Altered nociceptive C fibre input to primary somatosensory cortex in an animal model of hyperalgesia
Altered nociceptive C fibre input to primary somatosensory cortex in an animal model of hyperalgesia
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DOI：
10.1016/j.ejpain.2010.09.009
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发表时间：
2011-04-01
影响因子：
3.6
通讯作者：
Schouenborg, Jens
中科院分区：
文献类型：
--
作者：
Jensen, Tanja;Granmo, Marcus;Schouenborg, Jens
评估药物和各种治疗的潜在镇痛作用很大程度上取决于有效的疼痛动物模型。由于初级体感 (SI) 皮层可能在处理疼痛的感觉方面发挥重要作用，因此我们在此评估监测 SI 皮层伤害性 C 纤维诱发电位是否可以提供有关大鼠痛觉过敏相关中枢变化的有用信息。足跟 UV-B 照射后 20-24 小时，记录前肢和后肢 SI 皮层的触觉和 CO(2)-激光 C 纤维诱发电位 (LCEP)，剂量可产生痛觉过敏的行为症状。受照射皮肤的 LCEP 在持续时间上显着增加，但在幅度上没有显着变化，以曲线下面积 (AUC) 测量。相比之下，来自受照射皮肤附近皮肤部位的后肢 SI 皮质中的 LCEP 显示持续时间或发作潜伏期没有增加，但在紫外线照射后其幅度显着增加。从前肢皮肤引出的前肢或后肢 SI 皮质中的 LCEP 在幅度上没有变化，但在后肢 SI 皮质中显着延迟。曲马多是一种已知可减轻痛觉过敏的中枢镇痛药，它引起的变化抵消了 UV-B 照射从后爪传输到 SI 皮层所产生的变化，但对前肢皮肤 LCEP 的时程没有显着影响。触觉诱发电位不受 UV-B 照射或曲马多的影响。我们得出的结论是，与痛觉过敏相关的感觉处理的改变反映在 SI 皮质中 LCEP 的改变中。 (C) 2010 年欧洲联合会国际疼痛研究协会分会。由爱思唯尔有限公司出版。保留所有权利。
Evaluating potentially analgesic effects of drugs and various treatments is critically dependent on valid animal models of pain. Since primary somatosensory (SI) cortex is likely to play an important role in processing sensory aspects of pain, we here assess whether monitoring SI cortex nociceptive C fibre evoked potentials can provide useful information about central changes related to hyperalgesia in rats. Recordings of tactile and CO(2)-laser C fibre evoked potentials (LCEPs) in forelimb and hind limb SI cortex were made 20-24 h after UV-B irradiation of the heel at a dose that produced behavioural signs of hyperalgesia.LCEPs from irradiated skin increased significantly in duration but showed no significant change in magnitude, measured as area under curve (AUC). By contrast, LCEPs in hind limb SI cortex from skin sites nearby the irradiated skin showed no increase in duration or onset latency but increased significantly in magnitude after UV-Birradiation. The LCEPs in forelimb or hind limb SI cortex elicited from forelimb skin did not change in magnitude, but were significantly delayed in hind limb SI cortex. Tramadol, a centrally acting analgesic known to reduce hyperalgesia, induced changes that counteracted the changes produced by UV-B irradiation on transmission to SI cortex from the hind paw, but had no significant effect on time course of LCEPs from forelimb skin. Tactile evoked potentials were not affected by UV-B irradiation or tramadol. We conclude that altered sensory processing related to hyperalgesia is reflected in altered LCEPs in SI cortex. (C) 2010 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.