Selective Increase in Representations of Sounds Repeated at an Ethological Rate
Selective Increase in Representations of Sounds Repeated at an Ethological Rate
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DOI：
10.1523/jneurosci.0365-09.2009
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发表时间：
2009-04-22
影响因子：
5.3
通讯作者：
Bao, Shaowen
中科院分区：
文献类型：
--
作者：
Kim, Heesoo;Bao, Shaowen
在发育早期暴露在声音中会导致这些声音的皮质代表扩大，从而导致普遍认为刺激代表的大小随着刺激暴露的增加而增加。然而，仅仅根据刺激物的流行程度来表示刺激物可能效率低下，因为许多频繁的环境声音在行为上是无关的。在这里，我们表明，皮质可塑性不仅取决于暴露时间，还取决于刺激集的时间调制率。我们检测了早期暴露于7 kHz音调，以慢(2赫兹)、快(15赫兹)或行为学(6赫兹)频率重复时所诱导的皮质可塑性。某些老鼠的叫声是在6赫兹附近调制的。我们发现，仅在行为学速率饲养的动物中，7 kHz的频谱表示增加，而在慢速和快速率饲养的动物中，皮质神经元的夹带改善。这种光谱可塑性的时间速率依赖关系可以作为一种过滤机制，选择性地扩大物种特定发声的表征。此外，我们的结果表明，根据输入刺激的统计特性，光谱塑性和时间塑性可以分开进行。
Exposure to sounds during early development causes enlarged cortical representations of those sounds, leading to the commonly held view that the size of stimulus representations increases with stimulus exposure. However, representing stimuli based solely on their prevalence may be inefficient, because many frequent environmental sounds are behaviorally irrelevant. Here, we show that cortical plasticity depends not only on exposure time but also on the temporal modulation rate of the stimulus set. We examined cortical plasticity induced by early exposure to 7 kHz tone pips repeated at a slow (2 Hz), fast ( 15 Hz), or ethological ( 6 Hz) rate. Certain rat calls are modulated near 6 Hz. We found that spectral representation of 7 kHz increased only in the ethological-rate-reared animals, whereas improved entrainment of cortical neurons was seen in animals reared in the slow- and fast-rate condition. This temporal rate dependence of spectral plasticity may serve as a filtering mechanism to selectively enlarge representations of species-specific vocalizations. Furthermore, our results indicate that spectral and temporal plasticity can be separately engaged depending on the statistical properties of the input stimuli.