Evidence of oligodendrogliosis in MPTP-induced Parkinsonism.

International audienceAims: Mice and non-human primates administered with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) represent elective experimental models of Parkinsonism, in which degeneration of the nigro-striatal dopaminergic pathway is associated with prominent neuroinflammation, characterized by activated microglia and astrocytes in both substantia nigra (SN) and striatum. To date, it is unknown whether oligodendrocytes play a role in these events. Methods: We performed a detailed qualitative and quantitative analysis of oligodendrocyte-associated changes induced by acute and chronic MPTP treatment, in the SN and striatum of mice and macaques, respectively. Oligodendrocytes were immunolabeled by cell-specific markers and analyzed by confocal microscopy. Results: In both experimental models, MPTP treatment induces an increase in oligodendrocyte cell number and average size, as well as in the total area occupied by this cell type per tissue section, accompanied by evident morphological changes. This multifaceted array of changes, herein referred to as oligodendrogliosis, significantly correlate with the reduction in the level of dopaminergic innervation to the striatum. Conclusions: This event, associated with early damage of the dopaminergic neuron axons and of the complex striatal circuits of which they are part, may result in an important, although neglected, aspect in the onset and progression of Parkinsonism. © 2012 The Authors. Neuropathology and Applied Neurobiology © 2012 British Neuropathological Society