Mechanisms of deafferentation pain : examination in human and animal central nervous systems

在去传入性疼痛患者的脊髓背角和丘脑中发现高频放电的神经元。我们密切关注高频放电神经元(超活动神经元)与去传入痛的关系。在人类，在植入深刺激电极之前，细胞外的单一活动是由微电极记录的。在Vc核记录到大量的高活性神经元。间期直方图有三种类型的放电模式。因此，NDC激动剂尼卡地平周围静脉注射苯妥英钠后，Me高活动神经元表现出短暂的放电抑制。在动物实验中，按照Lombard等人(1979)的方法，雄性Wistar大鼠一侧背根从C5到Th1被切断。术后几个月，在丘脑内侧核和丘脑内侧丘脑记录到高活性神经元。多动神经元的放电模式和分布与人类非常相似。这些高活性神经元不受电刺激丘脑、丘脑、丘脑等核的影响。苯二氮卓类及其刺激物的PPI阳离子表现为燃烧的减少，而谷氨酸的放射治疗则表现为燃烧的增加。而GABA和NMDA拮抗剂MK-801则表现出明显的放电抑制作用。这些结果提示，过度活跃的神经元可能与谷氨酸能，尤其是NMDA和GABA能受体或纤维有关。

Neurones with high- frequency dischargew ere found in the spinal dorsal horn and the thalamus of deaffer entation pain patients. We paid close attention to the high- frequency discharging neurones (hyper active neurones) in relation to deaffere ntation pain.In human, prior to implantation of the deeps timulating electrodes, extracellular unitary activity was recorded by microelectrodes. A significant number of hyperactive neurones were recorded from the Vc nucleus. There were three types of discharge patterns in interval histograms. So me hyperactive neurones showed firing suppuression for a short time peri odb y intravenous administration of p henytoin a ndC alciuma ntagonist (Nicardipine).In a nimal experiments, unilateral dorsal roots ectioning from C5 to Th1 were made in male Wistarr ats according to the method of Lombard et al(1979). A few months after the operation, hyperactive neurones were recorded from the thalamic nuclei and lemniscus medialis. The firing patterns and distri bution of hyperactive neurones were very similar to those of humans. These hyper active neurones were unaffected by electrical stimulation of t hen ucleus r aphe d or salis and I ocus c eruleus. A ppi cation of benzodiazepine an d barb it ur ate showed reduction of firing.lontophoretical application of glutamate showed an in crease in firing. In contrast, GABA and NMDA antagonist MK- 801 showed remarkable firing suppression. These results suggest that hyperactive neurone may correlate with the glutamatergic, especially NMDA and GABA ergic receptor or fibers.