Analysis of mechanotransduction among ensembles of sensory hair cells in vivo is challenging in many species. To overcome this challenge, we used optical indicators to investigate mechanotransduction among collections of hair cells in intact zebrafish. Our imaging reveals a previously undiscovered disconnect between hair-cell mechanosensation and synaptic transmission. We show that saturating mechanical stimuli able to open mechanically gated channels are unexpectedly insufficient to evoke vesicle fusion in the majority of hair cells. Although synaptically silent, latent hair cells can be rapidly recruited after damage, demonstrating that they are synaptically competent. Therefore synaptically silent hair cells may be an important reserve that acts to maintain sensory function. Our results demonstrate a previously unidentified level of complexity in sculpting sensory transmission from the periphery.

The circadian clock ensures that behavioral and physiological processes occur at appropriate times during the 24-hour day/night cycle, and is regulated at both the cellular and organismal levels. To identify pathways acting on intact animals, we performed a small molecule screen using a luminescent reporter of molecular circadian rhythms in zebrafish larvae. We identified both known and novel pathways that affect circadian period, amplitude and phase. Several drugs identified in the screen did not affect circadian rhythms in cultured cells derived from luminescent reporter embryos or in established zebrafish and mammalian cell lines, suggesting they act via mechanisms absent in cell culture. Strikingly, using drugs that promote or inhibit inflammation, as well as a mutant that lacks microglia, we found that inflammatory state affects circadian amplitude. These results demonstrate a benefit of performing drug screens using intact animals and provide novel targets for treating circadian rhythm disorders.

In this paper, we propose a holographic three-dimensional (3D) head-mounted display based on 4K-spatial light modulators (SLMs). This work is to overcome the limitation of stereoscopic 3D virtual reality and augmented reality head-mounted display. We build and compare two systems using 2K and 4K SLMs with pixel pitches 8.1 μm and 3.74 μm, respectively. One is a monocular system for each eye, and the other is a binocular system using two tiled SLMs for two eyes. The viewing angle of the holographic head-mounted 3D display is enlarged from 3.8 ∘ to 16.4 ∘ by SLM tiling, which demonstrates potential applications of true 3D displays in virtual reality and augmented reality.

Holography as a true three-dimensional (3-D) technique is thought to be the ultimate display technique. However, dynamic holographic materials still have problems such as slow refresh, high applied electrical field, etc., to be solved to realize video-rate 3-D display. We present silver nanoparticles (Ag NPs) doped liquid crystal films with very big birefringence and super-fast hologram refresh speed as real-time dynamic holographic medium, which can be applied in holographic video display. And the fastest response time of both build-up and self-erasure of hologram can be up to 0.1 ms, which means the material has the ability to realize a smooth holographic video-rate display. The holographic diffraction efficiency dependent on the intensity of recording light, applied electrical field, etc. is investigated. The maximum diffraction efficiency is measured up to 50% under a low applied electrical field of 0.12 V/μm. Real-time holographic videos at red, green, and blue colors are obtained and the process of hologram formation is analyzed, which shows that the LC films doped Ag NPs can be a good candidate for applications of large-size, real-time, color holographic true 3-D display in future.