南美洲响尾蛇神经毒素对丘脑束旁核神经元痛诱发放电的影响  

The Influence of Crotoxin on Pain-evoked Discharge of Neurons in Thalamic Parafascicular Nucleus

作　　者：吴殿臣[1] 蒋星红[1] 龚珊[1] 秦正红[2] 周希平[3] 

机构地区：[1]苏州大学医学院神经生物学教研室,215123 [2]苏州大学医学院药理学教研室,江苏苏州215123 [3]苏州大学医学院生理学教研室,导师215123

出　　处：《苏州大学学报（医学版）》2006年第5期728-733,共6页Suzhou University Journal of Medical Science

基　　金：美国Receptogen公司;苏州大学基础医学系神经细胞分化发育重点实验室资助

摘　　要：目的以大鼠丘脑束旁核(Pf)神经元痛诱发放电为指标,来验证南美洲响尾蛇神经毒素(crotoxin)的镇痛作用。方法用玻璃微电极细胞外记录Pf神经元的单位放电,用电脉冲刺激坐骨神经作为伤害性刺激,诱发伤害性反应,观察侧脑室注射(i.c.v.)不同剂量crotoxin后痛诱发放电的变化。用i.c.v.注射生理盐水作为阴性对照,i.c.v.注射吗啡作为阳性对照。结果(1)侧脑室注射大剂量crotoxin(0.65μg/kg)后,Pf神经元的痛放电频率和持续时间明显降低,但放电潜伏期延长;(2)侧脑室注射中等剂量(0.4μg/kg)和小剂量(0.2μg/kg)crotoxin后,Pf神经元的痛放电频率和持续时间也降低,潜伏期也延长,但幅度依次递减。结论crotoxin对丘脑Pf神经元的痛诱发放电有明显的抑制作用,提示crotoxin有镇痛作用,且这种镇痛作用有一定的剂量依赖性。Objective To verify the analgesic effect of crotoxin through oberservation on the painevoked discharge of neurons in parafascicular nucleus. Methods Trains of electric impulses applied to the sciatic nerve were used as noxious stimuli to evoke nociceptive response, and the change of frequency, latency and duration of pain-evoked discharge after intracerebroventricularii, c. v. ） injection of different doses of Crotoxin was recorded extracellularly with glass microelectrode from parafascicular nu- cleus. Normal saline and morphine were used as negative and positive control, respectively. Result （ 1 ） The frequency and duration of pain-evoked discharge of thalamic parafascicular neurons were obviously depressed while the latency was prolonged after intracerebroventricular（ i. c. v. ） injection of large dose of crotoxin; （2） Frequency and duration of pain-evoked discharge were also depressed, and the latency was also prolonged after i. c.v. injection of a medium and small dose of crotoxin, but the extent was reduced in turn. Conclusion Crotoxin has analgesic effect which is dose-dependent.

关 键 词：南美洲响尾蛇神经毒素(crotoxin) 束旁核 单位放电 镇痛 

分 类 号：R338.8[医药卫生—人体生理学]