Sex differences associated with corpus callosum development in human infants: A longitudinal multimodal imaging study

Area of Science:

• Neuroscience
• Human Development
• Brain Imaging

Background:

• The corpus callosum (CC) is crucial for interhemispheric communication.
• Existing research on sex differences in CC size is conflicting, especially in infancy.
• Infancy is a critical period for rapid CC development.

Purpose of the Study:

• To investigate sex differences in CC development during infancy.
• To examine the relationship between CC microstructure and size.
• To explore correlations between CC length and cognitive abilities.

Main Methods:

• Longitudinal brain imaging (MRI) of 104 infants at 6, 12, and 24 months.
• Analysis of brain-size adjusted CC area and thickness.
• Diffusion tensor imaging (DTI) to assess microstructural organization.

Main Results:

• Males exhibited a steeper growth rate in CC area and thickness from 6-24 months.
• Infant males had larger CC size compared to females, contrary to adult findings.
• CC thickness correlated with microstructure, with no observed sex differences in this association.
• CC length was negatively associated with nonverbal ability in females.

Conclusions:

• Sex differences in CC growth emerge in infancy, with males showing accelerated development.
• The microstructural basis of CC thickness appears equivalent between sexes in early development.
• Early CC development patterns differ significantly from those observed in older individuals.