Vollrath Melissa A, Kwan Kelvin Y, Corey David P
Howard Hughes Medical Institute and Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Annu Rev Neurosci. 2007;30:339-65. doi: 10.1146/annurev.neuro.29.051605.112917.
Mechanical stimuli generated by head movements and changes in sound pressure are detected by hair cells with amazing speed and sensitivity. The mechanosensitive organelle, the hair bundle, is a highly elaborated structure of actin-based stereocilia arranged in precise rows of increasing height. Extracellular linkages contribute to its cohesion and convey forces to mechanically gated channels. Channel opening is nearly instantaneous and is followed by a process of sensory adaptation that keeps the channels poised in their most sensitive range. This process is served by motors, scaffolds, and homeostatic mechanisms. The molecular constituents of this process are rapidly being elucidated, especially by the discovery of deafness genes and antibody targets.
头部运动和声音压力变化产生的机械刺激能被毛细胞以惊人的速度和灵敏度检测到。机械敏感细胞器——毛束，是一种高度精细的结构，由基于肌动蛋白的静纤毛组成，这些静纤毛排列成精确的高度递增的排。细胞外连接有助于其凝聚，并将力传递给机械门控通道。通道开放几乎是瞬间的，随后是一个感觉适应过程，该过程使通道保持在最敏感的范围内。这个过程由马达、支架和稳态机制提供支持。这个过程的分子成分正在迅速被阐明，尤其是通过耳聋基因和抗体靶点的发现。
