晕动症易感性具有明显个体差异，筛选易感人群是避免晕动症发生的重要手段；但晕动症易感性差异的机制尚不明确；我们的前期实验发现，嗅觉受体olr81及下游G蛋白Gαolf在大鼠前庭核神经元内大量表达；研究证实，嗅觉受体基因多态性与某些疾病的易感性密切相关；我们进一步的实验发现，晕动症易感性与前庭核olr81 mRNA的转录水平有关；提示我们olr81可能是决定晕动症易感性个体差异的关键分子。因此，本研究在建立晕动症易感性判断行为学模型的基础上，观察晕动症易感性的性别、年龄差异及与olr81表达水平的关系；验证前庭核olr81的表达及活性变化对晕动症易感性的影响，确定在此过程中起主要作用的受体下游信号通路；了解olr81与NMDA及GABAB受体在前庭核内的相互作用及对晕动症易感性的影响；分析olr81基因多态性与晕动症易感性的关联性，以阐明前庭核olr81在决定个体晕动症易感性中的作用及机制。

Motion sickness susceptibility (MSS) shows an obvious character of large individual difference. Screening for susceptible individuals is an important method for prevention of motion sickness. However, the mechanism underlying MSS individual difference is still unclear. Our previous study found significant expression of olfactory receptor (OR) olr81 and its downstream G protein Gαolf in rat vestibular nucleus neurons. Previous studies confirmed that OR gene polymorphism correlate with the susceptibility of some diseases. Our further study found that transcription level of olr81 mRNA in vestibular nucleus relates to MSS. These evidences suggested that olr81 might be a key molecule for determination of MSS. In the present project, based on established animal behaviour model for MSS the correlation between olr81 expression level and sex & age variation for MSS will be examined. We will try to prove that the expression level and receptor activity of olr81 will influence individual difference of MSS and then determine the key down stream signal pathway involved in this process. We will further investigate the interaction between olr81 and NMDA or GABAB receptor and the impact on MSS.We will also perform the linkage analysis between OR gene polymorphism and MSS.The purpose for the upper experiments is to clarify the role of olr81 played in determinatin of MSS individual difference and the related mechanisms.