scholarly journals In vivo imaging of photoreceptor structure and function in a non-human primate model of retinal degeneration

2017 ◽  
Vol 17 (7) ◽  
pp. 53
Author(s):  
Sarah Walters ◽  
Christina Schwarz ◽  
Robin Sharma ◽  
William S. Fischer ◽  
David DiLoreto ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
In Vivo Imaging ◽  
Structure And Function ◽  
Primate Model ◽  
And Function ◽  
Human Primate

Functional biomedical hydrogels for in vivo imaging

2016 ◽  
Vol 4 (48) ◽  
pp. 7793-7812 ◽  
Author(s):  
Kewen Lei ◽  
Qian Ma ◽  
Lin Yu ◽  
Jiandong Ding
Keyword(s):  
Real Time ◽  
In Vivo Imaging ◽  
Structure And Function ◽  
Non Invasive ◽  
The Status ◽  
And Function

In vivo imaging of biomedical hydrogels enables real-time and non-invasive visualization of the status of structure and function of hydrogels.

scholarly journals Fast widefield imaging of neuronal structure and function with optical sectioning in vivo

2020 ◽  
Vol 6 (19) ◽  
pp. eaaz3870 ◽  
Author(s):  
Ziwei Li ◽  
Qinrong Zhang ◽  
Shih-Wei Chou ◽  
Zachary Newman ◽  
Raphaël Turcotte ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
In Vivo Imaging ◽  
Neuromuscular Junctions ◽  
Structure And Function ◽  
Structured Illumination ◽  
Neuronal Structure ◽  
Optical Sectioning ◽  
Structured Illumination Microscopy ◽  
And Function

Optical microscopy, owing to its noninvasiveness and subcellular resolution, enables in vivo visualization of neuronal structure and function in the physiological context. Optical-sectioning structured illumination microscopy (OS-SIM) is a widefield fluorescence imaging technique that uses structured illumination patterns to encode in-focus structures and optically sections 3D samples. However, its application to in vivo imaging has been limited. In this study, we optimized OS-SIM for in vivo neural imaging. We modified OS-SIM reconstruction algorithms to improve signal-to-noise ratio and correct motion-induced artifacts in live samples. Incorporating an adaptive optics (AO) module to OS-SIM, we found that correcting sample-induced optical aberrations was essential for achieving accurate structural and functional characterizations in vivo. With AO OS-SIM, we demonstrated fast, high-resolution in vivo imaging with optical sectioning for structural imaging of mouse cortical neurons and zebrafish larval motor neurons, and functional imaging of quantal synaptic transmission at Drosophila larval neuromuscular junctions.

Applications of phosphorescent materials for in-vivo imaging of brain structure and function

2016 ◽  
Author(s):  
Gregory Boverman ◽  
Xiaolei Shi ◽  
Victoria E. Cotero ◽  
Robert J. Filkins ◽  
Alok M. Srivastava ◽  
...  
Keyword(s):  
Brain Structure ◽  
In Vivo Imaging ◽  
Structure And Function ◽  
Brain Structure And Function ◽  
And Function

scholarly journals In vivo electrophysiological validation of DREADD-based inhibition of pallidal neurons in the non-human primate

2020 ◽  
Author(s):  
Marc Deffains ◽  
Tho Haï Nguyen ◽  
Hugues Orignac ◽  
Nathalie Biendon ◽  
Sandra Dovero ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Structure And Function ◽  
Designer Drugs ◽  
Post Mortem ◽  
Histochemical Analysis ◽  
High Level ◽  
And Function ◽  
Human Primate ◽  
Do So

AbstractDesigner Receptors Exclusively Activated by Designer Drugs (DREADDs) are widely used in rodents to manipulate neuronal activity and establish causal links between structure and function. Their utilization in non-human primates (NHPs) is however limited and their efficacy still debated. Here, we tested DREADD expression in the NHP external globus pallidus (GPe) and electrophysiologically validated DREADD-based inhibition of GPe neurons in the anesthetized monkey.To do so, we performed intracerebral injections of viral construct expressing hM4Di receptor under a neuron-specific promoter into the GPe. Then, we recorded the neuronal activity in the DREADD-transduced (test condition) and DREADD-free (control condition) GPe of two anesthetized animals following local intra-GPe microinjection of clozapine-N-oxide (CNO). In total, 19 and 8 well-isolated and stable units were recorded in the DREADD-transduced and DREADD-free GPe, respectively. Overall, we found that almost half (9/19) of the units modulated their activity following CNO injection in DREADD-transduced GPe. Surprisingly, neuronal activity of the GPe units exhibited diverse patterns in timing and polarity (increase/decrease) of firing rate modulations during and after CNO injection. Nevertheless, decreases were exclusive and stronger after CNO injection. In contrast, only one unit modulated its activity after CNO injection in DREADD-free GPe. Moreover, post-mortem histochemical analysis revealed that hM4Di DREADDs were expressed at high level in the GPe neurons located in the vicinity of the viral construct injection sites. Our results therefore show in vivo DREADD-based inhibition of pallidal neurons in the NHP model and reinforce the view that DREADD technology can be effective in NHPs.

