A function for binaural integration in auditory grouping and segregation in the inferior colliculus.
A function for binaural integration in auditory grouping and segregation in the inferior colliculus.
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DOI：
10.1152/jn.00472.2014
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发表时间：
2015-03
影响因子：
2.5
通讯作者：
K. Nakamoto;T. M. Shackleton;David Magezi;A. Palmer
中科院分区：
文献类型：
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作者：
K. Nakamoto;T. M. Shackleton;David Magezi;A. Palmer
本文报道了豚鼠下丘（IC）神经元对双耳复合声刺激的反应。为了评估声音分离和分组的和声线索的双耳整合，测量了对呈现给每只耳朵的具有不同基频的和声复合体的响应。分别对左右耳同时给予基频为125 Hz和145 Hz的谐波刺激，记录IC中央核中特征频率>2 kHz的96个神经元。在这些单位中，70个单位在整个刺激过程中不断作出反应，并在对侧耳的刺激下兴奋。根据对放电率的影响，同侧耳的刺激可兴奋（EE：14%; 10/70）、抑制（EI：33%; 23/70）或无显著影响（EO：53%; 37/70）。神经元相位锁定到每个耳朵的时间包络，根据信号水平的不同程度。许多细胞（主要是EO）的反应占主导地位的对侧刺激。另一组（主要是EI）同步对侧刺激，并抑制同侧刺激的相位方式。第三组在双耳同步刺激（主要是EE）。最后，只有当每只耳朵的波形峰重合时，一组人才有反应。我们的结论是，这些神经元代表不同的信息“流”，但表现出的反应，而不是编码的刺激，如音高的一个功能的修改。
Responses of neurons to binaural, harmonic complex stimuli in urethane-anesthetized guinea pig inferior colliculus (IC) are reported. To assess the binaural integration of harmonicity cues for sound segregation and grouping, responses were measured to harmonic complexes with different fundamental frequencies presented to each ear. Simultaneously gated harmonic stimuli with fundamental frequencies of 125 Hz and 145 Hz were presented to the left and right ears, respectively, and recordings made from 96 neurons with characteristic frequencies >2 kHz in the central nucleus of the IC. Of these units, 70 responded continuously throughout the stimulus and were excited by the stimulus at the contralateral ear. The stimulus at the ipsilateral ear excited (EE: 14%; 10/70), inhibited (EI: 33%; 23/70), or had no significant effect (EO: 53%; 37/70), defined by the effect on firing rate. The neurons phase locked to the temporal envelope at each ear to varying degrees depending on signal level. Many of the cells (predominantly EO) were dominated by the response to the contralateral stimulus. Another group (predominantly EI) synchronized to the contralateral stimulus and were suppressed by the ipsilateral stimulus in a phasic manner. A third group synchronized to the stimuli at both ears (predominantly EE). Finally, a group only responded when the waveform peaks from each ear coincided. We conclude that these groups of neurons represent different "streams" of information but exhibit modifications of the response rather than encoding a feature of the stimulus, like pitch.