Neurotransmitter transporters facilitate the reuptake of extracellular neurotransmitters to regulate signaling and for recycling. Over twenty protein families comprise this diverse class of membrane proteins. Transporter types include glutamate/aspartate transporters (EAATs, VLGUTs), monoamine transporters (DAT, NET, SERT), GABA transporters (GAT), glycine transporters, and nucleoside transporters. Vesicular transporters (VMAT, VAChT) transfer intracellular neurotransmitters into synaptic vesicles for secretion. These transporters are often the target of drugs, such as with antidepressant reuptake inhibitors, stimulants, and amphetamines.