VOLTAGE DEPENDENCE OF ADAPTATION AND ACTIVE BUNDLE MOVEMENT IN BULLFROG SACCULAR HAIR-CELLS
VOLTAGE DEPENDENCE OF ADAPTATION AND ACTIVE BUNDLE MOVEMENT IN BULLFROG SACCULAR HAIR-CELLS
复制标题
DOI：
10.1073/pnas.86.8.2918
复制
发表时间：
1989-04-01
影响因子：
11.1
通讯作者：
COREY, DP
中科院分区：
文献类型：
--
作者：
ASSAD, JA;HACOHEN, N;COREY, DP
牛蛙球囊的毛细胞以一种表明对到达转导通道的张力刺激的主动调节的方式适应维持的位移刺激。我们通过全细胞膜片钳记录和视频显微镜检查了分离毛细胞的适应。这些细胞中存在适应，并且依赖于细胞外钙。适应率以及静息电流位移曲线的位置也取决于膜电位，这表明钙进入细胞质到达其作用位点。突然超极化后，适应率在几毫秒内增加，表明钙位点位于钙进入的离子通道的几微米范围内。静息电流-位移曲线的电压依赖性，以及转导的“门弹簧”假说，预测了当细胞去极化时束远离动纤毛的运动。观察到了这一点。
Hair cells of the bullfrog sacculus adapt to maintained displacement stimuli in a manner that suggests an active regulation of the tension stimulus reaching transduction channels. We have examined adaptation in dissociated hair cells by whole-cell patch-clamp recording and video microscopy. Adaptation was present in these cells, and it depended on extracellular calcium. The adaptation rate-as well as the position of the resting current-displacement curve-also depended on membrane potential, suggesting that calcium passes into the cytoplasm to reach its site of action. After abrupt hyperpolarization, the adaptation rate increased within milliseconds, suggesting that the calcium site is within a few micrometers of the ion channels through which calcium enters. The voltage dependence of the resting current-displacement curve, together with the "gating springs" hypothesis for transduction, predicts movement of the bundle away from the kinocilium when the cell is depolarized. This was observed.