Frequency discrimination and stimulus deviance in the inferior colliculus and cochlear nucleus.
Frequency discrimination and stimulus deviance in the inferior colliculus and cochlear nucleus.
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DOI：
10.3389/fncir.2012.00119
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发表时间：
2012
影响因子：
3.5
通讯作者：
Malmierca MS
中科院分区：
文献类型：
--
作者：
Ayala YA;Pérez-González D;Duque D;Nelken I;Malmierca MS
表现出刺激特异性适应(SSA)的听神经元减少了对普通音调的反应，而保持了对稀有音调的反应。我们记录了已知发生SSA的下丘(IC)的单位反应，并首次探索了大鼠耳蜗核(CN)的SSA。我们评估了SSA的一个重要功能结果，即频率可识别性依赖于感觉环境的程度。为此，纯音以奇怪的序列呈现，作为标准(高概率发生)或偏离(低概率发生)刺激。为了研究不同概率语境下的频率可区分性，我们改变了出现概率和声调之间的频率分离。根据信号检测理论，用棘波计数概率来估计神经元的敏感性。我们复制了这一发现，即IC中的许多神经元显示SSA，但我们在CN样本中没有观察到显著的SSA。我们的结论是，强SSA在CN中并不是一个普遍存在的现象。正如预测的那样，当刺激呈现在奇怪的背景下时，IC的频率辨别力增强，并且这种增强与神经元显示的SSA的程度相关。相反，CN神经元的频率辨别与刺激环境无关。我们的结果表明，SSA并不广泛分布在整个听觉通路上，并表明SSA提高了单个神经元的频率辨别能力，超出了它们的调谐曲线的预期。
Auditory neurons that exhibit stimulus-specific adaptation (SSA) decrease their response to common tones while retaining responsiveness to rare ones. We recorded single-unit responses from the inferior colliculus (IC) where SSA is known to occur and we explored for the first time SSA in the cochlear nucleus (CN) of rats. We assessed an important functional outcome of SSA, the extent to which frequency discriminability depends on sensory context. For this purpose, pure tones were presented in an oddball sequence as standard (high probability of occurrence) or deviant (low probability of occurrence) stimuli. To study frequency discriminability under different probability contexts, we varied the probability of occurrence and the frequency separation between tones. The neuronal sensitivity was estimated in terms of spike-count probability using signal detection theory. We reproduced the finding that many neurons in the IC exhibited SSA, but we did not observe significant SSA in our CN sample. We concluded that strong SSA is not a ubiquitous phenomenon in the CN. As predicted, frequency discriminability was enhanced in IC when stimuli were presented in an oddball context, and this enhancement was correlated with the degree of SSA shown by the neurons. In contrast, frequency discrimination by CN neurons was independent of stimulus context. Our results demonstrated that SSA is not widespread along the entire auditory pathway, and suggest that SSA increases frequency discriminability of single neurons beyond that expected from their tuning curves.
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影响因子：
1.9
作者：
CONDON, CD;WEINBERGER, NM
通讯作者：
WEINBERGER, NM
影响因子：
1.9
作者：
Gutfreund, Yoram
通讯作者：
Gutfreund, Yoram
影响因子：
3
作者：
Gordon, Noam;Shackleton, Trevor M.;Nelken, Israel
通讯作者：
Nelken, Israel
影响因子：
3.5
作者：
Ayala YA;Malmierca MS
通讯作者：
Malmierca MS
影响因子：
3.4
作者：
Anderson, L. A.;Malmierca, M. S.
通讯作者：
Malmierca, M. S.