Auditory topography and temporal response dynamics of canary caudal telencephalon
Auditory topography and temporal response dynamics of canary caudal telencephalon
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DOI：
10.1002/neu.20219
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发表时间：
2006-02-15
期刊：
影响因子：
--
通讯作者：
Vicario, DS
中科院分区：
文献类型：
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作者：
Terleph, TA;Mello, CV;Vicario, DS
为了定位鸣禽听觉线索的编码，在清醒的、受限制的金丝雀的尾部端脑的373个位置上，记录了对纯音刺激(250-5000赫兹)的多单位电生理反应。我们发现，从低频率刺激到高频刺激的背侧腹侧张力梯度从吻区L2延伸到尾部最尾部的中缝中核(NCM)，类似于金丝雀NCM中Zenk基因表达的频率依赖模式，以及其他鸣禽物种的电生理反应。然而，该地区的反应特征有所不同。在L2视野中，反应是强烈的、阶段性的，不习惯于重复呈现相同的刺激。在L2位置的一个重要子集中，调谐宽度在响应过程中变窄，然后在刺激偏移量处迅速终止。这些特性与许多非首选频率的抑制和反应频率的刺激后抑制有关。相反，NCM部位习惯于重复的正弦波，具有更宽的调谐和更低的幅度反应，很少显示抑制效应。NCM的调谐曲线也比L2场的调谐曲线平坦，而且往往是多峰的。此外，调谐宽度随着反应的展开而增加，在NCM中刺激后的兴奋通常是持续的。总而言之，金丝雀尾状内侧端脑的特定部分的反应特性不同，提示它们在听觉加工中的作用不同。具体地说，NCM特性可以允许跨多个光谱变化的刺激元素的响应集成，例如在鸟鸣期间发生的那些刺激元素。(C)2005年威利期刊公司。
To map the encoding of auditory cues in songbirds, multiunit electrophysiological responses to pure tone stimuli (250-5000 Hz) were recorded at 373 sites throughout the avian analogue of the mammalian auditory cortex in the caudal telencephalon of awake, restrained canaries. We found that a dorso-ventral tonotopic gradient from low to high frequency stimuli extends from the rostral field L2 to caudal-most caudo-medial nidopallium (NCM), similar to the frequency-dependent patterns of ZENK gene expression in canary NCM and to electrophysiological responses in other songbird species. However, response characteristics differ across the region. In field L2, responses are vigorous, phasic, and do not habituate to repeated presentations of the same stimulus. In an important subset of field L2 sites, tuning width narrows over the course of the response, which then terminates rapidly at stimulus offset. These properties are associated with inhibition at many nonpreferred frequencies and poststimulus inhibition at responsive frequencies. In contrast, NCM sites habituate to repeated sine waves, have wider tuning and lower amplitude responses, and rarely show inhibitory effects. Tuning curves in NCM are also flatter than those of field L2, and are often multi-peaked. In addition, tuning width increases as the response unfolds and poststimulus excitation is often sustained in NCM. In sum, specific parts of the canary caudo-medial telencephalon differ in their response properties, suggesting differential roles in auditory processing. NCM properties, in particular, may allow for response integration across multiple spectrally varying stimulus elements, such as those that occur during birdsong. (C) 2005 Wiley Periodicals, Inc.