Many physiological, endocrine and behavioral functions are determined and regulated by monoamine signaling. Many brain disorders such as depression, drug abuse, schizophrenia, attention deficit hyperactivity disorder (ADHD) are caused by the malfunction of monoaminergic transmission. The intensity of monoaminergic signaling is determined by the availability of the monoamine, which is in turn determined in part by its uptake from the extracellular milieu via monoamine transporters. These transporters include DAT, SERT, and NET, responsible for uptaking dopamine, serotonin (5-HT) and noradrenaline respectively, and recycling them back for release. DAT, SERT and NET are members of the Na+/Cl– dependent membrane transporter family which also includes other members.