Coherence in the Visual Imagination.

PubMed

Vertolli, Michael O; Kelly, Matthew A; Davies, Jim

2018-04-01

An incoherent visualization is when aspects of different senses of a word (e.g., the biological "mouse" vs. the computer "mouse") are present in the same visualization (e.g., a visualization of a biological mouse in the same image with a computer tower). We describe and implement a new model of creating contextual coherence in the visual imagination called Coherencer, based on the SOILIE model of imagination. We show that Coherencer is able to generate scene descriptions that are more coherent than SOILIE's original approach as well as a parallel connectionist algorithm that is considered competitive in the literature on general coherence. We also show that co-occurrence probabilities are a better association representation than holographic vectors and that better models of coherence improve the resulting output independent of the association type that is used. Theoretically, we show that Coherencer is consistent with other models of cognitive generation. In particular, Coherencer is a similar, but more cognitively plausible model than the C 3 model of concept combination created by Costello and Keane (2000). We show that Coherencer is also consistent with both the modal schematic indices of perceptual symbol systems theory (Barsalou, 1999) and the amodal contextual constraints of Thagard's (2002) theory of coherence. Finally, we describe how Coherencer is consistent with contemporary research on the hippocampus, and we show evidence that the process of making a visualization coherent is serial. Copyright © 2017 Cognitive Science Society, Inc.

A reporter model to visualize imprinting stability at the Dlk1 locus during mouse development and in pluripotent cells.

PubMed

Swanzey, Emily; Stadtfeld, Matthias

2016-11-15

Genomic imprinting results in the monoallelic expression of genes that encode important regulators of growth and proliferation. Dysregulation of imprinted genes, such as those within the Dlk1-Dio3 locus, is associated with developmental syndromes and specific diseases. Our ability to interrogate causes of imprinting instability has been hindered by the absence of suitable model systems. Here, we describe a Dlk1 knock-in reporter mouse that enables single-cell visualization of allele-specific expression and prospective isolation of cells, simultaneously. We show that this 'imprinting reporter mouse' can be used to detect tissue-specific Dlk1 expression patterns in developing embryos. We also apply this system to pluripotent cell culture and demonstrate that it faithfully indicates DNA methylation changes induced upon cellular reprogramming. Finally, the reporter system reveals the role of elevated oxygen levels in eroding imprinted Dlk1 expression during prolonged culture and in vitro differentiation. The possibility to study allele-specific expression in different contexts makes our reporter system a useful tool to dissect the regulation of genomic imprinting in normal development and disease. © 2016. Published by The Company of Biologists Ltd.

Virtual finger boosts three-dimensional imaging and microsurgery as well as terabyte volume image visualization and analysis.

PubMed

Peng, Hanchuan; Tang, Jianyong; Xiao, Hang; Bria, Alessandro; Zhou, Jianlong; Butler, Victoria; Zhou, Zhi; Gonzalez-Bellido, Paloma T; Oh, Seung W; Chen, Jichao; Mitra, Ananya; Tsien, Richard W; Zeng, Hongkui; Ascoli, Giorgio A; Iannello, Giulio; Hawrylycz, Michael; Myers, Eugene; Long, Fuhui

2014-07-11

Three-dimensional (3D) bioimaging, visualization and data analysis are in strong need of powerful 3D exploration techniques. We develop virtual finger (VF) to generate 3D curves, points and regions-of-interest in the 3D space of a volumetric image with a single finger operation, such as a computer mouse stroke, or click or zoom from the 2D-projection plane of an image as visualized with a computer. VF provides efficient methods for acquisition, visualization and analysis of 3D images for roundworm, fruitfly, dragonfly, mouse, rat and human. Specifically, VF enables instant 3D optical zoom-in imaging, 3D free-form optical microsurgery, and 3D visualization and annotation of terabytes of whole-brain image volumes. VF also leads to orders of magnitude better efficiency of automated 3D reconstruction of neurons and similar biostructures over our previous systems. We use VF to generate from images of 1,107 Drosophila GAL4 lines a projectome of a Drosophila brain.

COMICS: Cartoon Visualization of Omics Data in Spatial Context Using Anatomical Ontologies

PubMed Central

2017-01-01

COMICS is an interactive and open-access web platform for integration and visualization of molecular expression data in anatomograms of zebrafish, carp, and mouse model systems. Anatomical ontologies are used to map omics data across experiments and between an experiment and a particular visualization in a data-dependent manner. COMICS is built on top of several existing resources. Zebrafish and mouse anatomical ontologies with their controlled vocabulary (CV) and defined hierarchy are used with the ontoCAT R package to aggregate data for comparison and visualization. Libraries from the QGIS geographical information system are used with the R packages “maps” and “maptools” to visualize and interact with molecular expression data in anatomical drawings of the model systems. COMICS allows users to upload their own data from omics experiments, using any gene or protein nomenclature they wish, as long as CV terms are used to define anatomical regions or developmental stages. Common nomenclatures such as the ZFIN gene names and UniProt accessions are provided additional support. COMICS can be used to generate publication-quality visualizations of gene and protein expression across experiments. Unlike previous tools that have used anatomical ontologies to interpret imaging data in several animal models, including zebrafish, COMICS is designed to take spatially resolved data generated by dissection or fractionation and display this data in visually clear anatomical representations rather than large data tables. COMICS is optimized for ease-of-use, with a minimalistic web interface and automatic selection of the appropriate visual representation depending on the input data. PMID:29083911

COMICS: Cartoon Visualization of Omics Data in Spatial Context Using Anatomical Ontologies.

PubMed

Travin, Dmitrii; Popov, Iaroslav; Guler, Arzu Tugce; Medvedev, Dmitry; van der Plas-Duivesteijn, Suzanne; Varela, Monica; Kolder, Iris C R M; Meijer, Annemarie H; Spaink, Herman P; Palmblad, Magnus

2018-01-05

COMICS is an interactive and open-access web platform for integration and visualization of molecular expression data in anatomograms of zebrafish, carp, and mouse model systems. Anatomical ontologies are used to map omics data across experiments and between an experiment and a particular visualization in a data-dependent manner. COMICS is built on top of several existing resources. Zebrafish and mouse anatomical ontologies with their controlled vocabulary (CV) and defined hierarchy are used with the ontoCAT R package to aggregate data for comparison and visualization. Libraries from the QGIS geographical information system are used with the R packages "maps" and "maptools" to visualize and interact with molecular expression data in anatomical drawings of the model systems. COMICS allows users to upload their own data from omics experiments, using any gene or protein nomenclature they wish, as long as CV terms are used to define anatomical regions or developmental stages. Common nomenclatures such as the ZFIN gene names and UniProt accessions are provided additional support. COMICS can be used to generate publication-quality visualizations of gene and protein expression across experiments. Unlike previous tools that have used anatomical ontologies to interpret imaging data in several animal models, including zebrafish, COMICS is designed to take spatially resolved data generated by dissection or fractionation and display this data in visually clear anatomical representations rather than large data tables. COMICS is optimized for ease-of-use, with a minimalistic web interface and automatic selection of the appropriate visual representation depending on the input data.

Imaging of Chromosome Dynamics in Mouse Testis Tissue by Immuno-FISH.

PubMed

Scherthan, Harry

2017-01-01

The mouse (Mus musculus) represents the central mammalian genetic model system for biomedical and developmental research. Mutant mouse models have provided important insights into chromosome dynamics during the complex meiotic differentiation program that compensates for the genome doubling at fertilization. Homologous chromosomes (homologues) undergo dynamic pairing and recombine during first meiotic prophase before they become partitioned into four haploid sets by two consecutive meiotic divisions that lack an intervening S-phase. Fluorescence in situ hybridization (FISH) has been instrumental in the visualization and imaging of the dynamic reshaping of chromosome territories and mobility during prophase I, in which meiotic telomeres were found to act as pacemakers for the chromosome pairing dance. FISH combined with immunofluorescence (IF) co-staining of nuclear proteins has been instrumental for the visualization and imaging of mammalian meiotic chromosome behavior. This chapter describes FISH and IF methods for the analysis of chromosome dynamics in nuclei of paraffin-embedded mouse testes. The techniques have proven useful for fresh and archived paraffin testis material of several mammalian species.

Retinal lesions induce fast intrinsic cortical plasticity in adult mouse visual system.

PubMed

Smolders, Katrien; Vreysen, Samme; Laramée, Marie-Eve; Cuyvers, Annemie; Hu, Tjing-Tjing; Van Brussel, Leen; Eysel, Ulf T; Nys, Julie; Arckens, Lutgarde

2016-09-01

Neuronal activity plays an important role in the development and structural-functional maintenance of the brain as well as in its life-long plastic response to changes in sensory stimulation. We characterized the impact of unilateral 15° laser lesions in the temporal lower visual field of the retina, on visually driven neuronal activity in the afferent visual pathway of adult mice using in situ hybridization for the activity reporter gene zif268. In the first days post-lesion, we detected a discrete zone of reduced zif268 expression in the contralateral hemisphere, spanning the border between the monocular segment of the primary visual cortex (V1) with extrastriate visual area V2M. We could not detect a clear lesion projection zone (LPZ) in areas lateral to V1 whereas medial to V2M, agranular and granular retrosplenial cortex showed decreased zif268 levels over their full extent. All affected areas displayed a return to normal zif268 levels, and this was faster in higher order visual areas than in V1. The lesion did, however, induce a permanent LPZ in the retinorecipient layers of the superior colliculus. We identified a retinotopy-based intrinsic capacity of adult mouse visual cortex to recover from restricted vision loss, with recovery speed reflecting the areal cortical magnification factor. Our observations predict incomplete visual field representations for areas lateral to V1 vs. lack of retinotopic organization for areas medial to V2M. The validation of this mouse model paves the way for future interrogations of cortical region- and cell-type-specific contributions to functional recovery, up to microcircuit level. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Specific excitatory connectivity for feature integration in mouse primary visual cortex

PubMed Central

Molina-Luna, Patricia; Roth, Morgane M.

2017-01-01

Local excitatory connections in mouse primary visual cortex (V1) are stronger and more prevalent between neurons that share similar functional response features. However, the details of how functional rules for local connectivity shape neuronal responses in V1 remain unknown. We hypothesised that complex responses to visual stimuli may arise as a consequence of rules for selective excitatory connectivity within the local network in the superficial layers of mouse V1. In mouse V1 many neurons respond to overlapping grating stimuli (plaid stimuli) with highly selective and facilitatory responses, which are not simply predicted by responses to single gratings presented alone. This complexity is surprising, since excitatory neurons in V1 are considered to be mainly tuned to single preferred orientations. Here we examined the consequences for visual processing of two alternative connectivity schemes: in the first case, local connections are aligned with visual properties inherited from feedforward input (a ‘like-to-like’ scheme specifically connecting neurons that share similar preferred orientations); in the second case, local connections group neurons into excitatory subnetworks that combine and amplify multiple feedforward visual properties (a ‘feature binding’ scheme). By comparing predictions from large scale computational models with in vivo recordings of visual representations in mouse V1, we found that responses to plaid stimuli were best explained by assuming feature binding connectivity. Unlike under the like-to-like scheme, selective amplification within feature-binding excitatory subnetworks replicated experimentally observed facilitatory responses to plaid stimuli; explained selective plaid responses not predicted by grating selectivity; and was consistent with broad anatomical selectivity observed in mouse V1. Our results show that visual feature binding can occur through local recurrent mechanisms without requiring feedforward convergence, and that such a mechanism is consistent with visual responses and cortical anatomy in mouse V1. PMID:29240769

aGEM: an integrative system for analyzing spatial-temporal gene-expression information

PubMed Central

Jiménez-Lozano, Natalia; Segura, Joan; Macías, José Ramón; Vega, Juanjo; Carazo, José María

2009-01-01

Motivation: The work presented here describes the ‘anatomical Gene-Expression Mapping (aGEM)’ Platform, a development conceived to integrate phenotypic information with the spatial and temporal distributions of genes expressed in the mouse. The aGEM Platform has been built by extending the Distributed Annotation System (DAS) protocol, which was originally designed to share genome annotations over the WWW. DAS is a client-server system in which a single client integrates information from multiple distributed servers. Results: The aGEM Platform provides information to answer three main questions. (i) Which genes are expressed in a given mouse anatomical component? (ii) In which mouse anatomical structures are a given gene or set of genes expressed? And (iii) is there any correlation among these findings? Currently, this Platform includes several well-known mouse resources (EMAGE, GXD and GENSAT), hosting gene-expression data mostly obtained from in situ techniques together with a broad set of image-derived annotations. Availability: The Platform is optimized for Firefox 3.0 and it is accessed through a friendly and intuitive display: http://agem.cnb.csic.es Contact: natalia@cnb.csic.es Supplementary information: Supplementary data are available at http://bioweb.cnb.csic.es/VisualOmics/aGEM/home.html and http://bioweb.cnb.csic.es/VisualOmics/index_VO.html and Bioinformatics online. PMID:19592395

Advanced multiphoton methods for in vitro and in vivo functional imaging of mouse retinal neurons (Conference Presentation)

NASA Astrophysics Data System (ADS)

Cohen, Noam; Schejter, Adi; Farah, Nairouz; Shoham, Shy

2016-03-01

Studying the responses of retinal ganglion cell (RGC) populations has major significance in vision research. Multiphoton imaging of optogenetic probes has recently become the leading approach for visualizing neural populations and has specific advantages for imaging retinal activity during visual stimulation, because it leads to reduced direct photoreceptor excitation. However, multiphoton retinal activity imaging is not straightforward: point-by-point scanning leads to repeated neural excitation while optical access through the rodent eye in vivo has proven highly challenging. Here, we present two enabling optical designs for multiphoton imaging of responses to visual stimuli in mouse retinas expressing calcium indicators. First, we present an imaging solution based on Scanning Line Temporal Focusing (SLITE) for rapidly imaging neuronal activity in vitro. In this design, we scan a temporally focused line rather than a point, increasing the scan speed and reducing the impact of repeated excitation, while maintaining high optical sectioning. Second, we present the first in vivo demonstration of two-photon imaging of RGC activity in the mouse retina. To obtain these cellular resolution recordings we integrated an illumination path into a correction-free imaging system designed using an optical model of the mouse eye. This system can image at multiple depths using an electronically tunable lens integrated into its optical path. The new optical designs presented here overcome a number of outstanding obstacles, allowing the study of rapid calcium- and potentially even voltage-indicator signals both in vitro and in vivo, thereby bringing us a step closer toward distributed monitoring of action potentials.

Whole mouse cryo-imaging

NASA Astrophysics Data System (ADS)

Wilson, David; Roy, Debashish; Steyer, Grant; Gargesha, Madhusudhana; Stone, Meredith; McKinley, Eliot

2008-03-01

The Case cryo-imaging system is a section and image system which allows one to acquire micron-scale, information rich, whole mouse color bright field and molecular fluorescence images of an entire mouse. Cryo-imaging is used in a variety of applications, including mouse and embryo anatomical phenotyping, drug delivery, imaging agents, metastastic cancer, stem cells, and very high resolution vascular imaging, among many. Cryo-imaging fills the gap between whole animal in vivo imaging and histology, allowing one to image a mouse along the continuum from the mouse -> organ -> tissue structure -> cell -> sub-cellular domains. In this overview, we describe the technology and a variety of exciting applications. Enhancements to the system now enable tiled acquisition of high resolution images to cover an entire mouse. High resolution fluorescence imaging, aided by a novel subtraction processing algorithm to remove sub-surface fluorescence, makes it possible to detect fluorescently-labeled single cells. Multi-modality experiments in Magnetic Resonance Imaging and Cryo-imaging of a whole mouse demonstrate superior resolution of cryo-images and efficiency of registration techniques. The 3D results demonstrate the novel true-color volume visualization tools we have developed and the inherent advantage of cryo-imaging in providing unlimited depth of field and spatial resolution. The recent results continue to demonstrate the value cryo-imaging provides in the field of small animal imaging research.

High-frequency Ultrasound Imaging of Mouse Cervical Lymph Nodes.

PubMed

Walk, Elyse L; McLaughlin, Sarah L; Weed, Scott A

2015-07-25

High-frequency ultrasound (HFUS) is widely employed as a non-invasive method for imaging internal anatomic structures in experimental small animal systems. HFUS has the ability to detect structures as small as 30 µm, a property that has been utilized for visualizing superficial lymph nodes in rodents in brightness (B)-mode. Combining power Doppler with B-mode imaging allows for measuring circulatory blood flow within lymph nodes and other organs. While HFUS has been utilized for lymph node imaging in a number of mouse  model systems, a detailed protocol describing HFUS imaging and characterization of the cervical lymph nodes in mice has not been reported. Here, we show that HFUS can be adapted to detect and characterize cervical lymph nodes in mice. Combined B-mode and power Doppler imaging can be used to detect increases in blood flow in immunologically-enlarged cervical nodes. We also describe the use of B-mode imaging to conduct fine needle biopsies of cervical lymph nodes to retrieve lymph tissue for histological  analysis. Finally, software-aided steps are described to calculate changes in lymph node volume and to visualize changes in lymph node morphology following image reconstruction. The ability to visually monitor changes in cervical lymph node biology over time provides a simple and powerful technique for the non-invasive monitoring of cervical lymph node alterations in preclinical mouse models of oral cavity disease.

Intelligent Visual Input: A Graphical Method for Rapid Entry of Patient-Specific Data

PubMed Central

Bergeron, Bryan P.; Greenes, Robert A.

1987-01-01

Intelligent Visual Input (IVI) provides a rapid, graphical method of data entry for both expert system interaction and medical record keeping purposes. Key components of IVI include: a high-resolution graphic display; an interface supportive of rapid selection, i.e., one utilizing a mouse or light pen; algorithm simplification modules; and intelligent graphic algorithm expansion modules. A prototype IVI system, designed to facilitate entry of physical exam findings, is used to illustrates the potential advantages of this approach.

Visualization of Motor Axon Navigation and Quantification of Axon Arborization In Mouse Embryos Using Light Sheet Fluorescence Microscopy.

