皮質ニューロンにおけるアクションポテンシャル開始のユニークな特徴
Björn Naundorf1, Fred Wolf, Maxim Volgushev
1Max Planck Institute for Dynamics and Self-Organization, University of Göttingen, Bunsenstr. 10, D-37073 Göttingen, Germany.
Nature
|April 21, 2006
まとめ
皮質ニューロンは,古典的なモデルから逸脱して,急速なアクションポテンシャル開始を示します. 新しいモデルは,協力的なナトリウムチャネル活性化を提案し,これらのダイナミクスを説明し,in vitro実験で確認しています.
科学分野:
- 神経科学は神経科学である.
- 計算神経科学とは
- バイオフィジックス 生物物理学
背景:
- ニューロンは,その生体物理的メカニズムによって支配されるプロセスであるアクションポテンシャルを通じて情報を暗号化します.
- これらのメカニズムの修正は,神経細胞のエンコーディング特性を大幅に変化させることができます.
研究 の 目的:
- 皮質ニューロンにおけるアクションポテンシャル開始ダイナミクスを定量的に分析する.
- 観察されたニューロン動力学と古典的なホジキン=ハクスリー理論の間の不一致を調査する.
- アクションポテンシャルイニシアチブの新しいモデルを提案し,検証する.
主な方法:
- 皮質ニューロンにおけるアクションポテンシャル開始の定量分析 (in vivo,in vitro,および計算モデル).
- 協力的なナトリウムチャネル活性化に基づく新しい生体物理モデルの開発.
- モデル予測のインビトロ実験的検証.
主要な成果:
- 皮質ニューロンのアクションポテンシャルの発起は,古典的なホジキン・ハクスリー理論によって予測されていない急速な動態と変数発生ポテンシャルを示しています.
- 提案された協力的なナトリウムチャネル活性化モデルは,観察されたイニシアーションダイナミクスを正確に再現しています.
- 実験では,ナトリウムチャネル密度の低下がホジキン=ハクスリーのようなダイナミクスを誘発することを確認した.
結論:
- ナトリウムチャネルの協同活性化は,皮質ニューロンにおけるアクションポテンシャル開始ダイナミクスの基礎となる重要なメカニズムである.
- この発見は,すべてのニューロン型におけるアクションポテンシャル発起に関する古典的なホジキン=ハクスリーモデルの普遍性に異議を唱えている.
- この研究は,神経刺激性と情報処理の精巧な理解を提供します.
さらに関連する動画
関連する概念動画
Action Potentials
Overview
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...
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.
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: 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...
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...


