Development and Application of a Mitochondrial Genetically Encoded Voltage Indicator in Narcosis

Area of Science:

• Cell Biology
• Neuroscience
• Biochemistry

Background:

• Mitochondrial membrane potential (MMP) is vital for cellular functions like energy production and cell survival.
• Existing genetically encoded fluorescence indicators (GEVIs) are insufficient for MMP monitoring.
• Accelerated Sensor of Action Potentials (ASAP) showed promise but had limitations.

Purpose of the Study:

• To develop novel GEVIs for accurate MMP measurement.
• To overcome limitations of existing indicators, such as ROS sensitivity.
• To validate new indicators in cellular and in vivo models.

Main Methods:

• Screening of GEVIs for mitochondrial targeting and depolarization sensitivity.
• Generation of ROS-resistant ASAP mutants.
• In vivo fiber photometry experiments in the M2 cortex.

Main Results:

• Four GEVIs (MPI-1-4) were developed, targeting mitochondria effectively.
• ASAP mutants showed improved ROS resistance.
• MPI-2 detected mitochondrial depolarization during isoflurane-induced narcosis in vivo.

Conclusions:

• MPI-1-4 are effective tools for monitoring MMP in various cell types.
• These indicators can be used to study mitochondrial function in physiological and pathological conditions.
• The study provides new tools for neuroscience and cell biology research.