Changes in properties of substantia gelatinosa neurons after surgical incision in the rat -: In vivo patch-clamp analysis
Changes in properties of substantia gelatinosa neurons after surgical incision in the rat -: In vivo patch-clamp analysis
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DOI：
10.1097/00000542-200603000-00009
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发表时间：
2006-03-01
期刊：
影响因子：
8.8
通讯作者：
Namiki, A
中科院分区：
文献类型：
--
作者：
Kawamata, M;Furue, H;Namiki, A
背景：伤害性信息通过A三角洲和C传入纤维传递到胶状质，这一过程在病理生理条件下伤害性加工的可塑性变化中起着重要作用。本研究采用在体膜片钳技术研究了手术切开后胶状质神经元特性的变化及其对利多卡因全身用药的敏感性。方法：在乌拉坦麻醉下，在电流钳制模式下，记录大鼠后肢毛皮切开1 cm前后胶状质神经元的自发活动和对无害性喷气刺激和伤害性挤压刺激的反应。结果：18个胶状质神经元在切开后30min获得稳定的记录，其中多感受性神经元8个，伤害性感受性神经元5个，阈值下神经元5个。多数多感受性和伤害性神经元的动作电位放电在伤口闭合完成后立即消失，23%的胶状质神经元观察到持续的自发动作电位放电。切开后，这些胶状质神经元的反应性增加，但阈值下神经元的反应性没有增加。结论：(1)切开后胶状质神经元特性的改变因胶状质神经元的分类而异；(2)全身应用利多卡因可逆转切开损伤后胶状质神经元反应性的增强。
Background: Noxious information through A delta and C afferent fibers is transmitted to substantia gelatinosa, a process that plays an important role in plastic changes of nociceptive processing in pathophysiological conditions. In this study, changes in properties of substantia gelatinosa neurons and their sensitivity to systemic administration of lidocaine after surgical incision were investigated using the in vivo patch-clamp technique.Methods: Under urethane anesthesia, in the current clamp mode, spontaneous activities and responses of substantia gelatinosa neurons to nonnoxious air-puff stimuli and noxious pinch stimuli were recorded before and after 1-cm-long incisions had been made in hairy skin of the hindquarters of rats. Systemic administration of lidocaine (2 mg/kg) was applied at 30 min after the incision.Results: Stable recordings for 30 min or more after the incision were obtained from 18 substantia gelatinosa neurons that were classified as multireceptive (n = 8), nociceptive (n = 5), and subthreshold (n = 5) neurons. Action potential firing disappeared immediately after completion of the wound closure in most multireceptive and nociceptive neurons, and sustained spontaneous action potential firing was observed in 23% of these substantia gelatinosa neurons. Responsiveness of these substantia gelatinosa neurons, but not that of subthreshold neurons, increased after the incision. Systemic administration of lidocaine suppressed spontaneous firings of action potentials of the substantia gelatinosa neurons and reversed the increased responsiveness of the neurons.Conclusions: The results suggest that (1) changes in properties of substantia gelatinosa neurons after incision vary depending on the classification of substantia gelatinosa neurons and (2) systemic administration of lidocaine can reverse increased responsiveness of substantia gelatinosa neurons after incision injury.