Laurdan monitors different lipids content in eukaryotic membrane during embryonic neural development

Area of Science:

• Neuroscience
• Biophysics
• Cell Biology

Background:

• Membrane fluidity is crucial for neuronal function.
• Assessing membrane fluidity in developing neurons is challenging.
• Existing methods lack precision in differentiating membrane compartments.

Purpose of the Study:

• To develop and validate a fluorescence-lifetime imaging microscopy (FLIM) method for quantifying neuronal membrane fluidity.
• To compare membrane fluidity in developing neuronal cells (E12 and E16) and NIH3T3 cells.
• To investigate differences in fluidity between internal and plasma membranes in developing neurons.

Main Methods:

• Utilized fluorescence-lifetime imaging microscopy (FLIM) with the Laurdan probe.
• Calibrated FLIM measurements using model lipid systems of varying compositions.
• Applied the FLIM method to assess membrane fluidity in E12 and E16 mouse neuronal cells and NIH3T3 cells.

Main Results:

• A distinct fluidity scale was established using FLIM and Laurdan probe.
• Neuronal plasma membranes exhibited lower fluidity compared to internal membranes.
• No significant differences in membrane fluidity were detected between E12 and E16 neuronal cells.
• Developing neuronal plasma membranes were found to be more fluid than those of NIH3T3 cancer cells.

Conclusions:

• FLIM provides a robust method for assessing neuronal membrane fluidity.
• Neuronal plasma membrane fluidity is lower than internal membranes but does not change significantly during late gestation.
• Developing neurons possess more fluid plasma membranes than NIH3T3 cells, suggesting implications for cell behavior.