Physiological analysis of retronasal olfaction

描述（由申请人提供）：在吸气或嗅闻期间，有气味的空气可通过外鼻孔以正鼻方式进入鼻子。它也可以在呼气或吞咽和咀嚼运动时从鼻后进入。人类和一些动物的研究表明，有不同的感觉诱发之间的正鼻和鼻后的路线。鼻后嗅觉在味道的欣赏中具有重要的功能，并且可以很好地促进衰老和疾病中味道欣赏的变化。鼻后嗅觉也可能对食物的脂肪含量有不同的敏感性，从而导致与肥胖问题非常相关的食物偏好。来自文献的一些证据表明，气味剂的物理化学性质可以解释鼻后刺激和鼻前刺激之间的感知差异，尽管三叉神经感觉和/或运动中心的协调活动也可能起作用。鼻子中的空气流速与气味物质的物理化学性质（包括粘膜溶解度和空气中的扩散性）相互作用。我们的记录大鼠嗅觉电图在鼻前和鼻后刺激表明，鼻后途径给了一个大大减少的反应极性（亲水性）气味与保存的反应，非极性（疏水性）气味。本研究将利用嗅电图记录和嗅球记录来研究气味特性如何与气流参数（包括正鼻和反鼻）相互作用。我们将研究这种制剂是否可以用作鼻后嗅觉的模型，并将特别包括一系列的风味增味剂。大鼠鼻后输入似乎优先激活嗅上皮的侧隐窝。这也可能为嗅球生理学的研究提供有用的工具，因为单个刺激可以导致非常不同的行为模式，在灯泡取决于路线的介绍。

DESCRIPTION (provided by applicant): Odorized air can enter the nose orthonasally through the external nares during inspiration or during sniffing. It can also enter retronasally during expiration or with swallowing and chewing movements. Human and some animal studies have indicated that there are differences in the sensations evoked between the orthonasal and retronasal routes. Retronasal olfaction is functionally important in appreciation of flavor and could well contribute to changes in flavor appreciation in aging and disease. Retronasal olfaction may also be differentially sensitive to the fat content of food thus contributing to food preferences that are very relevant to the issue of obesity. Some evidence from the literature suggests that physico-chemical properties of odorants may account for some of the differences in perception between orthonasal and retronasal stimulation, although very likely trigeminal sensation and/or coordinated activity in motor centers may also contribute. Air flow rate in the nose interacts with physicochemical properties of odorants (including mucosal solubility and diffusibility in air). Our recordings of rat electroolfactograms during orthonasal and retronasal stimulation show that the retronasal route gives a greatly reduced response for polar (hydrophilic) odorants with preserved responses to non-polar (hydrophobic) odorants. This investigation will utilize electroolfactogram recordings and recordings from the olfactory bulb to study how odorant properties interact with air flow parameters both orthonasally and retronasally. We will investigate whether this preparation can be used as a model of retronasal olfaction and will specifically include a range of flavor odorants. Retronasal inputs in the rat seem to preferentially activate the lateral recesses of the olfactory epithelium. This may also provide a useful tool for study of olfactory bulb physiology because a single stimulus can lead to very different patterns of action in the bulb depending on the route of presentation.