Partitioning variance in cortical morphometry into genetic, environmental, and subject-specific components

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• The interplay between genetics and environment in adolescent brain development remains incompletely understood.
• Previous research has not fully elucidated the specific contributions of genetic variation versus experience to brain morphology during adolescence.

Purpose of the Study:

• To quantify the relative contributions of genetic and subject-specific effects on cortical thickness, surface area, and sulcal depth in adolescents.
• To identify brain regions with heterogeneous heritability estimates.

Main Methods:

• Utilized longitudinal data from 11,665 participants in the Adolescent Brain Cognitive Development (ABCD) Study.
• Employed a computationally efficient framework to fit vertex-wise variance components, including family, genetic, and subject-level effects.
• Analyzed variance in cortical thickness, surface area, and sulcal depth.

Main Results:

• Genetic influence is the primary driver of variance in cortical thickness and surface area.
• Subject-level effects, potentially representing environmental influences and individual experiences, predominantly explain variance in sulcal depth.
• Identified specific cortical regions exhibiting novel, heterogeneous distributions of heritability.

Conclusions:

• Genetic factors play a substantial role in shaping adolescent brain morphology, particularly cortical thickness and surface area.
• Individual-specific variance is crucial for understanding sulcal depth development and highlights the impact of environmental factors.
• The findings underscore the complex interplay of genetic and environmental influences on brain maturation.