视网膜波对视网膜内ON、OFF系统非同步化修饰的特点和突触机制

发布时间：2018-05-18 00:36

本文选题：视网膜波 + ON-OFF系统　；参考：《天津医科大学》2013年博士论文

【摘要】：研究目的研究哺乳动物早期视觉发育期间谷氨酸能视网膜波对视网膜内ON、OFF系统分离修饰作用的突触特点及突触机制。研究方法1.采用生后8天和生后10-12天的ChAT-Cre-GCamp3小鼠视网膜,观察对比ON、OFF ChAT-band的钙依赖性电活动在第二、三视网膜波阶段的特点和差异;2.采用生后10-12天的ChAT-Cre-Tdtomato小鼠,应用全细胞双膜片钳技术,观察第三阶段视网膜波ON、OFF SAC在电压钳模式下兴奋性突触输入的时空模式的特点,比较时间模式的差异;3.应用药理学方法观察相关受体或通道对第三阶段视网膜波ON、OFF SAC时间模式的影响;4.应用膜片钳全细胞记录技术结合光遗传学方法,使用蓝色LED光源特异性激活mGluR6-ChannelRhodopsin-2小鼠视网膜ON双极细胞,观察ON系统的激活对不同类型神经节细胞的作用,结合药理学方法探讨可能的突触机制。研究结果1.ON、OFF ChAT-band的自发性钙依赖性电活动的时间模式在第二阶段视网膜波时期呈现同步化,在第三阶段视网膜波时期呈现非同步化,且遵循特定的时间顺序即ON在OFF之前,时间差异为743.31±190.75ms(n=4 retina,25 waves)。2.第三阶段视网膜波在ON、OFF SAC中发生的起始时间相对一致但呈现主波和副波两个波形:ON SAC为一大一小即主波在前副波在后,OFF SAC为一小一大,副波在前主波在后。主波波峰出现的时间在ON、OFF两个SAC中呈现非同步化,但遵循一个特定规律:即每次ON SAC的主波波峰的出现时间都先于OFF SAC,时间差为829.85±282.78(n=14 pairs);并且ON SAC的主波与OFF SAC的副波对应、ON SAC的副波与OFF SAC的主波对应,有相对一致的起始和结束时间。3.第三阶段ON GC视网膜波的起始时间、波形都和ON SAC大致吻合;OFF GC则和OFF SAC类似,OFF GC主波波峰在ON SAC之后,表现出和ON、OFF SAC相似的时间差异;ON-OFF GC则有两个主波,第一个主波和ON SAC的主波基本重合,第二个主波紧跟其后。4.甘氨酸能受体阻滞剂STR可以同步化第三阶段视网膜波ON、OFF SAC时间模式,STR联合GABA受体阻滞剂PTX可以起到协同作用,单纯PTX、缝隙连接阻滞剂18-betaGA不能改变ON、OFF SAC非同步化模式。5.单纯激活ON双极细胞可以诱发神经节细胞"视网膜波样"的反应:ON神经节细胞在ChR2反应结束后出现一个类似于副波的小波;OFF神经节细胞则在ON型双极细胞被激活时,受到某种抑制作用,表现为较小水平的去极化形成类似于副波的小波,当ChR2反应结束后,出现一个类似主波的反应幅度较大的波;ON-OFF GC表现为两个主波的双相波形。ON、OFF、ON-OFF RGC在ChR2反应结束后所诱发的内向电流可以被STR阻断。研究结论1.视网膜ON、OFF系统的修饰作用始于视网膜波第三阶段。在视网膜内ON、OFF系统各自独立的通路结构已经形成的基础上,视网膜波的兴奋性递质从乙酰胆碱过渡到谷氨酸,视网膜波对视网膜内ON、OFF系统的修饰作用才会启动。2.第三阶段视网膜波能够对视网膜内ON、OFF细胞进行非同步化修饰,这种修饰作用不仅作用于输出细胞还作用于输出细胞上游的中间神经元。3.ON、OFF细胞在第三阶段视网膜波期间表现出不同的时间模式和空间模式。这种时空差异由突触前机制所介导。4.视网膜波通过随机的、反复的、转换神经递质等方式使相同类型输出细胞同步化,不同类型输出细胞先后经历同步化与非同步化,对视网膜向高级视觉中枢的输出进行修饰、重塑与改建以引导高级中枢内在视觉发生以前视觉环路的精确修饰。5.在阻断了抑制性神经递质γ-氨基丁酸和甘氨酸传递后,来自ON、OFF双极细胞的兴奋性驱动是同步化的。甘氨酸对第三阶段视网膜ON、OFF系统分离起重要调控作用。6.第三阶段视网膜波时期,ON双极细胞通过甘氨酸能抑制性通路抑制OFF双极细胞的兴奋性释放,继而产生ON、OFF细胞反应的非同步化。
[Abstract]:The purpose of this study is to investigate the synaptic characteristics and synaptic mechanism of the effects of glutamic acid energy retinal waves on the ON and OFF system during early visual development in mammals. Methods 1. the study was performed on the retina of ChAT-Cre-GCamp3 mice at 8 days after birth and 10-12 days after birth, and the calcium dependent electrical activity of ON and OFF ChAT-band was second, Three the characteristics and differences of the stage of retina wave; 2. the ChAT-Cre-Tdtomato mice of 10-12 days after birth were used to observe the characteristics of the temporal and spatial patterns of the excitatory synaptic input in the third stage retina wave ON, OFF SAC under the voltage clamp mode, and compared the difference of time mode. 3. the application of pharmacological methods to observe the related receptors The influence of the channel on the third stage retinal wave ON, OFF SAC time pattern; 4. using the patch clamp whole cell recording technique combined with the photo genetics method, using the blue LED light source to activate the mGluR6-ChannelRhodopsin-2 mouse retinal ON bipolar cells specifically, to observe the effect of the activation of the ON system on the different types of ganglion cells, and to combine the pharmacology with the pharmacology of the ON system. Study methods explore possible synaptic mechanisms. Results 1.ON, OFF ChAT-band of spontaneous calcium dependent electrical activity synchronization in the second stage of the retinal wave period, in the third stage of the retinal wave period is non synchronous, and follow the specific time order that ON before OFF, the time difference is 743.31 + 190.75ms (n=4 Retina, 25 waves) the onset time of retinal waves in the.2. third stage is relatively consistent in the onset time