A light-sheet fluorescence microscope for flexible imaging of whole expanded mouse brains

Session

Poster Session

Authors

Niamh Brady (1), Elisa Imbimbo (1), Ludovico Silvestri (2, 1)

Affiliations

1. European Laboratory for Non-linear Spectroscopy
2. University of Florence

Abstract text

The neuron is the elemental unit of the brain, both in a structural and functional sense. Anatomical arrangement of neurons in large-scale circuits drives the emergence of complex activity patterns which, in turn, underly the many different cognitive and behavioral schemes observed in higher animals. Despite the paramount importance of neuronal connectivity, our knowledge of the anatomical organization of brain circuits is still limited to population-level studies, missing the large variability in axonal morphology demonstrated by the few available morphological reconstructions of entire neurons. The shortage of data related to full tracing of single axons is due to the lack of scalable and automated imaging methods affording sufficient fine resolution (sub-micrometric) and large field of view (whole brain).

Our approach to solve this technological issue is the combination of tissue expansion with light-sheet fluorescence microscopy. To this aim, we developed a light-sheet microscope to image expanded murine brains, which are several cm in size, using only standard optical equipment. The microscope design was aimed at maximum flexibility and ease of use, as well as easy replication by other laboratories. We demonstrated its capabilities in fluorescently labeled and expanded mouse brains, being able to disentangle single axons in macroscopic volumes.

Further development on the analysis software will finally provide the community with a tool for fast, scalable, and cost-effective tracing of single axons across the whole encephalon, revealing the computational structure of behaviorally relevant circuits in the mouse brain.