PubMed

Liau, Ee Shan; Yen, Ya-Ping; Chen, Jun-An

2018-05-11

Spinal motor neurons (MNs) extend their axons to communicate with their innervating targets, thereby controlling movement and complex tasks in vertebrates. Thus, it is critical to uncover the molecular mechanisms of how motor axons navigate to, arborize, and innervate their peripheral muscle targets during development and degeneration. Although transgenic Hb9::GFP mouse lines have long served to visualize motor axon trajectories during embryonic development, detailed descriptions of the full spectrum of axon terminal arborization remain incomplete due to the pattern complexity and limitations of current optical microscopy. Here, we describe an improved protocol that combines light sheet fluorescence microscopy (LSFM) and robust image analysis to qualitatively and quantitatively visualize developing motor axons. This system can be easily adopted to cross genetic mutants or MN disease models with Hb9::GFP lines, revealing novel molecular mechanisms that lead to defects in motor axon navigation and arborization.

Inferring cortical function in the mouse visual system through large-scale systems neuroscience.

PubMed

Hawrylycz, Michael; Anastassiou, Costas; Arkhipov, Anton; Berg, Jim; Buice, Michael; Cain, Nicholas; Gouwens, Nathan W; Gratiy, Sergey; Iyer, Ramakrishnan; Lee, Jung Hoon; Mihalas, Stefan; Mitelut, Catalin; Olsen, Shawn; Reid, R Clay; Teeter, Corinne; de Vries, Saskia; Waters, Jack; Zeng, Hongkui; Koch, Christof

2016-07-05

The scientific mission of the Project MindScope is to understand neocortex, the part of the mammalian brain that gives rise to perception, memory, intelligence, and consciousness. We seek to quantitatively evaluate the hypothesis that neocortex is a relatively homogeneous tissue, with smaller functional modules that perform a common computational function replicated across regions. We here focus on the mouse as a mammalian model organism with genetics, physiology, and behavior that can be readily studied and manipulated in the laboratory. We seek to describe the operation of cortical circuitry at the computational level by comprehensively cataloging and characterizing its cellular building blocks along with their dynamics and their cell type-specific connectivities. The project is also building large-scale experimental platforms (i.e., brain observatories) to record the activity of large populations of cortical neurons in behaving mice subject to visual stimuli. A primary goal is to understand the series of operations from visual input in the retina to behavior by observing and modeling the physical transformations of signals in the corticothalamic system. We here focus on the contribution that computer modeling and theory make to this long-term effort.

An Automated Mouse Tail Vascular Access System by Vision and Pressure Feedback.

PubMed

Chang, Yen-Chi; Berry-Pusey, Brittany; Yasin, Rashid; Vu, Nam; Maraglia, Brandon; Chatziioannou, Arion X; Tsao, Tsu-Chin

2015-08-01

This paper develops an automated vascular access system (A-VAS) with novel vision-based vein and needle detection methods and real-time pressure feedback for murine drug delivery. Mouse tail vein injection is a routine but critical step for preclinical imaging applications. Due to the small vein diameter and external disturbances such as tail hair, pigmentation, and scales, identifying vein location is difficult and manual injections usually result in poor repeatability. To improve the injection accuracy, consistency, safety, and processing time, A-VAS was developed to overcome difficulties in vein detection noise rejection, robustness in needle tracking, and visual servoing integration with the mechatronics system.

Grating acuity at different luminances in wild-type mice and in mice lacking rod or cone function.

PubMed

Schmucker, Christine; Seeliger, Mathias; Humphries, Pete; Biel, Martin; Schaeffel, Frank

2005-01-01

The mouse eye has become an important model in vision research. However, it is not known how visual acuity changes with luminance. Therefore, grating acuity of mice was measured at different luminances in an automated optomotor paradigm. Furthermore, mutant mice lacking either rods (RHO-/- and CNGB1-/-) or cones (CNGA3-/-), or both, were studied to determine the rod and cone contribution to visual acuity. Freely ranging individual mice were automatically tracked at a 25-Hz sampling rate with a self-programmed video system in a large rotating optomotor drum. The drum had a square-wave grating inside with adjustable spatial frequency. The angular speed of the mice with respect to the center of the drum and the angular orientation of the snout-tail body axis were analyzed. In addition, the motor activity of the wild-type mice was recorded at different luminances. The optomotor drum provided reliable data on visual input to the mouse's behavior and was convenient to use, since the experimenter's had only to place the mice individually in a Perspex cylinder. Optomotor grating acuity of the wild-type mice was limited to 0.3 to 0.4 cyc/deg. Maximum optomotor responses were obtained at 0.1 to 0.2 cyc/deg. The importance of visual input declined monotonically with decreasing luminance (30 cd/m2, 100%; 0.1 cd/m2, 76.4%; 0.005 cd/m2, 45.9%; and darkness, -9%). Mice lacking functional rods were able to resolve gratings up to 0.1 cyc/deg at 30 cd/m2. Surprisingly, mice lacking functional cones had an optomotor acuity that was similar to the wild-type. Double-knockout mice without rods and cones had no detectable grating acuity. Because the visual system of the mouse is more responsive at bright luminances, experiments in which visual input is important should be performed in photopic conditions (30 cd/m2 or even more). Apparently, spatial vision is governed by the rod system, which is not saturated in the mesopic or low photopic range. Mice lacking both rods and cones have no detectable grating acuity, indicating that the retinal melanopsin system does not contribute to spatial vision.

Exploration of the Visual System: Part 2: In Vivo Analysis Methods: Virtual-Reality Optomotor System, Fundus Examination, and Fluorescent Angiography.

PubMed

Marcelli, Fabienne; Escher, Pascal; Schorderet, Daniel F

2012-09-01

The mouse has emerged as an animal model for many diseases. At IRO, we have used this animal to understand the development of many eye diseases and treatment of some of them. Precise evaluation of vision is a prerequisite for both these approaches. In this unit we describe three ways to measure vision: testing the optokinetic response, and evaluating the fundus by direct observation and by fluorescent angiography. Curr. Protoc. Mouse Biol. 2:207-218 © 2012 by John Wiley & Sons, Inc. Copyright © 2012 John Wiley & Sons, Inc.

A Brain-Computer Interface (BCI) system to use arbitrary Windows applications by directly controlling mouse and keyboard.

PubMed

Spuler, Martin

2015-08-01

A Brain-Computer Interface (BCI) allows to control a computer by brain activity only, without the need for muscle control. In this paper, we present an EEG-based BCI system based on code-modulated visual evoked potentials (c-VEPs) that enables the user to work with arbitrary Windows applications. Other BCI systems, like the P300 speller or BCI-based browsers, allow control of one dedicated application designed for use with a BCI. In contrast, the system presented in this paper does not consist of one dedicated application, but enables the user to control mouse cursor and keyboard input on the level of the operating system, thereby making it possible to use arbitrary applications. As the c-VEP BCI method was shown to enable very fast communication speeds (writing more than 20 error-free characters per minute), the presented system is the next step in replacing the traditional mouse and keyboard and enabling complete brain-based control of a computer.

A simple and sensitive method to measure timing accuracy.

PubMed

De Clercq, Armand; Crombez, Geert; Buysse, Ann; Roeyers, Herbert

2003-02-01

Timing accuracy in presenting experimental stimuli (visual information on a PC or on a TV) and responding (keyboard presses and mouse signals) is of importance in several experimental paradigms. In this article, a simple system for measuring timing accuracy is described. The system uses two PCs (at least Pentium II, 200 MHz), a photocell, and an amplifier. No additional boards and timing hardware are needed. The first PC, a SlavePC, monitors the keyboard presses or mouse signals from the PC under test and uses a photocell that is placed in front of the screen to detect the appearance of visual stimuli on the display. The software consists of a small program running on the SlavePC. The SlavePC is connected through a serial line with a second PC. This MasterPC controls the SlavePC through an ActiveX control, which is used in a Visual Basic program. The accuracy of our system was investigated by using a similar setup of a SlavePC and a MasterPC to generate pulses and by using a pulse generator card. These tests revealed that our system has a 0.01-msec accuracy. As an illustration, the reaction time accuracy of INQUISIT for a few applications was tested using our system. It was found that in those applications that we investigated, INQUISIT measures reaction times from keyboard presses with millisecond accuracy.

3D Cryo-Imaging: A Very High-Resolution View of the Whole Mouse

PubMed Central

Roy, Debashish; Steyer, Grant J.; Gargesha, Madhusudhana; Stone, Meredith E.; Wilson, David L.

2009-01-01

We developed the Case Cryo-imaging system that provides information rich, very high-resolution, color brightfield, and molecular fluorescence images of a whole mouse using a section-and-image block-face imaging technology. The system consists of a mouse-sized, motorized cryo-microtome with special features for imaging, a modified, brightfield/ fluorescence microscope, and a robotic xyz imaging system positioner, all of which is fully automated by a control system. Using the robotic system, we acquired microscopic tiled images at a pixel size of 15.6 µm over the block face of a whole mouse sectioned at 40 µm, with a total data volume of 55 GB. Viewing 2D images at multiple resolutions, we identified small structures such as cardiac vessels, muscle layers, villi of the small intestine, the optic nerve, and layers of the eye. Cryo-imaging was also suitable for imaging embryo mutants in 3D. A mouse, in which enhanced green fluorescent protein was expressed under gamma actin promoter in smooth muscle cells, gave clear 3D views of smooth muscle in the urogenital and gastrointestinal tracts. With cryo-imaging, we could obtain 3D vasculature down to 10 µm, over very large regions of mouse brain. Software is fully automated with fully programmable imaging/sectioning protocols, email notifications, and automatic volume visualization. With a unique combination of field-of-view, depth of field, contrast, and resolution, the Case Cryo-imaging system fills the gap between whole animal in vivo imaging and histology. PMID:19248166

Design and Implementation of an Operations Module for the ARGOS paperless Ship System

DTIC Science & Technology

1989-06-01

A. OPERATIONS STACK SCRIPTS SCRIPTS FOR STACK: operations * BACKGROUND #1: Operations * on openStack hide message box show menuBar pass openStack end... openStack ** CARD #1, BUTTON #1: Up ***** on mouseUp visual effect zoom out go to card id 10931 of stack argos end mouseUp ** CARD #1, BUTTON #2...STACK SCRIPTS SCRIPTS FOR STACK: Reports ** BACKGROUND #1: Operations * on openStack hie message box show menuBar pass openStack end openStack ** CARD #1

Optimization of a GCaMP calcium indicator for neural activity imaging.

PubMed

Akerboom, Jasper; Chen, Tsai-Wen; Wardill, Trevor J; Tian, Lin; Marvin, Jonathan S; Mutlu, Sevinç; Calderón, Nicole Carreras; Esposti, Federico; Borghuis, Bart G; Sun, Xiaonan Richard; Gordus, Andrew; Orger, Michael B; Portugues, Ruben; Engert, Florian; Macklin, John J; Filosa, Alessandro; Aggarwal, Aman; Kerr, Rex A; Takagi, Ryousuke; Kracun, Sebastian; Shigetomi, Eiji; Khakh, Baljit S; Baier, Herwig; Lagnado, Leon; Wang, Samuel S-H; Bargmann, Cornelia I; Kimmel, Bruce E; Jayaraman, Vivek; Svoboda, Karel; Kim, Douglas S; Schreiter, Eric R; Looger, Loren L

2012-10-03

Genetically encoded calcium indicators (GECIs) are powerful tools for systems neuroscience. Recent efforts in protein engineering have significantly increased the performance of GECIs. The state-of-the art single-wavelength GECI, GCaMP3, has been deployed in a number of model organisms and can reliably detect three or more action potentials in short bursts in several systems in vivo. Through protein structure determination, targeted mutagenesis, high-throughput screening, and a battery of in vitro assays, we have increased the dynamic range of GCaMP3 by severalfold, creating a family of "GCaMP5" sensors. We tested GCaMP5s in several systems: cultured neurons and astrocytes, mouse retina, and in vivo in Caenorhabditis chemosensory neurons, Drosophila larval neuromuscular junction and adult antennal lobe, zebrafish retina and tectum, and mouse visual cortex. Signal-to-noise ratio was improved by at least 2- to 3-fold. In the visual cortex, two GCaMP5 variants detected twice as many visual stimulus-responsive cells as GCaMP3. By combining in vivo imaging with electrophysiology we show that GCaMP5 fluorescence provides a more reliable measure of neuronal activity than its predecessor GCaMP3. GCaMP5 allows more sensitive detection of neural activity in vivo and may find widespread applications for cellular imaging in general.

The Orphan Nuclear Receptor TLX/NR2E1 in Neural Stem Cells and Diseases.

PubMed

Wang, Tao; Xiong, Jian-Qiong

2016-02-01

The human TLX gene encodes an orphan nuclear receptor predominantly expressed in the central nervous system. Tailess and Tlx, the TLX homologues in Drosophila and mouse, play essential roles in body-pattern formation and neurogenesis during early embryogenesis and perform crucial functions in maintaining stemness and controlling the differentiation of adult neural stem cells in the central nervous system, especially the visual system. Multiple target genes and signaling pathways are regulated by TLX and its homologues in specific tissues during various developmental stages. This review aims to summarize previous studies including many recent updates from different aspects concerning TLX and its homologues in Drosophila and mouse.

Comparison of confocal microscopy and two-photon microscopy in mouse cornea in vivo.

PubMed

Lee, Jun Ho; Lee, Seunghun; Gho, Yong Song; Song, In Seok; Tchah, Hungwon; Kim, Myoung Joon; Kim, Ki Hean

2015-03-01

High-resolution imaging of the cornea is important for studying corneal diseases at cellular levels. Confocal microscopy (CM) has been widely used in the clinic, and two-photon microscopy (TPM) has recently been introduced in various pre-clinical studies. We compared the performance of CM and TPM in normal mouse corneas and neovascularized mouse corneas induced by suturing. Balb/C mice and C57BL/6 mice expressing green fluorescent protein (GFP) were used to compare modalities based on intrinsic contrast and extrinsic fluorescence contrast. CM based on reflection (CMR), CM based on fluorescence (CMF), and TPM based on intrinsic/extrinsic fluorescence and second harmonic generation (SHG) were compared by imaging the same sections of mouse corneas sequentially in vivo. In normal mouse corneas, CMR visualized corneal cell morphologies with some background noise, and CMF visualized GFP expressing corneal cells clearly. TPM visualized corneal cells and collagen in the stroma based on fluorescence and SHG, respectively. However, in neovascularized mouse corneas, CMR could not resolve cells deep inside the cornea due to high background noise from the effects of increased structural irregularity induced by suturing. CMF and TPM visualized cells and induced vasculature better than CMR because both collect signals from fluorescent cells only. Both CMF and TPM had signal decays with depth due to the structural irregularity, with CMF having faster signal decay than TPM. CMR, CMF, and TPM showed different degrees of image degradation in neovascularized mouse corneas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Locomotion Enhances Neural Encoding of Visual Stimuli in Mouse V1

PubMed Central

2017-01-01

Neurons in mouse primary visual cortex (V1) are selective for particular properties of visual stimuli. Locomotion causes a change in cortical state that leaves their selectivity unchanged but strengthens their responses. Both locomotion and the change in cortical state are thought to be initiated by projections from the mesencephalic locomotor region, the latter through a disinhibitory circuit in V1. By recording simultaneously from a large number of single neurons in alert mice viewing moving gratings, we investigated the relationship between locomotion and the information contained within the neural population. We found that locomotion improved encoding of visual stimuli in V1 by two mechanisms. First, locomotion-induced increases in firing rates enhanced the mutual information between visual stimuli and single neuron responses over a fixed window of time. Second, stimulus discriminability was improved, even for fixed population firing rates, because of a decrease in noise correlations across the population. These two mechanisms contributed differently to improvements in discriminability across cortical layers, with changes in firing rates most important in the upper layers and changes in noise correlations most important in layer V. Together, these changes resulted in a threefold to fivefold reduction in the time needed to precisely encode grating direction and orientation. These results support the hypothesis that cortical state shifts during locomotion to accommodate an increased load on the visual system when mice are moving. SIGNIFICANCE STATEMENT This paper contains three novel findings about the representation of information in neurons within the primary visual cortex of the mouse. First, we show that locomotion reduces by at least a factor of 3 the time needed for information to accumulate in the visual cortex that allows the distinction of different visual stimuli. Second, we show that the effect of locomotion is to increase information in cells of all layers of the visual cortex. Third, we show that the means by which information is enhanced by locomotion differs between the upper layers, where the major effect is the increasing of firing rates, and in layer V, where the major effect is the reduction in noise correlations. PMID:28264980

Daily visual stimulation in the critical period enhances multiple aspects of vision through BDNF-mediated pathways in the mouse retina

PubMed Central

Mui, Amanda M.; Yang, Victoria; Aung, Moe H.; Fu, Jieming; Adekunle, Adewumi N.; Prall, Brian C.; Sidhu, Curran S.; Park, Han na; Boatright, Jeffrey H.; Iuvone, P. Michael

2018-01-01

Visual experience during the critical period modulates visual development such that deprivation causes visual impairments while stimulation induces enhancements. This study aimed to determine whether visual stimulation in the form of daily optomotor response (OMR) testing during the mouse critical period (1) improves aspects of visual function, (2) involves retinal mechanisms and (3) is mediated by brain derived neurotrophic factor (BDNF) and dopamine (DA) signaling pathways. We tested spatial frequency thresholds in C57BL/6J mice daily from postnatal days 16 to 23 (P16 to P23) using OMR testing. Daily OMR-treated mice were compared to littermate controls that were placed in the OMR chamber without moving gratings. Contrast sensitivity thresholds, electroretinograms (ERGs), visual evoked potentials, and pattern ERGs were acquired at P21. To determine the role of BDNF signaling, a TrkB receptor antagonist (ANA-12) was systemically injected 2 hours prior to OMR testing in another cohort of mice. BDNF immunohistochemistry was performed on retina and brain sections. Retinal DA levels were measured using high-performance liquid chromatography. Daily OMR testing enhanced spatial frequency thresholds and contrast sensitivity compared to controls. OMR-treated mice also had improved rod-driven ERG oscillatory potential response times, greater BDNF immunoreactivity in the retinal ganglion cell layer, and increased retinal DA content compared to controls. VEPs and pattern ERGs were unchanged. Systemic delivery of ANA-12 attenuated OMR-induced visual enhancements. Daily OMR testing during the critical period leads to general visual function improvements accompanied by increased DA and BDNF in the retina, with this process being requisitely mediated by TrkB activation. These results suggest that novel combination therapies involving visual stimulation and using both behavioral and molecular approaches may benefit degenerative retinal diseases or amblyopia. PMID:29408880

The Effectiveness of Gaze-Contingent Control in Computer Games.

