title: Dynamic mobility of functional GABAA receptors at inhibitory synapses.
abstract: Importing functional GABAA receptors into synapses is fundamental for establishing and maintaining inhibitory transmission and for controlling neuronal excitability. By introducing a binding site for an irreversible inhibitor into the GABAA receptor alpha1 subunit channel lining region that can be accessed only when the receptor is activated, we have determined the dynamics of receptor mobility between synaptic and extrasynaptic locations in hippocampal pyramidal neurons. We demonstrate that the cell surface GABAA receptor population shows no fast recovery after irreversible inhibition. In contrast, after selective inhibition, the synaptic receptor population rapidly recovers by the import of new functional entities within minutes. The trafficking pathways that promote rapid importation of synaptic receptors do not involve insertion from intracellular pools, but reflect receptor diffusion within the plane of the membrane. This process offers the synapse a rapid mechanism to replenish functional GABAA receptors at inhibitory synapses and a means to control synaptic efficacy.
authors.affiliation: Department of Pharmacology, University College London, Gower Street, London WC1 E 6BT, UK.
authors.forename: Philip
authors.initials: P
authors.lastname: Thomas
authors.forename: Martin
authors.initials: M
authors.lastname: Mortensen
authors.forename: Alastair M
authors.initials: AM
authors.lastname: Hosie
authors.forename: Trevor G
authors.initials: TG
authors.lastname: Smart
mesh_terms: D001692:Biological Transport; D002478:Cells, Cultured; D004594:Electrophysiology; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D009433:Neural Inhibition / Q000502:physiology*; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D011963:Receptors, GABA-A / Q000235:genetics / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D011963:Receptors, GABA-A