Odor Concentration Change Coding in the Olfactory Bulb
Odor Concentration Change Coding in the Olfactory Bulb
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DOI：
10.1523/eneuro.0396-18.2019
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发表时间：
2019-01-01
期刊：
影响因子：
3.4
通讯作者：
Shusterman, Roman
中科院分区：
文献类型：
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作者：
Parabucki, Ana;Bizer, Alexander;Shusterman, Roman
环境的动态变化强烈地影响着我们的感知。同样，感觉系统优先表示刺激变化，增强时间对比度。在嗅觉中，连续吸入的气味浓度变化（Δ C-t）可以指导气味源定位，但尚未在脊椎动物中研究Δ C-t的神经表征。我们发现，在小鼠嗅球中，二尖瓣/簇状（M/T）细胞的子集代表Delta C-t，增强了不同浓度之间的对比度。这些浓度变化响应是方向选择性的：它们响应于浓度的增加或减少，使人联想到视网膜中的ON和OFF选择性。该对比度增强与浓度步骤的幅度成比例，但不与浓度步骤的持续时间成比例。此外，与由快速时间尖峰模式表示的气味身份和强度不同，Δ C-t可以从每次嗅探的总尖峰计数中读出。我们的研究结果表明，一个子集的M/T细胞代表Δ C-t，提供了一个信号，可以指导下游嗅觉回路的导航决策。
Dynamical changes in the environment strongly impact our perception. Likewise, sensory systems preferentially represent stimulus changes, enhancing temporal contrast. In olfaction, odor concentration changes across consecutive inhalations (Delta C-t) can guide odor source localization, yet the neural representation of Delta C-t has not been studied in vertebrates. We have found that, in the mouse olfactory bulb, a subset of mitral/tufted (M/T) cells represents Delta C-t, enhancing the contrast between different concentrations. These concentration change responses are direction selective: they respond either to increments or decrements of concentration, reminiscent of ON and OFF selectivity in the retina. This contrast enhancement scales with the magnitude, but not the duration of the concentration step. Further, Delta C-t can be read out from the total spike count per sniff, unlike odor identity and intensity, which are represented by fast temporal spike patterns. Our results demonstrate that a subset of M/T cells represents Delta C-t, providing a signal that may instruct navigational decisions in downstream olfactory circuits.