Intrinsic activity development unfolds along a sensorimotor-association cortical axis in youth

Area of Science:

• Neuroscience
• Developmental Biology
• Neuroimaging

Background:

• Animal studies show intrinsic cortical activity changes with maturation and declining plasticity.
• Resting-state functional MRI (fMRI) is a key tool for studying brain activity in humans.

Purpose of the Study:

• To investigate the developmental trajectory of intrinsic cortical activity in humans.
• To identify a potential cortical gradient of neurodevelopmental change.
• To explore the relationship between brain maturation, myelin, and environmental factors.

Main Methods:

• Analysis of resting-state fMRI data from 1,033 healthy youths (ages 8-23).
• Examination of intrinsic activity amplitude and spatiotemporal variability.
• Correlation with intracortical myelin maturation and neighborhood environmental data.

Main Results:

• Intrinsic fMRI activity amplitude declines heterochronously across cortical regions during development.
• These declines correlate with intracortical myelin maturation, a plasticity regulator.
• Developmental trajectories follow a hierarchical sensorimotor-association cortical axis.
• Environmental disadvantage effects on the brain diverge most along this axis in mid-adolescence.

Conclusions:

• A hierarchical neurodevelopmental axis exists in the human cortex.
• This axis reflects the progression of cortical plasticity and maturation.
• Environmental factors interact with neurodevelopmental trajectories during adolescence.