Classical neurotransmitters are synthesized in the cytoplasm, and so must be transported into synaptic vesicles for regulated exocytosis of vesicles filled with neurotransmitter. Although the vesicular transporters for monoamines and acetylcholine have been identified, the proteins responsible for packaging the primary inhibitory and excitatory transmitters, gamma aminobutyric acid (GABA) and glutamate have only recently been identified. Studies in the nematode Caenorhabditis elegans have implicated the gene unc-47 in the release of GABA. Recently, rat homolog of unc-47 have been cloned and characterized. Rat VGAT, a 525 aa membrane protein with ten transmembrane domains, is expressed by central GABA neurons. Both N and C-termini are predicted to be cytoplasmic. Rat VGAT and unc-47 share ~38% sequence identity. Rat VGAT is primarily expressed in the brain