Brain activity and connectivity changes in response to glucose ingestion

Area of Science:

• Neuroscience
• Neuroimaging
• Metabolic regulation

Background:

• The brain's role in regulating eating behavior is increasingly recognized.
• Limited data exists on brain responses post-caloric intake, especially functional changes.
• Understanding these responses is crucial for metabolic and behavioral research.

Purpose of the Study:

• To investigate whole-brain functional responses to glucose ingestion after fasting.
• To analyze changes in Blood Oxygen Level Dependent (BOLD) signal and brain connectivity.
• To differentiate brain activity patterns between glucose and water intake.

Main Methods:

• Functional MRI (fMRI) was used on 25 healthy adult males.
• Participants consumed either a glucose solution or plain water in a single-blind, randomized design.
• Analysis included BOLD signal changes, Eigenvector Centrality Mapping for connectivity, and functional network connectivity.

Main Results:

• Glucose ingestion increased thalamic centrality and decreased BOLD signal in several brain areas.
• Connectivity decreased in sensory-motor and dorsal visual stream networks after glucose intake.
• Water intake led to increased brain-wide centrality and visual cortex connectivity, with heightened BOLD in specific regions.

Conclusions:

• Glucose intake modulates brain networks associated with energy seeking and satiation, showing decreased activity.
• Water consumption appears to enhance connectivity related to food seeking and reward processing.
• These findings highlight distinct neural pathways influenced by caloric versus non-caloric fluid intake.