In situ measurement of the isoplanatic patch for imaging through intact bone

Abstract

Wavefront-shaping (WS) enables imaging through scattering tissues like bone, which is important for neuroscience and bone-regeneration research. WS corrects for the optical aberrations at a given depth and field-of-view (FOV) within the sample; the extent of the validity of which is limited to a region known as the isoplanatic patch (IP). Knowing this parameter helps to estimate the number of corrections needed for WS imaging over a given FOV. In this paper, we first present direct transmissive measurement of murine skull IP using digital optical phase conjugation (DOPC) based focusing. Second, we extend our previously reported Phase Accumulation Ray Tracing (PART) method to provide in-situ in-silico estimation of IP, called correlative PART (cPART). Our results show an IP range of 1-3 μm for mice within an age range of 8-14 days old and 1.00+/-0.25 μm in a 12-week old adult skull. Consistency between the two measurement approaches indicates that cPART can be used to approximate the IP before a WS experiment, which can be used to calculate the number of corrections required within a given field of view.

Tracking connectivity maps in human stem cell–derived neuronal networks by holographic optogenetics

“…DMDs can reach switching rates of several kHz but suffer from poor light or diffraction efficiency ( Ronzitti et al, 2017 ; Shemesh et al, 2017 ). Stimulation with computer-generated phase holograms is more flexible even without additional devices ( Papagiakoumou, 2013 ): It enables higher stimulation energies than DMD and organic light-emitting diodes, three-dimensional scanning ( Ronzitti et al, 2017 ), versatile fiber-optic approaches ( Büttner et al, 2020 ; Tehrani et al, 2021 ), and compensation of sample-induced aberrations ( Tehrani et al, 2021 ). Holographic optogenetic stimulation with single-cell spatial resolution and sufficient temporal precision, less than a millisecond, has been applied to brain slices and intact brain tissue ( Ronzitti et al, 2017 ; Shemesh et al, 2017 ; Gill et al, 2020 ).…”