While our prior work evaluated locomotor behavior in male Synj1+/− and Synj1+/+ mice at 7 and 12 months of age, in the current study we only evaluated male and female Synj1+/− and Synj1+/+ mice starting at 7–8 months of age, with the purpose of conducting a broad characterization of motivation in Synj1 mice, and early PD progression. This evidence concerns the gene SYNJ1 and Parkinson disease.