Related Experiment Video
Updated: Jun 5, 2025
05:55
Modeling the Functional Network for Spatial Navigation in the Human Brain
Published on: October 13, 2023
993
APOE ɛ4 and Insulin Resistance Influence Path-Integration-Based Navigation through Distinct Large-Scale Network
Karel M Lopez-Vilaret1, Marina Fernandez-Alvarez1,2, Anne Bierbrauer3
1Laboratory of Functional Neuroscience, Pablo de Olavide University, Seville, Spain.
Aging and Disease
|December 10, 2024
Summary
Alzheimer
Area of Science:
- Neuroscience
- Cognitive Science
- Gerontology
Background:
- Path integration (PI) navigation relies on entorhinal cortex grid cells, often impaired in Alzheimer's disease (AD) risk.
- Brain networks may compensate for entorhinal cortex dysfunction, especially with spatial cues, potentially altering network segregation.
- APOE ε4 carriers and individuals with insulin resistance face entorhinal cortex dysfunction risks.
Purpose of the Study:
- Investigate compensatory brain network mechanisms in APOE ε4 carriers and insulin-resistant individuals.
- Assess the impact of network segregation on path integration (PI) performance.
- Examine the role of spatial cues and cortical integrity in navigation.
Main Methods:
- Applied graph-theoretical segregation index to resting-state fMRI data from two cohorts (aged 50-75).
- Assessed path integration (PI) performance in virtual environments with and without spatial cues.
- Controlled for cortical thickness and intracortical myelin variability.
Main Results:
- Higher insulin resistance correlated with better PI and less segregated networks, irrespective of spatial cues.
- APOE ε4 carriers showed cue-dependent PI performance, outperforming ε3 homozygotes with landmarks (increased sensorimotor segregation).
- Without cues, ε4 carriers had reduced PI linked to lower secondary visual network segregation; cortical integrity modulated this effect.
Conclusions:
- APOE ε4 carriers rely on cortical integrity and landmarks for navigation; insulin resistance may involve less efficient PI neural mechanisms.
- Targeting insulin resistance is crucial for preventing cognitive decline, especially in aging and spatial cognition.
- Network segregation patterns offer insights into compensatory strategies for navigation deficits.
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