BDNF and Anxiety: We did not choose a model with >50% cortical BDNF reduction because mice with complete postnatal depletion of BDNF from the nervous system develop anxiety-like behavior (Rauskolb et al., 2010), hyperactivity, freezing, and a clasping phenotype (Baquet et al., 2004; Strand et al., 2007; Rauskolb et al., 2010) that might otherwise mask an effect on corticostriatal motor skill learning.