Department of General Internal and Psychosomatic Medicine, Ruprecht-Karls-University Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
Exp Brain Res. 2013 Feb;224(4):571-80. doi: 10.1007/s00221-012-3337-8. Epub 2012 Nov 18.
Nociceptive information from muscle and skin is differently processed at many levels of the central nervous system. In most articles on this issue, noxious stimuli were used that also excited non-nociceptive receptors. The effects of a pure nociceptive input from muscle or skin on spinal neurones are largely unknown. The aim of the study was to find out whether the Fos-protein expression in dorsal horn neurones induced by an exclusively nociceptive muscle input differs from that of the skin. Fos-proteins are transcription factors that regulate neuronal gene expression and induce neuroplastic effects that are involved in the development of chronic pain. A pure nociceptive input was achieved by tetrodotoxin (TTX) that is known to block all TTX-sensitive afferents and leave the TTX-resistant (TTX-r), presumably nociceptive, afferent fibres intact. We studied the c-Fos and FosB expression in the spinal cord following electrical stimulation of TTX-r afferent fibres in the gastrocnemius-soleus nerve (muscle) and compared it to the sural nerve (skin). In the spinal dorsal horn, the main effect of a TTX-r input from muscle was an increase in FosB (P < 0.05), but not in c-Fos expression (P = 0.51). In contrast, an input from the skin induced both FosB (P < 0.01) and c-Fos expression (P < 0.05). The data indicate that in the spinal, dorsal horn nociceptive input from skin and muscle has different effects on the Fos expression. The only effect of muscle input was an increase in FosB expression while skin input increased both c-Fos and FosB expression.
伤害性信息来自肌肉和皮肤，在中枢神经系统的多个水平上被不同地处理。在这个问题的大多数文章中，使用了也会兴奋非伤害性感受器的有害刺激。来自肌肉或皮肤的纯伤害性传入对脊髓神经元的影响在很大程度上是未知的。该研究的目的是确定由纯粹的肌肉传入引起的背角神经元中的 Fos-蛋白表达是否与皮肤的不同。Fos-蛋白是转录因子，调节神经元基因表达并诱导涉及慢性疼痛发展的神经可塑性效应。通过已知阻断所有 TTX 敏感传入纤维并使 TTX 抗性（TTX-r），可能是伤害性传入纤维完整的河豚毒素（TTX）来实现纯粹的伤害性传入。我们研究了电刺激腓肠肌-比目鱼肌神经（肌肉）中的 TTX-r 传入纤维后脊髓中 c-Fos 和 FosB 的表达，并将其与腓肠神经（皮肤）进行了比较。在脊髓背角，来自肌肉的 TTX-r 传入的主要作用是增加 FosB（P < 0.05），但不增加 c-Fos 表达（P = 0.51）。相比之下，来自皮肤的传入同时诱导了 FosB（P < 0.01）和 c-Fos 表达（P < 0.05）。这些数据表明，在脊髓背角中，来自皮肤和肌肉的伤害性传入对 Fos 表达有不同的影响。肌肉传入的唯一作用是增加 FosB 表达，而皮肤传入增加了 c-Fos 和 FosB 表达。
