Population Differences in Brain Morphology and Microstructure among Chinese, Malay, and Indian Neonates

Jordan Bai,Kenneth Kwek,Michael J Meaney,Keith M Godfrey,Yap-Seng Chong,Anqi Qiu,Peter D Gluckman,Anne Rifkin-Graboi,Muhammad Farid Abdul-Rahman,Marielle V Fortier,Seang-Mei Saw,Xi-Nian Zuo

doi:10.1371/journal.pone.0047816

Abstract

We studied a sample of 75 Chinese, 73 Malay, and 29 Indian healthy neonates taking part in a cohort study to examine potential differences in neonatal brain morphology and white matter microstructure as a function of ethnicity using both structural T2-weighted magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). We first examined the differences in global size and morphology of the brain among the three groups. We then constructed the T2-weighted MRI and DTI atlases and employed voxel-based analysis to investigate ethnic differences in morphological shape of the brain from the T2-weighted MRI, and white matter microstructure measured by fractional anisotropy derived from DTI. Compared with Malay neonates, the brains of Indian neonates’ tended to be more elongated in anterior and posterior axis relative to the superior-inferior axis of the brain even though the total brain volume was similar among the three groups. Although most anatomical regions of the brain were similar among Chinese, Malay, and Indian neonates, there were anatomical variations in the spinal-cerebellar and cortical-striatal-thalamic neural circuits among the three populations. The population-related brain regions highlighted in our study are key anatomical substrates associated with sensorimotor functions.

Highlights

Research into early development has yet to fully examine the impact of population and population-related influences on brain morphology and microstructure, despite studies demonstrating population differences in the brains of adults
Brain Global Size and Morphology Among the Chinese, Malay, and Indian neonates, no group differences were found in the total brain volume, AC-PC length, the three-dimensional lengths of the brain, brain length to width ratio, and the brain height to width ratio (Table 2)
The global brain size was similar among the three populations of neonates in terms of volume, we found that the brain of Indian neonates tended to be more elongated than that of Malay neonates in the anterior-posterior axis relative to the superior-inferior axis

Summary

Introduction

Research into early development has yet to fully examine the impact of population and population-related influences on brain morphology and microstructure, despite studies demonstrating population differences in the brains of adults. There is a paucity of studies examining brain morphological differences among healthy populations of different origins in early life. Substantial variations in brain anatomy have been reported across adults from different populations, including differences in both brain global size and structural volumes assessed using structural magnetic resonance imaging (MRI). Volumetric MRI analysis shows region-specific volume differences in the cerebellum, amygdala, and orbital frontal cortex between the African-Americans and Caucasians [4], and in the widespread frontal and temporal cortical regions, basal ganglia, and midbrain between Chinese and Caucasians [5]

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