Similar patterns of cortical expansion during human development and evolution

Area of Science:

• Neuroscience
• Developmental Biology
• Comparative Anatomy

Background:

• The term-born human infant cerebral cortex is complexly folded but has only one-third the adult surface area.
• Understanding postnatal cortical expansion is key to comprehending brain development and its vulnerabilities.

Purpose of the Study:

• To investigate the nonuniformity of postnatal cortical expansion in human infants.
• To compare human postnatal expansion patterns with evolutionary expansion and macaque monkey cortex.
• To explore the implications of differential expansion for neural architecture and sensitivity to experience.

Main Methods:

• Comparative analysis of cerebral cortex surface area in 12 healthy term infants and 12 healthy young adults.
• Comparison of human cortical expansion patterns with macaque monkey cerebral cortex data.

Main Results:

• Postnatal cortical expansion is highly nonuniform, with lateral temporal, parietal, and frontal regions expanding nearly twice as much as insular and medial occipital regions.
• The pattern of human postnatal expansion closely resembles the pattern of human evolutionary expansion.
• Differential expansion may relate to regional differences in neural maturity at birth and adult synaptic complexity.

Conclusions:

• Uneven postnatal cortical expansion is a significant feature of human brain development.
• The similarity between postnatal and evolutionary expansion suggests that recently evolved regions may benefit from delayed maturation to incorporate postnatal experience.
• This developmental strategy could influence the sensitivity of cortical circuits to environmental factors and early life challenges.