Relational representation in the olfactory system
Relational representation in the olfactory system
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DOI：
10.1073/pnas.0608564104
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发表时间：
2007-02-06
影响因子：
11.1
通讯作者：
Linster, Christiane
中科院分区：
文献类型：
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作者：
Cleland, Thomas A.;Johnson, Brett A.;Linster, Christiane
气味的感知质量通常对浓度的变化具有鲁棒性。然而，嗅球肾小球层的神经激活图在这方面并不稳定。相反，随着气味浓度的增加，肾小球的气味表征既扩大又增强。相反，肾小球之间的相对激活水平在不同浓度下保持相对稳定，这表明气味质量的表示可能依赖于这些相关的活动模式。然而，能够提取此类关系表示的神经标准化机制尚不清楚。使用大鼠嗅球的肾小球成像活动概况以及计算模型，我们在此表明：（i）全局标准化保留了与浓度无关的气味质量信息； (h) 通过行为评估，通过归一化比通过原始延髓活动概况可以更好地预测感知相似性； (M)最近在嗅球中描述的循环兴奋回路能够执行这种标准化。我们表明，感觉系统中的全局前馈归一化与行为相关，并且中心环绕神经架构并不一定意味着中心环绕功能。
The perceptual quality of odors usually is robust to variability in concentration. However, maps of neural activation across the olfactory bulb glomerular layer are not stable in this respect; rather, glomerular odor representations both broaden and intensify as odorant concentrations are increased. The relative levels of activation among glomeruli, in contrast, remain relatively stable across concentrations, suggesting that the representation of odor quality may rely on these relational activity patterns. However, the neural normalization mechanisms enabling extraction of such relational representations are unclear. Using glomerular imaging activity profiles from the rat olfactory bulb together with computational modeling, we here show that (i) global normalization preserves concentration-independent odor-quality information; (h) perceptual similarities, as assessed behaviorally, are better predicted by normalized than by raw bulbar activity profiles; and (M) a recurrent excitatory circuit recently described in the olfactory bulb is capable of performing such normalization. We show that global feed-forward normalization in a sensory system is behaviorally relevant, and that a center-surround neural architecture does not necessarily imply center-surround function.