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Category: Analysis

Description: A balance of excitatory and inhibitory signalling within key cortical regions in the motor network regulates overall network activity and connectivity in humans. This balance can be non-invasively assessed by quantifying glutamate and GABA across cortical regions using magnetic resonance spectroscopic imaging (MRSI). We present planned analyses of a large dataset comprising healthy adults across a range of ages, and patients with amyotrophic lateral sclerosis (ALS) - a neurodegenerative disorder of the motor system in which altered cortical excitability is consistently observed. Using a novel MRSI protocol, GABA and glutamate are mapped in high spatial resolution across a region of interest encompassing both primary motor cortices. We will use the free software FSL-MRS toolkit to pre-process the MRSI data, fit spectra and quantify metabolite concentration. This dataset will allow the spatial distribution of neurochemical concentrations to be characterised in healthy individuals and disease, and the effect of age to be addressed. Furthermore, by combining MRS and functional MRI data, the role of neurochemicals in determining motor network function can be investigated and biomarkers of future therapeutic response to be developed. Identifying physiological processes underlying motor function and plasticity may yield targets for modulation to improve function or treat disease.