Physical Sciences of Imaging in the Biomedical Sciences CDT
Completed in 2016.
Thesis project - "Investigating the neurobiological changes associated with cerebellar transcranial direct current stimulation (tDCS) using magnetic resonance imaging (MRI)"
Professor Chris Mial, School of Psychology
Dr Joseph Galea, School of Psychology
Professor Jeremy Wyatt, School of Computer Science
The cerebellum plays an important role in motor control and motor learning. However, it is very difficult to examine its precise role in humans because of its anatomical position, complicated network and scarcity of patients with isolated cerebellar lesions. Therefore, developing experimental techniques, which allow us to study the cerebellum in humans, is of vital importance. Non-invasive transcranial Direct Current Stimulation (tDCS) appears to be a promising technique for modulating cerebellar excitability and function (Galea et al., 2009, 2011), but its underlying mechanism of action is not understood. In this project, Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS) will be used to develop our understanding of the mechanisms of cerebellar tDCS.
First, a novel MRS radio frequency (RF) pulse sequence will be developed to detect brain metabolites from a single voxel within the cerebellum. Specifically, I will create and test an MRS sequence that enables the reliable detection of the inhibitory neurotransmitter GABA within a small voxel placed in the cerebellum. Next, I will examine for the first time whether concurrent tDCS causes any signal artefact when used in conjunction with MRS. Once any image artefact issues have been overcome, I plan to investigate the changes in GABA associated with cerebellar tdcs.
This work will be integrated with magnetic resting state (MRS) imaging to assess how localized neurochemical changes following tDCS relate to alterations in whole-brain connectivity.
This work will advance imaging science through the development of a new MRS sequence, the testing of concurrent tDCS/MRS and the development of our understanding regarding how local changes in metabolites changes whole brain connectivity.