背景:嗅觉系统和三叉神经系统紧密相连。现有文献主要集中在通过机械和化学刺激表征三叉神经刺激。到目前为止,忽略了热刺激。本研究旨在表征鼻内对热的敏感性和三叉神经受体的表达(瞬时受体电位通道,TRP).
方法:共有20名健康参与者(年龄21-27岁,11名女性)进行了嗅觉功能和三叉神经敏感性的筛查。在内窥镜控制下,热刺激器放置在7个鼻内位置:前隔膜,外侧前庭,内部鼻尖,下鼻甲,中隔,中鼻甲,和嗅觉裂缝来确定热阈值。在3个不同的位置获得鼻拭子(前隔,中鼻甲,嗅裂)分析三叉神经受体TRP的表达:TRPV1,TRPV3,TRPA1,TRPM8。
结果:位置之间的热阈值不同(p=0.018),在前隔有较高阈值的趋势(p=0.092)。不同部位的定量受体表达没有差异(p=0.46)。在所有位点上检测到TRPV1的最高总受体RNA表达(p<0.001)。与中鼻甲或嗅裂相比,TRPV3在前隔的表达最高。热敏感性与嗅觉敏感性相关,测试结果与三叉神经功能相关,如铵的强度等级,关于三叉神经功能的问卷,鼻腔通畅,和二氧化碳阈值。然而,受体表达与三叉神经功能的心理物理测量之间没有相关性.
结论:这项研究提供了有关鼻内热敏感性的初步见解,并表明热阈值存在地形差异。热敏感性与三叉神经mRNA受体表达无相关性。然而,发现热敏感性与三叉神经和嗅觉功能的心理物理测量有关。
BACKGROUND: The olfactory and trigeminal system are closely interlinked. Existing literature has primarily focused on characterizing trigeminal stimulation through mechanical and chemical stimulation, neglecting thermal stimulation thus far. The present
study aimed to characterize the intranasal sensitivity to heat and the expression of trigeminal receptors (transient receptor potential channels, TRP).
METHODS: A total of 20 healthy participants (aged 21-27 years, 11 women) were screened for olfactory function and trigeminal sensitivity using several tests. Under endoscopic control, a thermal stimulator was placed in 7 intranasal locations: anterior septum, lateral vestibulum, interior nose tip, lower turbinate, middle septum, middle turbinate, and olfactory cleft to determine the thermal threshold. Nasal swabs were obtained in 3 different locations (anterior septum, middle turbinate, olfactory cleft) to analyze the expression of trigeminal receptors TRP: TRPV1, TRPV3, TRPA1, TRPM8.
RESULTS: The thermal threshold differed between locations (p = 0.018), with a trend for a higher threshold at the anterior septum (p = 0.092). There were no differences in quantitative receptor expression (p = 0.46) at the different sites. The highest overall receptor RNA expression was detected for TRPV1 over all sites (p<0.001). The expression of TRPV3 was highest at the anterior septum compared to the middle turbinate or the olfactory cleft. The thermal sensitivity correlated with olfactory sensitivity and results from tests were related to trigeminal function like intensity ratings of ammonium, a questionnaire regarding trigeminal function, nasal patency, and CO2 thresholds. However, no correlation was found between receptor expression and psychophysical measures of trigeminal function.
CONCLUSIONS: This
study provided the first insights about intranasal thermal sensitivity and suggested the presence of topographical differences in thermal thresholds. There was no correlation between thermal sensitivity and trigeminal mRNA receptor expression. However, thermal sensitivity was found to be associated with psychophysical measures of trigeminal and olfactory function.