侧面Na+扩散的时空动力学在小鼠CA1金字塔神经元的尾牙中扩散
Joel S E Nelson1, Jan Meyer1, Niklas J Gerkau1
1Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany.
概括
离子 (Na+) 对大脑功能至关重要. 这项研究揭示了Na+的流入会导致树突内部的快速扩散,从而实现有效的信号恢复.
科学领域:
- 神经科学是一个神经科学.
- 细胞生理学 细胞生理学
- 交通运输 交通运输 交通运输
背景情况:
- 离子 (Na+) 是神经元激发和大脑生理学必不可少的电荷载体.
- 树突中的Na+信号和扩散性质的时空动态在很大程度上仍未被描述.
- 了解Na+动态对于理解神经元功能和激发至关重要.
研究的目的:
- 为了研究树突中的Na+信号的时空动力学.
- 在树突性环境中描述Na+扩散的特性.
- 阐明神经元中Na+信号传播和清除背后的机制.
主要方法:
- 多光子Na+成像与小鼠CA1金字塔神经元树突中的全细胞补丁记录相结合.
- 光终身显微镜以确定基线树突Na+度.
- 基于强度的线扫描成像,以跟踪Na+信号传播.
- 数学建模和模拟来分析扩散动态.
主要成果:
- 树突基线Na+度被确定为大约10mM.
- 谷氨酸引起的Na+信号沿着树突迅速传播,幅度随距离而减少,延迟随距离而增加.
- Na+扩散独立于树突形态 (直径,顺序) 和脊柱密度.
- 树突性Na+很容易进入脊柱,脊柱可能充当扩散障碍物.
- 数学模型支持正常扩散,扩散系数为600μm2/s.
- 侧向扩散被确定为早期Na+清除的关键,Na+/K+-ATPase在以后变得相关.
结论:
- 纳+的流入会在状树突中引发纳+的快速横向扩散.
- 这种扩散促进了有效的再分配和从局部Na+过渡物中快速恢复.
- 度梯度主要控制信号恢复早期阶段的Na+动态.
相关概念视频
01:41Action Potentials
Overview
01:14Action Potential
Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage.
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
01:19The 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.
01:14Action Potential
Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage.
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...