Laboratory of Cochlear Development, NIDCD, NIH, Bethesda, MD 20892, USA.
Hear Res. 2011 Jun;276(1-2):2-15. doi: 10.1016/j.heares.2011.01.011. Epub 2011 Jan 27.
Acoustic frequency analysis plays an essential role in sound perception, communication and behavior. The auditory systems of most vertebrates that perceive sounds in air are organized based on the separation of complex sounds into component frequencies. This process begins at the level of the auditory sensory epithelium where specific frequencies are distributed along the tonotopic axis of the mammalian cochlea or the avian/reptilian basilar papilla (BP). Mechanical and electrical mechanisms mediate this process, but the relative contribution of each mechanism differs between species. Developmentally, structural and physiological specializations related to the formation of a tonotopic axis form gradually over an extended period of time. While some aspects of tonotopy are evident at early stages of auditory development, mature frequency discrimination is typically not achieved until after the onset of hearing. Despite the importance of tonotopic organization, the factors that specify unique positional identities along the cochlea or basilar papilla are unknown. However, recent studies of developing systems, including the inner ear provide some clues regarding the signalling pathways that may be instructive for the formation of a tonotopic axis.
声频分析在声音感知、通讯和行为中起着至关重要的作用。大多数在空气中感知声音的脊椎动物的听觉系统是基于将复杂的声音分离成组成频率来组织的。这个过程始于听觉感觉上皮，在那里特定的频率沿着哺乳动物耳蜗或鸟类/爬行动物基底膜（BP）的音调拓扑轴分布。机械和电气机制介导了这个过程，但每个机制的相对贡献在不同的物种中有所不同。在发育过程中，与音调拓扑形成相关的结构和生理特征逐渐形成。虽然在听觉发育的早期阶段就可以看到音调拓扑的某些方面，但直到听觉开始后才能实现成熟的频率辨别。尽管音调组织很重要，但沿耳蜗或基底膜指定独特位置身份的因素尚不清楚。然而，最近对包括内耳在内的发育系统的研究为可能对音调拓扑形成有指导作用的信号通路提供了一些线索。
