Hyperactivity has been shown to be reduced by ATX in two other putative ADHD models—mice lacking pituitary adenylate cyclase-activating polypeptide and neurokinin-1 receptor ‘knockout’ mice [37,38]—while in spontaneously hypertensive rats (SHR), another putative ADHD model, results regarding impulsivity and inattention have been inconclusive [39]. The gene discussed is TACR1; the disease is attention deficit-hyperactivity disorder.