Long-range axonal calcium sweep induces axon retraction

Area of Science:

• Neuroscience
• Cell Biology
• Molecular Biology

Background:

• Axon guidance molecules are known to control axon development through growth cone signaling.
• The role of other subcellular compartments in regulating axon outgrowth remains largely unexplored.

Purpose of the Study:

• To investigate whether subcellular compartments beyond the axonal growth cone can influence axon outgrowth.
• To explore the mechanisms by which perisomatic environments modulate axon behavior.

Main Methods:

• Using isolated dentate granule cells.
• Applying glutamate locally to somatodendritic areas and the axon.
• Monitoring calcium waves using intracellular calcium dynamics.
• Blocking voltage-sensitive calcium channels.
• Utilizing calcium ionophore and depolarizing current injection.

Main Results:

• Local glutamate application to somatodendritic areas induced rapid axon retraction.
• A calcium wave propagated from the soma to the axon terminals during retraction.
• Inhibition of voltage-sensitive calcium channels and intracellular calcium dynamics blocked both the calcium wave and axon retraction.
• Perisomatic stimulation with calcium ionophore and depolarizing current induced axonal calcium sweep and retraction.

Conclusions:

• Perisomatic environments can modulate axon behavior.
• Long-range intracellular calcium signaling plays a crucial role in mediating somatodendritic control of axon retraction.