Background: Preclinical data demonstrate that gamma-aminobutyric acid (GABA) interneurons initiate connectivity in the developing brain. Objectives: The goal of this study was to compare GABA concentration and its relationship to functional connectivity in the brains of term and preterm infants at term-equivalent age. Methods: Infants received both magnetic resonance spectroscopy (MRS) and functional magnetic resonance imaging (fMRI) scans at term-equivalent age. Whole brain functional connectivity MRI data using intrinsic connectivity distribution maps were compared to identify areas with differences in resting-state functional connectivity between the preterm and term control groups. MRS measured concentrations of GABA, glutamate, N-acetyl-aspartate (NAA) and choline; NAA/choline was then calculated for comparison between the 2 groups. Results: Preterm infants had lower right frontal GABA and glutamate concentrations than term controls and showed a significantly different relationship between connectivity and GABA concentration in the right frontal lobe. Preterm infants had a positive correlation between GABA concentration and connectivity, while term controls demonstrated a negative correlation between these two developmentally regulated parameters. Conclusion: These results suggest that regional GABA concentrations are associated with normal and altered neonatal resting-state connectivity.

Keywords:
Preterm infant brain, Resting-state functional connectivity, Gamma-aminobutyric acid, Magnetic resonance spectroscopy, Intrinsic connectivity distribution
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2014
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