Resource Details

AMPA Receptor Cycling in the Synapse

Anis Contractor1*, Stephen F. Heinemann

1Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.


*Corresponding author. E-mail: //a-contractor{at}


Ionotropic glutamate receptors (GluRs) are involved in mediating calcium signaling in response to synaptic activity. The GluRs are classified according to their pharmacological profiles as α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA), kainate, and N-methyl-D-aspartate (NMDA) receptors. In addition to converting the chemical signal released from the presynaptic terminal to an electrical response in the postsynaptic neuron, these receptors are critically involved in activity-dependent, long-term changes in synaptic strength and, therefore, are central to processes thought to underlie learning and memory. Changes in the glutamate receptor composition and numbers at the synapse may contribute to synaptic plasticity.

This animation illustratesshows howthe constitutive GluR2/GluR3 AMPA receptors (red and yellow) constitutively recycle into and out of the plasma membrane at synapses. insertion of the GluR2-GluR3 AMPA receptors (red and yellow) Presynaptic activity, associated with sufficient postsynaptic depolarization, allows the relief of Mg+ blockade of the NMDA receptor (blue), and initiates the induction of and the activity-dependent insertion of the GluR1/-GluR2 AMPA receptors (yellow and green) into the postsynaptic membrane. The postsynaptic membrane also contain NMDA receptors (blue) and intracellular anchoring proteins, which are members of the postsynaptic density. The model is based on the studies of the induction of NMDA-dependent LTP at Schaffer Collateral- CA1 synapses in the hippocampus. After LTP induction, the complement of postsynaptic AMPA receptors is increased, effectively augmenting the postsynaptic responsiveness to subsequent activity. Increases in the strength of synaptic connections are thought to be the fundamental cellular processes involved in the formation and storage of memories in the mammalian CNS. After the synapse has been activated, then the insertion of GluR1-GluR2 AMPA receptors allows the postsynaptic cell to respond with a depolarization event strong enough to alleviate the magnesium block on the NMDA receptors allowing them to open.

Click on "Fire the Neuron" or "View Signal Transduction" to start the action.

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Educational Details

Learning Resource Type: Animation

Context: Undergraduate upper division, graduate, professional (degree program)

Intended Users: Teacher, learner

Intended Educational Use: Teach, learn

Discipline: Neurobiology

Keywords: Signal transduction, synapse, long term potentiation, glutamate receptor, learning and memory

Technical Details

Format: Shockwave Flash Objects (swf file)

Size: 239 kb

Requirements: Macromedia Flash 5 (

Related Resources

Review: A. Contractor, S. F. Heinemann, Glutamate receptor trafficking in synaptic plasticity. Sci. STKE 2002, re14 (2002). [Gloss] [Abstract] [Full Text]

Review: S. G. Cull-Candy, D. N. Leszkiewicz, Role of distinct NMDA receptor subtypes at central synapse. Sci. STKE 2004, re16 (2004). [Gloss] [Abstract] [Full Text]

Limits for Use

Cost: Free

Rights: This material may be downloaded, printed, linked to, and/or redistributed without modification for noncommercial, course-teaching purposes only, provided credit to STKE is included by listing the citation for the teaching resource.


Citation: A. Contractor, S. F. Heinemann, AMPA receptor cycling in the synapse. Sci. STKE2004, tr7 (2004).

© 2004 American Association for the Advancement of Science