Photoemission electron microscopy for connectomics

Area of Science:

• Neuroscience
• Microscopy
• Connectomics

Background:

• Large-volume connectomics is crucial for understanding neural circuits.
• Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are current modalities.
• A need exists for scalable and cost-effective connectomic imaging techniques.

Purpose of the Study:

• To evaluate Photoemission electron microscopy (PEEM) as a third modality for large-volume connectomics.
• To demonstrate PEEM's capability for synaptic resolution imaging.
• To assess PEEM's potential for high-throughput data acquisition.

Main Methods:

• Imaging osmium-stained, ultrathin brain sections on gold-coated silicon using commercial PEEMs.
• Utilizing ultraviolet laser illumination for gigavoxel-per-second acquisition rates.
• Comparing PEEM performance with established TEM and SEM techniques.

Main Results:

• Synaptic resolution was achieved using PEEM on brain sections.
• Gigavoxel-per-second acquisition rates were demonstrated with ultraviolet laser illumination.
• No thermal damage was observed at high acquisition rates.

Conclusions:

• PEEM is a viable third modality for large-volume connectomics.
• PEEM combines parallel detection (TEM-like) with solid supports (SEM-compatible).
• PEEM presents a potentially scalable and cost-effective approach for mapping neural connectomes.