Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu 700-412, South Korea.
J Chem Neuroanat. 2012 Oct;45(1-2):45-9. doi: 10.1016/j.jchemneu.2012.07.003. Epub 2012 Jul 17.
The transient receptor potential ankyrin 1 (TRPA1) is implicated in the mechanical and cold hyperalgesia following inflammation and nerve injury. Its expression has been presumed to be confined to primary afferent terminals. Here, we show that TRPA1 is expressed in astrocytes in the superficial laminae of the rat trigeminal caudal nucleus by use of electron microscopic immunoperoxidase and immunogold labeling techniques. Immunoreactivity for TRPA1 was consistently observed in somata and process of astrocytes and was weaker than that in presumed nociceptive primary afferent terminals, but increased significantly in the fine process of astrocyte in rats with experimental inflammation of the temporomandibular joint. Thus, we provide ultrastructural evidence that TRPA1 is expressed in astrocytes in the brain stem and propose a novel pathway of its involvement in the central mechanism of inflammatory hyperalgesia.
瞬时受体电位锚蛋白 1（TRPA1）参与炎症和神经损伤后的机械性和冷超敏反应。其表达被认为仅限于初级传入末梢。在这里，我们使用电子显微镜免疫过氧化物酶和免疫金标记技术显示，TRPA1 在大鼠三叉神经尾核的浅层表达于星形胶质细胞中。TRPA1 免疫反应在星形胶质细胞的体和突起中一致观察到，其强度比假定的伤害性初级传入末梢弱，但在颞下颌关节实验性炎症的大鼠中，星形胶质细胞的细突起中显著增加。因此，我们提供了超微结构证据，表明 TRPA1 在脑干星形胶质细胞中表达，并提出了它参与炎症性痛觉过敏的中枢机制的新途径。
