Genetic effect on working memory activation pattern and structural properties of cortical gray matter

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Behavioral Genetics

Background:

• Working memory is crucial for decision-making and executive functions.
• The relative contributions of genetics and environment to working memory brain activity are not fully understood.
• Identifying specific cortical areas involved in working memory and their heritability is a key research question.

Purpose of the Study:

• To identify working memory-related cortical areas using functional MRI.
• To assess the genetic influence on the activation patterns within these areas.
• To investigate the relationship between genetic influences on functional activation and structural brain properties.

Main Methods:

• Analysis of functional MRI data from 424 monozygotic (MZ) and dizygotic (DZ) twin pairs from the Human Connectome Project.
• Comparison of activation pattern similarity between MZ and DZ twins to determine genetic contribution.
• Structural MRI analyses to examine cortical curvature, thickness, and myelination in genetically influenced regions.

Main Results:

• Activation patterns in working memory-related areas showed significantly higher similarity in MZ twins compared to DZ twins, indicating a strong genetic influence.
• Key regions with notable genetic influence on activation include the Medial Intraparietal Area (MIP), various parietal and prefrontal cortex areas, and motor/premotor cortices.
• Genetic effects on brain structure differed, with stronger influences in posterior cingulate, visual, and medial temporal cortices. Cortical thickness and myelination also showed genetically influenced variations in specific areas (e.g., R-7Pm, R-AIP).

Conclusions:

• Genetic factors play a substantial role in shaping working memory-related functional brain activation.
• The genetic underpinnings of working memory functional activation are distinct from those influencing macroscopic structural brain features.
• This study provides novel insights into the complex interplay between genetic contributions to brain function and structure.