Quantitative analysis of synaptic connections in the fronto-corticostriatal system

额皮质纹状体系统突触连接的定量分析

基本信息

批准号：
12480242
负责人：
KAWAGUCHI Yasuo
金额：
$ 9.34万
依托单位：
Okazaki National Research Institutes
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

To understand the characteristics of the GABAergic circuit in the rat frontal cortex, we investigated (1) the synaptic connection patterns of GABA cell subtypes, (2) cholinergic effects on the GABAergic synaptic currents, and (3) firing patterns of GABA cell subtypes during the cortical synchronized activities.(1) FS cells innervated somata and dendritic spines as well as shafts. Somatostatin Martinotti cells innervated the dendritic shafts, and the heads and stalks of spines receiving other excitatory inputs simultaneously. The synaptic junctional area of axon terminals from FS cells linearly increased along with the circumference of postsynaptic dendrites or spines. The junctional area of axons from Martinotti cells linearly increased with the dendritic circumference or the surface area of the postsynaptic spine heads.(2) Both carbachol and muscarine caused two temporally different patterns of inhibitory postsynaptic current modulation in cortical cells : tonic and periodic increase … More of GABA-A receptor-mediated currents. The tonic pattern features continuous increase of inhibitory current frequency, while the periodic increase manifests itself as a rhythmic burst of inhibitory postsynaptic current. In nearby cells these are synchronized as a whole but individual inhibitory events within the bursts are not always temporally linked, suggesting synchronized depolarization of several presynaptic interneurons.(3) By lowering extracellular Mg^<2+> in vitro, we induced NMDA receptor-dependent spontaneous activities. After a series of spontaneous depolarization shifts, the long bursts occurred. The long burst composed of initial discharges and fast run-like potentials. At each phase of the synchronized activities, cortical neuron types exhibited distinct firing patterns. The firing patterns of cortical neurons are not only determined by the strength and temporal pattern of synchronized inputs, but also strongly dependent on the neuronal subtype with specific physiological, chemical and morphological characteristics. Less

为了了解大鼠额叶皮质中GABA能的特征，我们研究了（1）GABA细胞亚型的突触连接模式，（2）胆碱能对GABA能突触电流的影响，以及（3）在皮质式综合活性过程中GABA细胞亚型的发射模式。（1）FS细胞支配了somata和树突状刺以及轴。生长抑素马提尼托细胞支配了树突状轴，简单地接受其他兴奋输入的刺的头和茎。来自FS细胞的轴突末端的突触连接区域与突触后树突或棘突的周长一起增加。来自马丁纳蒂细胞的轴突的连接区域随着树突状圆周或突触后脊柱头部的表面积的线性增加。（2）卡尔巴醇和墨斯酸杏仁碱引起了两种暂时不同的抑制性抑制性抑制性抑制性抑制性抑制性抑制性电流的模式：皮质和周期性的增长：滋补和周期性的gaba-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a currents currents。补品模式具有抑制电流频率的连续增加，而周期性增加则表现为抑制性突触后电流的节奏爆发。在靠近细胞中，它们是整体同步的，但是爆发中的个体抑制事件并不总是暂时连接，表明通过在体外降低细胞外Mg^<2+>的同步沉积。（3）我们在体外降低了NMDA接收器依赖于NMDA接收器依赖的赞助物。在一系列赞助商爆发沉积转移之后，发生了长时间的爆发。长爆发由初始放电和快速奔跑的电势组成。在同步活动的每个阶段，皮质神经元类型都暴露了不同的射击模式。皮质神经元的发射模式不仅取决于同步输入的强度和临时模式，而且还强烈依赖于具有特定生理，化学和形态特征的神经元亚型。较少的