Key result
Boys with Autism Spectrum Disorder showed no significant difference in GABA+ levels in the left anterior cingulate cortex compared to typically developing controls, though lower GABA+/Cr correlated with greater symptom severity.
Why the study?
Does brain GABA concentration in the left anterior cingulate cortex differ between boys with ASD and typically developing controls, and does it correlate with symptom severity?
Cross-Sectional (n=38)
No
Does brain GABA concentration in the left anterior cingulate cortex differ between boys with ASD and typically developing controls, and does it correlate with symptom severity?
Absolute Event Rate: 2.49% vs 2.66%
p-value: p=0.41
While absolute GABA levels in the left anterior cingulate cortex did not differ significantly between boys with ASD and controls, lower GABA levels correlated with greater autism symptom severity, providing partial support for the excitatory/inhibitory imbalance theory.
No group GABA+ difference limits broad E/I imbalance claims in ASD; severity correlation is hypothesis-generating and needs longitudinal confirmation.
Magnetic resonance spectroscopy (MRS) from voxels placed in the left anterior cingulate cortex (ACC) was measured from 14 boys with Autism Spectrum Disorder (ASD) and 24 gender and age-matched typically developing (TD) control group. Our main aims were to compare the concentration of γ-aminobutyric acid (GABA) between the two groups, and to investigate the relationship between brain metabolites and autism symptom severity in the ASD group. We did find a significant negative correlation in the ASD group between Autism Spectrum Screening Questionnaire (ASSQ) and GABA+/Cr, which may imply that severity of symptoms in ASD is associated with differences in the level of GABA in the brain, supporting the excitatory/inhibitory (E/I) imbalance theory. However we did not find a significant difference between the two groups in GABA levels.
No takes yet. Share an insight, caveat, or question.
Brix et al. (2015) conducted a cross-sectional in Autism Spectrum Disorder (n=38). Autism Spectrum Disorder vs. Typically developing controls was evaluated on GABA+ concentration in the left anterior cingulate cortex (p=0.41). Boys with Autism Spectrum Disorder showed no significant difference in GABA+ levels in the left anterior cingulate cortex compared to typically developing controls, though lower GABA+/Cr correlated with greater symptom severity.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: