Co-localization of metabotropic glutamate receptor 2 with ASIC3 or TRPV1 in the dorsal root / 神经解剖学杂志

ABSTRACT

Metabotropie glutamate receptor (mGluR) 2/3 plays an important role on the nociceptive transmission from periphery to spinal cord.The previous studies demonstrated that mGluR2 can contribute to mechanical hypersensitivity and thermal hypersensitivity in rat.Therefore,in the present study,by using the immunofluorescenee histochemical technique,we try to explore that whether mGluR2 is colocalized with acid-sensing ion channel 3 (ASIC3),a muhi-modulator of mechanosensation,or transient receptor potential/vanilloid receptor subtype-1 (TRPV1),which responses for thermosensation in dorsal root ganglion (DRG).Morphological observations showed that mGluR2-immunoreactivity was mainly distributed in cellular plasma of neurons in DRG.The counting number results indicated that 35.84% of DRG neurons were mGluR2-immunoreactive (ir).On the other hand,82.61% of mGluR2-ir cells were the small-diameter neurons (diameter＜30 μm),5.79% of which were the medium-diameter neurons (diameter30-50μm) and 11.59% of which was the large-diameter neurons (diameter＞50 tun).Furthermore,42.45% and 79.78% of mGiuR2-ir cells was individually co-localized with ASIC3-or TRPVI-ir in small-diameter neurons in the double-labeled immunofluorescence sections.The present results suggest that mGhiR2 mainly exists in small neurons of the DRG,which are regarded as nociceptors consisting of AS-and C-fibers.While mGluR2 is highly co-localized with ASIC3 and TRPV1,implying their potential relationship in DRG may be involved in mechanical hypersensitivity and thermal hypersensitivity.