ION CHANNELS AND DEVELOPMENT OF HAIR CELLS

描述：通过声音或加速度刺激内耳 引起耳毛细胞的电反应，耳毛细胞是耳朵的感觉感受器。 在许多听觉器官中，每个毛细胞的反应都是高度敏感的。 电调谐介导的刺激频率 细胞膜上的离子通道 离子通道也参与了 突触传递素的释放刺激神经纤维，反过来， 将信息传递到大脑中。 两种细胞中离子通道的显著性 信号过程激发了对结构的研究 以及这些通道在毛细胞中的功能。 毛细胞高度 具有独特细胞器的专门细胞，用于捕获刺激 能量和控制突触递质的释放。 不幸的是， 耳朵中毛细胞的数量很少，这极大地阻碍了对 构成这些细胞器的蛋白质， 特性. 利用分子生物学的工具， 实验包括鉴定毛发中独特表达的基因 细胞，以及那些只在支持细胞中活跃的细胞。 这种方法 应该提供一个更好的了解蛋白质，占 毛细胞的特殊属性 人类内耳的毛细胞被许多遗传因素破坏， 条件，感染，响亮的声音，耳毒性药物和老化。 直到 最近，没有证据表明受体细胞的丢失是由于 这些过程可以被取代。 然而，在过去十年中， 研究小组已经证明， 鸟类甚至哺乳动物。 拟议的早期阶段研究 内耳的发育应该能显示出哪些化学因素 在决定创造新的毛细胞和每个毛细胞的重要性 成熟 更具体地说，关键的化学信使将是 通过使用病毒干扰其正常功能而识别。 头发 细胞可能是通过暴露于生长因子来维持的， 其他细胞类型。 类似的技术还将显示哪些因素 在这方面特别重要。 这些研究将提供 有助于促进生存，修复和最终 替代人类内耳中的毛细胞。

DESCRIPTION: Stimulation of the internal ear by a sound or an acceleration evokes an electrical response in hair cells, the ear's sensory receptors. In many auditory organs , each hair cell's response is highly sensitive to the frequency of stimulation as a result of electrical tuning mediated by ion channels in the cell's membrane. Ion channels are also involved in the release of synaptic transmitter that excites nerve fibers, which in turn, carry information into the brain. The prominence of ion channels in both signalling processes motivates the proposed investigations of the structures and function of such channels in hair cells. Hair cells are highly specialized cells endowed with unique organelles for the capture of stimulus energy and for the control of synaptic transmitter release. Unfortunately, the small number of hair cells in an ear greatly impedes the study of the proteins that constitute these organelles and account for their unique properties. Making use of the tools of molecular biology, the proposed experiments involve the identification of genes uniquely expressed in hair cells, as well as those active only in supporting cells. This approach should provide a better understanding of the proteins that account for the hair cell's specialized properties. Hair cells of the human internal ear are damaged by numerous genetic conditions, infections, loud sounds, ototoxic drugs, and aging. Until recently, there was no evidence that the receptor cells lost as a result of such processes could be replaced. During the past decade, however, several research groups have demonstrated hair cell regeneration in the ears of birds and even mammals. The proposed studies of early stages in the internal ear's development should indicate which chemical factors are of importance in the decision to create new hair cells and in each hair cell's maturation. More specifically, crucial chemical messengers will be identified by use of viruses to interfere with their normal functions. Hair cells are probably maintained by exposure to growth factors supplied by other cell types. Similar techniques will additionally show which factors are of particular importance in this context. These studies should provide information useful in promoting the survival, repair, and eventual replacement of hair cells in the human internal ear.