Deciphering the Nanoscale Architecture of Presynaptic Actin Using a Micropatterned Presynapse-on-Glass Model

Area of Science:

• Neuroscience
• Cell Biology
• Biophysics

Background:

• The actin cytoskeleton is crucial for synaptic structure and function, yet its precise organization within presynapses remains unclear.
• Understanding presynaptic nanostructures is key to deciphering information transmission in the nervous system.

Purpose of the Study:

• To develop and validate a presynapse-on-glass model for studying presynaptic actin architecture.
• To investigate the relationship between actin enrichment, synaptic activity, and vesicle release at the nanoscale.

Main Methods:

• Induction of presynaptic specializations on micropatterned neuroligin dots on glass.
• Cultured rat neurons and multicolor 3D Single Molecule Localization Microscopy (SMLM).
• Correlative live-cell imaging and SMLM to track exocytic events.

Main Results:

• The presynapse-on-glass model successfully recapitulates actin enrichment in induced presynapses.
• Distinct actin nanostructures (corrals, rails, mesh) were identified and visualized relative to active zones.
• Actin enrichment correlated with higher synaptic cycling activity and precise localization of vesicle release.

Conclusions:

• The presynapse-on-glass model is a powerful tool for investigating presynaptic nano-architecture.
• Actin nanostructures play a significant role in regulating synaptic vesicle release and presynaptic function.
• This model facilitates detailed studies of molecular mechanisms underlying synaptic transmission.