© American Epilepsy Society Current Review In Basic Science

AMPA receptors are ion channels localized to excitatory synapses in the central nervous system that mediate fast (mil-lisecond time scale) excitatory neurotransmission (Fig. 1) (1). In excitatory neurons, action potentials evoke the release of glu-tamate from presynaptic terminals at synapses onto postsyn-aptic excitatory and inhibitory neurons. Synapses onto excit-atory neurons are predominantly located on dendritic spines whereas excitatory synapses onto inhibitory interneurons are located on the aspiny dendritic shafts typical of these cells (2, 3). In either case, the glutamate released from the excitatory neuron axon terminals diffuses across the synaptic cleft and binds to AMPA receptors in the postsynaptic membrane. The AMPA receptors are large multisubunit protein complexes that span the membrane and have an ion-selective central pore that in the absence of glutamate is closed to ion flow. Bindin