Ultrafast Isolation of Synaptic Terminals From Rat Brain for Cryo-Electron Tomography Analysis

Area of Science:

• Neuroscience
• Structural Biology
• Biochemistry

Background:

• Synaptic transmission and plasticity rely on nanoscale organization.
• Traditional synaptosome isolation methods can damage structures, limiting cryo-electron tomography (cryo-ET) utility.
• High-resolution structural analysis requires intact synaptic components.

Purpose of the Study:

• To develop an ultrafast synaptosome isolation protocol optimized for cryo-electron tomography (cryo-ET).
• To preserve synaptic structures, including postsynaptic membranes and associated proteins, for detailed analysis.
• To enable high-resolution in situ structural studies of synaptic architecture.

Main Methods:

• Developed an ultrafast protocol for synaptic terminal isolation.
• Homogenization and vitrification completed in under 15 minutes.
• Yielded synaptosome and synaptoneurosome fractions suitable for cryo-ET.

Main Results:

• Preserved intact postsynaptic membranes apposed to presynaptic active zones.
• Produced thin, high-quality samples ideal for in situ cryo-ET.
• Enabled visualization of synaptic structures and postsynaptic membrane proteins like AMPA receptors.

Conclusions:

• The ultrafast isolation method is highly effective for cryo-ET analysis of synaptic structure.
• This protocol significantly advances the study of synaptic transmission and plasticity at a molecular level.
• Facilitates detailed structural investigations of synaptic components and their interactions.