Cross-species Standardised Cortico-Subcortical Tractography

Area of Science:

• Neuroimaging
• Neuroanatomy
• Diffusion MRI

Background:

• Cortico-subcortical white matter tracts are crucial for brain function but under-represented in diffusion MRI studies.
• Non-invasive mapping of these tracts is challenging and less explored than cortico-cortical bundles.

Purpose of the Study:

• To introduce standardized tractography protocols for delineating human and macaque cortico-subcortical white matter tracts.
• To enable comparative studies of these tracts across species and investigate individual variability.

Main Methods:

• Developed standardized diffusion MRI tractography protocols for cortex-to-subcortical structure connections (caudate, putamen, amygdala, thalamus, hippocampus).
• Protocols designed for both human and macaque brains to facilitate species-matched mapping.
• Validated tractography reconstructions against known topographical principles from macaque tracer studies.

Main Results:

• Demonstrated that tractography reconstructions align with established topographical principles and translate between macaque and human brains.
• Showcased the robustness of the proposed protocols against variations in data quality.
• Confirmed the preservation of individual variability in tract mapping, linked to family structure in humans.

Conclusions:

• The developed species-matched protocols provide a standardized and robust method for mapping cortico-subcortical white matter tracts.
• These protocols are valuable for comparative neuroanatomy and investigating homologous brain structures in humans and macaques.
• The findings advance the non-invasive study of essential white matter pathways in the brain.