Imaging long-range neuronal connections in the mouse brain by light sheet fluorescence expansion microscopy

Sensory perception is modulated in a top-down fashion by higher brain regions to regulate behavioral responses. In olfactory perception, the horizontal limb of the diagonal band of broca (HDB) modulates information processing by shaping excitatory olfactory bulb (OB) output. HDB to OB top-down projections are a central pathway for olfactory-mediated behaviors. Using genetically encoded fluorescent indicators, specifically labeling synaptic connections between OB interneurons and HDB projections, we elucidated the network architecture underlying olfactory information processing. Thick sagittal mouse brain slices were treated with an optimized light sheet fluorescence expansion microscopy (LSFEM) protocol, allowing preservation of even the smallest autofluorescence clusters present in the presynaptic terminals while avoiding the use of antibodies. This LSFEM technique allows zooming from a mesoscopic perspective into super-resolution in a single imaging session using the same sample. In this webinar we introduce the basics of LSFM and sample expansion and present our results revealing synaptic connections between OB interneurons and HDB projection neurons.

 

There will be time for questions and discussion after the 30-minute presentation.

 

Learning Objectives