Characterization of long-term motor deficits in the 6-OHDA model of Parkinson's disease in the common marmoset.

Research aimed at developing new therapies for Parkinson's disease (PD) critically depend on valid animal models of the disease that allows for repeated testing of motor disabilities over extended time periods. We here present an extensive characterization of a wide range of motor symptoms in the 6-OHDA marmoset model of PD when tested over several months. The severity of motor deficits was quantified in two ways: (i) through manual scoring protocols appropriately adapted to include species specific motor behavior and (ii) using automated quantitative motion tracking based on image processing of the digital video recordings. We show that the automated methods allow for rapid and reliable characterization of motor dysfunctions, thus complementing the manual scoring procedures, and that robust motor symptoms lasting for several months could be induced when using a two-stage neurotoxic lesioning procedure involving one hemisphere at a time. This non-human primate model of PD should therefore be well suited for long-term evaluation of novel therapies for treatment of PD.