Open-field test reveals abnormal exploratory behavior in LRRK2 KO mice at both 7 and 16 months of age. (a) KO mice tended to spend longer time on rest stops longer than 5 seconds. (b) KO mice spent significantly less time exploring the inner area of the open-field at both testing ages. (c) KO mice displayed significantly greater thigmotaxic (wall hugging) behavior at both testing ages. (d) KO mice take less turns and their travel path is less curvy than WT mice, this was significant at 16 months. (e) Aged KO mice spend less time exploring the object than their WT counterparts. (f) KO mice of both age time points approach the object less frequently. Data presented as mean ± SEM. Data was analyzed by repeated measures ANOVA (see results section for full details) followed by Student’s t-tests for independent samples (to assess the genotype effect at each testing age) and matched-pairs samples (to assess the age effect within each genotype). The p-values on the graphs reflect the independent sample t-test results. ** p <0.01, ***p <0.001.