Chemosensory properties of murine nasal and cutaneous trigeminal neurons identified by viral tracing
Chemosensory properties of murine nasal and cutaneous trigeminal neurons identified by viral tracing
复制标题
DOI：
10.1186/1471-2202-7-46
复制
发表时间：
2006-06-08
期刊：
影响因子：
2.4
通讯作者：
Wetzel, Christian H.
中科院分区：
文献类型：
--
作者：
Damann, Nils;Rothermel, Markus;Wetzel, Christian H.
背景资料：哺乳动物头部的躯体感觉主要由三叉神经介导，三叉神经为各种组织如面部皮肤、眼睛的结膜、血管以及口腔和鼻腔的粘膜提供神经支配。三叉神经知觉包括温度感觉、触觉和疼痛。鼻上皮的三叉神经化学感觉主要引起刺痛、烧灼或刺激性感觉。三叉神经初级感觉神经元的体外表征主要来自对感觉神经节制备的完整神经元群体的分析。因此，初级三叉神经传入取决于该地区的神经支配的功能特性在很大程度上仍不清楚。结果：我们建立了一个PrV为基础的跟踪技术，以确定鼻和皮肤三叉神经元在体外。这种方法允许通过电生理学和成像测量技术分析和比较所识别的初级传入神经元，用几种激动剂对已知受体（包括TRP通道和嘌呤能受体）表现出特异性。与皮肤神经元相比，鼻侧三叉神经元对薄荷醇和辣椒素的敏感性更高。这些发现表明TRPM8和TRPV1受体蛋白主要在鼻神经元中表达，而对于皮肤神经元，这些受体仅以较小的比例存在。大多数鼻神经元缺乏P2X（3）受体介导的电流，但在ATP刺激时显示P2X（2）介导的反应。有趣的是，皮肤神经元显示主要TTX耐钠电流。一个显着更高的分数的鼻和皮肤的传入表现出IB4结合相比，随机选择的trigeminal neurons.Conclusion：总之，证明了可用性的PrV介导的跟踪初级传入。使用这种技术，它可以表明，与神经支配皮肤的神经元相比，鼻三叉神经元显示出明显的TRPM8和TRPV1通道激动剂的化学敏感性，只有部分满足典型的伤害感受器的属性。与P2X3受体相反，TRPM8和TRPV1受体似乎与鼻内三叉神经感觉具有明显的生理相关性。
Background: Somatosensation of the mammalian head is mainly mediated by the trigeminal nerve that provides innervation of diverse tissues like the face skin, the conjunctiva of the eyes, blood vessels and the mucouse membranes of the oral and nasal cavities. Trigeminal perception encompasses thermosensation, touch, and pain. Trigeminal chemosensation from the nasal epithelia mainly evokes stinging, burning, or pungent sensations. In vitro characterization of trigeminal primary sensory neurons derives largely from analysis of complete neuronal populations prepared from sensory ganglia. Thus, functional properties of primary trigeminal afferents depending on the area of innervation remain largely unclear.Results: We established a PrV based tracing technique to identify nasal and cutaneous trigeminal neurons in vitro. This approach allowed analysis and comparison of identified primary afferents by means of electrophysiological and imaging measurement techniques.Neurons were challenged with several agonists that were reported to exhibit specificity for known receptors, including TRP channels and purinergic receptors. In addition, TTX sensitivity of sodium currents and IB4 binding was investigated.Compared with cutaneous neurons, a larger fraction of nasal trigeminal neurons showed sensitivity for menthol and capsaicin. These findings pointed to TRPM8 and TRPV1 receptor protein expression largely in nasal neurons whereas for cutaneous neurons these receptors are present only in a smaller fraction. The majority of nasal neurons lacked P2X(3) receptor-mediated currents but showed P2X(2)-mediated responses when stimulated with ATP. Interestingly, cutaneous neurons revealed largely TTX resistant sodium currents. A significantly higher fraction of nasal and cutaneous afferents showed IB4 binding when compared to randomly chosen trigeminal neurons.Conclusion: In conclusion, the usability of PrV mediated tracing of primary afferents was demonstrated. Using this technique it could be shown that compared with neurons innervating the skin nasal trigeminal neurons reveal pronounced chemosensitivity for TRPM8 and TRPV1 channel agonists and only partially meet properties typical for nociceptors. In contrast to P2X3 receptors, TRPM8 and TRPV1 receptors seem to be of pronounced physiological relevance for intranasal trigeminal sensation.