Multiple system atrophy (MSA) is a rare and fatal neurodegenerative disorder. The pathologic hallmark is the accumulation of aggregated alpha-synuclein in oligodendrocytes forming glial cytoplasmic inclusions. Some symptomatic treatments are available while disease-modification remains an unmet treatment need. Post-mortem findings suggest insulin resistance, i.e. reduced insulin signaling, in the brains of MSA patients. The aim of this study is to complete the target validation of insulin resistance for future treatment trials.