STIFFNESS OF SENSORY HAIR BUNDLES IN THE SACCULUS OF THE FROG
STIFFNESS OF SENSORY HAIR BUNDLES IN THE SACCULUS OF THE FROG
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DOI：
10.1016/0378-5955(86)90178-4
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发表时间：
1986-01-01
期刊：
影响因子：
2.8
通讯作者：
ASHMORE, JF
中科院分区：
文献类型：
--
作者：
HOWARD, J;ASHMORE, JF
使用校准的石英探针测量来自青蛙球囊的毛细胞的单个毛束的刚度。对于在任一方向上高达1 μ m的位移（高达± 1 μ m的角偏转），0.13 rad），刚度是恒定的。刚度并不取决于纤维束是处于压缩状态还是拉伸状态。在第一近似下，刚度与毛细胞顶面上方的力的施加高度的平方成反比。这与静纤毛在毛束内围绕其插入表皮板的点的枢转一致。束的枢转刚度近似地与束的横截面积成比例，因此与构成束的静纤毛的数量成比例。据推测，总束刚度的动纤毛的贡献是小的。得出的结论是，施加的力几乎相等的共享之间的所有静纤毛，在束偏转相邻静纤毛之间有相对剪切，每个静纤毛贡献了0.49 ±-的枢轴刚度。0.15. times. 10-15牛顿m.cntdot. rad-1。静纤毛测得的刚度与主要在锥形插入点弯曲的结构一致。这些数据也与肌动蛋白丝之间几乎没有交联一致。本文还讨论了毛束中静纤毛之间联系的性质。
The stiffness of individual hair bundles of hair cells from the frog sacculus was measured using calibrated quartz probes. For displacements of up to 1 .mu.m in either direction (angular deflections up to .+-. 0.13 rad) the stiffness was constant. The stiffness did not depend on whether the bundle was in compression or tension. At first approximation, the stiffness was inversely proportional to the square of the height of application of the force above the apical surface of the hair cell. This is consistent with pivoting of the stereocilia within the hair bundle about their points of insertion into the cuticular plate. The pivotal stiffness of the bundle was approximately proportional to the bundle''s cross-sectional area and hence to the number of stereocilia of which it is composed. It is inferred that the contribution of the kinocilium to the total bundle stiffness is small. It is concluded that applied forces are shared almost equally amongst all stereocilia, that there is relative shear between neighbouring stereocilia during bundle deflection and that each stereocilium contributes a pivotal stiffness of 0.49 .+-. 0.15 .times. 10-15 N .cntdot. m .cntdot. rad-1. The measured stiffness of the stereocilium is consistent with a structure which bends mainly at the tapering insertion point. The data are also consistent with little cross-linking here between actin filaments. The nature of the links between stereocilia in the hair bundle is also discussed.