Desmeules J A, Kayser V, Weil-Fuggaza J, Bertrand A, Guilbaud G
INSERM U 161, Unité de Recherches de Physiopharmacologie du Système Nerveux, Paris, France.
Neuroscience. 1995 Aug;67(4):941-51. doi: 10.1016/0306-4522(95)00098-4.
This study evaluated the effect of surgical sympathectomy on pain-related behaviours in a well established model of peripheral mononeuropathy produced by loose ligatures around the common sciatic nerve in the rat. Behavioural abnormalities include spontaneous abnormal position of the hindpaw after the nerve constriction, indicative of "spontaneous pain", and changes in responses to mechanical or thermal stimuli applied to this paw. These changes are usually maximal at week 2 after the surgery, stable until weeks 3-4, and disappear between weeks 8 and 12. To assess the role of the sympathetic nervous system in the development and persistence of these abnormalities, four groups of rats were behaviourally tested: (i) rats receiving a complete sham surgery, (ii) rats with a sciatic nerve constriction produced by loose ligatures around the common nerve trunk plus a sham sympathectomy, (iii) rats receiving a lumbar sympathectomy with a sham nerve ligature, and (iv) rats receiving a simultaneous surgical lumbar sympathectomy and a sciatic nerve constriction. The efficacy of the sympathectomy was assessed by the measure of the noradrenaline level in the sciatic nerve. Sympathectomy reduced selectively or even prevented the abnormal reaction to cold temperature and to heat (45 degrees C) in rats with a peripheral mononeuropathy. In contrast, the abnormal reaction to mechanical pressure was not influenced, and the behavioural abnormalities indicating spontaneous pain were still present. Sympathectomy alone resulted in a reduction of the vocalization threshold to pressure on both hindpaws, but also a short-lasting increased tolerance to cold immersion. This study confirms the selective role of the sympathetic nervous system in affecting the development and maintenance of some abnormal pain-related behaviours to thermal stimuli in rats with a moderate, but persistent, constriction of one sciatic nerve.
本研究在一个成熟的大鼠坐骨神经周围松结扎所致外周单神经病模型中，评估了手术交感神经切除术对疼痛相关行为的影响。行为异常包括神经结扎后后爪的自发异常姿势，这表明存在“自发痛”，以及对施加于该爪的机械或热刺激的反应变化。这些变化通常在手术后第2周达到最大值，在第3 - 4周保持稳定，并在第8至12周之间消失。为了评估交感神经系统在这些异常的发生和持续中的作用，对四组大鼠进行了行为测试：(i)接受完全假手术的大鼠；(ii)通过在坐骨神经干周围松结扎造成坐骨神经缩窄并进行假交感神经切除术的大鼠；(iii)接受腰交感神经切除术并进行假神经结扎的大鼠；(iv)同时接受腰交感神经切除术和坐骨神经缩窄的大鼠。通过测量坐骨神经中的去甲肾上腺素水平来评估交感神经切除术的效果。交感神经切除术选择性地减少甚至预防了外周单神经病大鼠对低温和热（45摄氏度）的异常反应。相比之下，对机械压力的异常反应未受影响，且表明自发痛的行为异常仍然存在。单独的交感神经切除术导致对双后爪压力的发声阈值降低，但对冷浸的耐受性也有短暂增加。本研究证实了交感神经系统在影响一侧坐骨神经中度但持续缩窄的大鼠对热刺激的某些异常疼痛相关行为的发生和维持中的选择性作用。
