Design and control of the head retractor muscle in a turtle, Pseudemys (Trachemys) scripta: II. Efferent innervation.
Design and control of the head retractor muscle in a turtle, Pseudemys (Trachemys) scripta: II. Efferent innervation.
复制标题
乌龟头部牵开肌的设计和控制，Pseudemys (Trachemys) scripta：II。
DOI：
10.1002/cne.903250308
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Peterson,EH
中科院分区：
文献类型：
--
作者：
Callister,RJ;Peterson,EH
拟鼠头部牵开肌是研究动物运动力和运动时间变化机制的重要模型。这种肌肉中的单纤维在附件、长度、直径、锥度特征和组织化学性质方面存在显著差异，这表明它们可能在能量和结构上专门用于头部运动的不同角色。在本论文中，我们报告了这些不同的肌肉细胞的外周和中枢传出神经支配，我们问如何设计的神经装置是匹配其目标肌肉fiber.Three四分之三的腹部在RCCQ的属性是由多个节段神经。这些神经的区域在肌腹内吻尾分离;因此，长肌纤维穿过两个或更多节段神经的区域。RCCQ中的运动终末类似于青蛙抽搐肌肉上的运动终末。它们的大小（长度，终扣数）与其靶肌纤维的直径相关。每根肌纤维具有2-14个均匀间隔的末端（约10个）。沿着其长度间隔5 mm）。因此，RCCQ中的单根肌纤维是多末端的，长纤维是多节段神经支配的。对照实验表明，每个节段神经中的轴突来自不同的运动神经元群体。因此，短的串联纤维由不同的运动神经元提供，RCCQ中的单个长纤维受多神经元支配。这些数据有助于解释传导速度相对较慢的长肌纤维如何产生快速的头部运动，并提出了关于协调RCCQ运动神经元募集的中枢机制的问题。© 1992 Wiley利斯公司
The head retractor muscle (RCCQ) ofPseudemys scriptais a useful model in which to study the mechanisms animals use to vary the force and timing of movement. Single fibers in this muscle differ significantly in attachments, length, diameter, taper characteristics, and histochemical properties, suggesting that they may be energetically and architecturally specialized for different roles in head movement. In the present paper, we report the peripheral and central efferent innervation of these diverse muscle cells, and we ask how the design of the neural apparatus is matched to the properties of its target muscle fibers.Three out of four bellies in RCCQ are supplied by multiple segmental nerves. The territories of these nerves are separated rostrocaudally within the muscle belly; thus, long muscle fibers cross the territories of two or more segmental nerves. Motor terminals in RCCQ resemble those on frog twitch muscles. Their sizes (length, bouton number) are correlated with the diameters of their target muscle fibers. Each muscle fiber bears 2–14 terminals evenly spaced (approx. 5 mm apart) along its length. Thus, single muscle fibers in RCCQ are multiterminally, and long fibers are multisegmentally innervated. Control experiments indicate that the axons in each segmental nerve arise from different motor neuron populations. Thus, short, in‐series fibers are supplied by different motor neurons, and individual long fibers in RCCQ are polyneuronally innervated. These data help explain how long muscle fibers with relatively slow conduction speeds can generate rapid head movements, and they raise questions about the central mechanisms that coordinate the recruitment of RCCQ motor neurons. © 1992 Wiley‐Liss, Inc.