Individual differences in GABA content are reliable but are not uniform across the human cortex
In this study we used magnetic resonance spectroscopy (MRS) to measure the content of the inhibitory neurotransmitter GABA in four different cortical regions. We discovered that individuals with higher GABA content in one cortical area don’t necessarily have higher GABA content in other cortical areas. We also show that our measurements are reliable across weeks. Our findings are important because they suggest that GABA levels are regionally specific, and they support earlier studies that suggest local individual differences in GABA content relate to behavior. Those earlier studies didn’t look at measurement reliability and regional specificity in the same individuals. We did that in our study.