The Physics of Chemoreception: Interactions of Fluid Flow and Chemosensory Morphology

对刺激的感觉接收通常涉及被称为“感受器周围”特征的结构或过程，这些结构或过程在感觉信号到达感受器细胞之前对其产生影响。例如眼睛的晶状体或耳朵的鼓膜。在味觉和嗅觉的化学感受器系统中，人们对溶解度、微观流体力学、扩散和化学反应如何影响对化学刺激的反应产生了新的兴趣。龙虾的触角是化学感受器在液体中工作的一个很好的例子；这个器官就像一个小天线，覆盖着细小的刷毛和化学感受器，在时间和空间上采样水中传来的气味羽流。龙虾“轻拍”触角，类似于用鼻子“嗅”，因为物理轻拍用新的样本水团取代了被困在刚毛周围的水团。该项目使用复杂的刺激传递技术、3D视频分析和新型传感器电极，以龙虾中不同的附属物作为模型系统，提供关于受体细胞周围微尺度环境中的时间和空间特征的新的量化数据。边界层和物理传输过程与感受器的详细结构相互作用，提供对输入信号的“过滤”，正是这种过滤有助于以一种适合动物的方式从环境中提取信息。将分析不同化学传感附件的形态和采样行为，以了解这些差异在决定化学信号的空间和时间分析中起到什么作用。这项工作的结果将导致对专门的化学感受器如何检测刺激模式的新理解，以及这些化学感觉器官是如何进化来检测特定类型的环境信号的。其影响将从化学感官神经科学延伸到行为科学、进化生物学、流体力学，可能还会对海洋水产养殖产生影响。

Sensory reception of a stimulus often involves structures or processes called "perireceptor" features that affect the sensory signal before it gets access to the receptor cells. Examples include the lens of the eye or the eardrum of the ear. In chemoreceptor systems for taste and smell, there is a new interest in how solubility, microscale fluid mechanics, diffusion, and chemical reactivity affect responses to chemical stimuli. The lobster antennule is a good example of a chemoreceptor working in a fluid; this organ, like a small antenna, is covered with fine bristles and chemoreceptors to sample, in time and space, odor plumes that come by in the water. The lobster "flicks" the antennule as an analogy to "sniffing" with a nose, as the physical flick displaces the water mass trapped around the bristles with a new sample water mass. This project uses sophisticated stimulus delivery techniques, 3-D video analysis, and novel sensor electrodes, working with this different appendages in the lobster as a model system, to provide novel quantitative data on temporal and spatial features in the microscale environment around the receptor cells. Boundary layer and physical transport processes interact with the detailed structure of the receptor organ to provide "filtering" of the input signals, and it is this filtering that helps extract information from the environment in a way adaptive for the animal. The morphology and sampling behavior of different chemosensory appendages will be analyzed to see what role the differences play in determining the spatial and temporal analysis of chemical signals. Results from this work will lead to new understanding of how specialized chemoreceptors detect patterns of stimuli, and how such chemosensory organs have evolved to detect particular kinds of environmental signals. The impact will extend beyond chemosensory neuroscience to behavioral science, evolutionary biology, fluid mechanics, and possibly also on marine aquaculture.