Transient receptor potential vanilloid 1 (TRPV1) modulates pain. Studies have indicated that TRPV1 is upregulated in the spinal dorsal horn in the neuropathic pain model, but its mechanism is unknown. Here, we examined the mechanism by which TRPV1 modulates neuropathic pain by employing partial sciatic nerve ligation (pSNL) in adult male C57BL/6 J (wild-type: WT) and TRPV1 knockout (Trpv1-/-) mice. We analyzed mechanical/heat sensitivities (von Frey test/hot plate test) and glial/neuronal activities (Iba-1/GFAP/FosB by immunofluorescence) in laminae I and II in the L5 ipsilateral dorsal horn of the spinal cord. Mechanical/heat sensitivities, expression levels of microglial Iba-1 and astrocytic GFAP, and the number of FosB-positive neurons were significantly increased on days 7 and 14 in the pSNL group compared with the sham-operated and non-operated groups of both WT and Trpv1-/- mice. While mechanical sensitivity was comparable between WT and Trpv1-/- mice, the threshold against heat sensitivity was markedly prolonged in Trpv1-/- than WT mice on day 14 after pSNL. Conversely, the increment of FosB positive neurons was significantly attenuated in Trpv1-/- than WT mice on days 7 and 14 after pSNL. These results suggest that TRPV1 may modulate thermal perception via increased astrocytes in the dorsal horn of the spinal cord.

瞬时受体电位香草素 1 (TRPV1) 调节疼痛。研究表明，在神经性疼痛模型中，TRPV1在脊髓背角上调，但其机制尚不清楚。在这里，我们通过在成年男性 C57BL/6 J（野生型：WT）和 TRPV1 敲除（Trpv1-/-） 老鼠。我们分析了脊髓 L5 同侧背角椎板 I 和 II 的机械/热敏感性（von Frey 测试/热板测试）和神经胶质/神经元活动（免疫荧光法 Iba-1/GFAP/FosB）。与 WT 的假手术组和非手术组相比，pSNL 组第 7 天和第 14 天的机械/热敏感性、小胶质细胞 Iba-1 和星形胶质细胞 GFAP 的表达水平以及 FosB 阳性神经元的数量显着增加和Trpv1-/-小鼠。虽然 WT 和Trpv1-/-小鼠的机械敏感性相当，但 Trpv1 - /-对热敏感性的阈值显着延长在 pSNL 后第 14 天比 WT 小鼠。相反，在 pSNL后第 7 天和第 14 天， Trpv1-/-中 FosB 阳性神经元的增加明显低于 WT 小鼠。这些结果表明，TRPV1 可能通过增加脊髓背角的星形胶质细胞来调节热感知。