fMRI
Functional Magnetic Resonance Imaging (BOLD fMRI)
機能的磁気共鳴画像法（BOLD-fMRI / 安静時機能的結合）
1. Biological & Technical Mechanism
Functional MRI (fMRI) exploits neurovascular coupling: localized neuronal synaptic activity increases cerebral metabolic rate of oxygen and triggers a disproportionate surge in regional cerebral blood flow, shifting the ratio of diamagnetic oxyhemoglobin to paramagnetic deoxyhemoglobin (the BOLD signal). Resting-state fMRI (rs-fMRI) measures spontaneous low-frequency (<0.1 Hz) fluctuations to map intrinsic large-scale networks such as the Default Mode Network (DMN), Salience Network, and Sensorimotor Network.
機能的MRI（fMRI）は、局所的なシナプス活動に伴う脳血流増加と還元ヘモグロビン濃度の変化（神経血管カップリング）をT2*強調画像上のBOLD（Blood-Oxygen-Level-Dependent）信号として非侵襲的に捉える手法です。課題遂行時の賦活マッピングだけでなく、安静時fMRI（rs-fMRI）による低周波変動（0.01〜0.1Hz）の相関解析を通じて、デフォルト・モード・ネットワーク（DMN）やサリエンス・ネットワーク等の大規模脳機能結合（Functional Connectivity）を定量化できます。
2. Open Science & Clinical Trial Significance
Thousands of raw BIDS-formatted fMRI datasets are openly shared on OpenNeuro. In Alzheimer's and FTD research, selective disruption of posterior DMN and fronto-insular functional connectivity serves as a sensitive systems-level marker of synaptic dysfunction.
OpenNeuro上にはBIDS規格に準拠した膨大なfMRI生データがCC0ライセンスで公開されています。アルツハイマー病における後部帯状回〜海馬間のデフォルトモードネットワーク結合低下や、前頭側頭型認知症におけるサリエンスネットワーク障害など、マクロ神経回路レベルの機能異常を捉える中核モダリティです。
Related Neuroscience Terms & Standards
Community ISO-aligned standard for organizing and describing neuroimaging (MRI, fMRI, dMRI, PET) and neurophysiological (EEG, MEG, iEEG) datasets.
Molecular neuroimaging technique using radiolabeled tracers to quantify in vivo protein pathology (amyloid plaques, tau tangles), glucose metabolism, or synaptic density.
MRI technique measuring anisotropic water diffusion along white matter tracts to quantify axonal integrity, demyelination, and structural connectomes.
High-temporal-resolution recording of postsynaptic cortical electrical potentials and neural oscillations (delta, theta, alpha, beta, gamma bands).
Open Datasets & Research Publications Related to fMRI
OpenNeuro ds004504: Multimodal MRI & PET Repository for Early Alzheimer’s Disease and Mild Cognitive Impairment (BIDS)
An exceptional multimodal neuroimaging repository providing 3T structural MRI, resting-state fMRI, and [18F]Florbetapir Amyloid-PET scans from 180 subjects formatted strictly to BIDS standard. This open dataset serves as a benchmark resource for deep learning and diagnostic biomarker discovery in early Alzheimer's and MCI.
OpenNeuro ds003505: Dopaminergic Striato-Cortical Circuit Connectivity in Parkinson’s Disease during Motor Execution
This open-access 3T fMRI dataset evaluates striato-cortical circuit connectivity across 72 Parkinsonian patients and controls under levodopa ON vs. OFF states. Complete with behavioral logs, it offers foundational data for modeling dopaminergic network dynamics in motor execution.
OpenNeuro ds008898: sample dataset for odor- and speech-evoked fMRI experiment at 7 Tesla
BIDS neuroimaging dataset containing MRI scans from 1 Subjects. Freely available for computational neuroscience.
Aligning transformer circuit mechanisms to neural representations in relational reasoning
Relational reasoning, the capacity to understand how elements relate to one another, is a defining feature of human intelligence, yet its computational basis remains unclear. Here, we combined human neuroimaging (7T fMRI) with artificial neural network modeling to identify circuit-level analogues of...
Differential task-related fMRI effects of a single dose of guanfacine and lisdexamfetamine in youth with ADHD: a randomised, double-blind, placebo-controlled crossover study
BackgroundStimulant and non-stimulant medications increase fronto-striato-thalamic activation in youth with Attention-Deficit/Hyperactivity Disorder (ADHD). However, comparative effects of the more recently licensed stimulant lisdexamfetamine and non-stimulant guanfacine on functional magnetic reson...
A cascade of attentional and default mode network dynamics following the resolution of perceptual ambiguity
The neural mechanisms underlying spontaneous perceptual switches during bistable perception, particularly the dynamic interplay between large-scale brain networks, remain incompletely understood. Here, using functional magnetic resonance imaging (fMRI) in six participants and a bistable kinetic dept...
Disclaimer: This encyclopedia entry is intended for academic neuroscience research and data science reference only, and does not constitute medical advice.