Quality time: representation of a multidimensional sensory domain through temporal coding.
Quality time: representation of a multidimensional sensory domain through temporal coding.
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DOI：
10.1523/jneurosci.5995-08.2009
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发表时间：
2009-07-22
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影响因子：
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通讯作者：
Victor JD
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文献类型：
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作者：
Di Lorenzo PM;Chen JY;Victor JD
大脑中感觉神经元的感受野通常局限于整个刺激域的一部分。然而，在味觉神经轴的所有水平，有许多细胞是广泛调谐的，即，它们对每一种基本的味道品质（甜、酸、咸和苦）都有很好的反应。虽然它可能看起来，这种广泛的调整排除了这些细胞在代表味觉空间的主要作用，在这里，我们显示相反的-即，味觉特异性的时间方面（发射率包络和尖峰定时）的反应，使每个细胞代表整个刺激域。具体来说，我们记录了孤束核（NTS）的细胞的反应模式的代表四个基本的味道的质量和他们的二元混合物。我们分析了这些反应的时间方面，并利用它们的相似性和差异来构建每个神经元所代表的味觉空间。我们发现，对于NTS中更广泛调谐的神经元，味觉空间是整个味觉域的系统表示。也就是说，这些广泛调谐的神经元的味觉空间是三维的，基本的味觉质量被广泛分离，二元混合物被放置在靠近它们的成分。此外，由发射率包络表示味道质量的方式在整个细胞群中是一致的。因此，NTS神经元群体中反应的时间特征，特别是那些更广泛调谐的，产生了味觉世界的全面和逻辑表示。
Receptive fields of sensory neurons in the brain are usually restricted to a portion of the entire stimulus domain. At all levels of the gustatory neuraxis, however, there are many cells that are broadly tuned, i.e., they respond well to each of the basic taste qualities (sweet, sour, salty and bitter). Although it might seem that this broad tuning precludes a major role for these cells in representing taste space, here we show the opposite – namely, that the tastant-specific temporal aspects (firing rate envelope and spike timing) of their responses enable each cell to represent the entire stimulus domain. Specifically, we recorded the response patterns of cells in the nucleus of the solitary tract (NTS) to representatives of four basic taste qualities and their binary mixtures. We analyzed the temporal aspects of these responses, and used their similarities and differences to construct the taste space represented by each neuron. We found that for the more broadly tuned neurons in the NTS, the taste space is a systematic representation of the entire taste domain. That is, the taste space of these broadly tuned neurons is three-dimensional, with basic taste qualities widely separated and binary mixtures placed close to their components. Further, the way that taste quality is represented by the firing rate envelope is consistent across the population of cells. Thus, the temporal characteristics of responses in the population of NTS neurons, especially those that are more broadly tuned, produce a comprehensive and logical representation of the taste world.