Santos-Sacchi Joseph
Department of Surgery (Otolaryngology) and Section of Neurobiology, BML 244, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA.
Pflugers Arch. 2002 Dec;445(3):331-6. doi: 10.1007/s00424-002-0928-4. Epub 2002 Sep 6.
The outer hair cell (OHC) of the mammalian inner ear is a highly partitioned neuroepithelial cell whose lateral membrane is devoted to electromotility, a fast mechanical length change owing to the motor protein, prestin. Spatially restricted measures of prestin-derived nonlinear capacitance or gating charge, using either electrical amputation or discrete membrane mechanical deformation, were used to determine that functional variation exists within the extensive lateral membrane of the cell. This was evidenced by variation in the motor's operating voltage range and sensitivity among microdomains within the lateral membrane. That is, localized regions of the membrane evidenced Boltzmann distributions of motor charge whose midpoint voltage and slope differed from those obtained for the whole cell. These data highlight the functional independence of microdomains and imply that measured whole cell characteristics may differ from the microscopic characteristics of elementary motors.
哺乳动物内耳的外毛细胞是一种高度分区的神经上皮细胞，其外侧膜专门用于电运动，这是一种由马达蛋白（prestin）引起的快速机械长度变化。通过电切除或离散膜机械变形等方法，对源自prestin的非线性电容或门控电荷进行空间限制测量，以确定该细胞广泛的外侧膜内存在功能差异。这一点在外侧膜内微区之间马达的工作电压范围和灵敏度变化中得到了证明。也就是说，膜的局部区域呈现出马达电荷的玻尔兹曼分布，其中点电压和斜率与整个细胞的不同。这些数据突出了微区的功能独立性，并表明测得的全细胞特征可能与基本马达的微观特征不同。
