Patten R M, Ovalle W K
Department of Anatomy, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Anat Rec. 1992 Apr;232(4):499-511. doi: 10.1002/ar.1092320407.
Muscle spindles and extrafusal fibers in the tenuissimus muscle of mature golden Syrian hamsters were studied morphologically and quantitatively using several light microscopic techniques. Muscle spindles were identified in serial-transverse frozen-sections of whole muscles stained with hematoxylin and eosin. Five tenuissimus muscles were examined from origin to insertion, and the locations of individual receptors were plotted in camera-lucida reconstructions. Spindles were found in proximity to the main neurovascular bundle in the central core of each muscle. A range of 16-20 receptors was noted per muscle. The mean muscle spindle index (the total number of spindles per gram of muscle weight) was 503 and the average spindle length was 7.5 mm. Oxidative enzyme and myosin adenosine-triphosphatase (ATPase) staining profiles were also evaluated in the intrafusal and extrafusal fibers in each muscle. Even numbers of type I and type IIA extrafusal fibers were distributed homogeneously throughout all muscle cross-sections. Histochemical staining patterns varied along the lengths of the three intrafusal fiber types. Nuclear chain fibers possessed staining properties similar to the type IIA extrafusal fibers and exhibited no regional variations. Bag1 fibers displayed staining variability, particularly when treated for myosin ATPase under acid preincubation conditions. Some spindles were isolated under darkfield illumination and then either treated with 7-nitrobenz-2-oxa-1,3-diazole (NBD)-phallacidin to detect filamentous actin by fluorescence microscopy, or prepared for conventional scanning electron microscopy (SEM). By fluorescence microscopy, a registered actin banding-pattern was observed in the sarcomeres of the intrafusal fibers, and variations in the intensity of banding were noted amongst different fibers. SEM revealed punctate sensory nerve endings that adhered intimately to the surfaces of underlying intrafusal fibers in the equatorial and juxtaequatorial regions. By transmission electron microscopy (TEM) these endings appeared crescent-shaped and were enveloped by external laminae. Each profile contained numerous mitochondria and cytoskeletal organelles. The high spindle density observed in this muscle suggests that the hamster tenuissimus may function in hindlimb proprioception.
利用多种光学显微镜技术，对成熟的金黄叙利亚仓鼠股薄肌中的肌梭和梭外肌纤维进行了形态学和定量研究。在苏木精和伊红染色的全肌连续横断冰冻切片中识别出肌梭。从起点到止点检查了5条股薄肌，并在明视野重建中绘制了各个感受器的位置。在每块肌肉中央核心的主要神经血管束附近发现了肌梭。每块肌肉中发现16 - 20个感受器。平均肌梭指数（每克肌肉重量中的肌梭总数）为503，平均肌梭长度为7.5毫米。还评估了每块肌肉中梭内肌纤维和梭外肌纤维的氧化酶和肌球蛋白三磷酸腺苷酶（ATP酶）染色情况。I型和IIA型梭外肌纤维数量相等，均匀分布于所有肌肉横切面。三种梭内肌纤维类型的组织化学染色模式沿长度方向有所不同。核链纤维具有与IIA型梭外肌纤维相似的染色特性，且无区域差异。袋1纤维显示出染色变异性，尤其是在酸性预孵育条件下处理肌球蛋白ATP酶时。在暗视野照明下分离出一些肌梭，然后用7 - 硝基苯 - 2 - 恶唑 - 1,3 - 二氮杂萘（NBD） - 鬼笔环肽通过荧光显微镜检测丝状肌动蛋白，或制备用于常规扫描电子显微镜（SEM）观察。通过荧光显微镜，在梭内肌纤维的肌节中观察到有规律的肌动蛋白带纹模式，并且不同纤维之间带纹强度存在差异。扫描电子显微镜显示点状感觉神经末梢紧密附着于赤道和近赤道区域下方梭内肌纤维的表面。通过透射电子显微镜（TEM）观察，这些末梢呈新月形，被外板包裹。每个断面包含许多线粒体和细胞骨架细胞器。在该肌肉中观察到的高肌梭密度表明仓鼠股薄肌可能在后肢本体感觉中发挥作用。
