Design and control of the head retractor muscle in a turtle, Pseudemys (Trachemys) scripta: I. Architecture and histochemistry of single muscle fibers.
Design and control of the head retractor muscle in a turtle, Pseudemys (Trachemys) scripta: I. Architecture and histochemistry of single muscle fibers.
复制标题
乌龟头部牵开肌的设计和控制，Pseudemys (Trachemys) scripta：I. 单肌纤维的结构和组织化学。
DOI：
10.1002/cne.903250307
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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;Callister,R;Peterson,EH
我们正在使用头牵开肌（RCCQ）的海龟，Pseudemys scripta，分析神经肌肉机制，生物体改变肌肉收缩的力量和时间。之前我们证明RCCQ包括三种组织化学定义的纤维类型：快速糖酵解（Fg）、快速氧化糖酵解（FOG）和缓慢氧化（SO）。本文报道了RCCQ中单根肌纤维的结构特征，包括其长度、直径和锥度特征，单根肌纤维的组织化学特征，以及我们的结构和组织化学变量之间的定量关系。大约40%跨越整个肌肉。其余的纤维通常在一端附着在骨或肌腱上，另一端在肌内逐渐变细;很少有纤维在两端都逐渐变细。单根纤维的最大直径呈双峰分布，形成两个直径等级。纤维也在它们的总长度的百分比上变化，锥形区域的形状也变化。大直径肌纤维通常比小直径纤维更长，并且具有更短、更钝的锥形。大直径纤维几乎都是Fg类型;这些纤维的中位直径为59.3 m/cm，约占RCCQ中纤维总数的60%。FOG和SO纤维通常具有小直径（中值：32.5 m/cm和35.8 m/cm），并且它们通常占总纤维的30%和10%。我们使用这些关系来推断糖酵解（Fg）和氧化（FOG，SO）纤维types.Taken在一起的附件和架构，我们的数据表明，在RCCQ单肌纤维可能是建筑以及组织化学专门执行不同的角色在头部回缩。在随附的文件中，我们报告了这些纤维的传出神经支配，并考虑这些不同的纤维类型所造成的一些神经控制问题。© 1992 Wiley利斯公司
We are using the head retractor muscle (RCCQ) of a turtle,Pseudemys scripta, to analyze the neuromuscular mechanisms by which organisms vary the force and timing of muscle contraction. Previously we demonstrated that RCCQ comprises three histochemically defined fiber types: fast glycolytic (Fg), fast oxidative glycolytic (FOG), and slow oxidative (SO). In the present paper we report the 1) architectural features of single muscle fibers in RCCQ, including their lengths, diameters, and taper characteristics, 2) histochemical profiles of single muscle fibers, and 3) quantitative relations between our architectural and histochemical variables.Single fibers in RCCQ exhibit an order of magnitude variation in length (4–60 mm). Approximately 40% span the full muscle. The remaining fibers generally attach to bone or tendon at one end, and the other end tapers intramuscularly; rarely a fiber may taper at both ends. The maximum (untapering) diameters of single fibers are bimodally distributed, forming two diameter classes. Fibers also vary in the percentage of their total length that tapers and in the shape of the tapering region. Large diameter muscle fibers generally are longer and have shorter, more blunted tapers than small diameter fibers. The large diameter fibers are almost all Fg types; these fibers have a median diameter of 59.3 m̈m, and they account for approximately 60% of total fibers in RCCQ. FOG and SO fibers generally have small diameters (median: 32.5 m̈m and 35.8 m̈m), and they typically account for 30% and 10% of total fibers. We use these relations to draw inferences about the attachments and architecture of glycolytic (Fg) and oxidative (FOG, SO) fiber types.Taken together, our data suggest that single muscle fibers in RCCQ may be architecturally as well as histochemically specialized to perform different roles in head retraction. In the accompanying paper we report the efferent innervation of these fibers and consider some of the neural control problems posed by these diverse fiber types. © 1992 Wiley‐Liss, Inc.