Youth with Down syndrome display widespread increased functional connectivity during rest

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Genetics

Background:

• Conflicting findings exist regarding resting-state functional connectivity in youth with Down syndrome (DS).
• Previous research has not investigated whole-brain, voxel-level connectivity or its relationship with network selectivity in this population.
• Understanding brain connectivity in DS is crucial for identifying potential clinical intervention targets.

Purpose of the Study:

• To examine whole-brain functional connectivity at the voxel level in youth with DS during an eyes-open resting-state fMRI scan.
• To investigate the relationship between functional connectivity and network selectivity in youth with DS.
• To explore potential links between brain connectivity, network selectivity, and cognitive abilities in DS.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was conducted on 19 youth with DS and 33 typically developing (TD) controls.
• Whole-brain functional connectivity was calculated by correlating the time series of each voxel with every other voxel.
• Network selectivity was computed and correlated with functional connectivity in the DS group; behavioral data (Verbal IQ) were also analyzed.

Main Results:

• Youth with DS demonstrated significantly higher whole-brain functional connectivity across widespread brain regions compared to TD controls.
• Participants with DS exhibited significantly reduced network selectivity relative to TD peers.
• Network selectivity was significantly correlated with functional connectivity in all participants; increased connectivity in specific regions predicted higher Verbal IQ in the DS group.

Conclusions:

• Network organization is disrupted in youth with Down syndrome, characterized by overly connected and less selective brain networks.
• These findings suggest that altered functional connectivity patterns in DS may be associated with differences in cognitive abilities, particularly verbal skills.
• The identified connectivity patterns and their relationship with network selectivity represent potential targets for future clinical interventions aimed at improving outcomes in individuals with DS.