MAOA-VNTR genotype affects structural and functional connectivity in distributed brain networks.

Area of Science:

• Neuroscience
• Genetics
• Neuroimaging

Background:

• The low expression variant of the monoamine oxidase A gene (MAOA-L) is associated with impulsivity, aggression, and altered brain function.
• The specific impact of MAOA-L on human brain network architecture remains unclear.

Purpose of the Study:

• To investigate the neurobiological effects of the MAOA-L variant on human brain network architecture.
• To determine the specificity of MAOA-L-related connectomic alterations to cortical-limbic circuits and emotion processing.

Main Methods:

• Multimodal neuroimaging (fMRI, DTI) and network-based statistics (NBS) were used in healthy individuals.
• Network architecture alterations were assessed across different neuroimaging tasks and data modalities.
• Sample sizes ranged from 219 to 284 participants across modalities.

Main Results:

• MAOA-L carriers exhibited significantly increased connectivity in a distributed network compared to high expression (H) variant carriers.
• This hyperconnectivity phenotype predominantly involved between-lobe (anisocoupled) links, with a notable emphasis on frontal-temporal connections.
• Hyperconnectivity was consistently observed across fMRI of emotion processing, resting-state fMRI, and diffusion tensor imaging data.
• No significant effects were found in fMRI data related to spatial working memory.

Conclusions:

• The MAOA-L variant is associated with specific alterations in brain network architecture, characterized by widespread hyperconnectivity.
• These connectomic changes are domain-specific, primarily impacting emotion processing networks rather than spatial working memory.
• Multimodal network connectomic approaches are valuable for understanding neurogenetic effects.