Recent biochemical studies of the dopamine transporter--a CNS drug target.

The DAT is an important component of the dopaminergic synapse. It is critical for removing dopamine from extracellular space and is a target or "receptor" for various drugs. Recent electron microscopic immunocytochemical studies indicate that DAT, while found in nerve terminal membranes, has a very low presence (if any) in the synapse itself, and is mainly found in perisynaptic areas. Also, different levels of DAT are found in different dopaminergic nuclei. These findings suggest that diffusion of the transmitter may be more important than previously thought. Finally, the turnover rate of the DAT protein is similar to other synaptic proteins such as receptors.