SLC6A3 and attention deficit-hyperactivity disorder: This animal model exhibits the behavioral characteristics of the disorder (Sagvolden, 2000) and displays several variations in the Dat1 gene encoding the dopamine transporter (Mill et al., 2005), known to be related to ADHD (Cook et al., 1995; Faraone et al., 2005; Madras et al., 2005).