Neurons communicate by propagating signals by vesicular release of neurotransmitters. Termination of signal
transduction is mediated by reuptake of these molecules back into the releasing pre-synaptic neuron. Neurotransmitter transporters are clinically relevant targets of licit and illicit drugs, which may act as transporter inhibitors or releasers. Understanding how substances interact with neurotransmitter transporters is the basis to characterize their mode of action.