Responses of neurons in primary auditory cortex (A1) to pure tones in the halothane-anesthetized cat
Responses of neurons in primary auditory cortex (A1) to pure tones in the halothane-anesthetized cat
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DOI：
10.1152/jn.00822.2005
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发表时间：
2006-06-01
影响因子：
2.5
通讯作者：
Nelken, Israel
中科院分区：
文献类型：
--
作者：
Moshitch, Dina;Las, Liora;Nelken, Israel
麻醉动物的初级听觉皮层 (A1) 神经元对纯音的反应通常被描述为具有大部分狭窄、单峰频率调谐和相位反应。因此，A1 神经元被认为不会携带太多关于声音开始之外的纯音的信息。然而，在清醒的猫中，调谐范围可能更广，反应的持续时间可能更长。在这里，我们分析了氟烷麻醉猫 A1 中 1,828 个单位的频率响应区域 (FRAs) 和时间响应模式。调谐范围通常很宽：高于阈值 40 dB 时的总带宽平均为 4 个八度。 FRA 形状变化很大，许多是分散的，不符合标准分类方案。分析每个单元最大响应的时间模式表明，只有 9% 的单元具有纯起始响应。大约 40% 的单元在整个刺激持续时间（115 毫秒）内具有持续响应，13% 的单元在刺激抵消后持续 300 毫秒或更长时间，具有显着且信息丰富的响应。我们的结论是，在氟烷麻醉下，神经反应表现出清醒反应的许多特征。此外，A1 单元不仅在整个声音呈现过程中，而且在刺激抵消后的数百毫秒内，在其活动中保留感觉信息，因此可能在感觉记忆中发挥作用。
The responses of primary auditory cortex (A1) neurons to pure tones in anesthetized animals are usually described as having mostly narrow, unimodal frequency tuning and phasic responses. Thus A1 neurons are believed not to carry much information about pure tones beyond sound onset. In awake cats, however, tuning may be wider and responses may have substantially longer duration. Here we analyze frequency-response areas (FRAs) and temporal-response patterns of 1,828 units in A1 of halothane-anesthetized cats. Tuning was generally wide: the total bandwidth at 40 dB above threshold was 4 octaves on average. FRA shapes were highly variable and many were diffuse, not fitting into standard classification schemes. Analyzing the temporal patterns of the largest responses of each unit revealed that only 9% of the units had pure onset responses. About 40% of the units had sustained responses throughout stimulus duration (115 ms) and 13% of the units had significant and informative responses lasting 300 ms and more after stimulus offset. We conclude that under halothane anesthesia, neural responses show many of the characteristics of awake responses. Furthermore, A1 units maintain sensory information in their activity not only throughout sound presentation but also for hundreds of milliseconds after stimulus offset, thus possibly playing a role in sensory memory.