ヒポキャンパスのモス繊維のエネルギー効率の良いアクションポテンシャル
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
まとめ
ネズミのヒッポカンプスのモッシュ繊維のアクションポテンシャルは非常にエネルギー効率が高い. 優化されたイオンチャネル機能は,アクションポテンシャルあたりのエネルギー需要を最小限に抑え,脳の代謝計算に影響を与えます.
科学分野:
- 神経科学は神経科学である.
- 細胞生物学 細胞生物学
- バイオエネルギー学 バイオエネルギー学
背景:
- 非ミエリン性アクソンにおけるアクションポテンシャルは,脳代謝の主要な原動力であると考えられています.
- 以前のエネルギー予算の計算では,神経活動に関連した高いエネルギーコストが推定されました.
研究 の 目的:
- 非ミエリン性アクソンにおけるアクションポテンシャルのエネルギー効率を調査する.
- 活動に依存する脳代謝に対する軸索運動ポテンシャルの貢献を決定する.
主な方法:
- ネズミの海馬のモス繊維におけるイオン伝導性パラメータの分析.
- アクションポテンシャル中のナトリウム (Na+) とカリウム (K+) イオンフローのモデリング.
主要な成果:
- 急速なNa+電流の衰退と遅れたK+電流の発生は,イオン流の重なりを最小限にします.
- アクションポテンシャルあたりのNa+の総流入量とエネルギー需要は,理論上の最低値のわずか1.3倍である.
- これは,理論上の最低値の4倍という以前の推定値と大きく対照的です.
結論:
- このモデルにおける軸軸の作用電位は,これまで考えられていたよりもエネルギー効率が著しく高い.
- Na+およびK+チャネルの特異的な性質は,エネルギー保存のために微調整されています.
- この発見は,神経活動の代謝コストの再評価を必要とします.
関連する概念動画
Action 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...
Action 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...
Action Potentials
Overview
Propagation 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...
Action 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...
Generation 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...