PubMed

Orlov, Paul A; Apraksin, Nikolay

2015-01-01

Eye-tracking technology and gaze-contingent control in human-computer interaction have become an objective reality. This article reports on a series of eye-tracking experiments, in which we concentrated on one aspect of gaze-contingent interaction: Its effectiveness compared with mouse-based control in a computer strategy game. We propose a measure for evaluating the effectiveness of interaction based on "the time of recognition" the game unit. In this article, we use this measure to compare gaze- and mouse-contingent systems, and we present the analysis of the differences as a function of the number of game units. Our results indicate that performance of gaze-contingent interaction is typically higher than mouse manipulation in a visual searching task. When tested on 60 subjects, the results showed that the effectiveness of gaze-contingent systems over 1.5 times higher. In addition, we obtained that eye behavior stays quite stabile with or without mouse interaction. © The Author(s) 2015.

HPC Access Using KVM over IP

DTIC Science & Technology

2007-06-08

Lightwave VDE /200 KVM-over-Fiber (Keyboard, Video and Mouse) devices installed throughout the TARDEC campus. Implementation of this system required...development effort through the pursuit of an Army-funded Phase-II Small Business Innovative Research (SBIR) effort with IP Video Systems (formerly known as...visualization capabilities of a DoD High- Performance Computing facility, many advanced features are necessary. TARDEC-HPC’s SBIR with IP Video Systems

Analogue mouse pointer control via an online steady state visual evoked potential (SSVEP) brain-computer interface

NASA Astrophysics Data System (ADS)

Wilson, John J.; Palaniappan, Ramaswamy

2011-04-01

The steady state visual evoked protocol has recently become a popular paradigm in brain-computer interface (BCI) applications. Typically (regardless of function) these applications offer the user a binary selection of targets that perform correspondingly discrete actions. Such discrete control systems are appropriate for applications that are inherently isolated in nature, such as selecting numbers from a keypad to be dialled or letters from an alphabet to be spelled. However motivation exists for users to employ proportional control methods in intrinsically analogue tasks such as the movement of a mouse pointer. This paper introduces an online BCI in which control of a mouse pointer is directly proportional to a user's intent. Performance is measured over a series of pointer movement tasks and compared to the traditional discrete output approach. Analogue control allowed subjects to move the pointer faster to the cued target location compared to discrete output but suffers more undesired movements overall. Best performance is achieved when combining the threshold to movement of traditional discrete techniques with the range of movement offered by proportional control.

Test systems for measuring ocular parameters and visual function in mice.

PubMed

Schaeffel, Frank

2008-05-01

New techniques are described to measure refractive state, pupil responses, corneal curvature, ocular dimensions and spatial vision in mice. These variables are important for studies on myopia development in mice, but they are also valuable for phenotyping mouse mutants and for pharmacological studies.

Stream-related preferences of inputs to the superior colliculus from areas of dorsal and ventral streams of mouse visual cortex.

PubMed

Wang, Quanxin; Burkhalter, Andreas

2013-01-23

Previous studies of intracortical connections in mouse visual cortex have revealed two subnetworks that resemble the dorsal and ventral streams in primates. Although calcium imaging studies have shown that many areas of the ventral stream have high spatial acuity whereas areas of the dorsal stream are highly sensitive for transient visual stimuli, there are some functional inconsistencies that challenge a simple grouping into "what/perception" and "where/action" streams known in primates. The superior colliculus (SC) is a major center for processing of multimodal sensory information and the motor control of orienting the eyes, head, and body. Visual processing is performed in superficial layers, whereas premotor activity is generated in deep layers of the SC. Because the SC is known to receive input from visual cortex, we asked whether the projections from 10 visual areas of the dorsal and ventral streams terminate in differential depth profiles within the SC. We found that inputs from primary visual cortex are by far the strongest. Projections from the ventral stream were substantially weaker, whereas the sparsest input originated from areas of the dorsal stream. Importantly, we found that ventral stream inputs terminated in superficial layers, whereas dorsal stream inputs tended to be patchy and either projected equally to superficial and deep layers or strongly preferred deep layers. The results suggest that the anatomically defined ventral and dorsal streams contain areas that belong to distinct functional systems, specialized for the processing of visual information and visually guided action, respectively.

Speed, spatial, and temporal tuning of rod and cone vision in mouse.

PubMed

Umino, Yumiko; Solessio, Eduardo; Barlow, Robert B

2008-01-02

Rods and cones subserve mouse vision over a 100 million-fold range of light intensity (-6 to 2 log cd m(-2)). Rod pathways tune vision to the temporal frequency of stimuli (peak, 0.75 Hz) and cone pathways to their speed (peak, approximately 12 degrees/s). Both pathways tune vision to the spatial components of stimuli (0.064-0.128 cycles/degree). The specific photoreceptor contributions were determined by two-alternative, forced-choice measures of contrast thresholds for optomotor responses of C57BL/6J mice with normal vision, Gnat2(cpfl3) mice without functional cones, and Gnat1-/- mice without functional rods. Gnat2(cpfl3) mice (threshold, -6.0 log cd m(-2)) cannot see rotating gratings above -2.0 log cd m(-2) (photopic vision), and Gnat1-/- mice (threshold, -4.0 log cd m(-2)) are blind below -4.0 log cd m(-2) (scotopic vision). Both genotypes can see in the transitional mesopic range (-4.0 to -2.0 log cd m(-2)). Mouse rod and cone sensitivities are similar to those of human. This parametric study characterizes the functional properties of the mouse visual system, revealing the rod and cone contributions to contrast sensitivity and to the temporal processing of visual stimuli.

Research issues of geometry-based visual languages and some solutions

NASA Astrophysics Data System (ADS)

Green, Thorn G.

This dissertation addresses the problem of how to design visual language systems that are based upon Geometric Algebra, and provide a visual coupling of algebraic expressions and geometric depictions. This coupling of algebraic expressions and geometric depictions provides a new means for expressing both mathematical and geometric relationships present in mathematics, physics, and Computer-Aided Geometric Design (CAGD). Another significant feature of such a system is that the result of changing a parameter (by dragging the mouse) can be seen immediately in the depiction(s) of all expressions that use that parameter. This greatly aides the cognition of the relationships between variables. Systems for representing such a coupling of algebra and geometry have characteristics of both visual language systems, and systems for scientific visualization. Instead of using a parsing or dataflow paradigm for the visual language representation, the systems instead represent equations as manipulatible constrained diagrams for their visualization. This requires that the design of such a system have (but is not limited to) a means for parsing equations entered by the user, a scheme for producing a visual representation of these equations; techniques for maintaining the coupling between the expressions entered and the diagrams displayed; algorithms for maintaining the consistency of the diagrams; and, indexing capabilities that are efficient enough to allow diagrams to be created, and manipulated in a short enough period of time. The author proposes solutions for how such a design can be realized.

Optimization of a GCaMP calcium indicator for neural activity imaging

PubMed Central

Akerboom, Jasper; Chen, Tsai-Wen; Wardill, Trevor J.; Tian, Lin; Marvin, Jonathan S.; Mutlu, Sevinç; Calderón, Nicole Carreras; Esposti, Federico; Borghuis, Bart G.; Sun, Xiaonan Richard; Gordus, Andrew; Orger, Michael B.; Portugues, Ruben; Engert, Florian; Macklin, John J.; Filosa, Alessandro; Aggarwal, Aman; Kerr, Rex; Takagi, Ryousuke; Kracun, Sebastian; Shigetomi, Eiji; Khakh, Baljit S.; Baier, Herwig; Lagnado, Leon; Wang, Samuel S.-H.; Bargmann, Cornelia I.; Kimmel, Bruce E.; Jayaraman, Vivek; Svoboda, Karel; Kim, Douglas S.; Schreiter, Eric R.; Looger, Loren L.

2012-01-01

Genetically encoded calcium indicators (GECIs) are powerful tools for systems neuroscience. Recent efforts in protein engineering have significantly increased the performance of GECIs. The state-of-the art single-wavelength GECI, GCaMP3, has been deployed in a number of model organisms and can reliably detect three or more action potentials (APs) in short bursts in several systems in vivo. Through protein structure determination, targeted mutagenesis, high-throughput screening, and a battery of in vitro assays, we have increased the dynamic range of GCaMP3 by several-fold, creating a family of “GCaMP5” sensors. We tested GCaMP5s in several systems: cultured neurons and astrocytes, mouse retina, and in vivo in Caenorhabditis chemosensory neurons, Drosophila larval neuromuscular junction and adult antennal lobe, zebrafish retina and tectum, and mouse visual cortex. Signal-to-noise ratio was improved by at least 2–3-fold. In the visual cortex, two GCaMP5 variants detected twice as many visual stimulus-responsive cells as GCaMP3. By combining in vivo imaging with electrophysiology we show that GCaMP5 fluorescence provides a more reliable measure of neuronal activity than its predecessor GCaMP3. GCaMP5 allows more sensitive detection of neural activity in vivo and may find widespread applications for cellular imaging in general. PMID:23035093

Mutational Analysis of Drosophila Basigin Function in the Visual System

PubMed Central

Munro, Michelle; Akkam, Yazan; Curtin, Kathryn D.

2009-01-01

Drosophila basigin is a cell-surface glycoprotein of the Ig superfamily and a member of a protein family that includes mammalian EMMPRIN/CD147/basigin, neuroplastin, and embigin. Our previous work on Drosophila basigin has shown that it is required for normal photoreceptor cell structure and normal neuron-glia interaction in the fly visual system. Specifically, the photoreceptor neurons of mosaic animals that are mutant in the eye for basigin show altered cell structure with nuclei, mitochondria and rER misplaced and variable axon diameter compared to wild-type. In addition, glia cells in the optic lamina that contact photoreceptor axons are misplaced and show altered structure. All these defects are rescued by expression of either transgenic fly basigin or transgenic mouse basigin in the photoreceptors demonstrating that mouse basigin can functionally replace fly basigin. To determine what regions of the basigin protein are required for each of these functions, we have created mutant basigin transgenes coding for proteins that are altered in conserved residues, introduced these into the fly genome, and tested them for their ability to rescue both photoreceptor cell structure defects and neuron-glia interaction defects of basigin. The results suggest that the highly conserved transmembrane domain and the extracellular domains are crucial for basigin function in the visual system while the short intracellular tail may not play a role in these functions. PMID:19782733

Data and animal management software for large-scale phenotype screening.

PubMed

Ching, Keith A; Cooke, Michael P; Tarantino, Lisa M; Lapp, Hilmar

2006-04-01

The mouse N-ethyl-N-nitrosourea (ENU) mutagenesis program at the Genomics Institute of the Novartis Research Foundation (GNF) uses MouseTRACS to analyze phenotype screens and manage animal husbandry. MouseTRACS is a Web-based laboratory informatics system that electronically records and organizes mouse colony operations, prints cage cards, tracks inventory, manages requests, and reports Institutional Animal Care and Use Committee (IACUC) protocol usage. For efficient phenotype screening, MouseTRACS identifies mutants, visualizes data, and maps mutations. It displays and integrates phenotype and genotype data using likelihood odds ratio (LOD) plots of genetic linkage between genotype and phenotype. More detailed mapping intervals show individual single nucleotide polymorphism (SNP) markers in the context of phenotype. In addition, dynamically generated pedigree diagrams and inventory reports linked to screening results summarize the inheritance pattern and the degree of penetrance. MouseTRACS displays screening data in tables and uses standard charts such as box plots, histograms, scatter plots, and customized charts looking at clustered mice or cross pedigree comparisons. In summary, MouseTRACS enables the efficient screening, analysis, and management of thousands of animals to find mutant mice and identify novel gene functions. MouseTRACS is available under an open source license at http://www.mousetracs.sourceforge.net.

Optical Histology: High-Resolution Visualization of Tissue Microvasculature

NASA Astrophysics Data System (ADS)

Moy, Austin Jing-Ming

Mammalian tissue requires the delivery of nutrients, growth factors, and the exchange of oxygen and carbon dioxide gases to maintain normal function. These elements are delivered by the blood, which travels through the connected network of blood vessels, known as the vascular system. The vascular system consists of large feeder blood vessels (arteries and veins) that are connected to the small blood vessels (arterioles and venules), which in turn are connected to the capillaries that are directly connected to the tissue and facilitate gas exchange and nutrient delivery. These small blood vessels and capillaries make up an intricate but organized network of blood vessels that exist in all mammalian tissues known as the microvasculature and are very important in maintaining the health and proper function of mammalian tissue. Due to the importance of the microvasculature in tissue survival, disruption of the microvasculature typically leads to tissue dysfunction and tissue death. The most prevalent method to study the microvasculature is visualization. Immunohistochemistry (IHC) is the gold-standard method to visualize tissue microvasculature. IHC is very well-suited for highly detailed interrogation of the tissue microvasculature at the cellular level but is unwieldy and impractical for wide-field visualization of the tissue microvasculature. The objective my dissertation research was to develop a method to enable wide-field visualization of the microvasculature, while still retaining the high-resolution afforded by optical microscopy. My efforts led to the development of a technique dubbed "optical histology" that combines chemical and optical methods to enable high-resolution visualization of the microvasculature. The development of the technique first involved preliminary studies to quantify optical property changes in optically cleared tissues, followed by development and demonstration of the methodology. Using optical histology, I successfully obtained high resolution, depth sectioned images of the microvasculature in mouse brain and the coronary microvasculature in mouse heart. Future directions of optical histology include the potential to facilitate visualization of the entire microvascular structure of an organ as well as visualization of other tissue molecular markers of interest.

Local Diversity and Fine-Scale Organization of Receptive Fields in Mouse Visual Cortex

PubMed Central

Histed, Mark H.; Yurgenson, Sergey

2011-01-01

Many thousands of cortical neurons are activated by any single sensory stimulus, but the organization of these populations is poorly understood. For example, are neurons in mouse visual cortex—whose preferred orientations are arranged randomly—organized with respect to other response properties? Using high-speed in vivo two-photon calcium imaging, we characterized the receptive fields of up to 100 excitatory and inhibitory neurons in a 200 μm imaged plane. Inhibitory neurons had nonlinearly summating, complex-like receptive fields and were weakly tuned for orientation. Excitatory neurons had linear, simple receptive fields that can be studied with noise stimuli and system identification methods. We developed a wavelet stimulus that evoked rich population responses and yielded the detailed spatial receptive fields of most excitatory neurons in a plane. Receptive fields and visual responses were locally highly diverse, with nearby neurons having largely dissimilar receptive fields and response time courses. Receptive-field diversity was consistent with a nearly random sampling of orientation, spatial phase, and retinotopic position. Retinotopic positions varied locally on average by approximately half the receptive-field size. Nonetheless, the retinotopic progression across the cortex could be demonstrated at the scale of 100 μm, with a magnification of ∼10 μm/°. Receptive-field and response similarity were in register, decreasing by 50% over a distance of 200 μm. Together, the results indicate considerable randomness in local populations of mouse visual cortical neurons, with retinotopy as the principal source of organization at the scale of hundreds of micrometers. PMID:22171051

Mouse Models as Tools to Identify Genetic Pathways for Retinal Degeneration, as Exemplified by Leber's Congenital Amaurosis.

PubMed

Chang, Bo

2016-01-01

Leber's congenital amaurosis (LCA) is an inherited retinal degenerative disease characterized by severe loss of vision in the first year of life. In addition to early vision loss, a variety of other eye-related abnormalities including roving eye movements, deep-set eyes, and sensitivity to bright light also occur with this disease. Many animal models of LCA are available and the study them has led to a better understanding of the pathology of the disease, and has led to the development of therapeutic strategies aimed at curing or slowing down LCA. Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human LCA. Such mice provide reproducible, experimental systems for elucidating pathways of normal development, function, designing strategies and testing compounds for translational research and gene-based therapies aimed at delaying the diseases progression. In this chapter, I describe tools used in the discovery and evaluation of mouse models of LCA including a Phoenix Image-Guided Optical Coherence Tomography (OCT) and a Diagnosys Espion Visual Electrophysiology System. Three mouse models are described, the rd3 mouse model for LCA12 and LCA1, the rd12 mouse model for LCA2, and the rd16 mouse model for LCA10.

Vision drives accurate approach behavior during prey capture in laboratory mice

PubMed Central

Hoy, Jennifer L.; Yavorska, Iryna; Wehr, Michael; Niell, Cristopher M.

2016-01-01

Summary The ability to genetically identify and manipulate neural circuits in the mouse is rapidly advancing our understanding of visual processing in the mammalian brain [1,2]. However, studies investigating the circuitry that underlies complex ethologically-relevant visual behaviors in the mouse have been primarily restricted to fear responses [3–5]. Here, we show that a laboratory strain of mouse (Mus musculus, C57BL/6J) robustly pursues, captures and consumes live insect prey, and that vision is necessary for mice to perform the accurate orienting and approach behaviors leading to capture. Specifically, we differentially perturbed visual or auditory input in mice and determined that visual input is required for accurate approach, allowing maintenance of bearing to within 11 degrees of the target on average during pursuit. While mice were able to capture prey without vision, the accuracy of their approaches and capture rate dramatically declined. To better explore the contribution of vision to this behavior, we developed a simple assay that isolated visual cues and simplified analysis of the visually guided approach. Together, our results demonstrate that laboratory mice are capable of exhibiting dynamic and accurate visually-guided approach behaviors, and provide a means to estimate the visual features that drive behavior within an ethological context. PMID:27773567

View-Dependent Streamline Deformation and Exploration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tong, Xin; Edwards, John; Chen, Chun-Ming

Occlusion presents a major challenge in visualizing 3D flow and tensor fields using streamlines. Displaying too many streamlines creates a dense visualization filled with occluded structures, but displaying too few streams risks losing important features. We propose a new streamline exploration approach by visually manipulating the cluttered streamlines by pulling visible layers apart and revealing the hidden structures underneath. This paper presents a customized view-dependent deformation algorithm and an interactive visualization tool to minimize visual cluttering for visualizing 3D vector and tensor fields. The algorithm is able to maintain the overall integrity of the fields and expose previously hidden structures.more » Our system supports both mouse and direct-touch interactions to manipulate the viewing perspectives and visualize the streamlines in depth. By using a lens metaphor of different shapes to select the transition zone of the targeted area interactively, the users can move their focus and examine the vector or tensor field freely.« less

Eye-movements and Voice as Interface Modalities to Computer Systems

NASA Astrophysics Data System (ADS)

Farid, Mohsen M.; Murtagh, Fionn D.

