Related Experiment Video

Updated: May 13, 2026

Developing Neuroimaging Phenotypes of the Default Mode Network in PTSD: Integrating the Resting State, Working Memory, and Structural Connectivity
10:43

Developing Neuroimaging Phenotypes of the Default Mode Network in PTSD: Integrating the Resting State, Working Memory, and Structural Connectivity

Published on: July 1, 2014

Amnestic mild cognitive impairment: topological reorganization of the default-mode network

Liang Wang1, He Li, Ying Liang

  • 1State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, 19 Xinjiekouwai St, Beijing 100875, P.R. China.

Radiology
|March 14, 2013
PubMed
Abstract

Insights

Mild cognitive impairment (MCI) patients show altered default-mode network (DMN) connectivity during memory tasks. These changes in functional connectivity and network efficiency may serve as early markers for Alzheimer's disease risk.

Area of Science:

  • Neuroscience
  • Cognitive Science
  • Medical Imaging

Background:

  • Mild cognitive impairment (MCI) represents a transitional stage between normal aging and Alzheimer's disease dementia.
  • The default-mode network (DMN) is crucial for cognitive functions, including memory, and its disruption is implicated in neurodegenerative diseases.

Purpose of the Study:

  • To investigate topological reorganization of the DMN in patients with MCI compared to healthy controls.
  • To determine if DMN functional connectivity and topology are altered during a memory task versus resting state in MCI patients.

Main Methods:

  • Functional magnetic resonance imaging (fMRI) was used to scan 25 patients with amnestic MCI (aMCI) and 26 healthy controls.
  • Participants underwent fMRI during both an episodic memory task and a resting state.
  • Graph theoretical approaches were applied to analyze DMN functional connectivity and topological properties.

Main Results:

  • MCI patients exhibited significantly decreased anterior-to-posterior DMN functional connectivity during the memory task.
  • Increased local efficiency within the DMN was observed in aMCI patients exclusively during the task.
  • Decreased functional connectivity correlated with increased local efficiency and cognitive performance, suggesting potential as early AD risk markers.

Conclusions:

  • The study indicates early-onset functional reorganization of the DMN in aMCI, shifting towards a less optimized configuration.
  • Findings enhance understanding of dynamic brain network changes across the aging to dementia continuum.
  • Altered DMN topology in MCI may serve as an early indicator for Alzheimer's disease progression.

More Related Videos

Network Analysis of the Default Mode Network Using Functional Connectivity MRI in Temporal Lobe Epilepsy12:09

Network Analysis of the Default Mode Network Using Functional Connectivity MRI in Temporal Lobe Epilepsy

Published on: August 5, 2014

Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network11:02

Combining Transcranial Magnetic Stimulation and fMRI to Examine the Default Mode Network

Published on: December 28, 2010

Related Concept Videos

Dementia l: Introduction01:22

Dementia l: Introduction

Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks...
Alzheimer's Disease: Overview01:26

Alzheimer's Disease: Overview

Alzheimer's Disease (AD) is a continually advancing neurodegenerative disorder, distinguished by escalating memory loss, cognitive dysfunction, and dementia. The disease unfolds in three stages: preclinical, mild cognitive impairment (MCI), and dementia. Its onset is insidious, and the progression gradual, with the cause not well explained by other disorders.
The clinical diagnosis of AD hinges on the presence of memory and other cognitive impairments. Biomarkers, such as changes in Aβ and tau...
Amnesia01:13

Amnesia

Amnesia is a condition marked by long-term memory loss, which impairs the ability to recall past events or create new memories.
The severity and duration of memory loss vary depending on the type and underlying cause. Amnesia is classified into two main types: retrograde and anterograde.
Retrograde amnesia is marked by the loss of memories formed before the onset of the condition. Patients may recall distant past events but often forget those occurring shortly before the incident.
Anterograde...
Alzheimer Disease ll: Pathophysiology01:23

Alzheimer Disease ll: Pathophysiology

Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal...