Tuning to Odor Solubility and Sorption Pattern in Olfactory Epithelial Responses
Tuning to Odor Solubility and Sorption Pattern in Olfactory Epithelial Responses
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DOI：
10.1523/jneurosci.3736-13.2014
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发表时间：
2014-02-05
影响因子：
5.3
通讯作者：
Zhao, Kai
中科院分区：
文献类型：
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作者：
Scott, John W.;Sherrill, Lisa;Zhao, Kai
当气味通过呼吸吸入鼻子时，气味信息首先被表示为跨嗅觉上皮的空间激活模式。这种上皮模式可能是由固有的嗅觉感觉神经元（OSN）敏感性和鼻腔空气动力学与气味剂的理化特性相互作用所产生的吸着模式引起的，尽管每种模式的精确贡献尚不清楚。在这里，我们使用大鼠鼻腔的计算流体动力学（CFD）模型来模拟大量气味物质的鼻腔空气动力学和吸附模式，并将结果与相同流量条件下电嗅图（EOG）测量的空间神经活动进行比较。计算和实验结果均表明，作为粘膜溶解度的函数，对窄范围气味剂有更大的吸附和响应，并且该范围可以通过鼻内流速和方向（鼻前流与鼻后流）的变化进一步调节。一个惊人的发现是，在没有气流限制的情况下，在手术打开的鼻子中测量的内在 EOG 响应曲线与鼻气流施加的吸附曲线的形状相似，强烈表明了调整过程。作为验证，将内在响应与非线性回归中 CFD 估计的粘膜浓度相结合，成功地解释了在所有流速和位置测量的鼻后和鼻前 EOG 响应。这些观察结果重新定义了吸附特性在嗅觉中的作用，并表明周围嗅觉系统，特别是中央区域，可以根据传入的刺激进行战略性的空间排列，以优化其功能。
Odor information is first represented as a spatial activation pattern across the olfactory epithelium, when odor is drawn into the nose through breathing. This epithelial pattern likely results from both the intrinsic olfactory sensory neuron (OSN) sensitivity and the sorptive patterns imposed by the interaction of nasal aerodynamics with physiochemical properties of odorants, although the precise contributions of each are ill defined. Here, we used a computational fluid dynamics (CFD) model of rat nasal cavity to simulate the nasal aerodynamics and sorption patterns for a large number of odorants, and compared the results with the spatial neural activities measured by electro-olfactogram (EOG) under same flow conditions. The computational and experimental results both indicate greater sorption and response to a narrow range odorants as a function of their mucosal solubility, and this range can be further modulated by changes of intranasal flow rates and direction (orthonasal vs retronasal flow). A striking finding is that the profile of intrinsic EOG response measured in surgically opened nose without airflow constraints is similar to the shape of the sorption profile imposed by nasal airflow, strongly indicating a tuning process. As validation, combining the intrinsic response with the mucosal concentration estimated by CFD in nonlinear regression successfully accounts for the measured retronasal and orthonasal EOG response at all flow rates and positions. These observations redefine the role of sorption properties in olfaction and suggest that the peripheral olfactory system, especially the central zone, may be strategically arranged spatially to optimize its functionality, depending on the incoming stimuli.