2003-03-01

We investigate the visual and vocal modalities of interaction with computer systems. We focus our attention on the integration of visual and vocal interface as possible replacement and/or additional modalities to enhance human-computer interaction. We present a new framework for employing eye gaze as a modality of interface. While voice commands, as means of interaction with computers, have been around for a number of years, integration of both the vocal interface and the visual interface, in terms of detecting user's eye movements through an eye-tracking device, is novel and promises to open the horizons for new applications where a hand-mouse interface provides little or no apparent support to the task to be accomplished. We present an array of applications to illustrate the new framework and eye-voice integration.

View-Dependent Streamline Deformation and Exploration

PubMed Central

Tong, Xin; Edwards, John; Chen, Chun-Ming; Shen, Han-Wei; Johnson, Chris R.; Wong, Pak Chung

2016-01-01

Occlusion presents a major challenge in visualizing 3D flow and tensor fields using streamlines. Displaying too many streamlines creates a dense visualization filled with occluded structures, but displaying too few streams risks losing important features. We propose a new streamline exploration approach by visually manipulating the cluttered streamlines by pulling visible layers apart and revealing the hidden structures underneath. This paper presents a customized view-dependent deformation algorithm and an interactive visualization tool to minimize visual clutter in 3D vector and tensor fields. The algorithm is able to maintain the overall integrity of the fields and expose previously hidden structures. Our system supports both mouse and direct-touch interactions to manipulate the viewing perspectives and visualize the streamlines in depth. By using a lens metaphor of different shapes to select the transition zone of the targeted area interactively, the users can move their focus and examine the vector or tensor field freely. PMID:26600061

View-Dependent Streamline Deformation and Exploration.

PubMed

Tong, Xin; Edwards, John; Chen, Chun-Ming; Shen, Han-Wei; Johnson, Chris R; Wong, Pak Chung

2016-07-01

Occlusion presents a major challenge in visualizing 3D flow and tensor fields using streamlines. Displaying too many streamlines creates a dense visualization filled with occluded structures, but displaying too few streams risks losing important features. We propose a new streamline exploration approach by visually manipulating the cluttered streamlines by pulling visible layers apart and revealing the hidden structures underneath. This paper presents a customized view-dependent deformation algorithm and an interactive visualization tool to minimize visual clutter in 3D vector and tensor fields. The algorithm is able to maintain the overall integrity of the fields and expose previously hidden structures. Our system supports both mouse and direct-touch interactions to manipulate the viewing perspectives and visualize the streamlines in depth. By using a lens metaphor of different shapes to select the transition zone of the targeted area interactively, the users can move their focus and examine the vector or tensor field freely.

Visual cortical areas of the mouse: comparison of parcellation and network structure with primates

PubMed Central

Laramée, Marie-Eve; Boire, Denis

2015-01-01

Brains have evolved to optimize sensory processing. In primates, complex cognitive tasks must be executed and evolution led to the development of large brains with many cortical areas. Rodents do not accomplish cognitive tasks of the same level of complexity as primates and remain with small brains both in relative and absolute terms. But is a small brain necessarily a simple brain? In this review, several aspects of the visual cortical networks have been compared between rodents and primates. The visual system has been used as a model to evaluate the level of complexity of the cortical circuits at the anatomical and functional levels. The evolutionary constraints are first presented in order to appreciate the rules for the development of the brain and its underlying circuits. The organization of sensory pathways, with their parallel and cross-modal circuits, is also examined. Other features of brain networks, often considered as imposing constraints on the development of underlying circuitry, are also discussed and their effect on the complexity of the mouse and primate brain are inspected. In this review, we discuss the common features of cortical circuits in mice and primates and see how these can be useful in understanding visual processing in these animals. PMID:25620914

Visual cortical areas of the mouse: comparison of parcellation and network structure with primates.

PubMed

Laramée, Marie-Eve; Boire, Denis

2014-01-01

Brains have evolved to optimize sensory processing. In primates, complex cognitive tasks must be executed and evolution led to the development of large brains with many cortical areas. Rodents do not accomplish cognitive tasks of the same level of complexity as primates and remain with small brains both in relative and absolute terms. But is a small brain necessarily a simple brain? In this review, several aspects of the visual cortical networks have been compared between rodents and primates. The visual system has been used as a model to evaluate the level of complexity of the cortical circuits at the anatomical and functional levels. The evolutionary constraints are first presented in order to appreciate the rules for the development of the brain and its underlying circuits. The organization of sensory pathways, with their parallel and cross-modal circuits, is also examined. Other features of brain networks, often considered as imposing constraints on the development of underlying circuitry, are also discussed and their effect on the complexity of the mouse and primate brain are inspected. In this review, we discuss the common features of cortical circuits in mice and primates and see how these can be useful in understanding visual processing in these animals.

Clinical evaluation of wireless inductive tongue computer interface for control of computers and assistive devices.

PubMed

Lontis, Eugen R; Lund, Morten E; Christensen, Henrik V; Bentsen, Bo; Gaihede, Michael; Caltenco, Hector A; Andreasen Struijk, Lotte N S

2010-01-01

Typing performance of a full alphabet keyboard and a joystick type of mouse (with on-screen keyboard) provided by a wireless integrated tongue control system (TCS) has been investigated. The speed and accuracy have been measured in a form of a throughput defining the true correct words per minute [cwpm]. Training character sequences were typed in a dedicated interface that provided visual feedback of activated sensors, a map of the alphabet associated, and the task character. Testing sentences were typed in Word, with limited visual feedback, using non-predictive typing (map of characters in alphabetic order associated to sensors) and predictive typing (LetterWise) for TCS keyboard, and non-predictive typing for TCS mouse. Two subjects participated for four and three consecutive days, respectively, two sessions per day. Maximal throughput of 2.94, 2.46, and 2.06, 1.68 [cwpm] were obtained with TCS keyboard by subject 1 and 2 with predictive and non-predictive typing respectively. Maximal throughput of 2.09 and 1.71 [cwpm] was obtained with TCS mouse by subject 1 and 2, respectively. Same experimental protocol has been planned for a larger number of subjects.

High quality optical microangiography of ocular microcirculation and measurement of total retinal blood flow in mouse eye

NASA Astrophysics Data System (ADS)

Zhi, Zhongwei; Yin, Xin; Dziennis, Suzan; Alpers, Charles E.; Wang, Ruikang K.

2013-03-01

Visualization and measurement of retinal blood flow (RBF) is important to the diagnosis and management of different eye diseases, including diabetic retinopathy. Optical microangiography (OMAG) is developed for generating 3D dynamic microcirculation image and later refined into ultra-high sensitive OMAG (UHS-OMAG) for true capillary vessels imaging. Here, we present the application of OMAG imaging technique for visualization of depth-resolved vascular network within retina and choroid as well as measurement of total retinal blood flow in mice. A fast speed spectral domain OCT imaging system at 820nm with a line scan rate of 140 kHz was developed to image mouse posterior eye. By applying UHS-OMAG scanning protocol and processing algorithm, we achieved true capillary level imaging of retina and choroid vasculature in mouse eye. The vascular pattern within different retinal layers and choroid was presented. An en face Doppler OCT approach [1] without knowing Doppler angle was adopted for the measurement of total retinal blood flow. The axial blood flow velocity is measured in an en face plane by raster scanning and the flow is calculated by integrating over the vessel area of the central retinal artery.

Pseudohaptic interaction with knot diagrams

NASA Astrophysics Data System (ADS)

Weng, Jianguang; Zhang, Hui

2012-07-01

To make progress in understanding knot theory, we need to interact with the projected representations of mathematical knots, which are continuous in three dimensions (3-D) but significantly interrupted in the projective images. One way to achieve such a goal is to design an interactive system that allows us to sketch two-dimensional (2-D) knot diagrams by taking advantage of a collision-sensing controller and explore their underlying smooth structures through a continuous motion. Recent advances of interaction techniques have been made that allow progress in this direction. Pseudohaptics that simulate haptic effects using pure visual feedback can be used to develop such an interactive system. We outline one such pseudohaptic knot diagram interface. Our interface derives from the familiar pencil-and-paper process of drawing 2-D knot diagrams and provides haptic-like sensations to facilitate the creation and exploration of knot diagrams. A centerpiece of the interaction model simulates a physically reactive mouse cursor, which is exploited to resolve the apparent conflict between the continuous structure of the actual smooth knot and the visual discontinuities in the knot diagram representation. Another value in exploiting pseudohaptics is that an acceleration (or deceleration) of the mouse cursor (or surface locator) can be used to indicate the slope of the curve (or surface) of which the projective image is being explored. By exploiting these additional visual cues, we proceed to a full-featured extension to a pseudohaptic four-dimensional (4-D) visualization system that simulates the continuous navigation on 4-D objects and allows us to sense the bumps and holes in the fourth dimension. Preliminary tests of the software show that main features of the interface overcome some expected perceptual limitations in our interaction with 2-D knot diagrams of 3-D knots and 3-D projective images of 4-D mathematical objects.

A Subtype-Specific Critical Period for Neurogenesis in the Postnatal Development of Mouse Olfactory Glomeruli

PubMed Central

Ito, Keishi; Arakawa, Sousuke; Murakami, Shingo; Sawamoto, Kazunobu

2012-01-01

Sensory input is essential for the normal development of sensory centers in the brain, such as the somatosensory, visual, auditory, and olfactory systems. Visual deprivation during a specific developmental stage, called the critical period, results in severe and irreversible functional impairments in the primary visual cortex. Olfactory deprivation in the early postnatal period also causes significant developmental defects in the olfactory bulb, the primary center for olfaction. Olfactory bulb interneurons are continuously generated from neural stem cells in the ventricular-subventricular zone, suggesting that the olfactory system has plasticity even in adulthood. Here, we investigated the effect of transient neonatal olfactory deprivation on the addition of interneurons to the glomerular layer of the adult mouse olfactory bulb. We found that the addition of one subtype of interneurons was persistently inhibited even after reopening the naris. BrdU pulse-chase experiments revealed that the neonatal olfactory deprivation predominantly affected an early phase in the maturation of this neuronal subtype in the olfactory bulb. Subjecting the mice to odor stimulation for 6 weeks after naris reopening resulted in significant recovery from the histological and functional defects caused by the olfactory deprivation. These results suggest that a subtype-specific critical period exists for olfactory bulb neurogenesis, but that this period is less strict and more plastic compared with the critical periods for other systems. This study provides new insights into the mechanisms of postnatal neurogenesis and a biological basis for the therapeutic effect of olfactory training. PMID:23133633

The structure of pairwise correlation in mouse primary visual cortex reveals functional organization in the absence of an orientation map.

PubMed

Denman, Daniel J; Contreras, Diego

2014-10-01

Neural responses to sensory stimuli are not independent. Pairwise correlation can reduce coding efficiency, occur independent of stimulus representation, or serve as an additional channel of information, depending on the timescale of correlation and the method of decoding. Any role for correlation depends on its magnitude and structure. In sensory areas with maps, like the orientation map in primary visual cortex (V1), correlation is strongly related to the underlying functional architecture, but it is unclear whether this correlation structure is an essential feature of the system or arises from the arrangement of cells in the map. We assessed the relationship between functional architecture and pairwise correlation by measuring both synchrony and correlated spike count variability in mouse V1, which lacks an orientation map. We observed significant pairwise synchrony, which was organized by distance and relative orientation preference between cells. We also observed nonzero correlated variability in both the anesthetized (0.16) and awake states (0.18). Our results indicate that the structure of pairwise correlation is maintained in the absence of an underlying anatomical organization and may be an organizing principle of the mammalian visual system preserved by nonrandom connectivity within local networks. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

An Efficient and Versatile System for Visualization and Genetic Modification of Dopaminergic Neurons in Transgenic Mice

PubMed Central

Kramer, Edgar R.

2015-01-01

Background & Aims The brain dopaminergic (DA) system is involved in fine tuning many behaviors and several human diseases are associated with pathological alterations of the DA system such as Parkinson’s disease (PD) and drug addiction. Because of its complex network integration, detailed analyses of physiological and pathophysiological conditions are only possible in a whole organism with a sophisticated tool box for visualization and functional modification. Methods & Results Here, we have generated transgenic mice expressing the tetracycline-regulated transactivator (tTA) or the reverse tetracycline-regulated transactivator (rtTA) under control of the tyrosine hydroxylase (TH) promoter, TH-tTA (tet-OFF) and TH-rtTA (tet-ON) mice, to visualize and genetically modify DA neurons. We show their tight regulation and efficient use to overexpress proteins under the control of tet-responsive elements or to delete genes of interest with tet-responsive Cre. In combination with mice encoding tet-responsive luciferase, we visualized the DA system in living mice progressively over time. Conclusion These experiments establish TH-tTA and TH-rtTA mice as a powerful tool to generate and monitor mouse models for DA system diseases. PMID:26291828

Integrating model behavior, optimization, and sensitivity/uncertainty analysis: overview and application of the MOUSE software toolbox

USDA-ARS?s Scientific Manuscript database

This paper provides an overview of the Model Optimization, Uncertainty, and SEnsitivity Analysis (MOUSE) software application, an open-source, Java-based toolbox of visual and numerical analysis components for the evaluation of environmental models. MOUSE is based on the OPTAS model calibration syst...

Rapid innate defensive responses of mice to looming visual stimuli.

PubMed

Yilmaz, Melis; Meister, Markus

2013-10-21

Much of brain science is concerned with understanding the neural circuits that underlie specific behaviors. While the mouse has become a favorite experimental subject, the behaviors of this species are still poorly explored. For example, the mouse retina, like that of other mammals, contains ∼20 different circuits that compute distinct features of the visual scene [1, 2]. By comparison, only a handful of innate visual behaviors are known in this species--the pupil reflex [3], phototaxis [4], the optomotor response [5], and the cliff response [6]--two of which are simple reflexes that require little visual processing. We explored the behavior of mice under a visual display that simulates an approaching object, which causes defensive reactions in some other species [7, 8]. We show that mice respond to this stimulus either by initiating escape within a second or by freezing for an extended period. The probability of these defensive behaviors is strongly dependent on the parameters of the visual stimulus. Directed experiments identify candidate retinal circuits underlying the behavior and lead the way into detailed study of these neural pathways. This response is a new addition to the repertoire of innate defensive behaviors in the mouse that allows the detection and avoidance of aerial predators. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mapping arealisation of the visual cortex of non-primate species: lessons for development and evolution

PubMed Central

Homman-Ludiye, Jihane; Bourne, James A.

2014-01-01

The integration of the visual stimulus takes place at the level of the neocortex, organized in anatomically distinct and functionally unique areas. Primates, including humans, are heavily dependent on vision, with approximately 50% of their neocortical surface dedicated to visual processing and possess many more visual areas than any other mammal, making them the model of choice to study visual cortical arealisation. However, in order to identify the mechanisms responsible for patterning the developing neocortex, specifying area identity as well as elucidate events that have enabled the evolution of the complex primate visual cortex, it is essential to gain access to the cortical maps of alternative species. To this end, species including the mouse have driven the identification of cellular markers, which possess an area-specific expression profile, the development of new tools to label connections and technological advance in imaging techniques enabling monitoring of cortical activity in a behaving animal. In this review we present non-primate species that have contributed to elucidating the evolution and development of the visual cortex. We describe the current understanding of the mechanisms supporting the establishment of areal borders during development, mainly gained in the mouse thanks to the availability of genetically modified lines but also the limitations of the mouse model and the need for alternate species. PMID:25071460

Orientation selectivity of synaptic input to neurons in mouse and cat primary visual cortex.

PubMed

Tan, Andrew Y Y; Brown, Brandon D; Scholl, Benjamin; Mohanty, Deepankar; Priebe, Nicholas J

2011-08-24

Primary visual cortex (V1) is the site at which orientation selectivity emerges in mammals: visual thalamus afferents to V1 respond equally to all stimulus orientations, whereas their target V1 neurons respond selectively to stimulus orientation. The emergence of orientation selectivity in V1 has long served as a model for investigating cortical computation. Recent evidence for orientation selectivity in mouse V1 opens cortical computation to dissection by genetic and imaging tools, but also raises two essential questions: (1) How does orientation selectivity in mouse V1 neurons compare with that in previously described species? (2) What is the synaptic basis for orientation selectivity in mouse V1? A comparison of orientation selectivity in mouse and in cat, where such measures have traditionally been made, reveals that orientation selectivity in mouse V1 is weaker than in cat V1, but that spike threshold plays a similar role in narrowing selectivity between membrane potential and spike rate. To uncover the synaptic basis for orientation selectivity, we made whole-cell recordings in vivo from mouse V1 neurons, comparing neuronal input selectivity-based on membrane potential, synaptic excitation, and synaptic inhibition-to output selectivity based on spiking. We found that a neuron's excitatory and inhibitory inputs are selective for the same stimulus orientations as is its membrane potential response, and that inhibitory selectivity is not broader than excitatory selectivity. Inhibition has different dynamics than excitation, adapting more rapidly. In neurons with temporally modulated responses, the timing of excitation and inhibition was different in mice and cats.

Orientation Selectivity of Synaptic Input to Neurons in Mouse and Cat Primary Visual Cortex

PubMed Central

Tan (陈勇毅), Andrew Y. Y.; Brown, Brandon D.; Scholl, Benjamin; Mohanty, Deepankar; Priebe, Nicholas J.

