I'm having problems with behavioral analysis with.

I tried acute MPTP model, 20 mg/kg every 2 hours x 4(I.P injection), 10 weeks old C57BL/6J. (Ref. Protocol for the MPTP mouse model of Parkinson’s disease. Nature Protocols, 2(1), 141–151.)

On the day of MPTP injection, mice show symptoms such as tremors, stiffness, slow movement, and gait disturbances. But after 2 days, the symptoms disappeared and mice behave like a normal. The behavioral analysis is performed 7 days after MPTP injection. There are no MPTP-induced abnormal behaviors in the behavioral analysis (Rota-rod, Pole test). no differences between the Control group and MPTP group. I tried acute, sub-acute, and chronic MPTP models to solve this problem, but the results were the same. Tissue analysis shows a decrease in TH positive cells, but behavioral analysis shows no difference.

Could anyone provide solutions on this problem? I really need the behavioral analysis data. Any advice would be appreciated.