A Preliminary Magnetic Resonance Spectroscopy Investigation Sex Differences in Gamma-Aminobutyric Acid in Autism Spectrum Disorder
Objectives: This study uses magnetic resonance spectroscopy (MRS) to investigate sex differences in GABA concentration (mM/L) between adults with ASD and typically developing controls. Further, this study investigates the relationship between GABA concentration at the rDLPFC and rSTS, and traits and characteristics associated with ASD.
Methods: GABA was measured as part of a large protocol using a 3T magnetic resonance imaging (MRI) scanner. Voxels were placed at the rDLPFC and rSTS based on the participant’s structural MRI. rDLPFC GABA concentration was obtained for 25 participants (9 ASD, 16 NT), and rSTS GABA concentration was obtained for 26 (12 ASD, 14 NT) participants. Data were analyzed using LCModel software.
Results: There were no differences in GABA concentration at either of these sites between groups, nor when data were stratified by sex. Following correction for multiple comparisons, there was a significant positive relationship between GABA concentration at the rSTS and social impairment in females with ASD.
Conclusions: Although inconsistent with a GABAergic model of autism, these findings provide preliminary support for sex differences in neurochemical mechanisms underlying social cognition in ASD.
See more of: Brain Function (fMRI, fcMRI, MRS, EEG, ERP, MEG)