of ON, OFF SAC, but presents two waveforms of the main wave and the secondary wave: ON SAC is a big one, that is, after the main wave is in the front side wave, the OFF SAC is a small one, the secondary wave is in the front of the main wave. The time of the main wave peak appears in ON, and the two OFF of OFF are non synchronous, but the time of the main wave peak is in ON. The time difference between the main wave peak of each ON SAC is preceded to OFF SAC, the time difference is 829.85 + 282.78 (n=14 pairs), and the main wave of ON SAC corresponds to the auxiliary wave of OFF SAC, and the secondary wave of ON SAC is corresponding to the main wave. Between the ON SAC and the OFF SAC, the OFF GC is similar to the OFF SAC, and the OFF GC main wave peak appears after ON SAC, showing a similar time difference between ON and OFF; the first main wave is basically coincided with the main wave of the primary wave and the main wave, and the third step can be synchronized with the glycine receptor blocker after the second main waves. Retina wave ON, OFF SAC time pattern, STR combined with GABA receptor blocker PTX can play a synergistic role, pure PTX, gap junction blocker 18-betaGA can not change ON, OFF SAC non synchronous mode.5. only activate bipolar cells can induce ganglion cell "retina wave like" response: ganglion cells after the end of the reaction out of the reaction A wavelet similar to the secondary wave is present; OFF ganglion cells are suppressed when ON type bipolar cells are activated, showing a small level of depolarization to form a wavelet similar to the vice wave. When the ChR2 reaction ends, a larger wave similar to the main wave is found; ON-OFF GC shows a dual phase waveform of two main waves.O. The introverted current induced by N, OFF, ON-OFF RGC can be blocked by STR after the end of ChR2 reaction. Conclusion 1. retina ON, the modification of OFF system begins at the third stage of retina wave. On the basis of the formation of the independent pathway structure of the ON in the retina, the excitatory transmitters of the omentum waves transition from acetylcholine to the valley. The modification of retina, retina wave to the ON, OFF system in the retina will initiate the.2. third stage of retinal waves to be able to unsynchronize the ON, OFF cells in the retina, which not only acts on the output cells but also acts on the intermediate deity.3.ON in the upstream of the output cell, and the OFF cell during the third stage of the retina wave. There are different time patterns and spatial patterns. This spatio-temporal difference is mediated by the presynaptic mechanism of.4. retina waves to synchronize the same type of output cells through random, repeated, and converted neurotransmitters, and the output of different types of cells successively experience synchronization and asynchronization, and the output of the retina to the advanced visual center. Modified, reshaped and remodeled to guide the precise modification of the visual loop prior to the inherent visual occurrence of the advanced center.5., after blocking the inhibitory neurotransmitters gamma aminobutyric acid and glycine transfer, the excitatory drive from ON, OFF bipolar cells is synchronized. Glycine plays an important role in the separation of the third stage retinal ON, OFF system. During the.6. third stage of the retina wave period, ON bipolar cells inhibit the excitatory release of OFF bipolar cells through the glycine inhibitory pathway, and then produce ON, OFF cell reaction asynchrony.
【学位授予单位】：天津医科大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R774.1

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