scholarly journals Optical imaging and modulation of neurovascular responses

2018 ◽  
Vol 38 (12) ◽  
pp. 2057-2072 ◽  
Author(s):  
Kazuto Masamoto ◽  
Alberto Vazquez
Keyword(s):  
Optical Imaging ◽  
Vascular Function ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Brain Regions ◽  
Transgenic Animal ◽  
Optical Methods ◽  
Vascular Networks ◽  
Temporal Properties ◽  
Dimensional Reconstruction

The cerebral microvasculature consists of pial vascular networks, parenchymal descending arterioles, ascending venules and parenchymal capillaries. This vascular compartmentalization is vital to precisely deliver blood to balance continuously varying neural demands in multiple brain regions. Optical imaging techniques have facilitated the investigation of dynamic spatial and temporal properties of microvascular functions in real time. Their combination with transgenic animal models encoding specific genetic targets have further strengthened the importance of optical methods for neurovascular research by allowing for the modulation and monitoring of neuro vascular function. Image analysis methods with three-dimensional reconstruction are also helping to understand the complexity of microscopic observations. Here, we review the compartmentalized cerebral microvascular responses to global perturbations as well as regional changes in response to neural activity to highlight the differences in vascular action sites. In addition, microvascular responses elicited by optical modulation of different cell-type targets are summarized with emphasis on variable spatiotemporal dynamics of microvascular responses. Finally, long-term changes in microvascular compartmentalization are discussed to help understand potential relationships between CBF disturbances and the development of neurodegenerative diseases and cognitive decline.

scholarly journals Regional Distribution and Kinetics of Three Sites on the GABAA Receptor: Lack of Effect of Portacaval Shunting

1992 ◽  
Vol 12 (2) ◽  
pp. 334-346 ◽  
Author(s):  
Anke M. Mans ◽  
Kelli M. Kukulka ◽  
Keith J. McAvoy ◽  
Norman C. Rokosz
Keyword(s):  
Kinetic Parameters ◽  
Regional Distribution ◽  
Three Dimensional ◽  
Portacaval Shunt ◽  
Brain Regions ◽  
Significant Heterogeneity ◽  
Heterogeneous Distribution ◽  
Dimensional Reconstruction ◽  
Benzodiazepine Site ◽  
Gaba Neurotransmission

The regional distribution of binding sites on the GABAA receptor and their kinetic parameters were measured by quantitative autoradiography in brains from normal rats and rats with a portacaval shunt, a model of portal systemic encephalopathy in which GABA neurotransmission may be altered. The ligands used were [3H]flunitrazepam (a benzodiazepine-site agonist), [3H]-Ro 15-1788 (a benzodiazepine-site antagonist), [3H]muscimol (a GABA-site agonist), and [35S] t-butylbicyclo-phosphorothionate (35S-TBPS, a convulsant that binds to a site near the chloride channel). Some brains were analyzed by computerized image analysis and three-dimensional reconstruction. The regional distribution of binding of the benzodiazepines was very similar, but the patterns obtained with [3H]muscimol and [35S]TBPS were different in many areas, suggesting a heterogeneous distribution of several subtypes of the GABAA receptor. The kinetic parameters were determined in brain regions for [3H]flunitrazepam, [3H]Ro15-1788, and [3H]muscimol. For each ligand, the Kd showed a significant heterogeneity among brain regions (at least threefold), contrary to conclusions drawn from earlier studies. In portacaval shunted rats, binding of all four ligands was essentially unchanged from that in control rats, indicating that, if there was an abnormality in GABA neurotransmission during portal systemic shunting, it was not reflected by altered binding to the main sites on the GABAA receptor.

Multimodal optical imaging

2003 ◽  
Vol 285 (2) ◽  
pp. L269-L280 ◽  
Author(s):  
Cindy Lawler ◽  
William A. Suk ◽  
Bruce R. Pitt ◽  
Claudette M. St. Croix ◽  
Simon C. Watkins
Keyword(s):  
Optical Imaging ◽  
Imaging Techniques ◽  
Basic Research ◽  
Optical Methods ◽  
Resonance Imaging ◽  
X Ray ◽  
Positron Emission ◽  
Technological Advances ◽  
Visual Imaging ◽  
Made In

