Fortunately, the detailed anatomy of the retina is well known and its cells are readily accessible. This allows us to study recognized synapses and complete experiments that would be more difficult in other brain areas. The control of vesicle cycling has been studied both in situ and with solitary cells. Transmission between identified cells is being studied in a retinal slice. The results can be used to determine the kinetics of synaptic vesicle mobilization and cycling.
Complimentary studies come from the study of solitary cells.
Transporters are proteins that move transmitters in both directions across cell membranes. In most neurons, transporters move transmitter molecules into a cell and function to recapture or uptake transmitter after release. However, in some neurons transporters also operate in the opposite direction and function in the release of transmitter. Voltage controls the balance between uptake and release. Experiments on native and cloned transporters are now designed to reveal the exact mechanism of how a transporter protein moves a transmitter molecule across a membrane.