Razak Khaleel A, Fuzessery Zoltan M
Department of Psychology and Graduate Neuroscience Program, University of California, Riverside, California.
Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming.
Dev Neurobiol. 2015 Oct;75(10):1125-39. doi: 10.1002/dneu.22226. Epub 2014 Aug 28.
Studies of birdsongs and neural selectivity for songs have provided important insights into principles of concurrent behavioral and auditory system development. Relatively little is known about mammalian auditory system development in terms of vocalizations or other behaviorally relevant sounds. This review suggests echolocating bats are suitable mammalian model systems to understand development of auditory behaviors. The simplicity of echolocation calls with known behavioral relevance and strong neural selectivity provides a platform to address how natural experience shapes cortical receptive field (RF) mechanisms. We summarize recent studies in the pallid bat that followed development of echolocation calls and cortical processing of such calls. We also discuss similar studies in the mustached bat for comparison. These studies suggest: (1) there are different developmental sensitive periods for different acoustic features of the same vocalization. The underlying basis is the capacity for some components of the RF to be modified independent of others. Some RF computations and maps involved in call processing are present even before the cochlea is mature and well before use of echolocation in flight. Others develop over a much longer time course. (2) Normal experience is required not just for refinement, but also for maintenance, of response properties that develop in an experience independent manner. (3) Experience utilizes millisecond range changes in timing of inhibitory and excitatory RF components as substrates to shape vocalization selectivity. We suggest that bat species and call diversity provide a unique opportunity to address developmental constraints in the evolution of neural mechanisms of vocalization processing.
对鸟鸣以及鸟鸣的神经选择性的研究为并行的行为和听觉系统发育原理提供了重要见解。就发声或其他与行为相关的声音而言，人们对哺乳动物听觉系统发育的了解相对较少。这篇综述表明，回声定位蝙蝠是理解听觉行为发育的合适哺乳动物模型系统。具有已知行为相关性和强大神经选择性的回声定位叫声的简单性提供了一个平台，以解决自然经验如何塑造皮层感受野（RF）机制的问题。我们总结了近期在苍白蝙蝠身上进行的有关回声定位叫声发育及其皮层处理的研究。我们还讨论了在髯蝠身上进行的类似研究以供比较。这些研究表明：（1）同一发声的不同声学特征存在不同的发育敏感期。其潜在基础是感受野的某些成分能够独立于其他成分进行修改。甚至在耳蜗成熟之前以及在飞行中使用回声定位之前很久，参与叫声处理的一些感受野计算和图谱就已存在。其他的则在更长的时间过程中发育。（2）正常的经验不仅对于以独立于经验的方式发育的反应特性的完善是必需的，而且对于其维持也是必需的。（3）经验利用抑制性和兴奋性感受野成分在毫秒范围内的时间变化作为塑造发声选择性的基础。我们认为蝙蝠物种和叫声的多样性为解决发声处理神经机制进化中的发育限制提供了独特的机会。
