Corticofugal Modulation of Initial Sound Processing in the Brain
Corticofugal Modulation of Initial Sound Processing in the Brain
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DOI：
10.1523/jneurosci.3972-08.2008
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发表时间：
2008-11-05
影响因子：
5.3
通讯作者：
Yan, Jun
中科院分区：
文献类型：
--
作者：
Luo, Feng;Wang, Qianzhou;Yan, Jun
大脑以自上而下的加工方式有选择地提取最相关的信息。离皮质系统，一种“反向投射系统”，是否构成了这种自上而下选择的神经基础？在这里，我们展示了如何与500 nA的电脉冲的听觉皮层的局部激活影响的听觉信息处理的耳蜗核（CN），直接从耳朵接收几乎未经处理的信息。我们发现，皮层激活增加的反应幅度和缩短生理匹配的CN神经元的反应时间，而不匹配的CN神经元的反应幅度和延长的反应时间。此外，皮层激活移动的频率调谐不匹配CN神经元对那些激活的皮层神经元。我们的数据表明，皮层激活选择性地增强特定听觉信息的神经处理，并根据听觉皮层中编码的声音频率在大脑的第一处理水平上减弱其他信息。听觉皮层显然实现了一种长距离反馈机制，以选择或过滤来自耳朵的传入信号。
The brain selectively extracts the most relevant information in top-down processing manner. Does the corticofugal system, a "back projection system," constitute the neural basis of such top-down selection? Here, we show how focal activation of the auditory cortex with 500 nA electrical pulses influences the auditory information processing in the cochlear nucleus (CN) that receives almost unprocessed information directly from the ear. We found that cortical activation increased the response magnitudes and shortened response latencies of physiologically matched CN neurons, whereas decreased response magnitudes and lengthened response latencies of unmatched CN neurons. In addition, cortical activation shifted the frequency tunings of unmatched CN neurons toward those of the activated cortical neurons. Our data suggest that cortical activation selectively enhances the neural processing of particular auditory information and attenuates others at the first processing level in the brain based on sound frequencies encoded in the auditory cortex. The auditory cortex apparently implements a long-range feedback mechanism to select or filter incoming signals from the ear.