Small Animal Muscle Dynamometry System

请求：我们请求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瞬时测量小动物（小鼠，青蛙，大鼠）骨骼肌中的肌肉力量，束长和单个肌节长度的变化，同时控制所有激活参数。该系统结合了多光子和二次谐波产生显微镜以及小型骨骼肌的机械测试仪。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驱动，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并准确识别单个肌节的各向异性带（a带或肌球蛋白丝区），从而允许在动态肌肉收缩过程中瞬时测量单个肌节长度、肌节速度和肌节长度的不均匀性。有了这个RTI应用程序，我们想扩展这个系统，包括一个小动物骨骼肌的力学测试系统，以全面描述肌肉收缩的力学，同时测量肌节动力学。这样的系统无法在商业上购买，我们建议购买所需的系统组件并自行构建系统。该系统的独特之处在于，我们将能够在整个肌肉收缩过程中可视化单个肌节，并量化瞬时肌节长度、肌节长度不均匀性以及整个肌肉中单个肌节的动态相互作用，从而为肌肉生理学家和生物力学家提供相关且目前无法获得的信息。***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，如等距力-长度关系，偏心收缩后的残余力增强，以及肌节长度和力在下降肢上的不稳定性。虽然其中一些想法已经被考虑了几十年，但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本地和国际同事协商后提出了这个想法，一旦这个系统得到全面实施，测试和验证，他们就会为我们的具体项目派遣学生。试验结果使用静态，稳态和被动肌肉使用二次谐波产生显微镜，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. **