Force Clamp Systems for Evaluation of Mechanotransduction

描述（由申请人提供）：这项工作提出了一个完全集成的方法来研究的机电转换的感觉，触摸，并专注于开发一种新的微系统为基础的工具，即，力钳，使用适当规模的piezeoristive的杠杆作为直接力传感器（PR力钳）。该提案包括充分表征第一代设备的能力，设计和构建能够在更高带宽下操作的第二代设备，以及使用这些设备通过模型机械感受器细胞（神经支配线虫的体壁的触觉感受器神经元）来分析和建模自由传递和机械-电转导的生物力学。C. elegans是一个很好的生物平台，用于开发所提出的工具，这可能会在其他机械感觉细胞，包括脊椎动物毛细胞和背根神经节的机械-电转导的研究中找到应用。一组只有六个触摸感受器神经元负责对触摸的行为反应。elegans（与脊椎动物中的数万个相比），并且这样的反应是通过施加到体壁的力激活MEC-4通道复合物而引发的。原型力钳系统使用PR力钳和压电致动器与可编程控制器，以施加校准的纳米到微牛顿点载荷分布与> 1 kHz的带宽。这项工作的一个关键和创新的方面是整合的PR力钳与膜片钳电生理同步力位移生理记录。该技术将能够首次直接测量在机械-电转换期间可能发生的组织刚度的动态变化并引起适应。与公共卫生的相关性。触觉可能会因遗传和后天疾病（包括艾滋病和糖尿病）以及化疗药物而退化。据估计，这种周围感觉神经病的并发症每年的医疗保健费用超过40亿美元。尽管如此，触觉及其在疾病中的退化仍然知之甚少。在这项工作中开发的研究工具有可能大大提高我们的认识。

DESCRIPTION (provided by applicant): This work proposes a fully integrated approach to the study of mechano-electrical transduction in the sense of touch and focuses on the development of a novel microsystems-based tool-namely, a force clamp that uses appropriately-scaled piezeoresistive cantilevers as direct force sensors (PR force clamp). The proposal includes work to fully characterize the capabilities of a first-generation device, to design and build a second- generation device capable of operating at higher bandwidth, and to use these devices to analyze and model the biomechanics offeree transfer and mechano-electrical transduction by a model mechahoreceptor cell, the touch receptor neurons that innervate the body wall of the nematode Caenorhabditis elegans. C. elegans is an excellent biological platform for developing the proposed tools, which are likely to find application in the study of mechano-electrical transduction in other mechanosensory cells including vertebrate hair cells and dorsal root ganglion. A set of only six touch receptor neurons is responsible for behavioral responses to touch in C. elegans (compared to tens of thousands in vertebrates) and such responses are initiated by activation of the MEC-4 channel complex by forces applied to the body wall. Prototype force clamp systems use PR force clamps and piezoelectric actuators with programmable controllers to apply calibrated nano- to micro-Newton point load profiles with > 1kHz bandwidth. A critical and innovative aspect of this work is the integration of the PR force clamp with patch-clamp electrophysiology for synchronous force-displacement- physiological recordings. This technology will enable the first direct measurement of dynamic changes in tissue stiffness that may occur during mechano-electrical transduction and give rise to adaptation. Relevance to public health. The sense of touch can be degraded by both inherited and acquired disease, including AIDS and diabetes, as well as by chemotherapeutic drugs. Complications from such peripheral sensory neuropathies are estimated to cost more than $4 billion annual in health care costs. Despite this, the sense of touch and its degradation in disease remain poorly understood. The research tools developed in the course of this work have the potential to significantly advance our understanding.