To investigate the relationship between specific sphingolipid changes and PD or LID severity, we examined correlations between sphingolipid levels and DAT binding in the Cd and Put of Ctrl and MPTP animals, as well as correlations between sphingolipid levels and dyskinesia scores and L-DOPA and dopamine levels in basal ganglia regions. This evidence concerns the gene SLC6A3 and Parkinson disease.