In-vivo fast non-linear microscopy reveals intraneuronal transport impairment induced by slight molecular motor imbalances in the brain of zebrafish larvae - Archive ouverte HAL Accéder directement au contenu
Poster De Conférence Année : 2022

In-vivo fast non-linear microscopy reveals intraneuronal transport impairment induced by slight molecular motor imbalances in the brain of zebrafish larvae

Karine Duroure
Filippo del Bene

Résumé

Intracellular transport is a vital process, especially in neurons. Axonal transport deficit is found in neurodegenerative diseases. Conventional methods used to measure intraneuronal transport are limited by moderate spatiotemporal resolutions. We developed a method using photostable optically active nanocrystals (NC) tracers spontaneously internalized in endosomes1,2. Here we demonstrate its application to zebrafish (Zf) larvae. We used NC exhibiting large second-order non-linear optical properties, injected in Zf brain. We harnessed these properties combined with fast raster scanning of the infrared laser beam to achieve 20 frames/s rate, allowing us to detect short pausing duration underpinning complex molecular mechanisms otherwise smeared out by low temporal resolution. Using this method in axons of neurons with known polarization, we were able to separate the retrograde from the anterograde phases of motion. Our pipeline of video dataset analysis extracts statistical distributions of transport metrics in normal and perturbed situations. To test the sensitivity of our assay, we modulated active motors concentration, either by applying dynapyrazole, a retrograde motor dynein inhibitor, or by using transgenic Zf engineered with loss-of-function alleles of the anterograde motor Kif5aa. Dynapyrazole induces a 32% reduction of mobile NC, with a 37% reduction of their retrograde run length. In kif5aa mutants the retrograde run length is increased by 46% compared to wildtype. The high sensitivity of our assay opens prospects in investigating in vivo endosomal transport molecular mechanism in depth. 1.S. Haziza, et al., Nat. Nanotechnol., 2017, 12, 322–328. 2.Q.-L. Chou et al, eNeuro, 2022, ENEURO.0227-21.2022

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Dates et versions

hal-04451527 , version 1 (11-02-2024)

Identifiants

  • HAL Id : hal-04451527 , version 1

Citer

Baptiste Grimaud, Maxence Frétaud, Fériel Terras, Antoine Bénassy, Karine Duroure, et al.. In-vivo fast non-linear microscopy reveals intraneuronal transport impairment induced by slight molecular motor imbalances in the brain of zebrafish larvae. FENS Forum 2022, Jul 2022, Paris, France. ⟨hal-04451527⟩
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