Assessing the relationship between glutamate, GABA, and synaptic density in healthy subjects after ketamine administration

Motivation: Confounding literature on the effects of ketamine on the glutamatergic and GABAergic mechanisms related to synaptogenesis. Goal(s): Measuring the relationship between glutamate, GABA and synaptic density in healthy subjects after ketamine administration. Approach: We perform simultaneous PET and single-voxel MR spectroscopy acquisition in healthy volunteers before and after a ketamine dose. Results: We report significant increased glutamate levels up to a week after ketamine dose, but no GABA trends. Trends toward increase in the PET synaptic marker, showing no association with glutamate levels. Impact: This study investigates the link between Glutamate and GABA levels, measured by 1H MRS, and synaptic density, measured by [11C]UCB-J PET, in healthy individuals within a week after ketamine administration, exploring neuroplasticity effects.