Investigating the mechanisms of focused ultrasound mediated neural plasticity using magnetic resonance spectroscopy
Magnetic resonance spectroscopy (MRS) is a technique that non-invasively measures molecular metabolite concentrations in the brain. MRS has been shown to be able to detect changes in excitatory and inhibitory neurotransmitter levels following the application of neuromodulatory techniques that target superficial regions of the brain like transcranial magnetic or electric stimulation.
Transcranial focused ultrasound (TUS) is an emerging technique that can modulate brain activity in deep brain regions with high spatial specificity. The biomechanisms by which TUS induces excitatory or inhibitory activity are still poorly understood. Combining TUS with MRS can shed light on how TUS affects measures of neurotransmission and help us understand the effects of TUS on cognition and behaviour in deep brain regions.
This research project aims to further our understanding of the bioeffects of TUS neuromodulation at the molecular level. We plan to quantify changes in excitatory (Glutamate) and inhibitory (GABA) neurotransmitter levels in specific brain regions using MRS after applying TUS to these regions. We will also investigate whole-brain functional connectivity changes related to TUS using functional MR imaging. This project will inform our future studies on understanding decision making in humans.
Left: TUS beam (in colour) and proposed MRS measurement location (in white) on a structural MR image. Right: MRS spectrum showing relative neurotransmitter levels.