The recent resurgence of interest in the use of intravital microscopy in lung research is a manifestation of extraordinary progress in visual imaging and optical microscopy. This review evaluates the tools and instrumentation available for a number of imaging modalities, with particular attention to recent technological advances, and addresses recent progress in use of optical imaging techniques in basic pulmonary research. 1 Limitations of existing methods and anticipated future developments are also identified. Although there have also been major advances made in the use of magnetic resonance imaging, positron emission tomography, and X-ray and computed tomography to image intact lungs and while these technologies have been instrumental in advancing the diagnosis and treatment of patients, the purpose of this review is to outline developing optical methods that can be evaluated for use in basic research in pulmonary biology.

scholarly journals Neuroanatomical phenotyping of the mouse brain with three-dimensional autofluorescence imaging

2012 ◽  
Vol 44 (15) ◽  
pp. 778-785 ◽  
Author(s):  
Jacqueline A. Gleave ◽  
Michael D. Wong ◽  
Jun Dazai ◽  
Maliha Altaf ◽  
R. Mark Henkelman ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Mouse Brain ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Brain Structures ◽  
Small Scale ◽  
Specimen Preparation ◽  
Normal Brain ◽  
Autofluorescence Imaging ◽  
The Brain

The structural organization of the brain is important for normal brain function and is critical to understand in order to evaluate changes that occur during disease processes. Three-dimensional (3D) imaging of the mouse brain is necessary to appreciate the spatial context of structures within the brain. In addition, the small scale of many brain structures necessitates resolution at the ∼10 μm scale. 3D optical imaging techniques, such as optical projection tomography (OPT), have the ability to image intact large specimens (1 cm3) with ∼5 μm resolution. In this work we assessed the potential of autofluorescence optical imaging methods, and specifically OPT, for phenotyping the mouse brain. We found that both specimen size and fixation methods affected the quality of the OPT image. Based on these findings we developed a specimen preparation method to improve the images. Using this method we assessed the potential of optical imaging for phenotyping. Phenotypic differences between wild-type male and female mice were quantified using computer-automated methods. We found that optical imaging of the endogenous autofluorescence in the mouse brain allows for 3D characterization of neuroanatomy and detailed analysis of brain phenotypes. This will be a powerful tool for understanding mouse models of disease and development and is a technology that fits easily within the workflow of biology and neuroscience labs.

Computational fluid dynamics in a model of the total cavopulmonary connection reconstructed using magnetic resonance images

2005 ◽  
Vol 15 (S3) ◽  
pp. 61-67 ◽  
Author(s):  
Laura Socci ◽  
Francesca Gervaso ◽  
Francesco Migliavacca ◽  
Giancarlo Pennati ◽  
Gabriele Dubini ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Magnetic Resonance Images ◽  
Total Cavopulmonary Connection ◽  
Anatomical Structures ◽  
Human Bones ◽  
Dimensional Reconstruction ◽  
Recent Developments ◽  
Cavopulmonary Connection

The recent developments in imaging techniques have created new opportunities to give an accurate description of the three-dimensional morphology of vessels. Such three-dimensional reconstruction of anatomical structures from medical images has achieved importance in several applications, such as the reconstruction of human bones, spine portions, and vascular districts.

scholarly journals Large-scale characterization of the microvascular geometry in development and disease by tissue clearing and quantitative ultramicroscopy

2020 ◽  
pp. 0271678X2096185
Author(s):  
Artur Hahn ◽  
Julia Bode ◽  
Allen Alexander ◽  
Kianush Karimian-Jazi ◽  
Katharina Schregel ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Basal Ganglia ◽  
Corpus Callosum ◽  
Large Scale ◽  
Three Dimensional ◽  
Branch Length ◽  
Brain Regions ◽  
Computer Hardware ◽  
Vascular Networks ◽  
Tissue Clearing

