Dinklo Theo, Meulenberg Cécil J W, van Netten Sietse M
Department of Neurobiophysics, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, Netherlands.
J Assoc Res Otolaryngol. 2007 Jun;8(2):167-82. doi: 10.1007/s10162-007-0080-0. Epub 2007 Mar 27.
The investigation of small physiological mechano-sensory systems, such as hair cells or their accessory structures in the inner ear or lateral line organ, requires mechanical stimulus equipment that allows spatial manipulation with micrometer precision and stimulation with amplitudes down to the nanometer scale. Here, we describe the calibration of a microfluid jet produced by a device that was designed to excite individual cochlear hair cell bundles or cupulae of the fish superficial lateral line system. The calibration involves a precise definition of the linearity and time- and frequency-dependent characteristics of the fluid jet as produced by a pressurized fluid-filled container combined with a glass pipette having a microscopically sized tip acting as an orifice. A procedure is described that can be applied during experiments to obtain a fluid jet's frequency response, which may vary with each individual glass pipette. At small orifice diameters (<15 mum), the fluid velocity of the jet is proportional to the displacement of the piezoelectric actuator pressurizing the container's volume and is suitable to stimulate the hair bundles of sensory hair cells. With increasing diameter, the fluid jet velocity becomes proportional to the actuator's velocity. The experimentally observed characteristics can be described adequately by a dynamical model of damped fluid masses coupled by elastic components.
对小型生理机械感觉系统进行研究，比如内耳或侧线器官中的毛细胞或其附属结构，需要能够实现微米级精度空间操作且刺激幅度低至纳米级的机械刺激设备。在此，我们描述了一种由专门设计用于激发单个耳蜗毛细胞束或鱼类浅表侧线系统的杯状嵴的装置所产生的微流体射流的校准。校准涉及精确确定由加压流体填充容器与具有微观尺寸尖端作为孔口的玻璃移液管相结合所产生的流体射流的线性度以及与时间和频率相关的特性。描述了一种可在实验过程中应用以获得流体射流频率响应的程序，该频率响应可能因每个玻璃移液管而异。在小孔径（<15 微米）时，射流的流体速度与对容器体积加压的压电致动器的位移成正比，适合刺激感觉毛细胞的毛束。随着直径增加，流体射流速度与致动器的速度成正比。实验观察到的特性可以通过由弹性部件耦合的阻尼流体质量的动力学模型来充分描述。
