Abstract：
UNASSIGNED: Neuropathic pain is characterized by long-lasting, intractable pain. Sciatic nerve ligation is often used as an animal model of neuropathic pain, and the spared nerve injury (SNI) model, in which the common peroneal nerve (CPN) and tibial nerve (TN) are ligated, is widely used. In the present study, we evaluated the analgesic effect of a cholinergic agonist, carbachol, on a neuropathic pain model prepared by sural nerve (SN) ligation in mice.
UNASSIGNED: The SN was tightly ligated as a branch of the sciatic nerve. Mechanical and thermal allodynia, and hyperalgesia were assessed using von Frey filaments and heat from a hot plate. The analgesic effects of intracerebroventricularly-administered morphine and carbachol were compared.
UNASSIGNED: SN ligation resulted in a significant decrease in pain threshold for mechanical stimulation 1 day after ligation. In response to thermal stimulation, allodynia was observed at 50°C and hyperalgesia at 53 and 56°C 3 days after ligation. Content of thiobarbituric acid reactive substances (TBARS) in the spinal cord increased significantly at 6 and 12 h after ligation. Acetylcholine content of the spinal cord also increased at 5 and 7 days after ligation. Intracerebroventricular administration of carbachol at 7 days after ligation produced a marked analgesic effect against mechanical and thermal stimuli, which was stronger and longer-lasting than morphine at all experimental time points.
UNASSIGNED: These findings suggest that cholinergic nerves are involved in allodynia and hyperalgesia of the SN ligation neuropathic pain model.
UNASSIGNED: The SN was tightly ligated as a branch of the sciatic nerve. Mechanical and thermal allodynia, and hyperalgesia were assessed using von Frey filaments and heat from a hot plate. The analgesic effects of intracerebroventricularly-administered morphine and carbachol were compared.
UNASSIGNED: SN ligation resulted in a significant decrease in pain threshold for mechanical stimulation 1 day after ligation. In response to thermal stimulation, allodynia was observed at 50°C and hyperalgesia at 53 and 56°C 3 days after ligation. Content of thiobarbituric acid reactive substances (TBARS) in the spinal cord increased significantly at 6 and 12 h after ligation. Acetylcholine content of the spinal cord also increased at 5 and 7 days after ligation. Intracerebroventricular administration of carbachol at 7 days after ligation produced a marked analgesic effect against mechanical and thermal stimuli, which was stronger and longer-lasting than morphine at all experimental time points.
UNASSIGNED: These findings suggest that cholinergic nerves are involved in allodynia and hyperalgesia of the SN ligation neuropathic pain model.
摘要：
■神经性疼痛的特点是持久的，顽固性疼痛.坐骨神经结扎常被用作神经性疼痛的动物模型,和备用神经损伤（SNI）模型，其中腓总神经（CPN）和胫神经（TN）结扎，被广泛使用。在本研究中,我们评估了胆碱能激动剂的镇痛作用，卡巴胆碱,在小鼠腓肠神经（SN）结扎制备的神经性疼痛模型上。
■SN紧密结扎为坐骨神经的分支。机械性和热性异常性疼痛，和痛觉过敏使用vonFrey丝和来自热板的热量进行评估。比较了脑室内给药吗啡和卡巴胆碱的镇痛效果。
■SN结扎导致结扎后1天机械刺激的疼痛阈值显着降低。为了响应热刺激，结扎后3天，在50°C观察到异常性疼痛，在53和56°C观察到痛觉过敏。结扎后6和12h，脊髓中硫代巴比妥酸反应性物质（TBARS）的含量显着增加。脊髓的乙酰胆碱含量也在结扎后5天和7天增加。结扎后7天，侧脑室内给药卡巴胆碱对机械和热刺激产生了明显的镇痛作用。在所有实验时间点都比吗啡更强且更持久。
■这些发现表明胆碱能神经参与SN结扎神经性疼痛模型的异常性疼痛和痛觉过敏。
■SN紧密结扎为坐骨神经的分支。机械性和热性异常性疼痛，和痛觉过敏使用vonFrey丝和来自热板的热量进行评估。比较了脑室内给药吗啡和卡巴胆碱的镇痛效果。
■SN结扎导致结扎后1天机械刺激的疼痛阈值显着降低。为了响应热刺激，结扎后3天，在50°C观察到异常性疼痛，在53和56°C观察到痛觉过敏。结扎后6和12h，脊髓中硫代巴比妥酸反应性物质（TBARS）的含量显着增加。脊髓的乙酰胆碱含量也在结扎后5天和7天增加。结扎后7天，侧脑室内给药卡巴胆碱对机械和热刺激产生了明显的镇痛作用。在所有实验时间点都比吗啡更强且更持久。
■这些发现表明胆碱能神经参与SN结扎神经性疼痛模型的异常性疼痛和痛觉过敏。
