⭐ High Impact

Towards circuit optogenetics.

Chen I-Wen, Papagiakoumou Eirini, Emiliani Valentina

📰 Current opinion in neurobiology 📅 2018 📊 72 citations

Abstract

Optogenetics neuronal targeting combined with single-photon wide-field illumination has already proved its enormous potential in neuroscience, enabling the optical control of entire neuronal networks and disentangling their role in the control of specific behaviors. However, establishing how a single or a sub-set of neurons controls a specific behavior, or how functionally identical neurons are connected in a particular task, or yet how behaviors can be modified in real-time by the complex wiring diagram of neuronal connections requires more sophisticated approaches enabling to drive neuronal circuits activity with single-cell precision and millisecond temporal resolution. This has motivated on one side the development of flexible optical methods for two-photon (2P) optogenetic activation using either, or a hybrid of two approaches: scanning and parallel illumination. On the other side, it has stimulated the engineering of new opsins with modified spectral characteristics, channel kinetics and spatial distribution of expression, offering the necessary flexibility of choosing the appropriate opsin for each application. The need for optical manipulation of multiple targets with millisecond temporal resolution has imposed three-dimension (3D) parallel holographic illumination as the technique of choice for optical control of neuronal circuits organized in 3D. Today 3D parallel illumination exists in several complementary variants, each with a different degree of simplicity, light uniformity, temporal precision and axial resolution. In parallel, the possibility to reach hundreds of targets in 3D volumes has prompted the development of low-repetition rate amplified laser sources enabling high peak power, while keeping low average power for stimulating each cell. All together those progresses open the way for a precise optical manipulation of neuronal circuits with unprecedented precision and flexibility.

🔬 Techniques

✨ Fluorophores

🧪 Sample Preparation

🔬 Cell Lines

🏛️ Research Organizations (ROR)

Affiliated research institutions:

📊 Figures

Figure 1

Spatiotemporal light-shaping

(a) Experimental scheme for microscope-implementation of Computer-Generated Holography (CGH). A laser beam is expanded (lenses L1, L2) to fit the SLM array size. The SLM is then imaged through lenses ...

Figure 2

Multiplane temporally focused pattern projection

(a) Experimental scheme for multi-plane temporally focused patterns. The system comprises a first beam-shaping part, which, according to the experimental needs, can generate a Gaussian, a holographic ...

Figure 3

Optogenetic toolbox and two-photon holographic activation

(a) 2P activation of optogenetic actuators. (i) 2P action spectra of diverse opsins 6 , 45 , 46 , 55 (grey lines with coloured markers) overlayed to the absorption spectrum of GCaMP 66 and RCaMP 67 . ...

Figure 4

Somatic opsins enable unbiased single-cell photoactivation and identifying neuronal connections

(a) Mapping neuronal connection by co-expressing the calcium indicator GCaMP6s and the somatic ChR2-P2A-H2B-mRubys. (i) In an example field-of-view (FOV) in acute brain slice of layer 2/3 mouse somato...

Figure images are served from the NIH/NLM PubMed Central Open Access Subset or Europe PMC; copyright remains with the publishers and authors.

🏛️ Imaging Facility

🏛️ CNRS

💬 Discussion

0 comments

No comments yet. Be the first to start a discussion!

Leave a Comment

MicroHub Assistant