Mass spectrometry imaging identifies abnormally elevated brain l-DOPA levels and extrastriatal monoaminergic dysregulation in l-DOPA-induced dyskinesia.

Fridjonsdottir E, Shariatgorji R, Nilsson A, Vallianatou T, Odell LR, Schembri LS, Svenningsson P, Fernagut P, Crossman AR, Bezard E, Andrén PE

Sci Adv 7 (2) - [2021-01-00; online 2021-01-06]

l-DOPA treatment for Parkinson's disease frequently leads to dyskinesias, the pathophysiology of which is poorly understood. We used MALDI-MSI to map the distribution of l-DOPA and monoaminergic pathways in brains of dyskinetic and nondyskinetic primates. We report elevated levels of l-DOPA, and its metabolite 3-O-methyldopa, in all measured brain regions of dyskinetic animals and increases in dopamine and metabolites in all regions analyzed except the striatum. In dyskinesia, dopamine levels correlated well with l-DOPA levels in extrastriatal regions, such as hippocampus, amygdala, bed nucleus of the stria terminalis, and cortical areas, but not in the striatum. Our results demonstrate that l-DOPA-induced dyskinesia is linked to a dysregulation of l-DOPA metabolism throughout the brain. The inability of extrastriatal brain areas to regulate the formation of dopamine during l-DOPA treatment introduces the potential of dopamine or even l-DOPA itself to modulate neuronal signaling widely across the brain, resulting in unwanted side effects.

Spatial Mass Spectrometry [Technology development]

PubMed 33523980

DOI 10.1126/sciadv.abe5948

Crossref 10.1126/sciadv.abe5948

pii: 7/2/eabe5948
pmc: PMC7787486