Hudspeth A
Howard Hughes Medical Institute, Laboratory of Sensory Neuroscience, Box 314, The Rockefeller University, 1230 York Avenue, New York, New York 10021-6399, USA.
Curr Opin Neurobiol. 1997 Aug;7(4):480-6. doi: 10.1016/s0959-4388(97)80026-8.
Unlike any other known sensory receptor, the hair cell uses positive feedback to augment the stimulus to which it responds. In the internal ears of many vertebrates, hair cells amplify the inputs to their mechanosensitive hair bundles. Outer hair cells of the mammalian cochlea display a unique form of somatal motility that may underlie their contribution to amplification. In other receptor organs, hair cells may effect amplification by hair-bundle movements driven by the activity of myosin or of transduction channels. Recent work has demonstrated the presence of several myosin isozymes in hair bundles, confirmed that bundles display myosin ATPase activity, and shown that the work performed by myosin molecules could account for one aspect of the amplificatory process.
与其他任何已知的感觉受体不同，毛细胞利用正反馈来增强其对刺激的反应。在许多脊椎动物的内耳中，毛细胞会放大传入其机械敏感毛束的信号。哺乳动物耳蜗的外毛细胞表现出一种独特的体细胞运动形式，这可能是它们对放大作用做出贡献的基础。在其他感觉器官中，毛细胞可能通过肌球蛋白或转导通道的活动驱动毛束运动来实现放大作用。最近的研究表明，毛束中存在几种肌球蛋白同工酶，证实了毛束具有肌球蛋白ATP酶活性，并表明肌球蛋白分子所做的功可以解释放大过程的一个方面。
