カテコアミン効果のネットワークモデル: ゲイン,シグナル対ノイズ比,行動モデル
D Servan-Schreiber1, H Printz, J D Cohen
1School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213.
Science (New York, N.Y.)
|August 24, 1990
まとめ
カテコラミンは,個々のニューロンの性能ではなく,ニューラルネットワークの信号検出を強化します. この発見は,中枢神経系の刺激剤が人間の信号検出能力を改善する方法を説明しています.
科学分野:
- 神経科学は神経科学である.
- 計算神経科学とは
- コグニティブ・サイエンス コグニティブ・サイエンス
背景:
- カテコラミンは,シナプス入力に対するニューロンの応答性を調節する.
- 神経ネットワークに対するカテキオラミンの効果を理解することは,認知機能にとって極めて重要です.
研究 の 目的:
- 信号検出に対するニューロンの応答性におけるカテキオラミン誘発の変化の影響をモデル化するために.
- 信号検出におけるネットワークレベルの改善が,ヒトにおける刺激効果を説明できるかどうかを調査する.
主な方法:
- カテコアミン効果をシミュレートするために,神経のような要素のコンピューティングモデルを開発しました.
- コンピュータシミュレーションのための並列分散処理原理を活用した.
- 個々の要素レベルとネットワークレベルの両方で,信号検出パフォーマンスを評価しました.
主要な成果:
- 個々のニューラル要素の信号検出能力は,応答性の変化によって影響を受けなかった.
- ニューラルネットワーク全体では,信号検出が改善され,要素の応答性が向上しました.
- シミュレーションでは,ヒトの信号検出における刺激剤誘発の強化を成功裏に説明しました.
結論:
- ネットワークレベルの相互作用は,信号検出におけるカテキオラミンの役割を理解するための鍵です.
- コンピューティングモデルは,認知機能に対する刺激効果の背後にあるメカニズムを明らかにすることができます.
関連する概念動画
01:29The Two-State Receptor Model
The two-state receptor model explains a drug's interaction with receptors, such as G protein-coupled receptors and ligand-gated ion channels, to induce or inhibit a biological response. When no natural ligands are present, a receptor exists in an equilibrium of inactive (Ri) and active (Ra) conformations. The inactive form does not produce a response, while the active form generates a basal effect known as constitutive activity.
The binding affinity of a drug determines its interaction with one...
The binding affinity of a drug determines its interaction with one...
01:27Adrenergic Neurons: Neurotransmission
Postganglionic sympathetic fibers (except those supplying the sweat glands) releasing noradrenaline or norepinephrine are called noradrenergic or adrenergic neurons. Noradrenaline, dopamine, adrenaline, or epinephrine are collectively called "catecholamines" as they contain a catechol moiety and an amine side chain. The five stages of neurotransmitter release involve their synthesis, storage, release, reuptake and metabolism.
Synthesis: Catecholamine synthesis requires tyrosine, which is taken...
Synthesis: Catecholamine synthesis requires tyrosine, which is taken...
01:25Adrenergic Agonists: Indirect-Acting Agents
Indirect-acting adrenergic agonists potentiate the effects of endogenous catecholamines through different mechanisms without directly binding to adrenoceptors.
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
01:16Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Adrenergic agonists' structure-activity relationship (SAR) determines their selectivity and efficacy. These agonists comprise a phenylethylamine moiety with an aromatic ring and an ethylamine side chain.
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
01:21Drugs Affecting Neurotransmitter Release or Uptake
Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking...
01:09Pharmacodynamic Models: Additive and Proportional Drug Effect Model
Drug response models describe how pharmacological agents interact with biological systems to produce measurable effects. Baseline responses are inherent physiological activities without a drug significantly influencing the observed pharmacological outcomes. Depending on the drug response model employed, these baseline responses may combine with the drug's effect in either an additive or proportional manner.Additive Drug Response ModelIn the additive model, the drug effect is independent of the...