Adolescent Tuning of Association Cortex in Human Structural Brain Networks

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Brain Imaging

Background:

• Adolescence involves significant brain maturation, including cortical thickness changes and myelination.
• Previous research indicates local cortical shrinkage and intracortical myelination during this period.
• Understanding age-related shifts in brain network topology is crucial for developmental neuroscience.

Purpose of the Study:

• To investigate age-related changes in the topological organization of cortical structural networks during adolescence.
• To correlate these network changes with neuroimaging markers like cortical thickness and myelination.
• To identify specific brain regions and network modules most affected by adolescent development.

Main Methods:

• Utilized magnetic resonance imaging (MRI) to measure cortical thickness in 308 regions from 297 healthy adolescents (aged 14-24).
• Employed a sliding-window analysis to assess age-related changes in network attributes (global, local, community partitions).
• Estimated structural correlation to represent the cortical structural network.

Main Results:

• A general decrease in the strength of structural correlation was observed with increasing age.
• Association cortical regions showed a significant decrease in nodal degree (hubness) peaking around age 19.
• Greater network changes correlated with faster rates of adolescent cortical myelination and shrinkage, particularly in prefrontal modules.

Conclusions:

• Adolescence is characterized by biologically plausible changes in brain network organization detectable via structural imaging.
• Findings support the concept of anatomical connectivity tuning and consolidation, especially between the frontal cortex and the broader connectome.
• Age-related network alterations are linked to ongoing neurodevelopmental processes like myelination and cortical thinning.