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Updated: Aug 24, 2025
10:08
Study of the Functions and Activities of Neuronal K-Cl Co-Transporter KCC2 Using Western Blotting
Published on: December 9, 2022
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KCC2 drives chloride microdomain formation in dendritic blebbing
Nicholas L Weilinger1, Leigh E Wicki-Stordeur1, Christopher J Groten1
1Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
Cell Reports
|October 26, 2022
Summary
Intracellular chloride ion concentration ([Cl-]i) homeostasis is vital for neuronal function. This study reveals how chloride shifts contribute to dendritic swelling during excitotoxicity, impacting neurological disorders.
Area of Science:
- Neuroscience
- Cell Biology
- Biophysics
Background:
- Intracellular chloride ion concentration ([Cl-]i) is crucial for neuronal excitability and volume regulation.
- Disruptions in [Cl-]i homeostasis are implicated in neurological disorders.
Purpose of the Study:
- To quantitatively map dendritic [Cl-]i dynamics during N-methyl-d-aspartate (NMDA) excitotoxicity.
- To understand the contribution of chloride shifts to localized dendritic swelling (blebbing) in stroke-like conditions.
Main Methods:
- Whole-cell patch clamp electrophysiology.
- Fluorescence lifetime imaging (FLIM) of the chloride dye MQAE.
- Simultaneous electrophysiology and FLIM to measure dendritic [Cl-]i.
Main Results:
- NMDA application induced spatially restricted, persistent high [Cl-]i subdomains at dendritic blebs.
- This process required Ca2+ influx and small-conductance Ca2+-activated K+ (SK) channel opening.
- Sustained K+ efflux increased extracellular K+ ([K+]o), reversing K+-Cl- cotransporter (KCC2) function and causing blebbing.
Conclusions:
- Established a mechanism where KCC2 generates pathological [Cl-]i microdomains during blebbing.
- Findings are relevant to understanding and potentially treating neurological disorders involving excitotoxicity and swelling.
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