Richard AE Edden1,2, C John J. Evans3,4,
David J. McGonigle3,5
1Russell H Morgan Department of
Radiology and Radiological Sciences, The Johns Hopkins University, Baltimore,
MD, United States; 2FM Kirby Research Center for Functional MRI,
Kennedy Krieger Institute, Baltimore, MD, United States; 3CUBRIC,
School of Psychology, Cardiff University, United Kingdom; 4GE
HealthCare, Slough, United Kingdom; 5School of Biosciences,
Cardiff University, United Kingdom
Edited
MRS measurements of GABA are being widely applied in clinical and basic
neuroscience studies. GABA concentration is known to vary with the menstrual
cycle, and GABA is key to the suprachiasmatic nucleis circadian clock, but
no study has addressed diurnal GABA variation in cortical regions. In spite
of this, it is rare to control for time-of-day in designing studies. This
study measures GABA in visual and sensorimotor cortex in 8 individuals at 5
timepoints in a day, and concludes that methods are insensitive to any
diurnal variation in GABA concentration, but that regional and inter-individual
differences can be seen.