From the article:
Infusion of D-beta-hydroxybutyrate (D-beta-HB) to mice suffering from Parkinson disease restored impaired brain function and protected against neurodegeneration and motor skill abnormalities.
[…]
Przedborski and colleagues administered the neurotoxin MPTP to mice, which caused dopaminergic neurodegeneration and deficits in the mitochondrial electron transport chain reminiscent of Parkinson disease. Using this model of disease, the authors showed that the infusion of the ketone body D-beta-HB restored mitochondrial respiration and protected against MPTP-induced neurodegeneration and motor deficits. The study supports a critical role for mitochondrial defect in Parkinson disease.