海马沼泽纤维中的节能作用潜力
Henrik Alle1, Arnd Roth, Jörg R P Geiger
1Independent Hertie Research Group, Max-Planck-Institute for Brain Research, 60528 Frankfurt, Germany. henrik.alle@charite.de
Science (New York, N.Y.)
|September 12, 2009
概括
鼠海马的纤维中的动作潜力具有高度的能源效率. 优化的离子通道功能最大限度地降低了每个动能电位的能量需求,影响了大脑代谢计算.
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
- 生物能源学 生物能源学
背景情况:
- 非髓化轴突中的作用潜力被认为是大脑新陈代谢的主要驱动因素.
- 之前的能源预算计算估计了与神经活动相关的高能源成本.
研究的目的:
- 为了研究非髓轴突中的作用电位的能量效率.
- 为了确定轴突作用电位对活动依赖的大脑代谢的贡献.
主要方法:
- 在老鼠海马的纤维中分析离子导电性参数.
- 在作用电位过程中模拟 (Na+) 和 (K+) 离子流.
主要成果:
- 快速的Na+电流衰变和延迟的K+电流开始将离子流的重叠最小化.
- 总的Na+流入量和每个动作电位的能量需求量仅是理论最小值的1.3倍.
- 这与之前估计的理论最低值的4倍形成鲜明对比.
结论:
- 在这个模型中,轴突作用潜力比以前假设的要节能得多.
- Na+和K+通道的特定特性为节能而微调.
- 这一发现需要重新评估神经活动的代谢成本.
相关概念视频
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...
01:14Action 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...
01:41Action Potentials
Overview
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...
01:28Action 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...
01:24Generation of Action Potential in Skeletal Muscles
Every cell in the body maintains a membrane potential due to an uneven distribution of positive and negative charges across its plasma membrane. The membrane potential is measured in millivolts and quantifies the difference in charge across the membrane.
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the cell's...
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the cell's...