Osseointegration interface of calcified bone and endosseous implants

1992 ◽  
Vol 50 (2) ◽  
pp. 1096-1097
Author(s):  
K.E. Krizan ◽  
J.E. Laffoon ◽  
M.J. Buckley
Keyword(s):  
Structure And Function ◽  
Titanium Implants ◽  
En Bloc ◽  
Endosseous Implants ◽  
Ultrastructural Studies ◽  
The Past ◽  
Cacodylate Buffer ◽  
One Year ◽  
And Function

With increase use of tissue-integrated prostheses in recent years it is a goal to understand what is happening at the interface between haversion bone and bulk metal. This study uses electron microscopy (EM) techniques to establish parameters for osseointegration (structure and function between bone and nonload-carrying implants) in an animal model. In the past the interface has been evaluated extensively with light microscopy methods. Today researchers are using the EM for ultrastructural studies of the bone tissue and implant responses to an in vivo environment. Under general anesthesia nine adult mongrel dogs received three Brånemark (Nobelpharma) 3.75 × 7 mm titanium implants surgical placed in their left zygomatic arch. After a one year healing period the animals were injected with a routine bone marker (oxytetracycline), euthanized and perfused via aortic cannulation with 3% glutaraldehyde in 0.1M cacodylate buffer pH 7.2. Implants were retrieved en bloc, harvest radiographs made (Fig. 1), and routinely embedded in plastic. Tissue and implants were cut into 300 micron thick wafers, longitudinally to the implant with an Isomet saw and diamond wafering blade [Beuhler] until the center of the implant was reached.

scholarly journals Development of a semi-automated segmentation tool for high frequency ultrasound image analysis of mouse echocardiograms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kristi Powers ◽  
Raymond Chang ◽  
Justin Torello ◽  
Rhonda Silva ◽  
Yannick Cadoret ◽  
...  
Keyword(s):  
Image Analysis ◽  
Automated Analysis ◽  
Structure And Function ◽  
Ultrasound Images ◽  
Cardiac Structure ◽  
Short Axis ◽  
Pixel Intensity ◽  
Cardiac Structure And Function ◽  
And Function

AbstractEchocardiography is a widely used and clinically translatable imaging modality for the evaluation of cardiac structure and function in preclinical drug discovery and development. Echocardiograms are among the first in vivo diagnostic tools utilized to evaluate the heart due to its relatively low cost, high throughput acquisition, and non-invasive nature; however lengthy manual image analysis, intra- and inter-operator variability, and subjective image analysis presents a challenge for reproducible data generation in preclinical research. To combat the image-processing bottleneck and address both variability and reproducibly challenges, we developed a semi-automated analysis algorithm workflow to analyze long- and short-axis murine left ventricle (LV) ultrasound images. The long-axis B-mode algorithm executes a script protocol that is trained using a reference library of 322 manually segmented LV ultrasound images. The short-axis script was engineered to analyze M-mode ultrasound images in a semi-automated fashion using a pixel intensity evaluation approach, allowing analysts to place two seed-points to triangulate the local maxima of LV wall boundary annotations. Blinded operator evaluation of the semi-automated analysis tool was performed and compared to the current manual segmentation methodology for testing inter- and intra-operator reproducibility at baseline and after a pharmacologic challenge. Comparisons between manual and semi-automatic derivation of LV ejection fraction resulted in a relative difference of 1% for long-axis (B-mode) images and 2.7% for short-axis (M-mode) images. Our semi-automatic workflow approach reduces image analysis time and subjective bias, as well as decreases inter- and intra-operator variability, thereby enhancing throughput and improving data quality for pre-clinical in vivo studies that incorporate cardiac structure and function endpoints.

scholarly journals Influence of High Pressure on the Dimerization of ToxR, a Protein Involved in Bacterial Signal Transduction

2008 ◽  
Vol 74 (24) ◽  
pp. 7821-7823 ◽  
Author(s):  
Kai Linke ◽  
Nagarajan Periasamy ◽  
Matthias Ehrmann ◽  
Roland Winter ◽  
Rudi F. Vogel
Keyword(s):  
Escherichia Coli ◽  
Signal Transduction ◽  
High Pressure ◽  
Structure And Function ◽  
Transmembrane Segments ◽  
Bacterial Signal Transduction ◽  
Reporter Strains ◽  
And Function ◽  
First Time

ABSTRACT High hydrostatic pressure (HHP) is suggested to influence the structure and function of membranes and/or integrated proteins. We demonstrate for the first time HHP-induced dimer dissociation of membrane proteins in vivo with Vibrio cholerae ToxR variants in Escherichia coli reporter strains carrying ctx::lacZ fusions. Dimerization ceased at 20 to 50 MPa depending on the nature of the transmembrane segments rather than on changes in the ToxR lipid bilayer environment.

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