大鼠在体海马CA1区场电位引导新技术——刺激/记录/给药一体化装置的开发和应用

A Novel Electrophysiological Technique for Rat Hippocampal CA1 Area Field Potential Recording in vivo:Development and Application of Stimulation/Recording/Drug Delivery System

大鼠海马场电位记录是研究学习记忆的一个重要手段,尤以在体记录更具生理学意义.为克服目前在体海马场电位记录的弊端和诸多不便,提高实验效率,设计并完善了一套简便易行,融刺激、记录、给药于一体的大鼠海马在体CA1区场电位实验技术.将雄性SD大鼠麻醉后固定于脑立体定位仪上,利用自制的刺激/记录/给药联合装置,引导海马CA1区场兴奋性突触后电位(fEPSP).结果表明,使用刺激/记录/给药联合装置能长时间稳定记录由测试刺激诱发的海马CA1区fEPSP.高频刺激条件下,能成功诱导早期时相长时程增强(E-LTP)和晚期时相型长时程增强(L-LTP).海马内注射AMPA受体阻断剂CNQX(100μmol/L,1μl)可迅速抑制fEPSP,注射NMDA受体拮抗剂AP-5(100μmol/L,1μl)可明显压抑LTP,药物发挥作用的时间较侧脑室给药明显缩短,剂量减少.采用此联合装置还成功实现了PPF的稳定记录.总之,采用刺激/记录/给药一体化技术进行在体海马CA1区场电位记录的特点是简单、可靠、高效,可以为开展脑认知功能活动的电生理学研究奠定良好的基础.

It is an important means to record rat hippocampal field potential,especially in vivo recording,in the study of learning and memory.To overcome the disadvantages and inconvenience in current hippocampal field potential recording and raise in vivo experimental efficiency,stimulation/recording/drug delivery system for in vivo hippocampal field potential recording was developed and applied.Anesthetized SD rats were fixed in a stereotaxic device and a homemade stimulation/recording/drug delivery system was used to record field excitatory postsynaptic potential（fEPSP） in hippocampal CA1 area.The results showed that fEPSPs were easily evoked by nearly every test stimulus and maintained steadily for a long time by using the stimulation/recording/drug delivery system;high frequency stimulation（HFS） successfully induced early-phase LTP（E-LTP） and 1ate-phase LTP（L-LTP）;the baseline fEPSPs and LTP were promptly and effectively suppressed by intrahippocampal injection（IH） of AMPA receptor antagonist CNQX（100 μmol/L,1 μl） and NMDA receptor antagonist AP-5（100 μmol/L,1 μl）,respectively,with a shorter latency and a reduced dose compared with intracerebraventricular injection（ICV）;the induction and recording of paired pulse facilitation（PPF） were also considerably easy and stable using the combination device.In short,the simplicity,reliability and high efficiency of stimulation/recording/drug delivery combination system in recording in vivo rat hippocampal CA1 area field potential make it more practical in the research of synaptic plasticity,and this technique established an important foundation for the study of higher cognitive brain function.