Rapid reconstruction of neural circuits using tissue expansion and light sheet microscopy

Area of Science:

• Neuroscience
• Molecular Biology
• Systems Biology

Background:

• Brain function relies on complex neural networks.
• Current methods for analyzing neural structure (electron microscopy) are low-throughput, while high-throughput methods (light microscopy) lack synaptic resolution.
• This limits understanding of how neural structure variations relate to behavior.

Purpose of the Study:

• To bridge the methodological gap between high-throughput molecular/cellular analysis and low-throughput synaptic-resolution analysis of neural circuits.
• To develop a high-throughput method for reconstructing neural circuits with single-synapse resolution and molecular contrast.

Main Methods:

• Developed an imaging protocol combining tissue expansion and light sheet microscopy (ExLLSM).
• Created a high-throughput analysis pipeline for rapid neuroanatomical reconstruction.
• Validated the approach using *Drosophila*.

Main Results:

• ExLLSM achieved single-synapse resolution and molecular contrast at high throughput.
• Synaptic counts obtained were comparable to electron microscopy.
• The method enabled comparison of synaptic connectivity across sex and experience in *Drosophila*.

Conclusions:

• The ExLLSM approach successfully bridges the gap between high-throughput and high-resolution neural circuit reconstruction.
• This method facilitates the study of variability in neural circuit structure and function across individuals.
• It enables correlation of structural connectivity, functional connectivity, and behavior.