Nanoscale Activity Mapping of Chloride-Permeable Pentameric Receptors

Area of Science:

• Neuroscience
• Molecular Biology
• Biophysics

Background:

• Pentameric glycine receptors (GlyRs) are crucial for inhibitory neurotransmission.
• Visualizing GlyR activity in neurons is challenging due to limitations of current tagging methods.

Purpose of the Study:

• To develop a novel, genetically encoded reporter for visualizing GlyRα2 activity.
• To enable real-time, nanoscale monitoring of receptor function and chloride dynamics.

Main Methods:

• Fusion of a chloride-sensitive fluorescent protein (mClYFP) to the extracellular N-terminus of GlyRα2.
• Utilizing total internal reflection fluorescence microscopy and ratio image analysis.
• Combining electrophysiological and fluorescence measurements for validation.

Main Results:

• The mClYFP-GlyRα2 reporter successfully visualized receptor activity and glycine-induced chloride changes.
• The reporter preserved GlyRα2 ion channel characteristics and detected physiological chloride fluctuations.
• Effective expression of mClYFP-GlyRα2 in striatal neurons was demonstrated.

Conclusions:

• The extracellular mCLYFP-GlyRα2 sensor enables non-invasive, nanoscale tracking of chloride dynamics.
• This tool facilitates the study of chloride-permeable ionotropic receptor signaling in live cells.
• The reporter offers a powerful method for investigating pentameric receptor function.