Regional differences in interhemispheric structural fibers in healthy, term infants

Area of Science:

• Neuroscience
• Developmental Biology
• Medical Imaging

Background:

• The corpus callosum (CC) is crucial for interhemispheric communication.
• Understanding early CC development and gender differences is vital for diagnosing neurodevelopmental disorders.

Purpose of the Study:

• To investigate early interhemispheric cortical development by analyzing CC substructures.
• To examine gender differences in CC microstructural development in healthy term neonates.

Main Methods:

• Diffusion tensor imaging (DTI) and fiber tracking (FACT algorithm) were used.
• The CC was segmented into five substructures: genu, rostrum, body, isthmus, and splenium.
• Microstructural (diffusion metrics) and macrostructural (volume) analyses were performed.

Main Results:

• Female infants exhibited higher radial and mean diffusivity in CC connections compared to males.
• No significant gender differences in CC substructure volumes were observed.
• Interhemispheric fiber integrity was more advanced in female infants across most CC subdivisions, except the isthmus.

Conclusions:

• Female infants demonstrate more developed CC cytoarchitecture and fiber integrity than males.
• These microstructural differences may stem from larger axonal diameter, denser fibers, or enhanced myelination in females.
• Findings suggest a gender-based divergence in early interhemispheric pathway maturation.