Spatial distribution and longitudinal development of DEEP cortical sulcal landmarks in infants

Sulcal pits, the locally deepest points in sulci of the cerebral cortex, are found to be spatially highly consistent across human adult individuals. It is suggested that sulcal pits are genetically controlled and have close relationships with functional areas. To date, most imaging studies of sulcal pits are focused on adult brains, yet little is known about the spatial distribution and temporal development of sulcal pits in the first 2 years of life, the most dynamic period of postnatal brain development. Studying sulcal pits during this period would enrich our current limited understanding of the developmental trajectories of sulcal pits and provide insights into neurodevelopmental disorders associated with abnormal cortical foldings. In this paper, by using surface-based morphometry, for the first time, we systemically investigated the spatial distribution and temporal development of sulcal pits in major sulci from 73 healthy infants, each with longitudinal 3T MR scans at term birth, 1 year, and 2 years of age. Our results suggest that the consistency of spatial distribution of sulcal pits in major sulci across subjects has already existed at term birth and this spatial distribution pattern is relatively stable during cortex development in the first 2 years, despite that the cortex expands dramatically and the sulcal depth increases considerably.

1. INTRODUCTION

The human cerebral cortex is highly folded and variable across individuals. Sulcal pits are the locally deepest points along sulcal lines in the cerebral cortex [1]. During the human brain development, the deepest parts of primary sulci are the first places to develop in an embryo's brain and then change least as the cortex growing [1]. Quantitative MR imaging studies provide strong evidences that the deeper parts of sulci are more genetically controlled than the superficial parts [12]. Abundant studies [1], [2], [3] indicate that there is a particularly spatial relationship between the deepest parts of sulci and functional areas.