Behavioral Assessments of Spontaneous Locomotion in a Murine MPTP-induced Parkinson's Disease Model

Parkinson's disease (PD) is a common neurodegenerative disorder disease, causing the phenomenon of shaking, rigidity, slowness of movement and dementia. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) can lead to some Parkinson's-like symptoms by destroying dopaminergic neurons in the substantia nigra of the brain. It has been thus used to establish PD models in various animal studies. Here, mice receive MPTP injections (20 mg/kg/day) for seven days and the behavioral tests are performed on the eighth day. This model is adapted efficiently in the study of PD. The behavioral tests here include the cylinder test and the open field test. The cylinder experiment is used to detect the animals' ability to lift their front paws when put into a different environment. As the PD model mice show arching—the mouse arches its back—the number of paw liftings decrease. This test is easy to execute. The open field test is used to detect the amount of time the mice spend on running, walking, and remaining immobile. We analyze animals' movements in open field using software and obtain data. Lastly, we use L-DOPA, one of the most commonly used PD drugs, as one example to show how to apply this model to the study of PD drugs. Our results indicate that MPTP neurotoxicity induces motor deficit which can be mitigated by L-DOPA.