Imaging intracellular protein interactions/activity in neurons using 2-photon fluorescence lifetime imaging...

Area of Science:

• Neuroscience
• Biophysics
• Molecular Biology

Background:

• Two-photon fluorescence microscopy enables high-resolution imaging of neural microstructures in deep brain tissue.
• Observing biochemical reactions, like protein activity and interactions, in vivo at subcellular resolution within light-scattering tissues remains challenging.
• Fluorescence lifetime imaging microscopy (FLIM) combined with two-photon excitation (2pFLIM) has emerged as a powerful tool for visualizing protein dynamics.

Purpose of the Study:

• To review the recent applications of 2pFLIM in neuronal research.
• To introduce a novel optogenetic tool for manipulating protein activity.
• To demonstrate the combined use of 2pFLIM and optogenetics for studying molecular dynamics in neurons.

Main Methods:

• Utilizing 2pFLIM for submicrometer resolution imaging of protein activity and interactions in neuronal tissues.
• Applying advanced microscopy techniques to overcome limitations in observing biochemical reactions in vivo.
• Integrating optogenetic tools to control and visualize specific protein activation pathways.

Main Results:

• 2pFLIM has been successfully applied to image kinase and small GTPase activation in hippocampal neurons.
• The technique's application has expanded to various subcellular structures, including axon terminals and nuclei.
• The study presents the successful combination of 2pFLIM with a new optogenetic tool.

Conclusions:

• 2pFLIM significantly enhances the understanding of spatially organized molecular dynamics in neurons.
• The integration of optogenetics with 2pFLIM opens new avenues for manipulating and observing cellular signaling pathways.
• This combined approach holds promise for future neuroscience research, enabling detailed studies of protein function in complex neural environments.