Experience-dependent corticofugal adjustment of midbrain frequency map in bat auditory system
Experience-dependent corticofugal adjustment of midbrain frequency map in bat auditory system
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DOI：
10.1073/pnas.95.21.12663
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发表时间：
1998-10-13
影响因子：
11.1
通讯作者：
Suga, N
中科院分区：
文献类型：
--
作者：
Gao, E;Suga, N
最近关于皮质调节听觉信息处理的研究表明，皮质神经元既介导高度集中的正反馈给“匹配”特定声学参数的皮质下神经元，也介导“不匹配”皮质下神经元的广泛侧抑制。这种调节和改善皮层下信息处理的皮质功能被称为自我中心选择。自我中心选择增强了中枢听觉系统中频繁出现的信号的神经表征。在本研究中，我们假设自我中心选择根据基于联想学习的听觉经验调整下丘（IC）的频率图。为了验证这一假设，我们对蝙蝠进行了声刺激和腿部电刺激的配对，因为这种配对刺激使动物了解到声刺激在行为上是重要的，并根据获得的声刺激的重要性做出行为和神经调整。我们发现，声刺激单独引起IC频率图的变化；当声刺激与电刺激相结合时，这种IC的变化会变得更大；collcolla的变化是由皮质系统介导的；并且IC本身可以在一段时间内维持由皮质系统引起的变化，我们的数据支持这一假设。
Recent studies of corticofugal modulation of auditory information processing indicate that cortical neurons mediate both a highly focused positive feedback to subcortical neurons "matched" in tuning to a particular acoustic parameter and a widespread lateral inhibition to "unmatched" subcortical neurons. This cortical function for the adjustment and improvement of subcortical information processing is called egocentric selection. Egocentric selection enhances the neural representation of frequently occurring signals in the central auditory system. For our present studies performed with the big brown bat (Eptesicus fuscus),we hypothesized that egocentric selection adjusts the frequency map of the inferior colliculus (IC) according to auditory experience based on associative learning. To test this hypothesis, we delivered acoustic stimuli paired with electric leg stimulation to the bat, because such paired stimuli allowed the animal to learn that the acoustic stimulus was behaviorally important and to make behavioral and neural adjustments based on the acquired importance of the acoustic stimulus, We found that acoustic stimulation alone evokes a change in the frequency map of the IC; that this change in the IC becomes greater when the acoustic stimulation is made behaviorally relevant by pairing it with electrical stimulation; that the collicular change is mediated by the corticofugal system; and that the IC itself can sustain the change evoked by the corticofugal system for some time, Our data support the hypothesis.