scholarly journals Fast multi-directional DSLM for confocal detection without striping artifacts

2020 ◽  
Author(s):  
Pietro Ricci ◽  
Giuseppe Sancataldo ◽  
Vladislav Gavryusev ◽  
Alessandra Franceschini ◽  
Marie Caroline Müllenbroich ◽  
...  

AbstractIn recent years light-sheet fluorescence microscopy (LSFM) has become a cornerstone technology for neuroscience, improving quality and capabilities of 3D imaging. By selectively illuminating a single plane, it provides intrinsic optical sectioning and fast image recording, while minimizing out of focus fluorescence background, sample photo-damage and photo-bleaching. However, images acquired with LSFM are often affected by light absorption or scattering effects, leading to un-even illumination and striping artifacts. In this work we present an optical solution to this problem, via fast multi-directional illumination of the sample, based on an acousto-optical deflector (AOD). We demonstrate that this pivoting system is compatible with confocal detection in digital scanned laser light-sheet fluorescence microscopy (DSLM) by using a pivoted elliptical-Gaussian beam. We tested its performance by acquiring signals emitted by specific fluorophores in several mouse brain areas, comparing the pivoting beam illumination and a traditional static one, measuring the point spread function response and quantifying the striping reduction. We observed real-time shadow suppression, while preserving the advantages of confocal detection for image contrast.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefanie Schwinn ◽  
Zeinab Mokhtari ◽  
Sina Thusek ◽  
Theresa Schneider ◽  
Anna-Leena Sirén ◽  
...  

AbstractMedulloblastoma is the most common high-grade brain tumor in childhood. Medulloblastomas with c-myc amplification, classified as group 3, are the most aggressive among the four disease subtypes resulting in a 5-year overall survival of just above 50%. Despite current intensive therapy regimens, patients suffering from group 3 medulloblastoma urgently require new therapeutic options. Using a recently established c-myc amplified human medulloblastoma cell line, we performed an in-vitro-drug screen with single and combinatorial drugs that are either already clinically approved or agents in the advanced stage of clinical development. Candidate drugs were identified in vitro and then evaluated in vivo. Tumor growth was closely monitored by BLI. Vessel development was assessed by 3D light-sheet-fluorescence-microscopy. We identified the combination of gemcitabine and axitinib to be highly cytotoxic, requiring only low picomolar concentrations when used in combination. In the orthotopic model, gemcitabine and axitinib showed efficacy in terms of tumor control and survival. In both models, gemcitabine and axitinib were better tolerated than the standard regimen comprising of cisplatin and etoposide phosphate. 3D light-sheet-fluorescence-microscopy of intact tumors revealed thinning and rarefication of tumor vessels, providing one explanation for reduced tumor growth. Thus, the combination of the two drugs gemcitabine and axitinib has favorable effects on preventing tumor progression in an orthotopic group 3 medulloblastoma xenograft model while exhibiting a favorable toxicity profile. The combination merits further exploration as a new approach to treat high-risk group 3 medulloblastoma.


2021 ◽  
Vol 84 ◽  
pp. 296
Author(s):  
Gideon Oluniran ◽  
James Blackwell ◽  
Emmanuel Reynaud ◽  
Marcin Krasny ◽  
Niall Colgan ◽  
...  

2020 ◽  
Vol 40 (10) ◽  
pp. 1975-1986
Author(s):  
Nicholas B Bèchet ◽  
Tekla M Kylkilahti ◽  
Bengt Mattsson ◽  
Martina Petrasova ◽  
Nagesh C Shanbhag ◽  
...  

Fluid transport in the perivascular space by the glia-lymphatic (glymphatic) system is important for the removal of solutes from the brain parenchyma, including peptides such as amyloid-beta which are implicated in the pathogenesis of Alzheimer’s disease. The glymphatic system is highly active in the sleep state and under the influence of certain of anaesthetics, while it is suppressed in the awake state and by other anaesthetics. Here we investigated whether light sheet fluorescence microscopy of whole optically cleared murine brains was capable of detecting glymphatic differences in sleep- and awake-mimicking anaesthesia, respectively. Using light-sheet imaging of whole brains, we found anaesthetic-dependent cerebrospinal fluid (CSF) influx differences, including reduced tracer influx along tertiary branches of the middle cerebral artery and reduced influx along dorsal and anterior penetrating arterioles, in the awake-mimicking anaesthesia. This study establishes that light sheet microscopy of optically cleared brains is feasible for quantitative analyses and can provide images of the entire glymphatic system in whole brains.


2016 ◽  
Vol 20 (12) ◽  
pp. 12-22

Scanning the Future of Medical Imaging Putting Numbers into Biology: The Combination of Light Sheet Fluorescence Microscopy and Fluorescence Spectroscopy Abyss Processing – Exploring the Deep in Medical Images


mBio ◽  
2014 ◽  
Vol 5 (6) ◽  
Author(s):  
Matthew Jemielita ◽  
Michael J. Taormina ◽  
Adam R. Burns ◽  
Jennifer S. Hampton ◽  
Annah S. Rolig ◽  
...  

ABSTRACTThe vertebrate intestine is home to microbial ecosystems that play key roles in host development and health. Little is known about the spatial and temporal dynamics of these microbial communities, limiting our understanding of fundamental properties, such as their mechanisms of growth, propagation, and persistence. To address this, we inoculated initially germ-free zebrafish larvae with fluorescently labeled strains of anAeromonasspecies, representing an abundant genus in the zebrafish gut. Using light sheet fluorescence microscopy to obtain three-dimensional images spanning the gut, we quantified the entire bacterial load, as founding populations grew from tens to tens of thousands of cells over several hours. The data yield the first ever measurements of the growth kinetics of a microbial species inside a live vertebrate intestine and show dynamics that robustly fit a logistic growth model. Intriguingly, bacteria were nonuniformly distributed throughout the gut, and bacterial aggregates showed considerably higher growth rates than did discrete individuals. The form of aggregate growth indicates intrinsically higher division rates for clustered bacteria, rather than surface-mediated agglomeration onto clusters. Thus, the spatial organization of gut bacteria both relative to the host and to each other impacts overall growth kinetics, suggesting that spatial characterizations will be an important input to predictive models of host-associated microbial community assembly.IMPORTANCEOur intestines are home to vast numbers of microbes that influence many aspects of health and disease. Though we now know a great deal about the constituents of the gut microbiota, we understand very little about their spatial structure and temporal dynamics in humans or in any animal: how microbial populations establish themselves, grow, fluctuate, and persist. To address this, we made use of a model organism, the zebrafish, and a new optical imaging technique, light sheet fluorescence microscopy, to visualize for the first time the colonization of a live, vertebrate gut by specific bacteria with sufficient resolution to quantify the population over a range from a few individuals to tens of thousands of bacterial cells. Our results provide unprecedented measures of bacterial growth kinetics and also show the influence of spatial structure on bacterial populations, which can be revealed only by direct imaging.


IBRO Reports ◽  
2019 ◽  
Vol 6 ◽  
pp. S140
Author(s):  
S. Olivia Park ◽  
Karam Kim ◽  
Wonchang Choe ◽  
Deokhui Chang ◽  
Yusuck Kim ◽  
...  

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