Most brain synapses release the neurotransmitter glutamate. Despite its ubiquitous nature, very little is known about how presynaptic terminals recycle or otherwise replace the released glutamate. Without an efficient glutamate recycling mechanism synapses would quickly become depleted of neurotransmitter, so deciphering these cellular processes is vitally important for understanding how synapses work over sustained periods of time.
To study this process we take advantage of the large calyx of Held synapse in the auditory brainstem. This giant glutamatergic synapse can be visualised with a light microscope and electrical (patch-clamp recordings) can be made from individual presynaptic terminals. This allows direct measurement of the membrane transporters that have to potential to recycle glutamate. This aim of this project is to identify these transporters and to discover their role in maintaining the supply of glutamate for continued neurotransmission.