催产素抑制大鼠海马CA1神经元电活动

Oxytocin inhibits electrical activities of hippocampal CA1 neurons in rats

应用细胞外记录单位放电技术 ,观察催产素 (oxytocin ,OT)对大鼠左背侧海马CA1神经元自发和诱发电活动的作用以及酚妥拉明对OT作用的影响。侧脑室注射 1,10和 10 0ng 5 μLOT分别使海马CA1内 6 0 % (9 15 )、73 3% (11 15 )和 75 % (9 12 )的神经元自发放电频率降低 ;不同剂量OT也可抑制神经元对电刺激坐骨神经产生的诱发放电且剂量依赖关系明显。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)能阻断OT(10ng 5 μL)对CA1神经元自发和诱发放电的抑制作用。酚妥拉明 (10ng 2 5 μL)可明显减弱OT(10ng 5 μL)的作用。结果表明OT对海马CA1神经元自发和诱发电活动的抑制作用是通过OT受体介导的 ,也与α 肾上腺素能受体有关。

The effects of oxytocin(OT) on spontaneous and evoked discharges of left dorsal hippocampal CA1 neurons were investigated with extracellular single-unit recording technique.All the drugs were administeredintracerebroventricularly. The results demonstrated that OT(1,10 and 100ng/5μL) decreased the spontaneous discharge frequencyby 60%(9/15),73.3%(11/15) and 75%(9/12) in hippocampal CA1 neurons.In addition, different doses of OT inhibited the evoked discharges induced by electrical stimulation of the sciatic nerves in a dose-dependent manner.The inhibitory effects of OT(10ng/5μL) on spontaneous and evoked discharges could be blocked by pretreatment with OT receptor antagonist, [d(CH 2) 5-OVT](200ng/2.5μL). Phentolamine could attenuate the effects of OT(10ng/5μL) significantly. It seems that the effects of OT on spontaneous and evoked discharges in hippocampal CA1 neurons might be mediated by OT receptor and related to α-adrenoceptor.