Next generation genetically encoded fluorescent sensors for serotonin.

Area of Science:

• Neuroscience
• Molecular Biology
• Biochemistry

Background:

• Serotonin (5-HT) is a crucial neurotransmitter regulating mood, cognition, and behavior.
• Accurate measurement of endogenous serotonin dynamics is essential for understanding neurological disorders.
• Existing methods for serotonin detection have limitations in temporal and spatial resolution.

Purpose of the Study:

• To develop a novel family of genetically encoded serotonin sensors.
• To enable high-resolution, real-time imaging of serotonin dynamics.
• To engineer sensor variants with tunable affinities for versatile applications.

Main Methods:

• Development of genetically encoded sensors based on the 5-HT1A receptor and circularly permuted GFP.
• Engineering of sensor variants with varying affinities for serotonin.
• In vitro and in vivo validation of sensor performance, including membrane expression, specificity, and signal-to-noise ratio.
• Application of sensors for two-photon in vivo imaging of endogenous serotonin release.

Main Results:

• Successful development of the sDarken family of serotonin sensors.
• sDarken sensors exhibit fluorescence quenching upon serotonin binding.
• Engineered variants offer tunable affinities for diverse imaging needs.
• Demonstrated high specificity, excellent membrane expression, and superior signal-to-noise ratio.
• Feasibility of imaging endogenous serotonin release with high temporal and spatial resolution in vivo.

Conclusions:

• The sDarken sensors provide a powerful new tool for studying serotonin signaling.
• These sensors facilitate real-time, high-resolution imaging of serotonin dynamics.
• The developed sensors are suitable for in vivo applications, advancing neuroscience research.