2011-01-01

Primary visual cortex (V1) is the site at which orientation selectivity emerges in mammals: visual thalamus afferents to V1 respond equally to all stimulus orientations whereas their target V1 neurons respond selectively to stimulus orientation. The emergence of orientation selectivity in V1 has long served as a model for investigating cortical computation. Recent evidence for orientation selectivity in mouse V1 opens cortical computation to dissection by genetic and imaging tools, but also raises two essential questions: 1) how does orientation selectivity in mouse V1 neurons compare with that in previously described species? 2) what is the synaptic basis for orientation selectivity in mouse V1? A comparison of orientation selectivity in mouse and in cat, where such measures have traditionally been made, reveals that orientation selectivity in mouse V1 is weaker than in cat V1, but that spike threshold plays a similar role in narrowing selectivity between membrane potential and spike rate. To uncover the synaptic basis for orientation selectivity, we made whole-cell recordings in vivo from mouse V1 neurons, comparing neuronal input selectivity - based on membrane potential, synaptic excitation, and synaptic inhibition - to output selectivity based on spiking. We found that a neuron's excitatory and inhibitory inputs are selective for the same stimulus orientations as is its membrane potential response, and that inhibitory selectivity is not broader than excitatory selectivity. Inhibition has different dynamics than excitation, adapting more rapidly. In neurons with temporally modulated responses, the timing of excitation and inhibition was different in mice and cats. PMID:21865476

Low cost light-sheet microscopy for whole brain imaging

NASA Astrophysics Data System (ADS)

Kumar, Manish; Nasenbeny, Jordan; Kozorovitskiy, Yevgenia

2018-02-01

Light-sheet microscopy has evolved as an indispensable tool in imaging biological samples. It can image 3D samples at fast speed, with high-resolution optical sectioning, and with reduced photobleaching effects. These properties make light-sheet microscopy ideal for imaging fluorophores in a variety of biological samples and organisms, e.g. zebrafish, drosophila, cleared mouse brains, etc. While most commercial turnkey light-sheet systems are expensive, the existing lower cost implementations, e.g. OpenSPIM, are focused on achieving high-resolution imaging of small samples or organisms like zebrafish. In this work, we substantially reduce the cost of light-sheet microscope system while targeting to image much larger samples, i.e. cleared mouse brains, at single-cell resolution. The expensive components of a lightsheet system - excitation laser, water-immersion objectives, and translation stage - are replaced with an incoherent laser diode, dry objectives, and a custom-built Arduino-controlled translation stage. A low-cost CUBIC protocol is used to clear fixed mouse brain samples. The open-source platforms of μManager and Fiji support image acquisition, processing, and visualization. Our system can easily be extended to multi-color light-sheet microscopy.

Rotational imaging optical coherence tomography for full-body mouse embryonic imaging

PubMed Central

Wu, Chen; Sudheendran, Narendran; Singh, Manmohan; Larina, Irina V.; Dickinson, Mary E.; Larin, Kirill V.

2016-01-01

Abstract. Optical coherence tomography (OCT) has been widely used to study mammalian embryonic development with the advantages of high spatial and temporal resolutions and without the need for any contrast enhancement probes. However, the limited imaging depth of traditional OCT might prohibit visualization of the full embryonic body. To overcome this limitation, we have developed a new methodology to enhance the imaging range of OCT in embryonic day (E) 9.5 and 10.5 mouse embryos using rotational imaging. Rotational imaging OCT (RI-OCT) enables full-body imaging of mouse embryos by performing multiangle imaging. A series of postprocessing procedures was performed on each cross-section image, resulting in the final composited image. The results demonstrate that RI-OCT is able to improve the visualization of internal mouse embryo structures as compared to conventional OCT. PMID:26848543

Photoacoustic imaging of lymphatic pumping

NASA Astrophysics Data System (ADS)

Forbrich, Alex; Heinmiller, Andrew; Zemp, Roger J.

2017-10-01

The lymphatic system is responsible for fluid homeostasis and immune cell trafficking and has been implicated in several diseases, including obesity, diabetes, and cancer metastasis. Despite its importance, the lack of suitable in vivo imaging techniques has hampered our understanding of the lymphatic system. This is, in part, due to the limited contrast of lymphatic fluids and structures. Photoacoustic imaging, in combination with optically absorbing dyes or nanoparticles, has great potential for noninvasively visualizing the lymphatic vessels deep in tissues. Multispectral photoacoustic imaging is capable of separating the components; however, the slow wavelength switching speed of most laser systems is inadequate for imaging lymphatic pumping without motion artifacts being introduced into the processed images. We investigate two approaches for visualizing lymphatic processes in vivo. First, single-wavelength differential photoacoustic imaging is used to visualize lymphatic pumping in the hindlimb of a mouse in real time. Second, a fast-switching multiwavelength photoacoustic imaging system was used to assess the propulsion profile of dyes through the lymphatics in real time. These approaches may have profound impacts in noninvasively characterizing and investigating the lymphatic system.

What can mice tell us about how vision works?

PubMed Central

Huberman, Andrew D.; Niell, Cristopher M.

2012-01-01

Understanding the neural basis of visual perception is a longstanding fundamental goal of neuroscience. Historically, most vision studies were carried out on humans, macaque monkeys and cats. Over the last five years, however, a growing number of researchers have begun using mice to parse the mechanisms underlying visual processing- the rationale is that despite having relatively poor acuity, mice are unmatched in terms of the variety and sophistication of tools available to label, monitor and manipulate specific cell types and circuits. In this review, we discuss recent advances in understanding the mouse visual system at the anatomical, receptive field and perceptual level, focusing on the opportunities and constraints those features provide toward the goal of understanding how vision works. PMID:21840069

Visual pigment coexpression in all cones of two rodents, the Siberian hamster, and the pouched mouse.

PubMed

Lukáts, Akos; Dkhissi-Benyahya, Ouria; Szepessy, Zsuzsanna; Röhlich, Pál; Vígh, Béla; Bennett, Nigel C; Cooper, Howard M; Szél, Agoston

2002-07-01

To decide whether the identical topography of short- and middle-wavelength cone photoreceptors in two species of rodents reflects the presence of both opsins in all cone cells. Double-label immunocytochemistry using antibodies directed against short-wavelength (S)-and middle- to long-wavelength (M/L)-sensitive opsin were used to determine the presence of visual pigments in cones of two species of rodents, the Siberian hamster (Phodopus sungorus) and the pouched mouse (Saccostomus campestris) from South Africa. Topographical distribution was determined from retinal whole-mounts, and the colocalization of visual pigments was examined using confocal laser scanning microscopy. Opsin colocalization was also confirmed in consecutive semithin tangential sections. The immunocytochemical results demonstrate that in both the Siberian hamster and the pouched mouse all retinal cones contain two visual pigments. No dorsoventral gradient in the differential expression of the two opsins is observed. The retina of the Siberian hamster and the pouched mouse is the first example to show a uniform coexpression of M and S cone opsins in all cones, without any topographical gradient in opsin expression. This finding makes these two species good models for the study of molecular control mechanisms in opsin coexpression in rodents, and renders them suitable as sources of dual cones for future investigations on the role and neural connections of this cone type.

Hybrid Antibody-Induced Topographical Redistribution of Surface Immunoglobulins, Alloantigens, and Concanavalin A Receptors on Mouse Lymphoid Cells

PubMed Central

Stackpole, Christopher W.; De Milio, Lawrence T.; Hämmerling, Ulrich; Jacobson, Janet B.; Lardis, Michael P.

1974-01-01

Redistribution of surface immunoglobulins, H-2b, Thy-1.2, and TL.1,2,3 alloantigens, and concanavalin A receptors on mouse lymphoid cells induced by hybrid rabbit F(ab′)2 antibody (anti-mouse immunoglobulin/anti-visual marker or anti-concanavalin A/anti-visual marker) was studied by immunofluorescence. When used directly to label surface immunoglobulin, and indirectly to label alloantigens and concanavalin A receptors, hybrid antibodies induced similar displacement of all surface components from a uniform distribution into “patches” and “caps” at 37°. One hybrid antibody preparation, antimouse immunoglobulin/anti-ferritin, contained negligible amounts of bivalent anti-mouse immunoglobulin antibody, and was therefore “monovalent” for the antimouse immunoglobulin specificity. This observation suggests that factors other than multivalent crosslinking are responsible for hybrid antibody-induced redistribution of cell-surface components. Cap formation induced by hybrid antibody was enhanced markedly by attachment of the visual marker, either ferritin or southern bean mosaic virus, at 37°. At -5°, hybrid antibody does not displace uniformly distributed H-2b alloantigen-alloantibody complexes, but patches of label develop when ferritin attaches to the hybrid antibody. These results explain the patchy distribution of cell-surface components, which is a temperature-independent characteristic of labeling with hybrid antibodies and visual markers for electron microscopy. Images PMID:4595577

Preparation of Murine Submandibular Salivary Gland for Upright Intravital Microscopy.

PubMed

Ficht, Xenia; Thelen, Flavian; Stolp, Bettina; Stein, Jens V

2018-05-07

The submandibular salivary gland (SMG) is one of the three major salivary glands, and is of interest for many different fields of biological research, including cell biology, oncology, dentistry, and immunology. The SMG is an exocrine gland comprised of secretory epithelial cells, myofibroblasts, endothelial cells, nerves, and extracellular matrix. Dynamic cellular processes in the rat and mouse SMG have previously been imaged, mostly using inverted multi-photon microscope systems. Here, we describe a straightforward protocol for the surgical preparation and stabilization of the murine SMG in anesthetized mice for in vivo imaging with upright multi-photon microscope systems. We present representative intravital image sets of endogenous and adoptively transferred fluorescent cells, including the labeling of blood vessels or salivary ducts and second harmonic generation to visualize fibrillar collagen. In sum, our protocol allows for surgical preparation of mouse salivary glands in upright microscopy systems, which are commonly used for intravital imaging in the field of immunology.

Visual Processing: Hungry Like the Mouse.

PubMed

Piscopo, Denise M; Niell, Cristopher M

2016-09-07

In this issue of Neuron, Burgess et al. (2016) explore how motivational state interacts with visual processing, by examining hunger modulation of food-associated visual responses in postrhinal cortical neurons and their inputs from amygdala. Copyright © 2016 Elsevier Inc. All rights reserved.

MONICA: A Compact, Portable Dual Gamma Camera System for Mouse Whole-Body Imaging

PubMed Central

Xi, Wenze; Seidel, Jurgen; Karkareka, John W.; Pohida, Thomas J.; Milenic, Diane E.; Proffitt, James; Majewski, Stan; Weisenberger, Andrew G.; Green, Michael V.; Choyke, Peter L.

2009-01-01

Introduction We describe a compact, portable dual-gamma camera system (named “MONICA” for MObile Nuclear Imaging CAmeras) for visualizing and analyzing the whole-body biodistribution of putative diagnostic and therapeutic single photon emitting radiotracers in animals the size of mice. Methods Two identical, miniature pixelated NaI(Tl) gamma cameras were fabricated and installed “looking up” through the tabletop of a compact portable cart. Mice are placed directly on the tabletop for imaging. Camera imaging performance was evaluated with phantoms and field performance was evaluated in a weeklong In-111 imaging study performed in a mouse tumor xenograft model. Results Tc-99m performance measurements, using a photopeak energy window of 140 keV ± 10%, yielded the following results: spatial resolution (FWHM at 1-cm), 2.2-mm; sensitivity, 149 cps/MBq (5.5 cps/μCi); energy resolution (FWHM), 10.8%; count rate linearity (count rate vs. activity), r2 = 0.99 for 0–185 MBq (0–5 mCi) in the field-of-view (FOV); spatial uniformity, < 3% count rate variation across the FOV. Tumor and whole-body distributions of the In-111 agent were well visualized in all animals in 5-minute images acquired throughout the 168-hour study period. Conclusion Performance measurements indicate that MONICA is well suited to whole-body single photon mouse imaging. The field study suggests that inter-device communications and user-oriented interfaces included in the MONICA design facilitate use of the system in practice. We believe that MONICA may be particularly useful early in the (cancer) drug development cycle where basic whole-body biodistribution data can direct future development of the agent under study and where logistical factors, e.g. limited imaging space, portability, and, potentially, cost are important. PMID:20346864

Mouse auditory cortex differs from visual and somatosensory cortices in the laminar distribution of cytochrome oxidase and acetylcholinesterase.

PubMed

Anderson, L A; Christianson, G B; Linden, J F

2009-02-03

Cytochrome oxidase (CYO) and acetylcholinesterase (AChE) staining density varies across the cortical layers in many sensory areas. The laminar variations likely reflect differences between the layers in levels of metabolic activity and cholinergic modulation. The question of whether these laminar variations differ between primary sensory cortices has never been systematically addressed in the same set of animals, since most studies of sensory cortex focus on a single sensory modality. Here, we compared the laminar distribution of CYO and AChE activity in the primary auditory, visual, and somatosensory cortices of the mouse, using Nissl-stained sections to define laminar boundaries. Interestingly, for both CYO and AChE, laminar patterns of enzyme activity were similar in the visual and somatosensory cortices, but differed in the auditory cortex. In the visual and somatosensory areas, staining densities for both enzymes were highest in layers III/IV or IV and in lower layer V. In the auditory cortex, CYO activity showed a reliable peak only at the layer III/IV border, while AChE distribution was relatively homogeneous across layers. These results suggest that laminar patterns of metabolic activity and cholinergic influence are similar in the mouse visual and somatosensory cortices, but differ in the auditory cortex.

Angiography reveals novel features of the retinal vasculature in healthy and diabetic mice.

PubMed

McLenachan, Samuel; Magno, Aaron Len; Ramos, David; Catita, Joana; McMenamin, Paul G; Chen, Fred Kuanfu; Rakoczy, Elizabeth Piroska; Ruberte, Jesus

2015-09-01

The mouse retina is a commonly used animal model for the study of pathogenesis and treatment of blinding retinal vascular diseases such as diabetic retinopathy. In this study, we aimed to characterize normal and pathological variations in vascular anatomy in the mouse retina using fluorescein angiography visualized with scanning laser ophthalmoscopy and optical coherence tomography (SLO-OCT). We examined eyes from C57BL/6J wild type mice as well as the Ins2(Akita) and Akimba mouse models of diabetic retinopathy using the Heidelberg Retinal Angiography (HRA) and OCT system. Angiography was performed on three focal planes to examine distinct vascular layers. For comparison with angiographic data, ex vivo analyses, including Indian ink angiography, histology and 3D confocal scanning laser microscopy were performed in parallel. All layers of the mouse retinal vasculature could be readily visualized during fluorescein angiography by SLO-OCT. Blood vessel density was increased in the deep vascular plexus (DVP) compared with the superficial vascular plexus (SVP). Arteriolar and venular typologies were established and structural differences were observed between venular types. Unexpectedly, the hyaloid artery was found to persist in 15% of C57BL/6 mice, forming anastomoses with peripheral retinal capillaries. Fluorescein leakage was easily detected in Akimba retinae by angiography, but was not observed in Ins2(Akita) mice. Blood vessel density was increased in the DVP of 6 month old Ins2(Akita) mice, while the SVP displayed reduced branching in precapillary arterioles. In summary, we present the first comprehensive characterization of the mouse retinal vasculature by SLO-OCT fluorescein angiography. Using this clinical imaging technique, we report previously unrecognized variations in C57BL/6J vascular anatomy and novel features of vascular retinopathy in the Ins2(Akita) mouse model of diabetes. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Thalamocortical Projection Neuron and Interneuron Numbers in the Visual Thalamic Nuclei of the Adult C57BL/6 Mouse.

PubMed

Evangelio, Marian; García-Amado, María; Clascá, Francisco

2018-01-01

A key parameter to constrain predictive, bottom-up circuit models of a given brain domain is the number and position of the neuronal populations involved. These include not only the neurons whose bodies reside within the domain, but also the neurons in distant regions that innervate the domain. The mouse visual cortex receives its main subcortical input from the dorsal lateral geniculate nucleus (dLGN) and the lateral posterior (LP) complex of the thalamus. The latter consists of three different nuclei: lateral posterior lateral (LPL), lateral posterior medial rostral (LPMR), and lateral posterior medial caudal (LPMC), each exhibiting specific patterns of connections with the various visual cortical areas. Here, we have determined the number of thalamocortical projection neurons and interneurons in the LP complex and dLGN of the adult C57BL/6 male mouse. We combined Nissl staining and histochemical and immunolabeling methods for consistently delineating nuclei borders, and applied unbiased stereological cell counting methods. Thalamic interneurons were identified using GABA immunolabeling. The C57BL/6 dLGN contains ∼21,200 neurons, while LP complex contains ∼31,000 total neurons. The dLGN and LP are the only nuclei of the mouse dorsal thalamus containing substantial numbers GABA-immunoreactive interneurons. These interneurons, however, are scarcer than previously estimated; they are 5.6% of dLGN neurons and just 1.9% of the LP neurons. It can be thus inferred that the dLGN contains ∼20,000 and the LP complex ∼30,400 thalamocortical projection neurons (∼12,000 in LPL, 15,200 in LPMR, and 4,200 in LPMC). The present dataset is relevant for constraining models of mouse visual thalamocortical circuits, as well as for quantitative comparisons between genetically modified mouse strains, or across species.

