Soft Matter and Biophysics Seminar: All-optical interrogation of brain circuits using optogenetics and holography

The Department of Physics is pleased to welcome Prof. Valentina Emiliani for a Soft Matter and Biophysics Seminar virtual presentation. Professor Emiliani is  Director of the Photonics Department at Sorbonne University and head of the Wavefront Modulation Microscope team at the Institut de la vision.

This is a virtual seminar. Please reach out to phyadmin@syr.edu for the link.

Abstract:

Genetic targeting of neuronal cells with activity reporters (calcium or voltage indicators) has initiated the paradigmatic transition whereby photons have replaced electrons for reading large-scale brain activities at cellular resolution. In parallel, optogenetics has demonstrated that targeting neuronal cells with photosensitive microbial opsins, enables the transduction of photons into electrical currents of opposite polarities thus writing, through activation or inhibition, neuronal signals in a non-invasive way.

These progresses have in turn stimulated the development of sophisticated optical methods to enable “all optical” in depth brain circuits interrogation with high spatial and temporal resolution on large volumes.

Here, we will review the most significant breakthroughs of the past years, which enable reading and writing neuronal activity at the relevant spatiotemporal scale for brain circuits manipulation, with particular emphasis on the most recent advances in what we named circuit optogenetics: a combination of approaches including holographic light illumination, temporal focusing, opsins engineering and laser development enabling the control of single or multiple targets independently in space and time with single-neuron and single-spike precision, at large depths.  Finally, we will show few examples of all-optical manipulation of neuronal circuits on different experimental paradigms including the demonstration of the presence hub cell in developing mouse brain, the investigation of interlayer signal propagation in mouse retina circuits and the investigation of neuronal connectivity in zebrafish larvae.