Synaptic localization of neurotransmitter receptors: comparing mechanisms for AMPA and GABAA receptors

• Molecular constituents of ionotropic neurotransmitter receptors in the brain.
• Receptor subunits responsible for synaptic localization of AMPARs and GABAARs.
• Anchoring proteins for AMPARs and GABAARs at each synapse.

Ionotropic neurotransmitter receptors mediate fast synaptic transmission by localizing at postsynapses. Changes in receptor number at synapses induce synaptic plasticity. Thus, mechanisms for the synaptic localization of receptors in basal transmission and synaptic plasticity have been investigated extensively. Recent findings reveal that synaptic localization of tetrameric AMPA receptors in basal transmission requires the PDZ binding of TARP auxiliary subunits, which modulate receptor properties and pharmacology. On the other hand, pentameric GABAA receptors require multiple receptor subunits for their synaptic localization in basal transmission. AMPA receptors seem to utilize distinct mechanisms for basal synaptic localization and synaptic insertion during plasticity. Revealing precise mechanisms for receptor synaptic localization may establish new approaches to control synaptic transmission.