γ-氨基丁酸对外侧缰核自发兴奋性突触后电流的节律性调节

发布时间：2018-04-24 10:09

本文选题：缰核 + 昼夜节律　；参考：《吉林大学》2007年硕士论文

【摘要】： 位于上丘脑的缰核在中枢占有显要位置,是边缘前脑至脑干的重要驿站。缰核与昼夜节律起搏器视交叉上核(SCN)有往返的纤维投射,并与松果体在形态和功能上有密切的联系,这两个部位是昼夜节律产生和调节的重要区域。缰核本身也有视网膜纤维投射,而且缰核神经元活动具有明显的昼夜节律性,这些都表明缰核有可能是哺乳动物昼夜节律系统中的重要组成部分。γ-氨基丁酸(GABA)是?SCN?中主要的神经递质,是介导昼夜节律的重要成分。在缰核内有丰富的GABA,而且内侧缰核缺乏?GABA_A受体,外侧缰核具有GABA_A受体,这进一步提示外侧缰核在昼夜节律调节当中的重要作用。本实验采用全细胞膜片钳技术,在缰核脑片上,电压钳模式下,在昼夜周期不同时相(白天:10:00-18:00,夜间:20:00-4:00)记录自发兴奋性突触后电流,并观察γ-氨基丁酸对缰核自发兴奋性突触后电流的影响。实验结果表明:1、外侧缰核自发性兴奋性突触后电流的发放频率具有明显的昼夜节律性,即白天高,夜间低;而内侧缰核自发性兴奋性突触后电流的发放频率无昼夜节律性。2、在外侧缰核GAB_A对自发兴奋性突触后电流的影响具有节律性,白天抑制,晚上兴奋;而在内侧缰核GABA对兴奋性突触后电流的影响无昼夜节律性,白天和晚上均为抑制。3、GAB_A对外侧缰核兴奋性突触后电流的影响主要是由GABA_A受体介导的。是什么机制导致GABA对外侧缰核白天和夜间作用不同还需要进一步研究。
[Abstract]:The habenular nucleus located in the superior thalamus occupies a prominent position in the center and is an important post station from the limbic forebrain to the brain stem. The habenular nucleus and SCN of the circadian rhythm pacemaker have a round trip fibrous projection and a close relationship with the pineal body in morphology and function. These two parts are important regions for the production and regulation of circadian rhythm. The habenular nucleus itself also has retinal fiber projections and the obvious circadian rhythm of habenular nucleus neuron activity, which suggests that habenular nucleus may be an important part of the circadian rhythm system of mammals. A major neurotransmitter that mediates circadian rhythms. There is abundant GABA in habenular nucleus, and the medial habenular nucleus lacks GABA A receptor, and the lateral habenular nucleus has GABA_A receptor, which further indicates that the lateral habenular nucleus plays an important role in the regulation of circadian rhythm. In this study, whole-cell patch clamp technique was used to record spontaneous excitatory postsynaptic currents on habenula slices and in voltage-clamp mode at different periods of day and night (10: 00-18: 00, 20: 00-4: 00 at night). The effect of 纬-aminobutyric acid on spontaneous excitatory postsynaptic current in habenula was observed. The results showed that the frequency of spontaneous excitatory postsynaptic currents in the lateral habenular nucleus had a significant circadian rhythm, i.e. high during the day and low at night. The frequency of spontaneous excitatory postsynaptic currents in the medial habenular nucleus had no circadian rhythm. The effects of GAB_A on spontaneous excitatory postsynaptic currents in the lateral habenular nucleus were rhythmic and inhibited during the day and excited at night. The effect of GABA on the excitatory postsynaptic current in the medial habenular nucleus was not circadian rhythmic. During the day and at night, the inhibitory effect of GABA A on the excitatory postsynaptic current in the lateral habenular nucleus was mainly mediated by the GABA_A receptor. What causes GABA to have different daytime and nocturnal effects on the lateral habenular nucleus needs further study.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R33

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