The lack of endogenous control over motor activity by endogenous LRRK2 is further supported by the absence of a clear motor phenotype in LRRK2 knockout mice (Herzig et al., 2011, Lin et al., 2009), although exploratory changes consistent with anxiety-like behavior, and (transient) facilitation of rotarod performance have also been reported in these mice (Hinkle et al., 2012). This evidence concerns the gene LRRK2 and Anxiety.