Three-dimensional assessment of optically cleared, entire organs and organisms has recently become possible by tissue clearing and selective plane illumination microscopy (“ultramicroscopy”). Resulting datasets can be highly complex, encompass over a thousand images with millions of objects and data of several gigabytes per acquisition. This constitutes a major challenge for quantitative analysis. We have developed post-processing tools to quantify millions of microvessels and their distribution in three-dimensional datasets from ultramicroscopy and demonstrate the capabilities of our pipeline within entire mouse brains and embryos. Using our developed acquisition, segmentation, and analysis platform, we quantify physiological vascular networks in development and the healthy brain. We compare various geometric vessel parameters (e.g. vessel density, radius, tortuosity) in the embryonic spinal cord and brain as well as in different brain regions (basal ganglia, corpus callosum, cortex). White matter tract structures (corpus callosum, spinal cord) showed lower microvascular branch densities and longer vessel branch length compared to grey matter (cortex, basal ganglia). Furthermore, we assess tumor neoangiogenesis in a mouse glioma model to compare tumor core and tumor border. The developed methodology allows rapid quantification of three-dimensional datasets by semi-automated segmentation of fluorescently labeled objects with conventional computer hardware. Our approach can aid preclinical investigations and paves the way towards “quantitative ultramicroscopy”.

scholarly journals Leveraging Neural Networks in Preclinical Alcohol Research

2020 ◽  
Vol 10 (9) ◽  
pp. 578
Author(s):  
Lauren C. Smith ◽  
Adam Kimbrough
Keyword(s):  
Neural Networks ◽  
Alcohol Use ◽  
Alcohol Drinking ◽  
Imaging Techniques ◽  
Structural Connectivity ◽  
Three Dimensional ◽  
Brain Regions ◽  
Tissue Imaging ◽  
Imaging Data ◽  
Neural Imaging

Alcohol use disorder is a pervasive healthcare issue with significant socioeconomic consequences. There is a plethora of neural imaging techniques available at the clinical and preclinical level, including magnetic resonance imaging and three-dimensional (3D) tissue imaging techniques. Network-based approaches can be applied to imaging data to create neural networks that model the functional and structural connectivity of the brain. These networks can be used to changes to brain-wide neural signaling caused by brain states associated with alcohol use. Neural networks can be further used to identify key brain regions or neural “hubs” involved in alcohol drinking. Here, we briefly review the current imaging and neurocircuit manipulation methods. Then, we discuss clinical and preclinical studies using network-based approaches related to substance use disorders and alcohol drinking. Finally, we discuss how preclinical 3D imaging in combination with network approaches can be applied alone and in combination with other approaches to better understand alcohol drinking.

Giving up knowledge is almost never a good idea: an interview with Dr Evan Zahn

2019 ◽  
Vol 29 (12) ◽  
pp. 1419-1425
Author(s):  
Sebastian Góreczny ◽  
Evan M. Zahn
Keyword(s):  
Imaging Techniques ◽  
Three Dimensional ◽  
Interventional Cardiology ◽  
Cardiac Catheterisation ◽  
Natural Order ◽  
Treatment Technique ◽  
Rotational Angiography ◽  
New Device ◽  
Imaging Tool ◽  
Dimensional Reconstruction

The history of congenital interventional cardiology has seen numerous groundbreaking innovations typically related to the introduction of a new device or a novel treatment technique. Similarly, imaging of cardiac defects has changed dramatically over the past decades, although some of the advancements have seemed to omit the catheterisation laboratories. Rotational angiography, one of the imaging techniques for guidance of cardiac catheterisation currently referred to as “advanced”, in fact was described already in 1960s.1 More recently its improved version, including three-dimensional reconstruction (3DRA), became a valuable intra-procedural imaging tool in interventional cardiology and neuroradiology.2 Dr Evan Zahn was one of the pioneers of 3DRA in the field of congenital cardiology, setting an example for many to follow. With his innovative publication and subsequent lecture at 2011 Pediatric and Adult Interventional Cardiac Symposium (PICS-AICS) on “The Emerging Use of 3-Dimensional Rotational Angiography in Congenital Heart Disease” he motivated many to explore benefits of this modality to strive for improved procedural outcomes and reduced patients’ burden of cardiac catheterisation3. I was one of those to take Dr Zahn’s thoughts and implement them into routine workflow.4–6 However, almost a decade after Dr Zahn shared his important work, despite tremendous efforts by teams from Utrecht, (Netherlands) and Columbus (Ohio, United States of America) to popularise 3D imaging in catheterisation laboratory during dedicated meetings, two-dimensional (2D) angiography does not seem to be threatened in many, otherwise-progressive, laboratories. During the recent 30th Japanese Pediatric Interventional Cardiology (JPIC) meeting I had the opportunity to ask Dr Zahn why giving up knowledge is almost never a good idea, what is technology’s natural order of things, and why the technology has to be more than just exciting, pretty, and new.

