HAIR CELL REGENERATION--FUNCTIONAL SIGNIFICANCE

我们知道，至少有一些种类的鸟类保留了 在创伤后或衰老过程中失去的毛细胞。 在鹌鹑中， 然而，第八神经的神经节细胞数量减少， 即使这些毛细胞被替换了。 这些 结果表明，如果这些新的头发， 神经细胞受到神经支配并影响听觉功能。 目前 关于毛细胞再生对hering的影响知之甚少。 本提案比较了功能性后果（即对 听力）的毛细胞再生后，声损伤在三个 不同种类的鸟。 行为测试包括10项 心理声学测量，包括新的、全面的形状测量， 和时间窗的形状。 这些都 从未在鸟类中测量过。 心理声学措施将是 与相同动物的解剖学研究平行进行 以及在相同条件下暴露的动物， 毛细胞，神经支配模式，静纤毛，盖膜，和 血管盖 关于鹌鹑的试验数据表明， 毛细胞再生的基端的乳头吻合良好 与TTS恢复的时间进程有关。 比较法 这个问题应该能让我们更深入地了解 与那些没有康复的人相比。 其他行为实验 发声和发声学习的精确度将评估 解剖学和心理声学恢复是在支持其他自然， 对沟通很重要的依赖行为。 这些 实验将提供我们所知的最全面的数据库， 替代外周感觉上皮的功能后果 成熟的动物 这些结果将与 神经和感觉细胞再生的未来研究 耳蜗及其与听力的相关性。 我们希望这些发现也能 与未来任何替代感觉上皮的努力都有关系， 哺乳动物的耳蜗，希望也是人类的耳蜗

We know that at least some species of birds retain the capacity to replace hair cells which are lost following trauma or during aging. In quail, the ganglion cells of the VIIIth nerve, however, are reduced in number following hair cell loss, even though those hair cells are replaced. These results suggest that some active process must be involved if these new hair cells are to be innervated and influence auditory function. Currently little is known about the consequences of hair cell regeneration on hering. This proposal compares the functional consequences (i.e. the effects on hearing) of hair cell regeneration following acoustic insult in three different species of birds. The battery of behavioral tests consists of 10 psychoacoustic measures including new, comprehensive measures of the shape of the auditory filter and the shape of the temporal window. These have never been measured before in birds. Psychoacoustic measures will be conducted in parallel with anatomical investigations on the same animals and animals exposed under identical conditions to assess changes occurring to hair cells, innervation patterns, stereocilia, tectorial membrane, and tegmentum vasculosum. Pilot data on quail have shown that the time course of hair cell regeneration at the basal end of the papilla coincides well with the time course of recovery from TTS. The comparative approach to this problem should provide insight into the anatomical changes important for recovery versus those that are not. Other behavioral experiments on the precision of vocal production and vocal learning will assess how well anatomical and psychoacoustic recovery is in supporting other natural, auditory-dependent behaviors important for communication. These experiments will provide the most comprehensive data base we know of on the functional consequences of replacing the peripheral sensory epithelium in a mature animal. These results will have relevance for the direction of future studies on regeneration of the nerve and sensory cells in the cochlea and their relevance for hearing. We expect these findings to also have relevance for any future efforts to replace the sensory epithelium in mammalian and, hopefully, the human cochlea.