Small Animal Muscle Dynamometry System

请求：我们申请121，330美元用于购买世界上独一无二的小动物肌肉测试系统，该系统将允许同时和即时测量小动物（小鼠，青蛙，大鼠）骨骼肌中肌肉力量，肌束长度和单个肌节长度的变化，同时控制所有激活参数。该系统是多光子和二次谐波发生显微镜和小骨骼肌力学测试仪的组合。我们已经有了一个尖端的多光子激发显微镜，由两个飞秒脉冲激光器供电，允许二次谐波产生显微镜。该系统是用加拿大创新基金会最近的一笔约120万加元的赠款购买的。显微镜系统允许深入组织穿透和准确识别个体肌节的各向异性带（A带或肌球蛋白丝区域），从而允许在动态肌肉收缩期间瞬时测量个体肌节长度、肌节速度和肌节长度不均匀性。有了这个RTI应用程序，我们想扩展这个系统，包括一个机械测试系统的骨骼肌从小动物的肌肉收缩力学的充分描述，同时测量肌节动力学。这种系统无法通过商业途径购买，我们建议购买所需的系统部件，并在内部建造该系统。该系统的独特之处在于，我们将能够可视化单个肌节沿着串的串行肌节在整个肌肉收缩过程中，并量化瞬时肌节长度，肌节长度不均匀性，和动态的相互作用的单个肌节在整个肌肉，从而提供相关的和目前无法访问的信息，肌肉生理学家和生物力学。* 一旦最终确定，该设备系统将使我们能够解决肌肉力学中的一些基本问题，包括肌节长度不均匀性与基本肌肉特性之间的关系，例如等长力-长度关系，离心收缩后的残余力增强，以及肌节长度和力-长度关系下降肢上的力的不稳定性。虽然其中一些想法已经考虑了几十年，但所提出的系统将是第一个允许系统评估肌节长度不均匀性和骨骼肌特性和功能的系统。我们在与渴望与我们合作的当地和国际同事协商后构思了这个想法，并在该系统完全实施，测试和验证后向我们发送学生进行特定项目。利用二次谐波显微镜进行静态、稳态和被动肌肉的试验结果提供了令人鼓舞的结果。 **

Request: We are requesting $ 121,330 for the purchase of a world-unique small animal muscle testing system, that will allow for the simultaneous and instantaneous measurement of muscle force, fascicle length, and changes in individual sarcomere lengths in skeletal muscles of small animals (mice, frogs, rats), while controlling all activation parameters. The system is a combination of multi-photon and second harmonic generation microscopy and a mechanical tester for small skeletal muscles. We already have a cutting-edge multi-photon excitation microscope powered by two femto-second pulsed lasers that allow for second harmonic generation microscopy. This system was purchased with a recent Canada Foundation for Innovation grant for approximately $ CDN 1.2 million. The microscope system allows for deep tissue penetration and accurate identification of the anisotropic bands (A-bands or myosin filament region) of individual sarcomeres, thus allowing for instantaneous measurements of individual sarcomere lengths, sarcomere velocities and sarcomere length non-uniformities during dynamic muscle contractions. With this RTI application, we would like to expand this system to include a mechanical testing system for skeletal muscles from small animals for full description of the mechanics of muscle contraction while measuring simultaneously the sarcomere dynamics. Such a system cannot be purchased commercially, and we propose to buy the required system components and build the system in house. The uniqueness of the system lies in the fact that we will be able to visualize single sarcomeres along strings of serial sarcomeres in an entire muscle during contraction, and quantify instantaneous sarcomere lengths, sarcomere length non-uniformities, and dynamic interactions of individual sarcomeres in an entire muscle, thus providing relevant and currently inaccessible information to muscle physiologists and biomechanists. ***Once finalized, this equipment system will allow us to address some fundamental questions in muscle mechanics, including the relationship between sarcomere length non-uniformities and basic muscle properties, such as the isometric force-length relationship, residual force enhancement following eccentric contraction, and instabilities of sarcomere length and force on the descending limb of the force-length relationship. Although some of these ideas have been contemplated for decades, the proposed system will be the first to allow for systematic evaluation of sarcomere lengths non-uniformities and skeletal muscle properties and function.***We have conceived this idea in consultation with local and international colleagues who are eager to collaborate with us, and send us students for specific projects, once this system has been fully implemented, tested and validated. Pilot results using static, steady- state, and passive muscles using second harmonic generation microscopy, have provided encouraging results. **