Amoeboid-like neuronal migration ensures correct horizontal cell layer formation in the developing vertebrate retina

Abstract

As neurons are often born at positions different than where they ultimately function, neuronal migration is key to ensure successful nervous system development. Radial migration during which neurons featuring unipolar and bipolar morphology, employ pre-existing processes or underlying cells for directional guidance, is the most well explored neuronal migration mode. However, how neurons that display multipolar morphology, without such processes, move through highly crowded tissue environments towards their final positions remains elusive. To understand this, we here investigated multipolar migration of horizontal cells in the zebrafish retina. We found that horizontal cells tailor their movements to the environmental spatial constraints of the crowded retina, by featuring several characteristics of amoeboid migration. These include cell and nucleus shape changes, and persistent rearward polarization of stable F-actin, which enable horizontal cells to successfully move through the crowded retina. Interference with the organization of the developing retina by changing nuclear properties or overall tissue architecture, hampers efficient horizontal cell migration and layer formation. Thus, cell-tissue interplay is crucial for efficient migration of horizontal cells in the retina. In view of high proportion of multipolar neurons, the here uncovered ameboid-like neuronal migration mode might also be crucial in other areas of the developing brain.

In vivoassessment of mechanical properties during axolotl development and regeneration using confocal Brillouin microscopy

“…In recent years, confocal Brillouin microscopy has emerged as a powerful label-free and contact-free tool to probe mechanical properties of biological samples (reviewed in [36]). Measurements of diverse systems have been carried out in vitro and ex vivo ; however, the adaptation of confocal Brillouin microscopy for in vivo animal models has only been performed using zebrafish larvae to study spinal cord repair and growth [39], the material properties in the notochord [65] and retina development [68]. In this report, we present for the first time an assessment of the in vivo mechanical properties of the axolotl, both during development and regeneration.…”

In vivoassessment of mechanical properties during axolotl development and regeneration using confocal Brillouin microscopy

“…In recent years, confocal Brillouin microscopy has emerged as a powerful label-free and contact-free tool to probe mechanical properties of biological samples (reviewed in Prevedel et al, 2019). Measurements of diverse systems have been carried out in vitro and ex vivo ; however, the adaptation of confocal Brillouin microscopy for in vivo animal models has only been performed using zebrafish larvae to study spinal cord repair and growth (Schlüßler et al, 2018), the material properties in the notochord (Bevilacqua et al, 2019) and retina development (Amini et al, 2021). In this report, we present for the first time an assessment of the in vivo mechanical properties of the axolotl, both during development and regeneration.…”