Sensitivity to spectral interaural intensity difference cues in space-specific neurons of the barn owl
Sensitivity to spectral interaural intensity difference cues in space-specific neurons of the barn owl
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DOI：
10.1007/s00359-003-0476-1
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发表时间：
2004-02-01
影响因子：
2.1
通讯作者：
Arthur, BJ
中科院分区：
文献类型：
--
作者：
Arthur, BJ
谷仓猫头鹰利用耳间强度差异来定位垂直平面上的声音。在给定高度处，耳间强度差提示的幅度随频率变化，从而创建作为该方向特征的耳间强度差提示频谱。为了测试空间特异性细胞是否对光谱耳间强度差线索敏感，对下丘外核中的单个神经元在多个不同频率下获取纯音耳间强度差调谐曲线。对于给定的神经元，引发最大响应的耳间强度差异（最佳耳间强度差异）随刺激频率的变化而变化，平均最大差异为 9.4+/-6.2 dB。这些神经偏好的耳间强度差的频谱模式与空间受限区域的声学耳间强度差频谱特征表现出高度的相似性。与耳间强度差频谱与首选频谱匹配的刺激相比，具有倒置频谱的刺激引起较小的反应，表明空间特异性神经元对频谱的形状敏感。潜在的机制是抑制与首选频谱模式不同的频率特定的耳间强度差异。总的来说，这些数据表明，空间特异性神经元对耳间光谱强度差异线索敏感，并支持行为仓鸮使用此类线索来精确定位声音的观点。
Barn owls use interaural intensity differences to localize sounds in the vertical plane. At a given elevation the magnitude of the interaural intensity difference cue varies with frequency, creating an interaural intensity difference spectrum of cues which is characteristic of that direction. To test whether space-specific cells are sensitive to spectral interaural intensity difference cues, pure-tone interaural intensity difference tuning curves were taken at multiple different frequencies for single neurons in the external nucleus of the inferior colliculus. For a given neuron, the interaural intensity differences eliciting the maximum response (the best interaural intensity differences) changed with the frequency of the stimulus by an average maximal difference of 9.4+/-6.2 dB. The resulting spectral patterns of these neurally preferred interaural intensity differences exhibited a high degree of similarity to the acoustic interaural intensity difference spectra characteristic of restricted regions in space. Compared to stimuli whose interaural intensity difference spectra matched the preferred spectra, stimuli with inverted spectra elicited a smaller response, showing that space-specific neurons are sensitive to the shape of the spectrum. The underlying mechanism is an inhibition for frequency-specific interaural intensity differences which differ from the preferred spectral pattern. Collectively, these data show that space-specific neurons are sensitive to spectral interaural intensity difference cues and support the idea that behaving barn owls use such cues to precisely localize sounds.