Neurotransmitter transporters: fruitful targets for CNS drug discovery.

More than 20 members have been identified in the neurotransmitter transporter family. These include the cell surface re-uptake mechanisms for monoamine and amino acid neurotransmitters and vesicular transporter mechanisms involved in neurotransmitter storage. The norepinephrine and serotonin re-uptake transporters are key targets for antidepressant drugs. Clinically effective antidepressants include those with selectivity for either NE or serotonin uptake, and compounds with mixed actions. The dopamine transporter plays a key role in mediating the actions of cocaine and the amphetamines and in conferring selectivity on dopamine neurotoxins. The only clinically used compound to come so far from research on amino acid transporters is the antiepileptic drug tiagabine, a GABA uptake inhibitor.