Official websites use. Share sensitive information only on official, secure websites. Corresponding author: Valentina Emiliani valentina. 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 3D parallel holographic illumination as the technique of choice for optical control of neuronal circuits organized in 3D. Today 3D parallel illumination exists in different complementary variants, which privilege either simplicity or temporal precision or 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 higher peak power, while keeping low average power for stimulating each cell.
