抑制と刺激の相対的な代謝需要

D Waldvogel¹, P van Gelderen, W Muellbacher

¹Human Motor Control Section, NINDS, NIH, Bethesda, Maryland 20892, USA.

Nature

|September 13, 2000

まとめ

脳の抑制は,興奮よりも代謝的に要求が少ない. この研究では,機能的磁気共鳴画像を用いて,運動皮質の阻害が血液の酸素レベルに依存する信号を変えないことを示すため,興奮駆動が示唆されています.

科学分野:

神経科学は神経科学である.
神経エネルギー学
認知神経科学とは

背景:

阻害は代謝的に活性なシナプスプロセスであり, (14C) 2-デオキシグルコースと磁気共振スペクトロスコピーの研究によって証明されています.
阻害性シナプスは刺激性シナプスよりも少なく,よりよい位置にあり,より高い代謝効率の可能性を示唆しています.

研究の目的:

神経阻害が神経刺激よりもエネルギー消費量が少ないという仮説を検証する.
機能神経画像を用いて,人間の運動皮質における抑制の代謝要求を調査する.

主な方法:

イベント関連の機能性磁気共鳴画像 (fMRI) をヒトボランティアで撮影した.
"Go/no-go"タスクの"no-go"状態中に誘発された運動皮質の阻害.
皮質の阻害を確認するために,トランスクレニアル磁気刺激 (TMS) を行う.

主要な成果:

運動皮質の抑制は,血液の酸素レベル依存 (BOLD) 信号に測定可能な変化をもたらさなかった.
これは,神経刺激に関連した予想される BOLD 信号の変化と対照的です.
発見は,抑制は,刺激よりも代謝的に要求が少ないことを示しています.

結論:

神経阻害は,神経刺激と比較して,より少ない代謝エネルギーを必要とします.
機能的イメージング研究で観察された"活性化"は,阻害的ではなく刺激的プロセスを反映している可能性が高い.
この研究は,脳の興奮と抑制の異なる代謝プロフィールを明らかにします.

さらに関連する動画

07:56

A Plate-Based Assay for the Measurement of Endogenous Monoamine Release in Acute Brain Slices

Published on: August 11, 2021

05:13

Estimation of Structural Sensitivity of Intrinsically Disordered Regions in Response to Hyperosmotic Stress in Living Cells Using FRET

Published on: January 12, 2024

関連する概念動画

00:46

Feedback Inhibition

Biochemical reactions are occurring constantly in cells, converting starting substances to different products, usually with the help of enzymes that speed the reactions. Without enzymes, it would take far too long for most reactions to occur to be useful to the cell!

01:30

Enzyme Inhibition

Inhibitors are molecules that reduce enzyme activity by binding to the enzyme. In a normally functioning cell, enzymes are regulated by a variety of inhibitors. Drugs and other toxins can also inhibit enzymes. Some inhibitors bind to the enzyme’s active site, while others inhibit enzymatic activity by binding to other sites on the protein structure.

01:19

Regulation of Metabolism

Cellular needs and conditions vary from cell to cell and change within individual cells over time. For example, the required enzymes and energetic demands of stomach cells are different from those of fat storage cells, skin cells, blood cells, and nerve cells. Furthermore, a digestive cell works much harder to process and break down nutrients during the time that closely follows a meal compared with many hours after a meal. As these cellular demands and conditions vary, so do the amounts and...

01:29

Excitatory and Inhibitory Effects of Neurotransmitters

When an action potential reaches the presynaptic axon terminal, it releases neurotransmitters from the neuron into the synaptic cleft at a chemical synapse. The released neurotransmitter can be excitatory or inhibitory. The critical criteria commonly used to determine whether a molecule is a neurotransmitter at a chemical synapse are the molecule's presence in the presynaptic neuron. Second, its release is in response to strong presynaptic depolarization. And lastly, the presence of specific...

01:03

Dose-Response Relationship: Overview

Agonists can bind with and activate receptors, resulting in the formation of drug-receptor complexes. Once formed, these complexes catalyze many biochemical processes at the cellular level and subsequently induce a pharmacologic response. The degree of response is directly proportional to the fraction of activated receptors, which in turn, depends on the concentration of the drug at the receptor site as well as the sensitivity of the receptor. An increase in the administered dose contributes to...