A genetically encoded optical probe of membrane voltage

Area of Science:

• Neuroscience
• Molecular Biology
• Biophysics

Background:

• Accurate measurement of cellular electrical activity is crucial for understanding neural development and information processing.
• Existing methods often lack the required spatial or temporal resolution for studying complex neural systems.

Purpose of the Study:

• To develop a novel, genetically encoded probe for measuring transmembrane voltage in single cells with high resolution.
• To create a tool that overcomes limitations of current voltage-sensitive dyes and enables noninvasive cellular monitoring.

Main Methods:

• Constructed a genetically encoded probe by fusing a modified green fluorescent protein (GFP) into a voltage-sensitive potassium (K+) channel.
• Engineered the probe so that voltage-dependent conformational changes in the K+ channel alter GFP fluorescence.

Main Results:

• The probe achieved a maximal fractional fluorescence change of 5.1%, comparable to leading organic voltage-sensitive dyes.
• The fluorescent signal exhibited temporal expansion, increasing detectability by 30-fold.
• The DNA-encoded sensor allows for noninvasive introduction and targeted expression in specific cells and tissues.

Conclusions:

• The novel genetically encoded voltage probe provides a sensitive and versatile tool for measuring cellular electrical activity.
• This technology facilitates advanced research in neural development, information processing, and targeted cellular studies.