Assad J A, Shepherd G M, Corey D P
Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115.
Neuron. 1991 Dec;7(6):985-94. doi: 10.1016/0896-6273(91)90343-x.
An attractive hypothesis for hair-cell transduction is that fine, filamentous "tip links" pull directly on mechanically sensitive ion channels located at the tips of the stereocilia. We tested the involvement of tip links in the transduction process by treating bundles with a BAPTA-buffered, low-Ca2+ saline (10(-9) M). BAPTA abolished the transduction current in a few hundred milliseconds. BAPTA treatment for a few seconds eliminated the tip links observed by either scanning or transmission electron microscopy. BAPTA also eliminated the voltage-dependent movement and caused a positive bundle displacement of 133 nm, in quantitative agreement with a model for regulation of tension. We conclude that tip links convey tension to the transduction channels of hair cells.
一种关于毛细胞转导的诱人假说是，纤细的丝状“顶端连接”直接拉动位于静纤毛顶端的机械敏感离子通道。我们通过用BAPTA缓冲的低钙盐溶液（10⁻⁹ M）处理毛束来测试顶端连接在转导过程中的作用。BAPTA在几百毫秒内消除了转导电流。用BAPTA处理几秒钟就消除了通过扫描或透射电子显微镜观察到的顶端连接。BAPTA还消除了电压依赖性运动，并导致毛束正向位移133 nm，这与张力调节模型在定量上是一致的。我们得出结论，顶端连接将张力传递给毛细胞的转导通道。
