Dynamics of brain neurotransmitters levels in response to a short visual stimulus measured using functional MRS at 3T

Motivation: Current assumptions propose that rapid fluctuations in Glu levels are associated with its release from vesicles in response to an event-related stimulus. Therefore, there should be rapid changes in GABA and Glu in response to a short stimulus that will show local stimulus-induced inhibition and excitation. Goal(s): To quantify GABA and Glu levels following a brief visual stimulus lasting three seconds. Approach: Single voxel 1H-MRS was used to measure GABA (MEGA-PRESS) and Glx (PRESS) levels. Flickering checkerboard (3s) was used for stimulation. Results: Both neurotransmitter levels showed increase in first seconds after stimulus presentation and following decrease to a basic level. Impact: This study tests hypothesis regarding rapid neurotransmitter level changes induced by vesicular release in response to short stimuli. The findings from this research have the potential to offer novel insights and methodologies for investigating neural processes.