阿片受体参与催产素对大鼠海马CA1神经元诱发放电的调制作用

目的 :探讨侧脑室注射催产素 (oxytocin ,OT)对大鼠左背侧海马CA1神经元诱发放电的影响以及OT与阿片受体之间可能的相互作用。方法 :应用细胞外记录单位放电技术 ,通过电刺激坐骨神经诱导神经元诱发放电。结果 :侧脑室分别注射 1,10和 10 0ng·(5 μl) -1OT使海马CA1神经元诱发放电频率明显降低 ,剂量依赖关系明显 ,OT对CA1神经元诱发放电的抑制作用可被侧脑室预先注射催产素受体拮抗剂d(CH2 ) 5 OVT 2 0 0ng·(2 .5 μl) -1所阻断 ;侧脑室注射纳洛酮 1μg·(2 .5 μl) -1可明显减弱OT 10ng·(5 μl) -1的作用。结论 :OT通过激活OT受体可抑制海马CA1神经元对外周传入电信号的反应 ,中枢内阿片受体在其中也起着重要作用。

Modulation Effect of Oxytocin on Evoked Discharge of Hippocampal CA1 Neurons in Rats

Objective: To investigate the effect of oxytocin(OT) administered by intracerebroventricularly(i.c.v) on evoked discharge of left dorsal hippocampal CA1 neurons in rats and the possible interaction between oxytocinergic and opioidergic system. Methods: Extracellular single-unit recording technique and electrical stimulation of the sciatic nerves.Results: OT\1,10 and 100 ng·(5 μl) -1 \] administered by intracerebroventricularly decreased the evoked discharge of hippocampal CA1 neurons in a dose-dependent manner. The inhibitory effect of OT\could be blocked by pretreated i.c.v injection of d(CH_2)_5-OVT \200 ng·(2.5 μl) -1 ,OT receptor antagonist\]. Intracerebroventricular injection of naloxone could attenuate the effect of OT \ significantly. Conclusion: The results demonstrated that OT can inhibit the electrical activities of hippocampal CA1 neurons to external electrical signal through activating the oxytocin receptor.Moreover,opioid receptor in central nervous system is involved in the inhibitory effect of OT.