New insights and system designs for temporally focused multiphoton optogenetics

Abstract

Temporal focusing (TF) multiphoton systems constitute a powerful solution for cellular resolution optogenetic stimulation and recording in three-dimensional, scattering tissue. Here, we address two fundamental aspects in the design of such systems: first, we examine the design of TF systems with specific optical sectioning by comparatively analyzing previously published results. Next, we develop a solution for obtaining TF in a flexible three-dimensional pattern of cellmatched focal spots. Our solution employs spatio-temporal focusing (SSTF) in a unique optical system design that can be integrated before essentially any multiphoton imaging or stimulation system.

Three-dimensional scanless holographic optogenetics with temporal focusing (3D-SHOT)

“…This strategy introduces a secondary axial confinement mechanism that restricts the two-photon response to a thin layer around the focal plane. Since the thickness of this layer no longer depends on the dimensions of the targeted area, but rather on the bandwidth of the pulse, this property has been successfully applied for depth-selective two-photon fluorescence imaging 32 , 33 , and has been implemented with mechanical scanning 34 and with random-access volume sampling of functional fluorescence 35 .…”

Neurophotonic Tools for Microscopic Measurements and Manipulation: Status Report

“…555 While holographic patterning of diffraction-limited focal spots in 3D is quite straightforward, development of temporally focused holographic stimulation required creative optical solutions. 311,531,542,[556][557][558]…”

Closed-Loop and Activity-Guided Optogenetic Control

“…Further, TF may be more robust to scattering than focused spots (Bègue et al, 2013; Papagiakoumou 2013; Dana and Shoham, 2011) and has been shown to work for cellular or near-cellular resolution optogenetic stimulation of single neurons within densely labeled populations in vivo (Rickgauer et al, 2014). TF in combination with digital holography has been demonstrated for multispot optogenetic stimulation in mammalian tissue in vitro (Bègue et al, 2013; Papagiakoumou, 2013; Oron et al, 2012), and a recent design in principle allows volumetric scanning of TF for sequential optogenetic stimulation (Mayblum et al, 2015). However, it is still an open question how well combined TF and digital holography approaches could scale for stimulation of larger numbers of neurons.…”