Glutamate and capsaicin effects on trigeminal nociception I: Activation and peripheral sensitization off deep craniofacial nociceptive afferents
Glutamate and capsaicin effects on trigeminal nociception I: Activation and peripheral sensitization off deep craniofacial nociceptive afferents
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DOI：
10.1016/j.brainres.2008.11.029
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发表时间：
2009-01-28
期刊：
影响因子：
2.9
通讯作者：
Hu, James W.
中科院分区：
文献类型：
--
作者：
Lam, David K.;Sessle, Barry J.;Hu, James W.
我们已经研究了谷氨酸和辣椒素的外周应用到深部颅面组织中影响深部颅面伤害性传入的激活和外周敏化的效果。在55只氟烷麻醉的大鼠上，用细胞外方法记录了三叉神经伤害性传入神经元在颅面深部组织的感受野活动。在将0.5 M谷氨酸（或载体）和1%辣椒素（或载体）注射到感受野之前和之后评估每个传入的机械激活阈值（MAT）。对68个颅面深部组织（咬肌23个，颞肌5个，颞下颌关节40个）的钝性伤害性机械刺激可激活的传入纤维进行了研究。当单独注射时，谷氨酸和辣椒素激活并诱导外周敏化，反映为许多传入神经中MAT减少。谷氨酸注射后，辣椒素诱发的活性大于单独辣椒素诱发的活性，而辣椒素注射后，谷氨酸诱发的反应类似于单独的谷氨酸。这些研究结果表明，外周应用谷氨酸或辣椒素可能激活或诱导外周敏化三叉神经伤害性传入神经支配深颅面组织的亚群，反映在MAT和其他传入反应特性的变化。这些数据进一步表明，外周谷氨酸和辣椒素受体机制可能相互作用，以调节激活和外周敏化在一些深颅面伤害性传入。皇冠版权所有（c）2008年出版的爱思唯尔B.V.保留所有权利。
We have examined the effect of the peripheral application of glutamate and capsaicin to deep craniofacial tissues in influencing the activation and peripheral sensitization of deep craniofacial nociceptive afferents. The activity of single trigeminal nociceptive afferents with receptive fields in deep craniofacial tissues were recorded extracellularly in 55 halothane-anesthetized rats. The mechanical activation threshold (MAT) of each afferent was assessed before and after injection of 0.5 M glutamate (or vehicle) and 1% capsaicin (or vehicle) into the receptive field. A total of 68 afferents that could be activated by blunt noxious mechanical stimulation of the deep craniofacial tissues (23 masseter, 5 temporalis, 40 temporomandibular joint) were studied. When injected alone, glutamate and capsaicin activated and induced peripheral sensitization reflected as MAT reduction in many afferents. Following glutamate injection, capsaicin-evoked activity was greater than that evoked by capsaicin alone, whereas following capsaicin injection, glutamate-evoked responses were similar to glutamate alone. These findings indicate that peripheral application of glutamate or capsaicin may activate or induce peripheral sensitization in a subpopulation of trigeminal nociceptive afferents innervating deep craniofacial tissues, as reflected in changes in MAT and other afferent response properties. The data further suggest that peripheral glutamate and capsaicin receptor mechanisms may interact to modulate the activation and peripheral sensitization in some deep craniofacial nociceptive afferents. Crown Copyright (c) 2008 Published by Elsevier B.V. All rights reserved.