摘要
目的观察伏核(NAc)注射γ-氨基丁酸(GABA)后,NAc中痛反应神经元的放电变化以及荷包牡丹碱(Bic)对GABA的阻断效应,研究GABA与NAc在痛觉信息通路中的作用。方法在60只成年Wistar大鼠上采用NAc内注药,以串脉冲刺激坐骨神经作为伤害性刺激,玻璃微电极细胞外记录痛反应神经元的放电变化。结果(1)NAc内分别注射GABA25、50、75μg/μl能够使正常大鼠NAc中痛兴奋神经元(Pain excitation neurons,PEN)的痛诱发放电频率减少,潜伏期延长;痛抑制神经元(Pain inhibition neurons,PIN)的痛诱发放电频率增加,诱发放电完全抑制时程缩短。PEN与PIN的反应与GABA剂量间呈量效关系;(2)侧脑室注入GABAA受体拮抗剂Bic能够阻断其上述效应。结论GABA可通过同时影响NAc中PEN和PIN的放电活动而产生镇痛效应。
Objective : To study the roles of γ-aminobutyric acid (GABA) and nucleus accumbens (NAc) in pain modulation, and the effects of GABA injected into NAc on the discharge activities of pain-related neurons in NAc. Methods: Extracellular recordings with glass microdectrode in 60 Wistar rats and NAc injection were used in the experiment. Results: (1) Injection of GABA (25, 50, 75 μg/μl) into NAc caused a decrease in the pain-evoked discharge frequency and the prolongation of latency of pain-excitation neurons (PEN) , while increased the pain related discharge frequency and shortened the inhibitory duration of pain-inhibition neurons (PIN). (2) GABAA-receptor antagonist (bicuculline) injected i. c. v. could antagonize the GABA-induced effects. Conclusion: Through influencing the PEN and PIN of NAc, GABA may play an important role in relieving pain.
出处
《中国疼痛医学杂志》
CAS
CSCD
北大核心
2005年第6期349-353,共5页
Chinese Journal of Pain Medicine
基金
国家自然科学基金资助课题(30240058)