Macrophages Mediate Mesoscale Brain Mechanical Homeostasis

Area of Science:

• Neuroscience
• Biophysics
• Immunology

Background:

• Cellular behavior in the brain is influenced by mechanical cues.
• The interplay between mechanical forces and immune regulation in the brain is not fully understood.

Purpose of the Study:

• To investigate the mechanical impact of macrophage activity on brain tissue.
• To explore the relationship between immune responses and neural tissue mechanics.

Main Methods:

• Integration of gigahertz-frequency Brillouin microscopy and optical trap-based active microrheology.
• In vivo assessment of macrophage colony-stimulating factor 1 receptor (csf1r)-driven stromal remodeling.

Main Results:

• Microglia actively sustain brain tissue viscoelasticity, contrary to the assumption of quiescence.
• csf1r-driven remodeling significantly alters in vivo brain mechanical properties.
• Established a direct link between immune activity, tissue viscoelasticity, and neural structural plasticity.

Conclusions:

• Immune cells play a dynamic role in maintaining brain tissue mechanics.
• Biophysical properties are crucial regulators of neural signaling.
• Findings offer mechanistic insights for enhancing csf1r-targeted therapies in neurological diseases and cancer.