Neural Mechanisms of Mixture Suppression in Olfaction

气味是物质的复杂混合物。很难通过对气味混合物的个别成分的反应来预测对气味混合物的行为或生理反应。混合物的刺激性往往比预期的要小得多，这种现象被称为混合物抑制。这至少部分是由于人们对多种气味同时激活嗅觉通路时发生的相互作用知之甚少。这个项目通过考虑混合物抑制中的几种可能的机制来解决这个问题：即受体和中枢神经系统嗅觉部分抑制性突触连接的相互干扰机制。研究的动物是带刺龙虾，在龙虾中，已知受体和中枢事件都有助于嗅觉中的混合物抑制。电生理学方法被用来确定不同的气味成分是否激活了感受器细胞中相反的转导过程。使用类似的方法以及细胞染色和特殊技术来定位神经细胞相互通信的各种物质，以确定中枢神经系统中的抑制细胞及其在嗅觉区域的联系。混合物抑制提供了一个特定的背景，在其中解释了这些抑制在识别气味质量中的作用。由于基本的分子和细胞过程在进化中往往是保守的，因此可以预期这一结果将有助于普遍理解龙虾以外的动物(包括人类)是如何识别复杂气味的。

Odors are complex mixtures of substances. It is difficult to predict behavioral or physiological responses to odor mixtures from the responses to the individual componentsof the mixtures. Mixtures are often significantly less stimulatory than predicted, a phenomenon called mixture suppression. This is at least partly due to poorly understood interactions that occur when multiple odorants activate the olfactory pathway simultaneously. This project addresses this problem by considering several possible mechanisms in mixture suppression: namely, mutually interfering mechanisms of transduction by the receptors and inhibitory synaptic connections in the olfactory part of the central nervous system. The research animal is the spiny lobster, in which it is known that receptor and central events both contribute to mixture suppression in olfaction. Electrophysiological methods are used to determine if different odor components activate opposing transduction processes inreceptor cells. Similar methods as well as cell staining and special techniques to localize the various substances by which nerve cells communicate with each other are used to identify inhibitory cells in the central nervous system and their connections in its olfactory areas. Mixture suppression provides a specific context in which to interpret the role of these inhibitions in recognizing odor quality. Since basic molecular and cellular processes tend to be conserved in evolution, the results can be expected to contribute to the general understanding of how complex odors are recognized in animals other than lobsters, including humans.