摘要
目的 研究脑室注射谷氨酸 (Glu)对吗啡引起的大鼠两侧丘脑束旁核痛反应神经元电活动的影响。 方法 以电脉冲刺激右侧坐骨神经作为伤害性刺激 ,同时用两根玻璃微电极细胞外记录两侧丘脑束旁核神经元的放电。 结果 (1)腹腔注射吗啡 (10mg /kg)可抑制痛兴奋神经元 (PEN)和加强痛抑制神经元 (PIN)的电活动 ;(2 )脑室注射Glu(1.5 μg /10 μl)能对抗吗啡引起PEN放电的抑制作用和PIN电活动的加强作用 ;(3)Glu可同时对抗吗啡所引起束旁核中PEN和PIN的电变化。 结论 Glu对吗啡引起的镇痛效应有明显的对抗作用 ,提示Glu在中枢伤害性信息整合方面发挥重要作用。
Objective To study the effects of morphine on the simultaneously recorded electric activities of pain-related neurons in thalamus nucleus parafascicularis in both sides of rat brain after intracerebroventricular (i.c.v.) injection of Glu. Methods Trains of the electric impuses applied to the right sciatic nerve were used as noxious stimuli, the discharges of neurons were led out at one time by extracellular recording method with two glass microelectrodes in both sides of thalamus nucleus parafascicularis. Results ⑴ Intraperitoneal (i.p.) injection of morphine (10 mg / kg) resulted in an inhibition of evoked response of the pain-excitation neurons (PEN) as well as an excitation of evoked response of the pain-inhibition neurons (PIN); ⑵ Both the inhibitory effect on the electric discharges of PEN and the excitatory effect on the electric discharges of PIN of morphine were almost eliminated by i.c.v. administration of Glu at the dose of 1.5 μg/ 10 μl; ⑶ The electric changes of PEN and PIN in nucleus parafascicularis induced by morphine were simultaneously antagonized by Glu. Conclusion The results suggest that Glu is antagonistic to the antinociceptive effect of morphine, and it may play an essential role in integration of the pain information.
基金
国家自然科学基金资助项目 (3 0 2 40 0 5 8)
黑龙江省科技攻关资助项目 (GC0 1C14 1 0 1)
黑龙江省青年基金资助项目(QCO3C2 2 )
