Development of the sensorimotor cortex in the human fetus: a morphological description.

Area of Science:

• Neuroscience
• Developmental Biology
• Human Anatomy

Background:

• The development of the human cerebral cortex, particularly the sensorimotor cortex, involves complex morphological changes.
• Understanding sulcal and gyral development is crucial for comprehending normal brain maturation and identifying potential abnormalities.

Purpose of the Study:

• To macroscopically describe the morphological stages of sulcal and gyral development in the human sensorimotor cortex.
• To define chronological stages of sensorimotor cortex development based on observable morphological features.
• To note the morphological appearance and vascularization of the pericentral lateral cortex and opercula.

Main Methods:

• Macroscopic study of 21 human fetal brains.
• Age range: 13 to 28 gestational weeks.
• Focus on the sensorimotor cortex, pericentral lateral cortex, and opercula, including vascularization.

Main Results:

• The central cerebral sulci were the first macroscopical structures identified.
• Four distinct chronological stages of sensorimotor cortex development were defined between 18 and 28 gestational weeks.
• Stage 1 (18-19 GWs): Inferior central cerebral sulcus appearance. Stage 2 (20-22 GWs): Pericentral lateral regions develop, opercularization begins. Stage 3 (24-26 GWs): Parietal/temporal cortices develop, insular region covered. Stage 4 (27-28 GWs): Central cerebral regions mature.
• Initiation of maturation in pericentral cerebral cortices is concomitant.

Conclusions:

• The study provides a detailed chronological framework for sensorimotor cortex development.
• The defined stages offer a valuable reference for understanding fetal brain morphology.
• Observations highlight the coordinated maturation processes within the developing sensorimotor cortex.