-01-15
影响因子：
2.5
通讯作者：
PETERSON, EH
中科院分区：
文献类型：
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作者：
CALLISTER, RJ;BRICHTA, AM;PETERSON, EH
本文研究了大鼠颈后肌：脾肌(SP)、颈二头肌(BC)和复合肌(COM)的结构、组织化学、纺锤体组成和运动池组织。我们还考虑了(1)是否像乌龟和猫那样，单个大鼠颈部肌肉由多个运动神经元支配，以及(2)这些肌肉中的运动神经元大小是否具有肌纤维型。背颈肌肉被肌腱铭文分成准连续排列的间隔。每个隔室由一支独立的外周神经分支供应，分别来自C1-C5背侧支；因此，每条背颈肌由多个节段支配。我们的组织化学数据表明，慢抽动氧化(SO)纤维总是数量最少的一类，而快速纤维几乎平均分为快速氧化糖酵解(FOG)和快速糖酵解(FG)类型。每种纤维类型的相对频率在肌肉间存在显著差异。形态分析显示，肌纤维类型呈马赛克状，没有明显的区划，肌梭分布基本均匀。供应大鼠背颈肌的运动神经元仅限于同侧腹侧角的腹侧三分之一，从下延髓到C4。SP运动池位于腹角的背侧，BC和COM运动池在顶端形成重叠的柱状结构。几乎没有证据表明，这些肌肉是由不止一组运动神经元供应的，就像在海龟和猫身上所报道的那样。为了帮助评估这些不同的结果，我们在两只猫身上将C2神经渗透到BC和COM；我们的结果与先前在猫身上报道的结果相似，包括对侧运动神经元的存在。因此，大鼠和猫实验之间的不同结果可能代表了颈部肌肉神经支配的物种差异。在五个实验中，我们对为肌肉提供显著不同组织化学成分的运动神经元的大小进行了直接比较。在每种情况下，在由肌肉的组织化学特征预测的方向上，运动神经元的平均大小是不同的，因此，提示在这些肌肉中，运动神经元的大小可能随着肌肉纤维的类型而扩大。
In this paper we characterize the architecture, histochemistry, spindle composition, and motor pool organization of rat dorsal neck muscles: splenius (SP), biventer cervicis (BC), and complexus (COM). We also consider (1) whether individual rat neck muscles are innervated by more than one population of motor neurons as they are in turtles and cats and (2) whether in these muscles motor neuron size scales with muscle fiber type. Dorsal neck muscles are divided by tendinous inscriptions into quasiserially arranged compartments. Each compartment is supplied by a separate peripheral nerve branch from C1-C5 dorsal rami; thus each dorsal neck muscle is innervated from multiple segments. Our histochemical data indicate that slow-twitch oxidative (SO) fibers are always the least numerous group, and fast fibers are split almost equally between fast oxidative glycolytic (FOG) and fast glycolytic (FG) types. There are significant cross-muscle differences in the relative frequency of each fiber type. Topographic analyses reveal a mosaic pattern of fiber types with no clear compartmentalization, and muscle spindle distribution is essentially homogeneous. Motor neurons supplying rat dorsal neck muscles are restricted to the ventral third of the ipsilateral ventral horn from lower medulla to C4. The SP motor pool is located dorsally in the ventral horn, and BC and COM motor poools form overlapping columns in the tip. There is little evidence that these muscles are supplied by more than one population of motor neurons, as reported in turtles and cats. To help assess these differing results, in two cats we infiltrated the C2 nerve to BC and COM; our results were similar to those previously reported in cats including the presence of contralateral motor neurons. Thus disparate results between rat and cat experiments may represent species differences in neck muscle innervation. In five experiments we made direct comparisons between the sizes of motor neurons that supply muscles with significantly different histochemical compositions. In each case there was a difference in mean soma size in the direction predicted by the muscles'' histochemical profiles, thus suggesting that in these muscles motor neuron size may scale with muscle fiber type.