Synchronization in collectively moving inanimate and living active matter

Area of Science:

• Cellular dynamics and collective behavior
• Biophysics of self-organization
• Developmental biology and tissue regeneration

Background:

• Collective motion in biological systems (insects, birds, bacteria) arises from coordinated individual velocities.
• Understanding velocity unification in dense cell populations, crucial for development and regeneration, remains a challenge.
• Confined environments necessitate coordinated migration for collective movement.

Purpose of the Study:

• To elucidate the mechanism by which individual cells coordinate their velocities for collective motion.
• To identify the key factors driving the emergence of self-organized cell migration in confined spaces.

Main Methods:

• Investigated finite cell populations within circular confinements.
• Identified and analyzed waves of polymerizing actin as pacemakers for individual cell speed.
• Utilized a mechanical model system of active spheres to study synchronization requirements.

Main Results:

• Collective motion onset correlates with synchronized nucleation frequencies of actin waves across the cell population.
• Synchronization of internal oscillators in the active sphere model is essential for achieving a collective state.
• Nearest neighbor coupling was identified as the mechanism for achieving global synchrony in the mechanical model.

Conclusions:

• Polymerizing actin waves act as pacemakers, synchronizing cell speeds for collective motion.
• Synchronization of internal oscillators and local coupling are critical for emergent, self-organized cell migration.
• Findings provide insights into coordinated movement in dense cell populations during biological processes.