One maladaptive consequence of inflammatory stimulation of the afferent somatosensory system is the manifestation of inflammatory pain. We established and characterized a neuroglial primary culture of the rat superficial dorsal horn (SDH) of the spinal cord to test responses of this structure to neurochemical, somatosensory, or inflammatory stimulation. Primary cultures of the rat SDH consist of neurons (43%), oligodendrocytes (35%), astrocytes (13%), and microglial cells (9%). Neurons of the SDH responded to cooling (7%), heating (18%), glutamate (80%), substance P (43%), prostaglandin E₂ (8%), and KCl (100%) with transient increases in the intracellular calcium [Ca²⁺]_i. Short-term stimulation of SDH primary cultures with LPS (10 μg/ml, 2 h) caused increased expression of pro-inflammatory cytokines, inflammatory transcription factors, and inducible enzymes responsible for inflammatory prostaglandin E₂ synthesis. At the protein level, increased concentrations of tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6) were measured in the supernatants of LPS-stimulated SDH cultures and enhanced TNFα and IL-6 immunoreactivity was observed specifically in microglial cells. LPS-exposed microglial cells further showed increased nuclear immunoreactivity for the inflammatory transcription factors NFκB, NF-IL6, and pCREB, indicative of their activation. The short-term exposure to LPS further caused a reduction in the strength of substance P as opposed to glutamate-evoked Ca²⁺-signals in SDH neurons. However, long-term stimulation with a low dose of LPS (0.01 μg/ml, 24 h) resulted in a significant enhancement of glutamate-induced Ca²⁺ transients in SDH neurons, while substance P-evoked Ca²⁺ signals were not influenced. Our data suggest a critical role for microglial cells in the initiation of inflammatory processes within the SDH of the spinal cord, which are accompanied by a modulation of neuronal responses.

炎症刺激传入躯体感觉系统的一种适应不良后果是炎症性疼痛的表现。我们建立并表征了大鼠脊髓浅背角 (SDH) 的神经胶质原代培养物，以测试该结构对神经化学、体感或炎症刺激的反应。大鼠 SDH 的原代培养物由神经元 (43%)、少突胶质细胞 (35%)、星形胶质细胞 (13%) 和小胶质细胞 (9%) 组成。SDH 的神经元对冷却 (7%)、加热 (18%)、谷氨酸 (80%)、P 物质 (43%)、前列腺素 E ₂ (8%) 和 KCl (100%)做出反应，并在细胞内钙 [Ca ²⁺ ] _i. 用 LPS（10 μg/ml，2 小时）短期刺激 SDH 原代培养物会导致促炎细胞因子、炎症转录因子和负责炎症前列腺素 E ₂合成的诱导酶的表达增加。在蛋白质水平上，在 LPS 刺激的 SDH 培养物的上清液中测量到肿瘤坏死因子-α (TNFα) 和白细胞介素-6 (IL-6) 浓度增加，并在小胶质细胞中观察到增强的 TNFα 和 IL-6 免疫反应性. LPS 暴露的小胶质细胞进一步显示炎症转录因子 NFκB、NF-IL6 和 pCREB ​​的核免疫反应性增加，表明它们的激活。与谷氨酸诱发的 Ca 相比，短期暴露于 LPS 进一步导致物质 P 的强度降低SDH 神经元中的^{2+ -}信号。然而，低剂量 LPS（0.01 μg/ml，24 小时）的长期刺激导致SDH 神经元中谷氨酸诱导的 Ca ²⁺瞬变显着增强，而 P 物质诱发的 Ca ²⁺信号不受影响. 我们的数据表明小胶质细胞在脊髓 SDH 内炎症过程的启动中起着关键作用，伴随着神经元反应的调节。