Uncovering Astrocyte Morphological Dynamics Using Optical Diffraction Tomography and Shape-Based Trajectory...

Area of Science:

• Neuroscience
• Cell Biology
• Biophysics

Background:

• Astrocytes are crucial central nervous system cells with roles extending beyond mere support.
• Understanding the dynamic morphological changes of astrocytes is essential but remains limited.
• Conventional imaging techniques struggle to provide quantitative, label-free insights into astrocyte morphology.

Purpose of the Study:

• To establish a novel, label-free method for quantitatively observing astrocyte morphological dynamics.
• To analyze the developmental trajectory and morphological transformations of astrocytes over a 7-day in-vitro period.
• To introduce a new approach for inferring morphological trajectories in neural cells using unsupervised clustering and pseudotime analysis.

Main Methods:

• Utilizing optical diffraction tomography (ODT) for label-free, real-time quantitative measurements of cell volume, dry mass, and area.
• Performing comprehensive analysis of 3D refractive index maps and shape characterization.
• Applying unsupervised clustering and pseudotime trajectory analysis to infer morphological evolution.

Main Results:

• ODT successfully captured dynamic morphological changes in astrocytes over 7 days in-vitro.
• Observed astrocyte development included increased cell area, a transition to larger, flattened shapes, and altered cell volume and density.
• A novel morphological trajectory inference method was developed, tracking astrocyte evolution from elongated to spread shapes.

Conclusions:

• Optical diffraction tomography provides a powerful, label-free tool for quantitative analysis of astrocyte morphology.
• The study reveals significant morphological shifts during astrocyte development, indicating changes in cellular composition.
• This work pioneers morphological trajectory inference for neural cells, paving the way for future studies on astrocyte dynamics and interactions.