Referenced in: none

Automatically associated channels: TRP , TRPA , TRPA1

Title: TRPA1 channels regulate astrocyte resting calcium and inhibitory synapse efficacy through GAT-3.

Authors: Eiji Shigetomi, Xiaoping Tong, Kelvin Y Kwan, David P Corey, Baljit S Khakh

Journal, date & volume: Nat. Neurosci., 2012 Jan , 15, 70-80

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22158513

Abstract
Astrocytes contribute to the formation and function of synapses and are found throughout the brain, where they show intracellular store-mediated Ca(2+) signals. Here, using a membrane-tethered, genetically encoded calcium indicator (Lck-GCaMP3), we report the serendipitous discovery of a new type of Ca(2+) signal in rat hippocampal astrocyte-neuron cocultures. We found that Ca(2+) fluxes mediated by transient receptor potential A1 (TRPA1) channels gave rise to frequent and highly localized 'spotty' Ca(2+) microdomains near the membrane that contributed appreciably to resting Ca(2+) in astrocytes. Mechanistic evaluations in brain slices showed that decreases in astrocyte resting Ca(2+) concentrations mediated by TRPA1 channels decreased interneuron inhibitory synapse efficacy by reducing GABA transport by GAT-3, thus elevating extracellular GABA. Our data show how a transmembrane Ca(2+) source (TRPA1) targets a transporter (GAT-3) in astrocytes to regulate inhibitory synapses.