scholarly journals Customized Scaffold Design Based on Natural Peripheral Nerve Fascicle Characteristics for Biofabrication in Tissue Regeneration

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Zhi Yao ◽  
Li-Wei Yan ◽  
Shuai Qiu ◽  
Fu-Lin He ◽  
Fan-Bin Gu ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Tibial Nerve ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Common Peroneal Nerve ◽  
Nerve Graft ◽  
Three Dimensional Reconstruction ◽  
Scaffold Design ◽  
Dimensional Reconstruction ◽  
Nerve Fascicle

Objective. The use of a biofabrication nerve scaffold, which mimics the nerve microstructure, as an alternative for autologous nerve transplantation is a promising strategy for treating peripheral nerve defects. This study aimed to design a customized biofabrication scaffold model with the characteristics of human peripheral nerve fascicles. Methods. We used Micro-MRI technique to obtain different nerve fascicles. A full-length 28 cm tibial nerve specimen was obtained and was divided into 14 two-centimetre nerve segments. 3D models of the nerve fascicles were obtained by three-dimensional reconstruction after image segmentation. The central line of the nerve fascicles was fitted, and the aggregation of nerve fascicles was analysed quantitatively. The nerve scaffold was designed by simulating the clinical nerve defect and extracting information from the acquired nerve fascicle data; the scaffold design was displayed by 3D printing to verify the accuracy of the model. Result. The microstructure of the sciatic nerve, tibial nerve, and common peroneal nerve in the nerve fascicles could be obtained by three-dimensional reconstruction. The number of cross fusions of tibial nerve fascicles from proximal end to distal end decreased gradually. By designing the nerve graft in accordance with the microstructure of the nerve fascicles, the 3D printed model demonstrated that the two ends of the nerve defect can be well matched. Conclusion. The microstructure of the nerve fascicles is complicated and changeable, and the spatial position of each nerve fascicle and the long segment of the nerve fascicle aggregation show great changes at different levels. Under the premise of the stability of the existing imaging techniques, a large number of scanning nerve samples can be used to set up a three-dimensional database of the peripheral nerve fascicle microstructure, integrating the gross imaging information, and provide a template for the design of the downstream nerve graft model.

scholarly journals Descriptive anatomy of the largest known specimen of Protoichthyosaurus prostaxalis (Reptilia: Ichthyosauria) including computed tomography and digital reconstruction of a three-dimensional skull

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6112 ◽  
Author(s):  
Dean R. Lomax ◽  
Laura B. Porro ◽  
Nigel R. Larkin
Keyword(s):  
Computed Tomography ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Lower Jurassic ◽  
Science Museum ◽  
Three Dimensional Reconstruction ◽  
Digital Reconstruction ◽  
Reconstruction Methods ◽  
Dimensional Reconstruction ◽  
Marine Reptile

Ichthyosaur fossils are abundant in Lower Jurassic sediments with nine genera found in the UK. In this paper, we describe the partial skeleton of a large ichthyosaur from the Lower Jurassic (lower Sinemurian) of Warwickshire, England, which was conserved and rearticulated to form the centrepiece of a new permanent gallery at the Thinktank, Birmingham Science Museum in 2015. The unusual three-dimensional preservation of the specimen permitted computed tomography (CT) scanning of individual braincase elements as well as the entire reassembled skull. This represents one of the first times that medical imaging and three-dimensional reconstruction methods have been applied to a large skull of a marine reptile. Data from these scans provide new anatomical information, such as the presence of branching vascular canals within the premaxilla and dentary, and an undescribed dorsal (quadrate) wing of the pterygoid hidden within matrix. Scanning also revealed areas of the skull that had been modelled in wood, clay and other materials after the specimen’s initial discovery, highlighting the utility of applying advanced imaging techniques to historical specimens. Additionally, the CT data served as the basis for a new three-dimensional reconstruction of the skull, in which minor damage was repaired and the preserved bones digitally rearticulated. Thus, for the first time a digital reconstruction of the skull and mandible of a large marine reptile skull is available. Museum records show the specimen was originally identified as an example of Ichthyosaurus communis but we identify this specimen as Protoichthyosaurus prostaxalis. The specimen features a skull nearly twice as long as any previously described specimen of P. prostaxalis, representing an individual with an estimated total body length between 3.2 and 4 m.

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