Super-resolution STED microscopy for investigating the brain extracellular space in live tissue
DIPC Seminars
- Speaker
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Jan Tonnesen, University of the Basque Country and Achucarro Basque Center for Neuroscience
- When
-
2023/03/09
13:00 - Place
- Hybrid Seminar: Donostia International Physics Center
- Add to calendar
- iCal
The brain extracellular space (ECS) is a reticular continuum of interconnected
channels and reservoirs. The ranges of ECS channel widths, lengths, and shapes
easily exceed the morphological complexity of individual neural cells, so that
on one hand the ECS is comparatively vast in extent, while at the same time
its even more geometrically complex. The combination of spatial continuity and
a fine mesh-like structure makes the ECS geometry extremely difficult to
visualize in live tissue, because conventional light- microscopy simply blurs
out structural details beyond cell somata and large dendrites. Current data on
ECS structure are therefore based largely on volume-averaging imaging
techniques or on electron microscopy in fixed tissue. Accordingly, our
knowledge about ECS structure and putative dynamics, not to mention functional
roles, is rudimentary.
In a step forward, we recently introduced super-resolution shadow imaging
(SUSHI) as a new way to image the extracellular space in live brain slices by
combining fluorescent perfusion-labeling of the interstitial fluid with STED
microscopy. This approach reveals the complex geometry and dynamics of the
ECS, while simultaneously outlining all cellular structures in the field of
view at around 50 nm resolution.
In this talk I will introduce STED microscopy for imaging in live organotypic
mouse brain slices, and how we went from imaging individual synapses on
neurons to also imaging the extracellular space. I will show preliminary
results from a computational diffusion model we are establishing based on
SUSHI images of the ECS, which may help us understand functional aspects of
extrasynaptic signaling, and metabolite clearance from dense parenchyma.
Host: Aitzol Garcia-Etxarri
**Zoom: **[https://dipc-org.zoom.us/j/95507559580](https://dipc-
org.zoom.us/j/95507559580)