The contribution of spinal neuronal changes to development of prolonged, tonic nociceptive responses of the cat induced by subcutaneous bee venom injection
The contribution of spinal neuronal changes to development of prolonged, tonic nociceptive responses of the cat induced by subcutaneous bee venom injection
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DOI：
10.1016/s1090-3801(98)90034-9
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发表时间：
1998-01-01
期刊：
影响因子：
--
通讯作者：
Li, HL
中科院分区：
文献类型：
--
作者：
Chen, J;Luo, C;Li, HL
为阐明组织损伤后持续性疼痛的神经生理机制，本研究旨在探讨皮下注射对组织损伤后持续性疼痛的影响。蜂毒注射对麻醉猫和清醒猫背角伤害性神经元反应和行为反应的影响。还进行了平行比较研究，以比较s.c.使用细胞外单单位记录技术研究蜂毒和福尔马林注射对神经元反应的影响。结果表明，s.c.蜂毒注射到外周皮肤感受野导致延长，紧张性单相增加的尖峰反应的宽动态范围（WDR）神经元超过1小时，而注射相同体积的车辆没有这样的效果。在蜜蜂毒液之后的60分钟期间的尖峰的平均数目为6.74 +/-2.58尖峰/s（n=10），其显示出放电速率比背景活动（2.23 +/-0.96尖峰/s）显著增加。行为观察表明，s.c.蜂毒注射到后爪的背部也产生了一个延长的、紧张性的单相反应，表明猫中枢神经元的变化可能有助于蜂毒诱导的延长的、紧张性疼痛的发展。s.c.蜂毒可被单剂量静脉注射吗啡抑制，并可被纳洛酮恢复。用利多卡因阻断坐骨神经导致蜂毒诱导的神经元放电的完全抑制，表明在s.c.蜂毒是外周依赖性的比较研究表明，蜂毒诱导的神经元反应的持续时间和频率与s.c.福尔马林;然而，WDR神经元对施加到两种化学试剂的注射部位的机械刺激的反应是完全不同的。蜂毒引起WDR神经元的机械反应显著增强，而福尔马林则相反，引起注射部位感觉受体的脱敏，这表明两种强直性疼痛模型可能具有不同的潜在机制。
To elucidate neurophysiological mechanisms of persistent pain induced by tissue injury, the present study was designed to investigate the effects of s.c. bee venom injection on responses of the dorsal horn nociceptive neurons and those of behavior in anesthetized and awake cats, respectively. A parallel comparative study was also performed to compare the effects of s.c. bee Venom and formalin injections on neuronal responses by using an extracellular single-unit recording technique. The present results showed that s.c. bee venom injection into the peripheral cutaneous receptive field resulted in a protracted, tonic monophase of increase in spike responses of wide-dynamic-range (WDR) neurons for more than 1 h, while injection of the same volume of vehicle did not have such an effect. The mean number of spikes during the 60-min period after bee venom was 6.74 +/- 2.58 spikes/s (n=10), which showed a significant increase in firing rate over the background activity (2.23 +/- 0.96 spikes/s). Behavioral observations showed that s.c. bee venom injection into the dorsum of a hind paw also produced a prolonged, tonic single phase of response indicative of pain, suggesting that central neuronal changes may contribute to development of bee venom-induced prolonged, tonic pain in cats. The increased neuronal firing induced by s.c. bee venom could be suppressed by a single dose of i.v. morphine and resumed by naloxone. Blockade of the sciatic nerve with lidocaine resulted in a complete suppression of the bee venom-induced neuronal firing, suggesting that the central neuronal changes following s.c. bee venom are peripherally-dependent. Comparative studies showed that the duration and frequency of the bee venom-induced neuronal responses were comparable to those induced by s.c. formalin; however, responses of WDR neurons to mechanical stimuli applied to the injection site of the two chemical agents were quite different. Bee venom produced a significant enhancement of mechanical responses of WDR neurons, while, on the contrary, formalin produced a desensitization of sensory receptors in the injection site, suggesting that the two tonic pain models may have different underlying mechanisms.