快速时间的迷你课程和在 cerebellar synapses in situ 中引起的刺激电流
R A Silver1, S F Traynelis, S G Cull-Candy
1Department of Pharmacology, University College London, UK.
Nature
|January 9, 1992
概括
小脑中的神经递质主要使用L-谷氨酸. 这项研究揭示了快速的非N-甲基-D-酸盐受体电流和较慢的N-甲基-D-酸盐通道在小脑颗粒细胞中的开放,挑战了替代理论.
科学领域:
- 神经科学是一个神经科学.
- 细胞生物学 细胞生物学
- 神经生理学 神经生理学
背景情况:
- 大脑小粒细胞从的纤维终端接收神经传递.
- 据推测,L-谷氨酸是中介这种信号通路的神经递质.
- 之前的研究提出了这些细胞中突触电流的不同机制.
研究的目的:
- 研究神经传递到小脑颗粒细胞的精确机制和动力学.
- 描述微型刺激后突触电流 (m.e.p.s.c.) 的组成部分.
- 评估最近关于NMDA通道参与颗粒细胞突触电流的假设.
主要方法:
- 高分辨率的电生理学记录m.e.p.s.cs和唤起的电流.
- 使用细小脑切片来利用颗粒细胞的独特特性 (小 soma,有限的过程,短树突).
- 分析了当前的时间流程,药理学和振幅分布.
主要成果:
- 鉴定出异常快的非N-甲基-D-酸盐 (非NMDA) 受体电流 (上升时间<100μs,衰变t = 1.0ms).
- 在非NMDA组件之后观察到可直接解决的50 pS N-甲基-D-酸盐 (NMDA) 通道开放.
- 没有发现任何证据支持单独通过NMDA通道调解m.e.p.s.c,并采用新的时间过程.
- 非NMDA组件表现出偏斜的振幅分布,影响了量子分析.
结论:
- 神经传递到小脑颗粒细胞中涉及快速的非NMDA成分,其次是NMDA通道开放.
- 这些发现驳斥了单独NMDA道调解这些突触电流的假设.
- 突触电流动力学的差异可能源于不同的突触功能或电波过效应.
相关概念视频
01:41Action Potentials
Overview
01:28Electrical Synapses
Electrical synapses found in all nervous systems play important and unique roles. In these synapses, the presynaptic and postsynaptic membranes are very close together (3.5 nm) and are actually physically connected by channel proteins forming gap junctions.
Gap junctions allow the current to pass directly from one cell to the next. In contrast, in the chemical synapse, the neurotransmitters carry the information through the synaptic cleft from one neuron to the next. They consist of two...
Gap junctions allow the current to pass directly from one cell to the next. In contrast, in the chemical synapse, the neurotransmitters carry the information through the synaptic cleft from one neuron to the next. They consist of two...
01:28Action Potential: Phases of Stimulation
The action potential is a complex electrical event that occurs in excitable cells, such as neurons and muscle cells. It consists of several distinct phases, each with specific characteristics.
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
01:23Propagation of Action Potentials
The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron.
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
01:27Fast Reactions
Fast reactions occurring in times shorter than the time needed to mix reactants pose a unique challenge for investigation. In a liquid-phase continuous-flow system, reactants A and B are swiftly pushed into the mixing chamber, where mixing occurs within 1 ms. The reaction mixture then flows through an observation tube, and one measures light absorption to determine species concentrations at various points of the tube. This method is most appropriate when relatively large volumes of reactants...