Thalamocortical Projection Neuron and Interneuron Numbers in the Visual Thalamic Nuclei of the Adult C57BL/6 Mouse

PubMed Central

Evangelio, Marian; García-Amado, María; Clascá, Francisco

2018-01-01

A key parameter to constrain predictive, bottom-up circuit models of a given brain domain is the number and position of the neuronal populations involved. These include not only the neurons whose bodies reside within the domain, but also the neurons in distant regions that innervate the domain. The mouse visual cortex receives its main subcortical input from the dorsal lateral geniculate nucleus (dLGN) and the lateral posterior (LP) complex of the thalamus. The latter consists of three different nuclei: lateral posterior lateral (LPL), lateral posterior medial rostral (LPMR), and lateral posterior medial caudal (LPMC), each exhibiting specific patterns of connections with the various visual cortical areas. Here, we have determined the number of thalamocortical projection neurons and interneurons in the LP complex and dLGN of the adult C57BL/6 male mouse. We combined Nissl staining and histochemical and immunolabeling methods for consistently delineating nuclei borders, and applied unbiased stereological cell counting methods. Thalamic interneurons were identified using GABA immunolabeling. The C57BL/6 dLGN contains ∼21,200 neurons, while LP complex contains ∼31,000 total neurons. The dLGN and LP are the only nuclei of the mouse dorsal thalamus containing substantial numbers GABA-immunoreactive interneurons. These interneurons, however, are scarcer than previously estimated; they are 5.6% of dLGN neurons and just 1.9% of the LP neurons. It can be thus inferred that the dLGN contains ∼20,000 and the LP complex ∼30,400 thalamocortical projection neurons (∼12,000 in LPL, 15,200 in LPMR, and 4,200 in LPMC). The present dataset is relevant for constraining models of mouse visual thalamocortical circuits, as well as for quantitative comparisons between genetically modified mouse strains, or across species. PMID:29706872

Emergence of Orientation Selectivity in the Mammalian Visual Pathway

PubMed Central

Scholl, Benjamin; Tan, Andrew Y. Y.; Corey, Joseph

2013-01-01

Orientation selectivity is a property of mammalian primary visual cortex (V1) neurons, yet its emergence along the visual pathway varies across species. In carnivores and primates, elongated receptive fields first appear in V1, whereas in lagomorphs such receptive fields emerge earlier, in the retina. Here we examine the mouse visual pathway and reveal the existence of orientation selectivity in lateral geniculate nucleus (LGN) relay cells. Cortical inactivation does not reduce this orientation selectivity, indicating that cortical feedback is not its source. Orientation selectivity is similar for LGN relay cells spiking and subthreshold input to V1 neurons, suggesting that cortical orientation selectivity is inherited from the LGN in mouse. In contrast, orientation selectivity of cat LGN relay cells is small relative to subthreshold inputs onto V1 simple cells. Together, these differences show that although orientation selectivity exists in visual neurons of both rodents and carnivores, its emergence along the visual pathway, and thus its underlying neuronal circuitry, is fundamentally different. PMID:23804085

Target dependence of orientation and direction selectivity of corticocortical projection neurons in the mouse V1

PubMed Central

Matsui, Teppei; Ohki, Kenichi

2013-01-01

Higher order visual areas that receive input from the primary visual cortex (V1) are specialized for the processing of distinct features of visual information. However, it is still incompletely understood how this functional specialization is acquired. Here we used in vivo two photon calcium imaging in the mouse visual cortex to investigate whether this functional distinction exists at as early as the level of projections from V1 to two higher order visual areas, AL and LM. Specifically, we examined whether sharpness of orientation and direction selectivity and optimal spatial and temporal frequency of projection neurons from V1 to higher order visual areas match with that of target areas. We found that the V1 input to higher order visual areas were indeed functionally distinct: AL preferentially received inputs from V1 that were more orientation and direction selective and tuned for lower spatial frequency compared to projection of V1 to LM, consistent with functional differences between AL and LM. The present findings suggest that selective projections from V1 to higher order visual areas initiates parallel processing of sensory information in the visual cortical network. PMID:24068987

Mouse Cone Photoreceptors Co-express Two Functional Visual Arrestins

PubMed Central

Nikonov, Sergei S.; Brown, Bruce M.; Davis, Jason A.; Zuniga, Freddi I.; Bragin, Alvina; Pugh, Edward N.; Craft, Cheryl M.

2008-01-01

Arrestins are members of a superfamily of proteins that arrest the activity of G-protein coupled receptors. Mouse cone photoreceptors express two visual arrestins, Arr1 and Arr4 (Carr). We quantified their expression levels and subcellular distributions in mouse cones: total Arr1 was estimated to be in an ~ 6:1 ratio to cone opsin, about 50-fold higher than Arr4. Recordings from single cones of Arr1−/− and Arr4−/− mice establish that both proteins are competent to arrest the activity of photoactivated S- and M- cone opsins. Recordings from Arr1−/− , Arr4−/− double-knockout mice establish a requirement for at least one of the two visual arrestins for normal cone opsin inactivation at all flash intensities. These recordings also reveal low activity photoproducts of S- and M-opsins that are absent when Grk1 and an arrestin are co-expressed, but which decay 70-fold more rapidly than the comparable photoproducts of rhodopsin in rods. PMID:18701071

Adaptive-optics SLO imaging combined with widefield OCT and SLO enables precise 3D localization of fluorescent cells in the mouse retina.

PubMed

Zawadzki, Robert J; Zhang, Pengfei; Zam, Azhar; Miller, Eric B; Goswami, Mayank; Wang, Xinlei; Jonnal, Ravi S; Lee, Sang-Hyuck; Kim, Dae Yu; Flannery, John G; Werner, John S; Burns, Marie E; Pugh, Edward N

2015-06-01

Adaptive optics scanning laser ophthalmoscopy (AO-SLO) has recently been used to achieve exquisite subcellular resolution imaging of the mouse retina. Wavefront sensing-based AO typically restricts the field of view to a few degrees of visual angle. As a consequence the relationship between AO-SLO data and larger scale retinal structures and cellular patterns can be difficult to assess. The retinal vasculature affords a large-scale 3D map on which cells and structures can be located during in vivo imaging. Phase-variance OCT (pv-OCT) can efficiently image the vasculature with near-infrared light in a label-free manner, allowing 3D vascular reconstruction with high precision. We combined widefield pv-OCT and SLO imaging with AO-SLO reflection and fluorescence imaging to localize two types of fluorescent cells within the retinal layers: GFP-expressing microglia, the resident macrophages of the retina, and GFP-expressing cone photoreceptor cells. We describe in detail a reflective afocal AO-SLO retinal imaging system designed for high resolution retinal imaging in mice. The optical performance of this instrument is compared to other state-of-the-art AO-based mouse retinal imaging systems. The spatial and temporal resolution of the new AO instrumentation was characterized with angiography of retinal capillaries, including blood-flow velocity analysis. Depth-resolved AO-SLO fluorescent images of microglia and cone photoreceptors are visualized in parallel with 469 nm and 663 nm reflectance images of the microvasculature and other structures. Additional applications of the new instrumentation are discussed.

A pseudo-haptic knot diagram interface

NASA Astrophysics Data System (ADS)

Zhang, Hui; Weng, Jianguang; Hanson, Andrew J.

2011-01-01

To make progress in understanding knot theory, we will need to interact with the projected representations of mathematical knots which are of course continuous in 3D but significantly interrupted in the projective images. One way to achieve such a goal would be to design an interactive system that allows us to sketch 2D knot diagrams by taking advantage of a collision-sensing controller and explore their underlying smooth structures through a continuous motion. Recent advances of interaction techniques have been made that allow progress to be made in this direction. Pseudo-haptics that simulates haptic effects using pure visual feedback can be used to develop such an interactive system. This paper outlines one such pseudo-haptic knot diagram interface. Our interface derives from the familiar pencil-and-paper process of drawing 2D knot diagrams and provides haptic-like sensations to facilitate the creation and exploration of knot diagrams. A centerpiece of the interaction model simulates a "physically" reactive mouse cursor, which is exploited to resolve the apparent conflict between the continuous structure of the actual smooth knot and the visual discontinuities in the knot diagram representation. Another value in exploiting pseudo-haptics is that an acceleration (or deceleration) of the mouse cursor (or surface locator) can be used to indicate the slope of the curve (or surface) of whom the projective image is being explored. By exploiting these additional visual cues, we proceed to a full-featured extension to a pseudo-haptic 4D visualization system that simulates the continuous navigation on 4D objects and allows us to sense the bumps and holes in the fourth dimension. Preliminary tests of the software show that main features of the interface overcome some expected perceptual limitations in our interaction with 2D knot diagrams of 3D knots and 3D projective images of 4D mathematical objects.

Simultaneous submicrometric 3D imaging of the micro-vascular network and the neuronal system in a mouse spinal cord

PubMed Central

Fratini, Michela; Bukreeva, Inna; Campi, Gaetano; Brun, Francesco; Tromba, Giuliana; Modregger, Peter; Bucci, Domenico; Battaglia, Giuseppe; Spanò, Raffaele; Mastrogiacomo, Maddalena; Requardt, Herwig; Giove, Federico; Bravin, Alberto; Cedola, Alessia

2015-01-01

Faults in vascular (VN) and neuronal networks of spinal cord are responsible for serious neurodegenerative pathologies. Because of inadequate investigation tools, the lacking knowledge of the complete fine structure of VN and neuronal system represents a crucial problem. Conventional 2D imaging yields incomplete spatial coverage leading to possible data misinterpretation, whereas standard 3D computed tomography imaging achieves insufficient resolution and contrast. We show that X-ray high-resolution phase-contrast tomography allows the simultaneous visualization of three-dimensional VN and neuronal systems of ex-vivo mouse spinal cord at scales spanning from millimeters to hundreds of nanometers, with nor contrast agent nor sectioning and neither destructive sample-preparation. We image both the 3D distribution of micro-capillary network and the micrometric nerve fibers, axon-bundles and neuron soma. Our approach is very suitable for pre-clinical investigation of neurodegenerative pathologies and spinal-cord-injuries, in particular to resolve the entangled relationship between VN and neuronal system. PMID:25686728

Cortico-fugal output from visual cortex promotes plasticity of innate motor behaviour.

PubMed

Liu, Bao-Hua; Huberman, Andrew D; Scanziani, Massimo

2016-10-20

The mammalian visual cortex massively innervates the brainstem, a phylogenetically older structure, via cortico-fugal axonal projections. Many cortico-fugal projections target brainstem nuclei that mediate innate motor behaviours, but the function of these projections remains poorly understood. A prime example of such behaviours is the optokinetic reflex (OKR), an innate eye movement mediated by the brainstem accessory optic system, that stabilizes images on the retina as the animal moves through the environment and is thus crucial for vision. The OKR is plastic, allowing the amplitude of this reflex to be adaptively adjusted relative to other oculomotor reflexes and thereby ensuring image stability throughout life. Although the plasticity of the OKR is thought to involve subcortical structures such as the cerebellum and vestibular nuclei, cortical lesions have suggested that the visual cortex might also be involved. Here we show that projections from the mouse visual cortex to the accessory optic system promote the adaptive plasticity of the OKR. OKR potentiation, a compensatory plastic increase in the amplitude of the OKR in response to vestibular impairment, is diminished by silencing visual cortex. Furthermore, targeted ablation of a sparse population of cortico-fugal neurons that specifically project to the accessory optic system severely impairs OKR potentiation. Finally, OKR potentiation results from an enhanced drive exerted by the visual cortex onto the accessory optic system. Thus, cortico-fugal projections to the brainstem enable the visual cortex, an area that has been principally studied for its sensory processing function, to plastically adapt the execution of innate motor behaviours.

A mouse model of ocular blast injury that induces closed globe anterior and posterior pole damage

PubMed Central

Hines-Beard, Jessica; Marchetta, Jeffrey; Gordon, Sarah; Chaum, Edward; Geisert, Eldon E.; Rex, Tonia S.

2012-01-01

We developed and characterized a mouse model of primary ocular blast injury. The device consists of: a pressurized air tank attached to a regulated paintball gun with a machined barrel; a chamber that protects the mouse from direct injury and recoil, while exposing the eye; and a secure platform that enables fine, controlled movement of the chamber in relation to the barrel. Expected pressures were calculated and the optimal pressure transducer, based on the predicted pressures, was positioned to measure output pressures at the location where the mouse eye would be placed. Mice were exposed to one of three blast pressures (23.6, 26.4, or 30.4psi). Gross pathology, intraocular pressure, optical coherence tomography, and visual acuity were assessed 0, 3, 7, 14, and 28 days after exposure. Contralateral eyes and non-blast exposed mice were used as controls. We detected increased damage with increased pressures and a shift in the damage profile over time. Gross pathology included corneal edema, corneal abrasions, and optic nerve avulsion. Retinal damage was detected by optical coherence tomography and a deficit in visual acuity was detected by optokinetics. Our findings are comparable to those identified in Veterans of the recent wars with closed eye injuries as a result of blast exposure. In summary, this is a relatively simple system that creates injuries with features similar to those seen in patients with ocular blast trauma. This is an important new model for testing the short-term and long-term spectrum of closed globe blast injuries and potential therapeutic interventions. PMID:22504073

Low cost labeling with highlighter ink efficiently visualizes developing blood vessels in avian and mouse embryos.

PubMed

Takase, Yuta; Tadokoro, Ryosuke; Takahashi, Yoshiko

2013-12-01

To understand how blood vessels form to establish the intricate network during vertebrate development, it is helpful if one can visualize the vasculature in embryos. We here describe a novel labeling method using highlighter ink, easily obtained in stationery stores with a low cost, to visualize embryo-wide vasculatures in avian and mice. We tested 50 different highlighters for fluorescent microscopy with filter sets equipped in a standard fluorescent microscope. The yellow and violet inks yielded fluorescent signals specifically detected by the filters used for green fluorescent protein (GFP) and red fluorescent protein (RFP) detections, respectively. When the ink solution was infused into chicken/quail and mouse embryos, vasculatures including large vessels and capillaries were labeled both in living and fixed embryos. Ink-infused embryos were further subjected to histological sections, and double stained with antibodies including QH-1 (quail), α smooth muscle actin (αSMA), and PECAM-1 (mouse), revealing that the endothelial cells were specifically labeled by the infused highlighter ink. Highlighter-labeled signals were detected with a resolution comparable to or higher than signals of fluorescein isothiocyanate (FITC)-lectin and Rhodamine-dextran, conventionally used for angiography. Furthermore, macroconfocal microscopic analyses with ink-infused embryos visualized fine vascular structures of both embryo proper and extra-embryonic plexus in a Z-stack image of 2400 μm thick with a markedly high resolution. Together, the low cost highlighter ink serves as an alternative reagent useful for visualization of blood vessels in developing avian and mouse embryos and possibly in other animals. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

Gradiency and Visual Context in Syntactic Garden-Paths

ERIC Educational Resources Information Center

Farmer, Thomas A.; Anderson, Sarah E.; Spivey, Michael J.

2007-01-01

Through recording the streaming x- and y-coordinates of computer-mouse movements, we report evidence that visual context provides an immediate constraint on the resolution of syntactic ambiguity in the visual-world paradigm. This finding converges with previous eye-tracking results that support a constraint-based account of sentence processing, in…

A Web-based Visualization System for Three Dimensional Geological Model using Open GIS

NASA Astrophysics Data System (ADS)

Nemoto, T.; Masumoto, S.; Nonogaki, S.

2017-12-01

A three dimensional geological model is an important information in various fields such as environmental assessment, urban planning, resource development, waste management and disaster mitigation. In this study, we have developed a web-based visualization system for 3D geological model using free and open source software. The system has been successfully implemented by integrating web mapping engine MapServer and geographic information system GRASS. MapServer plays a role of mapping horizontal cross sections of 3D geological model and a topographic map. GRASS provides the core components for management, analysis and image processing of the geological model. Online access to GRASS functions has been enabled using PyWPS that is an implementation of WPS (Web Processing Service) Open Geospatial Consortium (OGC) standard. The system has two main functions. Two dimensional visualization function allows users to generate horizontal and vertical cross sections of 3D geological model. These images are delivered via WMS (Web Map Service) and WPS OGC standards. Horizontal cross sections are overlaid on the topographic map. A vertical cross section is generated by clicking a start point and an end point on the map. Three dimensional visualization function allows users to visualize geological boundary surfaces and a panel diagram. The user can visualize them from various angles by mouse operation. WebGL is utilized for 3D visualization. WebGL is a web technology that brings hardware-accelerated 3D graphics to the browser without installing additional software. The geological boundary surfaces can be downloaded to incorporate the geologic structure in a design on CAD and model for various simulations. This study was supported by JSPS KAKENHI Grant Number JP16K00158.

Cryo-imaging of fluorescently labeled single cells in a mouse

NASA Astrophysics Data System (ADS)

Steyer, Grant J.; Roy, Debashish; Salvado, Olivier; Stone, Meredith E.; Wilson, David L.

2009-02-01

We developed a cryo-imaging system to provide single-cell detection of fluorescently labeled cells in mouse, with particular applicability to stem cells and metastatic cancer. The Case cryoimaging system consists of a fluorescence microscope, robotic imaging positioner, customized cryostat, PC-based control system, and visualization/analysis software. The system alternates between sectioning (10-40 μm) and imaging, collecting color brightfield and fluorescent blockface image volumes >60GB. In mouse experiments, we imaged quantum-dot labeled stem cells, GFP-labeled cancer and stem cells, and cell-size fluorescent microspheres. To remove subsurface fluorescence, we used a simplified model of light-tissue interaction whereby the next image was scaled, blurred, and subtracted from the current image. We estimated scaling and blurring parameters by minimizing entropy of subtracted images. Tissue specific attenuation parameters were found [uT : heart (267 +/- 47.6 μm), liver (218 +/- 27.1 μm), brain (161 +/- 27.4 μm)] to be within the range of estimates in the literature. "Next image" processing removed subsurface fluorescence equally well across multiple tissues (brain, kidney, liver, adipose tissue, etc.), and analysis of 200 microsphere images in the brain gave 97+/-2% reduction of subsurface fluorescence. Fluorescent signals were determined to arise from single cells based upon geometric and integrated intensity measurements. Next image processing greatly improved axial resolution, enabled high quality 3D volume renderings, and improved enumeration of single cells with connected component analysis by up to 24%. Analysis of image volumes identified metastatic cancer sites, found homing of stem cells to injury sites, and showed microsphere distribution correlated with blood flow patterns. We developed and evaluated cryo-imaging to provide single-cell detection of fluorescently labeled cells in mouse. Our cryo-imaging system provides extreme (>60GB), micron-scale, fluorescence, and bright field image data. Here we describe our image preprocessing, analysis, and visualization techniques. Processing improves axial resolution, reduces subsurface fluorescence by 97%, and enables single cell detection and counting. High quality 3D volume renderings enable us to evaluate cell distribution patterns. Applications include the myriad of biomedical experiments using fluorescent reporter gene and exogenous fluorophore labeling of cells in applications such as stem cell regenerative medicine, cancer, tissue engineering, etc.

Orientation-selective Responses in the Mouse Lateral Geniculate Nucleus

PubMed Central

Zhao, Xinyu; Chen, Hui; Liu, Xiaorong

2013-01-01

The dorsal lateral geniculate nucleus (dLGN) receives visual information from the retina and transmits it to the cortex. In this study, we made extracellular recordings in the dLGN of both anesthetized and awake mice, and found that a surprisingly high proportion of cells were selective for stimulus orientation. The orientation selectivity of dLGN cells was unchanged after silencing the visual cortex pharmacologically, indicating that it is not due to cortical feedback. The orientation tuning of some dLGN cells correlated with their elongated receptive fields, while in others orientation selectivity was observed despite the fact that their receptive fields were circular, suggesting that their retinal input might already be orientation selective. Consistently, we revealed orientation/axis-selective ganglion cells in the mouse retina using multielectrode arrays in an in vitro preparation. Furthermore, the orientation tuning of dLGN cells was largely maintained at different stimulus contrasts, which could be sufficiently explained by a simple linear feedforward model. We also compared the degree of orientation selectivity in different visual structures under the same recording condition. Compared with the dLGN, orientation selectivity is greatly improved in the visual cortex, but is similar in the superior colliculus, another major retinal target. Together, our results demonstrate prominent orientation selectivity in the mouse dLGN, which may potentially contribute to visual processing in the cortex. PMID:23904611

Researchers Find Essential Brain Circuit in Visual Development

MedlinePlus

... Release Monday, August 26, 2013 Researchers find essential brain circuit in visual development NIH-funded study could ... shows the connections from the eyes to the brain in a mouse. The right image shows the ...

