树突式电压门的通道的分子特征
Andrea Lorincz1, Zoltan Nusser
1Laboratory of Cellular Neurophysiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, 1083 Budapest, Hungary. lorincz@koki.hu
概括
纳维1.6通道子单元存在于金字塔神经元的树突中,使行动潜力的反向传播成为大脑可塑性所必需的. 这一发现确定了一种关键分子为树突刺激性.
科学领域:
- 神经科学是一个神经科学.
- 分子生物学分子生物学
- 细胞电生理学 细胞电生理学
背景情况:
- 动作潜能 (AP) 侵入树状树对突触可塑性和神经网络形成至关重要.
- 负责皮质金字塔细胞 (PC) 中AP反向传播的电压 (Nav) 通道的分子特征仍然未知.
研究的目的:
- 为了确定皮质金字塔细胞中树突性Nav通道的分子基质.
- 描述树状树内已识别的Nav通道子单元的亚细胞分布.
主要方法:
- 使用一种高度敏感的电子显微镜免疫金技术.
- 在海马CA1PC近端和远端树突和轴突初始段中的量化Nav子单位密度.
主要成果:
- 在海马CA1 PCs的近端和远端树突中确定了Nav1.6子单元.
- 树突中Nav1.6亚单元密度明显低 (35-80倍),而不是轴突初始段.
- 沿着树突的近距离轴观察到Nav1.6密度的逐渐减少,树突脊柱没有标记.
结论:
- 纳维1.6亚单元在金字塔细胞树突中表现出特定的亚细胞分布.
- Nav1.6被确定为一个关键的分子组成部分,使得树突刺激和AP反向传播成为可能.
- 这一发现提供了对突触可塑性和神经元组合形成的基础机制的洞察.
相关概念视频
Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
The Role of Ion Channels in Neuronal Computation
A postsynaptic neuron usually receives numerous impulses from several other presynaptic neurons. The axon hillock of the postsynaptic neuron integrates all these signals and determines the likelihood of firing an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Mechanically-gated Ion Channels
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...


