Brain-Derived Neurotrophic Factor Modulates Fast Synaptic Inhibition by Regulating GABAA Receptor Phosphorylation Activity and Cell-Surface Stability

摘要

The efficacy of GABAergic synaptic inhibition is a principal factor in controlling neuronal activity. We demonstrate here that brain-derived neurotrophic factor modulates the activity of GABAA receptors, the main sites of fast synaptic inhibition in the brain, within minutes of application. Temporally, this comprised an early enhancement in the miniature IPSC amplitude, followed by a prolonged depression. This modulation was concurrent with enhanced PKC-mediated phosphorylation, followed by protein phosphatase 2A (PP2A)-mediated dephosphorylation of the GABAA receptor. Mechanistically, these events were facilitated by differential recruitment of PKC, receptor for activated C-kinase, and PP2A to GABAA receptors, depending on the phosphorylation state of the receptor β3-subunit. Thus, transient formation of GABAA receptor signaling complexes has the potential to provide a basis for acute changes in receptor function underlying GABAergic synaptic plasticity.