C. John Evans1, Jim F. M. Myers2, Nicola Kalk2, Richard Anthony Edward Edden3, Anne Lingford-Hughes4
1CUBRIC, School of Psychology, Cardiff University, Cardiff, Wales, United Kingdom; 2Psychopharmacology Unit,, University of Bristol, Bristol, United Kingdom; 3Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States; 4Neuropsychopharmacology Unit, Imperial College London, London, United Kingdom
Tiagabine, an antiepileptic drug, acts by blocking the reuptake of inhibitory neurotransmitter GABA from the synapse, thus increasing GABA concentration at the synaptic cleft. We performed J-difference edited 1H-MRS before and after tiagabine administration to investigate whether MRS was sensitive to changes in extracellular GABA concentration. Ten participants were studied, and MRS data were acquired from occipital and limbic voxels. No significant change was detected in GABA, thus indicating that although tiagabine has GABAergic action, it does not affect the total GABA concentration.