Episode 5: Robust Correlative Workflows to Study Structure-Function of Mammalian Neuronal Circuits​

Integrating physiology and structure at the neuronal circuit scale can provide a mechanistic understanding on how that circuit works. A correlative multimodal imaging pipeline that starts combining in vivo 2-photon microscopy and synchrotron X-ray computed tomography with propagation-based phase contrast provides a robust and versatile approach to identify all neurons imaged in vivo in a multi-mm3 resin-embedded brain tissue sample. This is then is compatible with follow-up targeted imaging with either volumeEM or X-ray nanoholotomography, for which a targeted milling approach using a femtosecond laser is particularly useful. Altogether, this approach enables harnessing the resolving power of multiphoton, hardX-ray and volume electron microscopy technologies to create detailed multimodal maps of brain circuits.​

This presentation was recorded during the BioXRM symposium at the Museum of Natural History in London, October 2023.

Key Learnings:

• Neuronal circuits can be mapped in time and in space: in vivo with 2-photon microscopy and in space studing the ultrastructure with serial block-face electron microscopy. ​
• X-ray imaging is a non-destructive imaging modality and is compatible with follow-up techniques such as volume EM techniques. ​
• Femtosecond laser milling streamlines sample trimming for EM and X-ray microscopy.