Schomburg E D, Jankowska E, Wiklund Fernström K
Department of Physiology, University of Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany.
Neurosci Res. 2000 Dec;38(4):447-50. doi: 10.1016/s0168-0102(00)00196-6.
Effects of noxious stimulation of the skin by radiant heat were tested on responses of first order interneurones in reflex pathways from group II muscle afferents in mid-lumbar, lower-lumbar and sacral segments of the spinal cord. In mid- and lower-lumbar segments both background discharges and monosynaptically evoked responses of intermediate zone interneurones were facilitated. Those of mid-lumbar dorsal horn interneurones were also facilitated suggesting that both these interneuronal populations contribute to the facilitation of flexion reflexes by nociceptors. In contrast, the dominating effects of noxious heat on sacral dorsal horn group II interneurones were inhibitory. The effects evoked by selective activation of C fibres, after A-delta fibres had been blocked by TTX, were similar to those obtained before TTX application.
通过对脊髓中腰段、腰下段和骶段II类肌传入神经反射通路中一级中间神经元的反应进行测试，研究了辐射热对皮肤的伤害性刺激的影响。在中腰段和腰下段，中间带中间神经元的背景放电和单突触诱发反应均得到易化。中腰段背角中间神经元的反应也得到易化，这表明这两类中间神经元群体均有助于伤害感受器对屈肌反射的易化作用。相比之下，伤害性热对骶段背角II类中间神经元的主要作用是抑制性的。在用河豚毒素阻断Aδ纤维后，选择性激活C纤维所诱发的效应与应用河豚毒素之前所获得的效应相似。
