Olfactory Coding: Inhibition Reshapes Odor Responses
Olfactory Coding: Inhibition Reshapes Odor Responses
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DOI：
10.1016/j.cub.2005.11.052
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发表时间：
2005-12
期刊：
影响因子：
9.2
通讯作者：
M. Stopfer
中科院分区：
文献类型：
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作者：
M. Stopfer
空间分布的受体特异性传入纤维在肾小球中的显著分类和汇聚可能会给人一种感觉，嗅觉信息沿着一条直线和简单的路径进行，受体特异性轨迹之间的相互作用最小：受体、肾小球、主神经元和OUT。这种直接的跟踪可能存在于一些具有特殊生物意义的气味中，例如二氧化碳[8]。然而，最近的研究表明，总体情况要复杂得多，经常被忽视的抑制性LNS可以在解剖上连接多个肾小球，促进功能相互作用，最终导致嗅觉表征的戏剧性重组。威尔逊等人[1]直接研究了这种重组：通过一系列具有技术挑战性的全细胞贴片记录，作者表明，给定的PN可以对许多不同化学类型的气味做出反应，通常具有复杂的尖峰模式，其中可能包括抑制期。对于不同的气味，这些尖峰模式可能会有所不同。研究发现，LN的调谐范围很广，通常对一系列测试气味有反应。然后，作者在细胞内记录了在特定细胞中表达荧光标记的基因操作的果蝇，明确地比较了嗅觉感受器神经元和它们的直接突触后PN的气味敏感性。这个优雅的实验结果表明，三叉神经节的调谐范围比直接与它们联系的突触前感受神经元的范围更广。此外，三叉神经节的放电模式具有比受体神经元更复杂的时间结构。总之，这些发现对于理解嗅觉编码具有重要的意义
The remarkable sorting and convergence of spatially distributed, receptor-specific afferent fibers into glomeruli may give the impression that olfactory information proceeds along a straight and simple path, with minimal interaction among receptor-specific tracks: receptor, glomerulus, principal neuron and out. Such straight-ahead tracks may exist for a few odorants of particular biological significance, such as CO2 [8]. Yet, recent work shows that the general picture is more complex, with the often overlooked inhibitory LNs, which can anatomically link multiple glomeruli, contributing to functional interactions culminating in a dramatic restructuring of the olfactory representation. Wilson et al.[1] directly investigated this restructuring: through a series of technically challenging whole-cell patch recordings, the authors showed that a given PN can respond to odorants of many different chemical types, often with elaborate patterns of spiking that could include periods of inhibition. These spiking patterns can be different for different odorants. LNs were found to be broadly tuned, often responding to a range of test odorants. Then, recording intracellularly from flies genetically manipulated to express fluorescent labels in specific cells, the authors explicitly compared the odor sensitivities of olfactory receptor neurons and their immediate postsynaptic PNs. The results of this elegant experiment showed that PNs are more broadly tuned than the receptor neurons immediately presynaptic to them. Furthermore, the firing patterns of PNs have temporal structures that are more complex than those of the receptor neurons. Together, these findings have important implications for understanding olfactory coding in