Related Experiment Video
Updated: Aug 21, 2026

Direct Imaging of ER Calcium with Targeted-Esterase Induced Dye Loading (TED)
Published on: May 7, 2013
Osmotic tension as a possible link between GABA(A) receptor activation and intracellular calcium elevation
Joël Chavas1, Maria Elisa Forero, Thibault Collin
1Laboratoire de Physiologie Cérébrale, CNRS UMR 8118, Université Paris 5, 45 rue des Saints Pères, 75006 Paris, France.
Abstract:
Intracellular calcium concentration rises have been reported following activation of GABA(A) receptors in neonatal preparations and attributed to activation of voltage-dependent Ca(2+) channels. However, we show that, in cerebellar interneurons, GABA(A) agonists induce a somatodendritic Ca(2+) rise that persists at least until postnatal day 20 and is not mediated by depolarization-induced Ca(2+) entry. A local Ca(2+) elevation can likewise be elicited by repetitive stimulation of presynaptic GABAergic afferent fibers. We find that, following GABA(A) receptor activation, bicarbonate-induced Cl(-) entry leads to cell depolarization, Cl(-) accumulation, and osmotic tension. We propose that this tension induces the intracellular Ca(2+) rise as part of a regulatory volume decrease reaction. This mechanism introduces an unexpected link between activation of GABA(A) receptors and intracellular Ca(2+) elevation, which could contribute to activity-driven synaptic plasticity.
Related Concept Videos
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
G-Protein Gated Ion Channels
Sensory organs,...
IP3/DAG Signaling Pathway
Activation and Inactivation of G Proteins

