Diffusion tensor imaging reveals evolution of primate brain architectures.

Area of Science:

• Neuroscience
• Evolutionary Biology
• Comparative Anatomy

Background:

• Brain evolution is a long-standing scientific inquiry.
• Neuroimaging techniques, particularly diffusion tensor imaging (DTI) tractography, offer powerful tools for studying brain evolution.
• Consistent white matter fiber connection patterns reveal common brain architecture and predict function.

Purpose of the Study:

• To identify conserved and divergent brain structures across primate species using novel connectivity-based landmarks.
• To map the evolutionarily preserved and variable aspects of primate brain architecture.

Main Methods:

• Utilized 358 dense individualized and common connectivity-based cortical landmarks (DICCCOLs) derived from DTI datasets.
• Compared DICCCOLs across human, chimpanzee, and macaque monkey brains.
• Performed qualitative and quantitative evaluations of landmark locations and fiber connections.

Main Results:

• Identified 65 DICCCOLs common to humans, chimpanzees, and macaques, indicating conserved brain architecture.
• Discovered 175 DICCCOLs showing significant discrepancies among the three species.
• Demonstrated consistency in anatomical locations and fiber connections for common DICCCOLs.

Conclusions:

• The 65 common DICCCOLs suggest an evolutionarily preserved foundational brain architecture across these primate species.
• The 175 discrepant DICCCOLs highlight regional patterns of evolutionary complexity and variability.
• This study provides a novel framework for understanding primate brain evolution through connectivity-based landmarks.