Neurotransmitter Transporters


Neurotransmitters are released into the extracellular space during synaptic transmission. The actions of these chemical signals are terminated through active uptake by transporters that are located in the plasma membrane of neurons and glial cells. Transporters harness electrochemical gradients to force the movement of transmitter back into cells against its concentration radient. These proteins play an important role in determining how long chemical signals persist, and as a result drugs that inhibit transporters produce profound behavioural effects.

Keywords: uptake; synapse; transmitter; diffusion; glutamate

Figure 1.

Neurotransmitter released during synaptic transmission is removed from the extracellular space by high‐affinity transporters (T) in the membranes of neurons and surrounding glial cells (astrocytes). The action of neurotransmitters is limited by diffusion away from receptors and uptake by transporters.

Figure 2.

Alternating access model for transport of the neurotransmitter glutamate. (a) When the outer gate is open Na+, glutamate (GLU) and an H+ bind within the pore. (b) The outer gate closes. (c) With some delay the inner gate opens, allowing Na+, glutamate and an H+ to dissociate. K+ then binds within the pore, closing the inner gate. (d) With some delay the outer gate opens, allowing K+ to unbind and revealing the binding sites for Na+, glutamate and an H+, starting the cycle over again.


Further Reading

Cooper JR, Bloom FE and Roth RH (1991) The Biochemical Basis of Neuropharmacology, 6th edn. New York: Oxford University Press.

Lauger P (1991) Electrogenic Ion Pumps. Distinguished Lecture Series of the Society of General Physiologists, vol. 5. Sunderland, MA: Sinauer.

Shepherd G (1997) The Synaptic Organization of the Brain, 4th edn. New York: Oxford University Press.

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How to Cite close
Bergles, Dwight E(Apr 2001) Neurotransmitter Transporters. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0000286]