Boye Larsen Dennis, Ingemann Kristensen Gunda, Panchalingam Vinodenee, Laursen Jens Christian, Nørgaard Poulsen Jeppe, Skallerup Andersen Maria, Kandiah Aginsha, Gazerani Parisa
Center for Sensory-Motor Interaction, Department of Health Science and Technology, Faculty of Medicine , Aalborg University, Frederik Bajers Vej, Aalborg East , Denmark.
J Recept Signal Transduct Res. 2014 Aug;34(4):261-9. doi: 10.3109/10799893.2014.885049. Epub 2014 Feb 4.
CONTEXT/OBJECTIVE: Previous studies have demonstrated that various subtypes of the metabotropic glutamate receptors (mGluRs) are expressed in the dorsal root ganglion (DRG) of the peripheral nervous system (PNS), implicating that glutamate potentially contributes to sensory transmission through these receptors. While mGluR expression has been investigated largely in the DRG, the present study focused on mGluR expression on neurons and satellite glial cells (SGCs) of the trigeminal ganglion (TG).
To address the presence of mGluRs in rat TG neurons and their corresponding SGCs, the trigeminal ganglia from six adult male Wistar rats were isolated and immunohistochemistry and immunocytochemistry were performed. The expression of mGluR1α-, mGluR2/3- and mGluR8 on TG neurons and SGCs was investigated in tissue slices and isolated cells.
35.1 ± 6.0% of the TG neurons were positive for mGluR1α, whereas 39.9 ± 7.7% and 55.5 ± 6.3% were positive for mGluR2/3 and mGluR8, respectively. Immunoreactive neurons expressing mGluRs were mainly medium- to large sized, with a smaller population of small-sized neurons showing immunoreactivity. The SGCs showed immunoreactivity toward mGluR1α and mGluR8, but not mGluR2/3, both in the tissue and in isolated cells.
Findings from the present study showed that trigeminal neurons express mGluR1α, mGluR2/3 and mGluR8, while SGCs only express mGluR1α and mGluR8. This novel evidence may advance investigations on a possible role of mGluRs in relation to trigeminal pain transmission within the craniofacial region.
背景/目的：先前的研究表明，代谢型谷氨酸受体（mGluRs）的各种亚型在外周神经系统（PNS）的背根神经节（DRG）中表达，这意味着谷氨酸可能通过这些受体促进感觉传递。虽然mGluR的表达主要在DRG中进行了研究，但本研究聚焦于三叉神经节（TG）神经元和卫星神经胶质细胞（SGCs）上的mGluR表达。
为了研究大鼠TG神经元及其相应SGCs中mGluRs的存在情况，分离了6只成年雄性Wistar大鼠的三叉神经节，并进行了免疫组织化学和免疫细胞化学实验。在组织切片和分离细胞中研究了mGluR1α、mGluR2/3和mGluR8在TG神经元和SGCs上的表达。
35.1±6.0%的TG神经元mGluR1α呈阳性，而mGluR2/3和mGluR8呈阳性的分别为39.9±7.7%和55.5±6.3%。表达mGluRs的免疫反应性神经元主要为中大型，少数小型神经元也显示出免疫反应性。在组织和分离细胞中，SGCs对mGluR1α和mGluR8呈免疫反应性，但对mGluR2/3无免疫反应性。
本研究结果表明，三叉神经元表达mGluR1α、mGluR2/3和mGluR8，而SGCs仅表达mGluR1α和mGluR8。这一新证据可能推动关于mGluRs在颅面部区域三叉神经痛传递中可能作用的研究。