Ultra High-Resolution In vivo Computed Tomography Imaging of Mouse Cerebrovasculature Using a Long Circulating Blood Pool Contrast Agent

PubMed Central

Starosolski, Zbigniew; Villamizar, Carlos A.; Rendon, David; Paldino, Michael J.; Milewicz, Dianna M.; Ghaghada, Ketan B.; Annapragada, Ananth V.

2015-01-01

Abnormalities in the cerebrovascular system play a central role in many neurologic diseases. The on-going expansion of rodent models of human cerebrovascular diseases and the need to use these models to understand disease progression and treatment has amplified the need for reproducible non-invasive imaging methods for high-resolution visualization of the complete cerebral vasculature. In this study, we present methods for in vivo high-resolution (19 μm isotropic) computed tomography imaging of complete mouse brain vasculature. This technique enabled 3D visualization of large cerebrovascular networks, including the Circle of Willis. Blood vessels as small as 40 μm were clearly delineated. ACTA2 mutations in humans cause cerebrovascular defects, including abnormally straightened arteries and a moyamoya-like arteriopathy characterized by bilateral narrowing of the internal carotid artery and stenosis of many large arteries. In vivo imaging studies performed in a mouse model of Acta2 mutations demonstrated the utility of this method for studying vascular morphometric changes that are practically impossible to identify using current histological methods. Specifically, the technique demonstrated changes in the width of the Circle of Willis, straightening of cerebral arteries and arterial stenoses. We believe the use of imaging methods described here will contribute substantially to the study of rodent cerebrovasculature. PMID:25985192

An optimized fluorescent probe for visualizing glutamate neurotransmission.

PubMed

Marvin, Jonathan S; Borghuis, Bart G; Tian, Lin; Cichon, Joseph; Harnett, Mark T; Akerboom, Jasper; Gordus, Andrew; Renninger, Sabine L; Chen, Tsai-Wen; Bargmann, Cornelia I; Orger, Michael B; Schreiter, Eric R; Demb, Jonathan B; Gan, Wen-Biao; Hires, S Andrew; Looger, Loren L

2013-02-01

We describe an intensity-based glutamate-sensing fluorescent reporter (iGluSnFR) with signal-to-noise ratio and kinetics appropriate for in vivo imaging. We engineered iGluSnFR in vitro to maximize its fluorescence change, and we validated its utility for visualizing glutamate release by neurons and astrocytes in increasingly intact neurological systems. In hippocampal culture, iGluSnFR detected single field stimulus-evoked glutamate release events. In pyramidal neurons in acute brain slices, glutamate uncaging at single spines showed that iGluSnFR responds robustly and specifically to glutamate in situ, and responses correlate with voltage changes. In mouse retina, iGluSnFR-expressing neurons showed intact light-evoked excitatory currents, and the sensor revealed tonic glutamate signaling in response to light stimuli. In worms, glutamate signals preceded and predicted postsynaptic calcium transients. In zebrafish, iGluSnFR revealed spatial organization of direction-selective synaptic activity in the optic tectum. Finally, in mouse forelimb motor cortex, iGluSnFR expression in layer V pyramidal neurons revealed task-dependent single-spine activity during running.

Molecular visualizing and quantifying immune-associated peroxynitrite fluxes in phagocytes and mouse inflammation model.

PubMed

Li, Zan; Yan, Shi-Hai; Chen, Chen; Geng, Zhi-Rong; Chang, Jia-Yin; Chen, Chun-Xia; Huang, Bing-Huan; Wang, Zhi-Lin

2017-04-15

Reactions of peroxynitrite (ONOO - ) with biomolecules can lead to cytotoxic and cytoprotective events. Due to the difficulty of directly and unambiguously measuring its levels, most of the beneficial effects associated with ONOO - in vivo remain controversial or poorly characterized. Recently, optical imaging has served as a powerful noninvasive approach to studying ONOO - in living systems. However, ratiometric probes for ONOO - are currently lacking. Herein, we report the design, synthesis, and biological evaluation of F 482 , a novel fluorescence indicator that relies on ONOO - -induced diene oxidation. The remarkable sensitivity, selectivity, and photostability of F 482 enabled us to visualize basal ONOO - in immune-stimulated phagocyte cells and quantify its generation in phagosomes by high-throughput flow cytometry analysis. With the aid of in vivo ONOO - imaging in a mouse inflammation model assisted by F 482 , we envision that F 482 will find widespread applications in the study of the ONOO - biology associated with physiological and pathological processes in vitro and in vivo. Copyright © 2016 Elsevier B.V. All rights reserved.

Touchscreen learning deficits in Ube3a, Ts65Dn and Mecp2 mouse models of neurodevelopmental disorders with intellectual disabilities.

PubMed

Leach, P T; Crawley, J N

2017-12-20

Mutant mouse models of neurodevelopmental disorders with intellectual disabilities provide useful translational research tools, especially in cases where robust cognitive deficits are reproducibly detected. However, motor, sensory and/or health issues consequent to the mutation may introduce artifacts that preclude testing in some standard cognitive assays. Touchscreen learning and memory tasks in small operant chambers have the potential to circumvent these confounds. Here we use touchscreen visual discrimination learning to evaluate performance in the maternally derived Ube3a mouse model of Angelman syndrome, the Ts65Dn trisomy mouse model of Down syndrome, and the Mecp2 Bird mouse model of Rett syndrome. Significant deficits in acquisition of a 2-choice visual discrimination task were detected in both Ube3a and Ts65Dn mice. Procedural control measures showed no genotype differences during pretraining phases or during acquisition. Mecp2 males did not survive long enough for touchscreen training, consistent with previous reports. Most Mecp2 females failed on pretraining criteria. Significant impairments on Morris water maze spatial learning were detected in both Ube3a and Ts65Dn, replicating previous findings. Abnormalities on rotarod in Ube3a, and on open field in Ts65Dn, replicating previous findings, may have contributed to the observed acquisition deficits and swim speed abnormalities during water maze performance. In contrast, these motor phenotypes do not appear to have affected touchscreen procedural abilities during pretraining or visual discrimination training. Our findings of slower touchscreen learning in 2 mouse models of neurodevelopmental disorders with intellectual disabilities indicate that operant tasks offer promising outcome measures for the preclinical discovery of effective pharmacological therapeutics. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Web-based visualization of very large scientific astronomy imagery

NASA Astrophysics Data System (ADS)

Bertin, E.; Pillay, R.; Marmo, C.

2015-04-01

Visualizing and navigating through large astronomy images from a remote location with current astronomy display tools can be a frustrating experience in terms of speed and ergonomics, especially on mobile devices. In this paper, we present a high performance, versatile and robust client-server system for remote visualization and analysis of extremely large scientific images. Applications of this work include survey image quality control, interactive data query and exploration, citizen science, as well as public outreach. The proposed software is entirely open source and is designed to be generic and applicable to a variety of datasets. It provides access to floating point data at terabyte scales, with the ability to precisely adjust image settings in real-time. The proposed clients are light-weight, platform-independent web applications built on standard HTML5 web technologies and compatible with both touch and mouse-based devices. We put the system to the test and assess the performance of the system and show that a single server can comfortably handle more than a hundred simultaneous users accessing full precision 32 bit astronomy data.

Scientific Visualization of Radio Astronomy Data using Gesture Interaction

NASA Astrophysics Data System (ADS)

Mulumba, P.; Gain, J.; Marais, P.; Woudt, P.

2015-09-01

MeerKAT in South Africa (Meer = More Karoo Array Telescope) will require software to help visualize, interpret and interact with multidimensional data. While visualization of multi-dimensional data is a well explored topic, little work has been published on the design of intuitive interfaces to such systems. More specifically, the use of non-traditional interfaces (such as motion tracking and multi-touch) has not been widely investigated within the context of visualizing astronomy data. We hypothesize that a natural user interface would allow for easier data exploration which would in turn lead to certain kinds of visualizations (volumetric, multidimensional). To this end, we have developed a multi-platform scientific visualization system for FITS spectral data cubes using VTK (Visualization Toolkit) and a natural user interface to explore the interaction between a gesture input device and multidimensional data space. Our system supports visual transformations (translation, rotation and scaling) as well as sub-volume extraction and arbitrary slicing of 3D volumetric data. These tasks were implemented across three prototypes aimed at exploring different interaction strategies: standard (mouse/keyboard) interaction, volumetric gesture tracking (Leap Motion controller) and multi-touch interaction (multi-touch monitor). A Heuristic Evaluation revealed that the volumetric gesture tracking prototype shows great promise for interfacing with the depth component (z-axis) of 3D volumetric space across multiple transformations. However, this is limited by users needing to remember the required gestures. In comparison, the touch-based gesture navigation is typically more familiar to users as these gestures were engineered from standard multi-touch actions. Future work will address a complete usability test to evaluate and compare the different interaction modalities against the different visualization tasks.

Immunostaining, dehydration, and clearing of mouse embryos for ultramicroscopy.

PubMed

Becker, Klaus; Jährling, Nina; Saghafi, Saiedeh; Dodt, Hans-Ulrich

2013-08-01

This protocol describes the preparation of mouse embryos for ultramicroscopy (UM), a powerful imaging technique that achieves precise and accurate three-dimensional (3D) reconstructions of intact macroscopic specimens with micrometer resolution. In UM, a specimen in the size range of ∼1-15 mm is illuminated perpendicular to the observation pathway by two thin counterpropagating sheets of laser light. In combination with fluorescein isothiocyanate (FITC) immunostaining, UM allows visualization of somatic motor and sensorial nerve fibers in whole mouse embryos. Even the fine branches of the sensomotoric fibers can be visualized over a distance of up to several millimeters. In this protocol, mouse embryos are fixed and immunostained in preparation for UM. Because UM requires the excitation light sheet to travel throughout the entire horizontal width of the specimen, specimens usually have to be rendered transparent before microscope inspection. Here, the embryos are dehydrated in ethanol and then cleared in a solution of benzyl alcohol and benzyl benzoate.

Modularity in the Organization of Mouse Primary Visual Cortex

PubMed Central

Ji, Weiqing; Gămănuţ, Răzvan; Bista, Pawan; D’Souza, Rinaldo D.; Wang, Quanxin; Burkhalter, Andreas

2015-01-01

SUMMARY Layer 1 (L1) of primary visual cortex (V1) is the target of projections from many brain regions outside of V1. We found that inputs to the non-columnar mouse V1 from the dorsal lateral geniculate nucleus and feedback projections from multiple higher cortical areas to L1 are patchy. The patches are matched to a pattern of M2 muscarinic acetylcholine receptor expression at fixed locations of mouse, rat and monkey V1. Neurons in L2/3 aligned with M2-rich patches have high spatial acuity whereas cells in M2-poor zones exhibited high temporal acuity. Together M2+ and M2− zones form constant-size domains that are repeated across V1. Domains map subregions of the receptive field, such that multiple copies are contained within the point image. The results suggest that the modular network in mouse V1 selects spatiotemporally distinct clusters of neurons within the point image for top-down control and differential routing of inputs to cortical streams. PMID:26247867

Low-cost, high-speed back-end processing system for high-frequency ultrasound B-mode imaging.

PubMed

Chang, Jin Ho; Sun, Lei; Yen, Jesse T; Shung, K Kirk

2009-07-01

For real-time visualization of the mouse heart (6 to 13 beats per second), a back-end processing system involving high-speed signal processing functions to form and display images has been developed. This back-end system was designed with new signal processing algorithms to achieve a frame rate of more than 400 images per second. These algorithms were implemented in a simple and cost-effective manner with a single field-programmable gate array (FPGA) and software programs written in C++. The operating speed of the back-end system was investigated by recording the time required for transferring an image to a personal computer. Experimental results showed that the back-end system is capable of producing 433 images per second. To evaluate the imaging performance of the back-end system, a complete imaging system was built. This imaging system, which consisted of a recently reported high-speed mechanical sector scanner assembled with the back-end system, was tested by imaging a wire phantom, a pig eye (in vitro), and a mouse heart (in vivo). It was shown that this system is capable of providing high spatial resolution images with fast temporal resolution.

Low-Cost, High-Speed Back-End Processing System for High-Frequency Ultrasound B-Mode Imaging

PubMed Central

Chang, Jin Ho; Sun, Lei; Yen, Jesse T.; Shung, K. Kirk

2009-01-01

For real-time visualization of the mouse heart (6 to 13 beats per second), a back-end processing system involving high-speed signal processing functions to form and display images has been developed. This back-end system was designed with new signal processing algorithms to achieve a frame rate of more than 400 images per second. These algorithms were implemented in a simple and cost-effective manner with a single field-programmable gate array (FPGA) and software programs written in C++. The operating speed of the back-end system was investigated by recording the time required for transferring an image to a personal computer. Experimental results showed that the back-end system is capable of producing 433 images per second. To evaluate the imaging performance of the back-end system, a complete imaging system was built. This imaging system, which consisted of a recently reported high-speed mechanical sector scanner assembled with the back-end system, was tested by imaging a wire phantom, a pig eye (in vitro), and a mouse heart (in vivo). It was shown that this system is capable of providing high spatial resolution images with fast temporal resolution. PMID:19574160

A Mouse Model of Visual Perceptual Learning Reveals Alterations in Neuronal Coding and Dendritic Spine Density in the Visual Cortex.

PubMed

Wang, Yan; Wu, Wei; Zhang, Xian; Hu, Xu; Li, Yue; Lou, Shihao; Ma, Xiao; An, Xu; Liu, Hui; Peng, Jing; Ma, Danyi; Zhou, Yifeng; Yang, Yupeng

2016-01-01

Visual perceptual learning (VPL) can improve spatial vision in normally sighted and visually impaired individuals. Although previous studies of humans and large animals have explored the neural basis of VPL, elucidation of the underlying cellular and molecular mechanisms remains a challenge. Owing to the advantages of molecular genetic and optogenetic manipulations, the mouse is a promising model for providing a mechanistic understanding of VPL. Here, we thoroughly evaluated the effects and properties of VPL on spatial vision in C57BL/6J mice using a two-alternative, forced-choice visual water task. Briefly, the mice underwent prolonged training at near the individual threshold of contrast or spatial frequency (SF) for pattern discrimination or visual detection for 35 consecutive days. Following training, the contrast-threshold trained mice showed an 87% improvement in contrast sensitivity (CS) and a 55% gain in visual acuity (VA). Similarly, the SF-threshold trained mice exhibited comparable and long-lasting improvements in VA and significant gains in CS over a wide range of SFs. Furthermore, learning largely transferred across eyes and stimulus orientations. Interestingly, learning could transfer from a pattern discrimination task to a visual detection task, but not vice versa. We validated that this VPL fully restored VA in adult amblyopic mice and old mice. Taken together, these data indicate that mice, as a species, exhibit reliable VPL. Intrinsic signal optical imaging revealed that mice with perceptual training had higher cut-off SFs in primary visual cortex (V1) than those without perceptual training. Moreover, perceptual training induced an increase in the dendritic spine density in layer 2/3 pyramidal neurons of V1. These results indicated functional and structural alterations in V1 during VPL. Overall, our VPL mouse model will provide a platform for investigating the neurobiological basis of VPL.

Ultrahigh-speed ultrahigh-resolution adaptive optics: optical coherence tomography system for in-vivo small animal retinal imaging

NASA Astrophysics Data System (ADS)

Jian, Yifan; Xu, Jing; Zawadzki, Robert J.; Sarunic, Marinko V.

2013-03-01

Small animal models of human retinal diseases are a critical component of vision research. In this report, we present an ultrahigh-resolution ultrahigh-speed adaptive optics optical coherence tomography (AO-OCT) system for small animal retinal imaging (mouse, fish, etc.). We adapted our imaging system to different types of small animals in accordance with the optical properties of their eyes. Results of AO-OCT images of small animal retinas acquired with AO correction are presented. Cellular structures including nerve fiber bundles, capillary networks and detailed double-cone photoreceptors are visualized.

Cortico-fugal output from visual cortex promotes plasticity of innate motor behaviour

PubMed Central

Liu, Bao-hua; Huberman, Andrew D.; Scanziani, Massimo

2017-01-01

The mammalian visual cortex massively innervates the brainstem, a phylogenetically older structure, via cortico-fugal axonal projections1. Many cortico-fugal projections target brainstem nuclei that mediate innate motor behaviours, but the function of these projections remains poorly understood1–4. A prime example of such behaviours is the optokinetic reflex (OKR), an innate eye movement mediated by the brainstem accessory optic system3,5,6, that stabilizes images on the retina as the animal moves through the environment and is thus crucial for vision5. The OKR is plastic, allowing the amplitude of this reflex to be adaptively adjusted relative to other oculomotor reflexes and thereby ensuring image stability throughout life7–11. Although the plasticity of the OKR is thought to involve subcortical structures such as the cerebellum and vestibular nuclei10–13, cortical lesions have suggested that the visual cortex might also be involved9,14,15. Here we show that projections from the mouse visual cortex to the accessory optic system promote the adaptive plasticity of the OKR. OKR potentiation, a compensatory plastic increase in the amplitude of the OKR in response to vestibular impairment11,16–18, is diminished by silencing visual cortex. Furthermore, targeted ablation of a sparse population of cortico-fugal neurons that specifically project to the accessory optic system severely impairs OKR potentiation. Finally, OKR potentiation results from an enhanced drive exerted by the visual cortex onto the accessory optic system. Thus, cortico-fugal projections to the brainstem enable the visual cortex, an area that has been principally studied for its sensory processing function19, to plastically adapt the execution of innate motor behaviours. PMID:27732573

Simple and rapid determination of homozygous transgenic mice via in vivo fluorescence imaging.

PubMed

Lin, Xiaolin; Jia, Junshuang; Qin, Yujuan; Lin, Xia; Li, Wei; Xiao, Gaofang; Li, Yanqing; Xie, Raoying; Huang, Hailu; Zhong, Lin; Wu, Qinghong; Wang, Wanshan; Huang, Wenhua; Yao, Kaitai; Xiao, Dong; Sun, Yan

2015-11-17

Setting up breeding programs for transgenic mouse strains require to distinguish homozygous from the heterozygous transgenic animals. The combinational use of the fluorescence reporter transgene and small animal in-vivo imaging system might allow us to rapidly and visually determine the transgenic mice homozygous for transgene(s) by the in vivo fluorescence imaging. RLG, RCLG or Rm17LG transgenic mice ubiquitously express red fluorescent protein (RFP). To identify homozygous RLG transgenic mice, whole-body fluorescence imaging for all of newborn F2-generation littermates produced by mating of RFP-positive heterozygous transgenic mice (F1-generation) derived from the same transgenic founder was performed. Subsequently, the immediate data analysis of the in vivo fluorescence imaging was carried out, which greatly facilitated us to rapidly and readily distinguish RLG transgenic individual(s) with strong fluorescence from the rest of F2-generation littermates, followed by further determining this/these RLG individual(s) showing strong fluorescence to be homozygous, as strongly confirmed by mouse mating. Additionally, homozygous RCLG or Rm17LG transgenic mice were also rapidly and precisely distinguished by the above-mentioned optical approach. This approach allowed us within the shortest time period to obtain 10, 8 and 2 transgenic mice homozygous for RLG, RCLG and Rm17LG transgene, respectively, as verified by mouse mating, indicating the practicality and reliability of this optical method. Taken together, our findings fully demonstrate that the in vivo fluorescence imaging offers a visual, rapid and reliable alternative method to the traditional approaches (i.e., mouse mating and real-time quantitative PCR) in identifying homozygous transgenic mice harboring fluorescence reporter transgene under the control of a ubiquitous promoter in the situation mentioned in this study.

Simple and rapid determination of homozygous transgenic mice via in vivo fluorescence imaging

PubMed Central

Li, Wei; Xiao, Gaofang; Li, Yanqing; Xie, Raoying; Huang, Hailu; Zhong, Lin; Wu, Qinghong; Wang, Wanshan; Huang, Wenhua; Yao, Kaitai; Xiao, Dong; Sun, Yan

2015-01-01

Setting up breeding programs for transgenic mouse strains require to distinguish homozygous from the heterozygous transgenic animals. The combinational use of the fluorescence reporter transgene and small animal in-vivo imaging system might allow us to rapidly and visually determine the transgenic mice homozygous for transgene(s) by the in vivo fluorescence imaging. RLG, RCLG or Rm17LG transgenic mice ubiquitously express red fluorescent protein (RFP). To identify homozygous RLG transgenic mice, whole-body fluorescence imaging for all of newborn F2-generation littermates produced by mating of RFP-positive heterozygous transgenic mice (F1-generation) derived from the same transgenic founder was performed. Subsequently, the immediate data analysis of the in vivo fluorescence imaging was carried out, which greatly facilitated us to rapidly and readily distinguish RLG transgenic individual(s) with strong fluorescence from the rest of F2-generation littermates, followed by further determining this/these RLG individual(s) showing strong fluorescence to be homozygous, as strongly confirmed by mouse mating. Additionally, homozygous RCLG or Rm17LG transgenic mice were also rapidly and precisely distinguished by the above-mentioned optical approach. This approach allowed us within the shortest time period to obtain 10, 8 and 2 transgenic mice homozygous for RLG, RCLG and Rm17LG transgene, respectively, as verified by mouse mating, indicating the practicality and reliability of this optical method. Taken together, our findings fully demonstrate that the in vivo fluorescence imaging offers a visual, rapid and reliable alternative method to the traditional approaches (i.e., mouse mating and real-time quantitative PCR) in identifying homozygous transgenic mice harboring fluorescence reporter transgene under the control of a ubiquitous promoter in the situation mentioned in this study. PMID:26472024

PC-PVT 2.0: An updated platform for psychomotor vigilance task testing, analysis, prediction, and visualization.

PubMed

Reifman, Jaques; Kumar, Kamal; Khitrov, Maxim Y; Liu, Jianbo; Ramakrishnan, Sridhar

2018-07-01

The psychomotor vigilance task (PVT) has been widely used to assess the effects of sleep deprivation on human neurobehavioral performance. To facilitate research in this field, we previously developed the PC-PVT, a freely available software system analogous to the "gold-standard" PVT-192 that, in addition to allowing for simple visual reaction time (RT) tests, also allows for near real-time PVT analysis, prediction, and visualization in a personal computer (PC). Here we present the PC-PVT 2.0 for Windows 10 operating system, which has the capability to couple PVT tests of a study protocol with the study's sleep/wake and caffeine schedules, and make real-time individualized predictions of PVT performance for such schedules. We characterized the accuracy and precision of the software in measuring RT, using 44 distinct combinations of PC hardware system configurations. We found that 15 system configurations measured RTs with an average delay of less than 10 ms, an error comparable to that of the PVT-192. To achieve such small delays, the system configuration should always use a gaming mouse as the means to respond to visual stimuli. We recommend using a discrete graphical processing unit for desktop PCs and an external monitor for laptop PCs. This update integrates a study's sleep/wake and caffeine schedules with the testing software, facilitating testing and outcome visualization, and provides near-real-time individualized PVT predictions for any sleep-loss condition considering caffeine effects. The software, with its enhanced PVT analysis, visualization, and prediction capabilities, can be freely downloaded from https://pcpvt.bhsai.org. Published by Elsevier B.V.

Spatial integration in mouse primary visual cortex.

PubMed

Vaiceliunaite, Agne; Erisken, Sinem; Franzen, Florian; Katzner, Steffen; Busse, Laura

2013-08-01

Responses of many neurons in primary visual cortex (V1) are suppressed by stimuli exceeding the classical receptive field (RF), an important property that might underlie the computation of visual saliency. Traditionally, it has proven difficult to disentangle the underlying neural circuits, including feedforward, horizontal intracortical, and feedback connectivity. Since circuit-level analysis is particularly feasible in the mouse, we asked whether neural signatures of spatial integration in mouse V1 are similar to those of higher-order mammals and investigated the role of parvalbumin-expressing (PV+) inhibitory interneurons. Analogous to what is known from primates and carnivores, we demonstrate that, in awake mice, surround suppression is present in the majority of V1 neurons and is strongest in superficial cortical layers. Anesthesia with isoflurane-urethane, however, profoundly affects spatial integration: it reduces the laminar dependency, decreases overall suppression strength, and alters the temporal dynamics of responses. We show that these effects of brain state can be parsimoniously explained by assuming that anesthesia affects contrast normalization. Hence, the full impact of suppressive influences in mouse V1 cannot be studied under anesthesia with isoflurane-urethane. To assess the neural circuits of spatial integration, we targeted PV+ interneurons using optogenetics. Optogenetic depolarization of PV+ interneurons was associated with increased RF size and decreased suppression in the recorded population, similar to effects of lowering stimulus contrast, suggesting that PV+ interneurons contribute to spatial integration by affecting overall stimulus drive. We conclude that the mouse is a promising model for circuit-level mechanisms of spatial integration, which relies on the combined activity of different types of inhibitory interneurons.

Alpha-fetoprotein-targeted reporter gene expression imaging in hepatocellular carcinoma.

PubMed

Kim, Kwang Il; Chung, Hye Kyung; Park, Ju Hui; Lee, Yong Jin; Kang, Joo Hyun

2016-07-21

Hepatocellular carcinoma (HCC) is one of the most common cancers in Eastern Asia, and its incidence is increasing globally. Numerous experimental models have been developed to better our understanding of the pathogenic mechanism of HCC and to evaluate novel therapeutic approaches. Molecular imaging is a convenient and up-to-date biomedical tool that enables the visualization, characterization and quantification of biologic processes in a living subject. Molecular imaging based on reporter gene expression, in particular, can elucidate tumor-specific events or processes by acquiring images of a reporter gene's expression driven by tumor-specific enhancers/promoters. In this review, we discuss the advantages and disadvantages of various experimental HCC mouse models and we present in vivo images of tumor-specific reporter gene expression driven by an alpha-fetoprotein (AFP) enhancer/promoter system in a mouse model of HCC. The current mouse models of HCC development are established by xenograft, carcinogen induction and genetic engineering, representing the spectrum of tumor-inducing factors and tumor locations. The imaging analysis approach of reporter genes driven by AFP enhancer/promoter is presented for these different HCC mouse models. Such molecular imaging can provide longitudinal information about carcinogenesis and tumor progression. We expect that clinical application of AFP-targeted reporter gene expression imaging systems will be useful for the detection of AFP-expressing HCC tumors and screening of increased/decreased AFP levels due to disease or drug treatment.

Alpha-fetoprotein-targeted reporter gene expression imaging in hepatocellular carcinoma

PubMed Central

Kim, Kwang Il; Chung, Hye Kyung; Park, Ju Hui; Lee, Yong Jin; Kang, Joo Hyun

2016-01-01

Hepatocellular carcinoma (HCC) is one of the most common cancers in Eastern Asia, and its incidence is increasing globally. Numerous experimental models have been developed to better our understanding of the pathogenic mechanism of HCC and to evaluate novel therapeutic approaches. Molecular imaging is a convenient and up-to-date biomedical tool that enables the visualization, characterization and quantification of biologic processes in a living subject. Molecular imaging based on reporter gene expression, in particular, can elucidate tumor-specific events or processes by acquiring images of a reporter gene’s expression driven by tumor-specific enhancers/promoters. In this review, we discuss the advantages and disadvantages of various experimental HCC mouse models and we present in vivo images of tumor-specific reporter gene expression driven by an alpha-fetoprotein (AFP) enhancer/promoter system in a mouse model of HCC. The current mouse models of HCC development are established by xenograft, carcinogen induction and genetic engineering, representing the spectrum of tumor-inducing factors and tumor locations. The imaging analysis approach of reporter genes driven by AFP enhancer/promoter is presented for these different HCC mouse models. Such molecular imaging can provide longitudinal information about carcinogenesis and tumor progression. We expect that clinical application of AFP-targeted reporter gene expression imaging systems will be useful for the detection of AFP-expressing HCC tumors and screening of increased/decreased AFP levels due to disease or drug treatment. PMID:27468205

[Risks and health problems caused by the use of video terminals].

PubMed

Tamez González, Silvia; Ortiz-Hernández, Luis; Martínez-Alcántara, Susana; Méndez-Ramírez, Ignacio

2003-01-01

To evaluate the association between video display terminal (VDT) use and health hazards, occupational risks, and psychosocial factors, in newspaper workers. A cross-sectional study was conducted in 1998 in a representative sample (n = 68) drawn from a population of 218 VDT operators in Mexico City. Data were collected using a self-administered questionnaire. Data were confirmed by performing physical examinations. The research hypothesis was that both the current and cumulative use of VDT are associated with visual, musculoskeletal system, and skin illnesses, as well as with fatigue and mental or psychosomatic disorders. Occupational health hazards were assessed (visual problems, postural risks, sedentary work, computer mouse use, excessive heat, and overcrowding), as well as psychosocial factors related to work organization (psychological demands, work control, and social support). Prevalence ratios were adjusted for confounding variables like age, sex and schooling. Women were more likely than men to have upper extremity musculoskeletal disorders (MSD), dermatitis, and seborrheic eczema. VDT use was associated with neuro-visual fatigue, upper extremity MSD, dermatitis, and seborrheic eczema. Computer mouse use and postural risks were significantly associated with health problems. Psychosocial factors were mainly associated with mental problems, psychosomatic disorders, and fatigue. Intense use of video screens has been found to cause musculoskeletal disorders of the hand. The diversification of tasks and control of labor processes itself had a protective effect against psychosomatic disorders and pathological fatigue.

Anti-amyloid therapy protects against retinal pigmented epithelium damage and vision loss in a model of age-related macular degeneration.

PubMed

Ding, Jin-Dong; Johnson, Lincoln V; Herrmann, Rolf; Farsiu, Sina; Smith, Stephanie G; Groelle, Marybeth; Mace, Brian E; Sullivan, Patrick; Jamison, Jeffrey A; Kelly, Una; Harrabi, Ons; Bollini, Sangeetha Subbarao; Dilley, Jeanette; Kobayashi, Dione; Kuang, Bing; Li, Wenlin; Pons, Jaume; Lin, John C; Bowes Rickman, Catherine

2011-07-12

Age-related macular degeneration (AMD) is a leading cause of visual dysfunction worldwide. Amyloid β (Aβ) peptides, Aβ1-40 (Aβ40) and Aβ1-42 (Aβ42), have been implicated previously in the AMD disease process. Consistent with a pathogenic role for Aβ, we show here that a mouse model of AMD that invokes multiple factors that are known to modify AMD risk (aged human apolipoprotein E 4 targeted replacement mice on a high-fat, cholesterol-enriched diet) presents with Aβ-containing deposits basal to the retinal pigmented epithelium (RPE), histopathologic changes in the RPE, and a deficit in scotopic electroretinographic response, which is reflective of impaired visual function. Strikingly, these electroretinographic deficits are abrogated in a dose-dependent manner by systemic administration of an antibody targeting the C termini of Aβ40 and Aβ42. Concomitant reduction in the levels of Aβ and activated complement components in sub-RPE deposits and structural preservation of the RPE are associated with anti-Aβ40/42 antibody immunotherapy and visual protection. These observations are consistent with the reduction in amyloid plaques and improvement of cognitive function in mouse models of Alzheimer's disease treated with anti-Aβ antibodies. They also implicate Aβ in the pathogenesis of AMD and identify Aβ as a viable therapeutic target for its treatment.

Mapping social behavior-induced brain activation at cellular resolution in the mouse

PubMed Central

Kim, Yongsoo; Venkataraju, Kannan Umadevi; Pradhan, Kith; Mende, Carolin; Taranda, Julian; Turaga, Srinivas C.; Arganda-Carreras, Ignacio; Ng, Lydia; Hawrylycz, Michael J.; Rockland, Kathleen; Seung, H. Sebastian; Osten, Pavel

2014-01-01

Understanding how brain activation mediates behaviors is a central goal of systems neuroscience. Here we apply an automated method for mapping brain activation in the mouse in order to probe how sex-specific social behaviors are represented in the male brain. Our method uses the immediate early gene c-fos, a marker of neuronal activation, visualized by serial two-photon tomography: the c-fos-GFP-positive neurons are computationally detected, their distribution is registered to a reference brain and a brain atlas, and their numbers are analyzed by statistical tests. Our results reveal distinct and shared female and male interaction-evoked patterns of male brain activation representing sex discrimination and social recognition. We also identify brain regions whose degree of activity correlates to specific features of social behaviors and estimate the total numbers and the densities of activated neurons per brain areas. Our study opens the door to automated screening of behavior-evoked brain activation in the mouse. PMID:25558063

Expanding Functionality of Commercial Optical Coherence Tomography Systems by Integrating a Custom Endoscope

PubMed Central

Welge, Weston A.; Barton, Jennifer K.

2015-01-01

Optical coherence tomography (OCT) is a useful imaging modality for detecting and monitoring diseases of the gastrointestinal tract and other tubular structures. The non-destructiveness of OCT enables time-serial studies in animal models. While turnkey commercial research OCT systems are plenty, researchers often require custom imaging probes. We describe the integration of a custom endoscope with a commercial swept-source OCT system and generalize this description to any imaging probe and OCT system. A numerical dispersion compensation method is also described. Example images demonstrate that OCT can visualize the mouse colon crypt structure and detect adenoma in vivo. PMID:26418811

Multi-modality endoscopic imaging for the detection of colorectal cancer

NASA Astrophysics Data System (ADS)

Wall, Richard Andrew

Optical coherence tomography (OCT) is an imaging method that is considered the optical analog to ultrasound, using the technique of optical interferometry to construct two-dimensional depth-resolved images of tissue microstructure. With a resolution on the order of 10 um and a penetration depth of 1-2 mm in highly scattering tissue, fiber optics-coupled OCT is an ideal modality for the inspection of the mouse colon with its miniaturization capabilities. In the present study, the complementary modalities laser-induced fluorescence (LIF), which offers information on the biochemical makeup of the tissue, and surface magnifying chromoendoscopy, which offers high contrast surface visualization, are combined with OCT in endoscopic imaging systems for the greater specificity and sensitivity in the differentiation between normal and neoplastic tissue, and for the visualization of biomarkers which are indicative of early events in colorectal carcinogenesis. Oblique incidence reflectometry (OIR) also offers advantages, allowing the calculation of bulk tissue optical properties for use as a diagnostic tool. The study was broken up into three specific sections. First, a dual-modality OCTLIF imaging system was designed, capable of focusing light over 325-1300 nm using a reflective distal optics design. A dual-modality fluorescence-based SMC-OCT system was then designed and constructed, capable of resolving the stained mucosal crypt structure of the in vivo mouse colon. The SMC-OCT instrument's OIR capabilities were then modeled, as a modified version of the probe was used measure tissue scattering and absorption coefficients.

Neuroprotection in a Novel Mouse Model of Multiple Sclerosis

PubMed Central

Lidster, Katie; Jackson, Samuel J.; Ahmed, Zubair; Munro, Peter; Coffey, Pete; Giovannoni, Gavin; Baker, Mark D.; Baker, David

2013-01-01

Multiple sclerosis is an immune-mediated, demyelinating and neurodegenerative disease that currently lacks any neuroprotective treatments. Innovative neuroprotective trial designs are required to hasten the translational process of drug development. An ideal target to monitor the efficacy of strategies aimed at treating multiple sclerosis is the visual system, which is the most accessible part of the human central nervous system. A novel C57BL/6 mouse line was generated that expressed transgenes for a myelin oligodendrocyte glycoprotein-specific T cell receptor and a retinal ganglion cell restricted-Thy1 promoter-controlled cyan fluorescent protein. This model develops spontaneous or induced optic neuritis, in the absence of paralytic disease normally associated with most rodent autoimmune models of multiple sclerosis. Demyelination and neurodegeneration could be monitored longitudinally in the living animal using electrophysiology, visual sensitivity, confocal scanning laser ophthalmoscopy and optical coherence tomography all of which are relevant to human trials. This model offers many advantages, from a 3Rs, economic and scientific perspective, over classical experimental autoimmune encephalomyelitis models that are associated with substantial suffering of animals. Optic neuritis in this model led to inflammatory damage of axons in the optic nerve and subsequent loss of retinal ganglion cells in the retina. This was inhibited by the systemic administration of a sodium channel blocker (oxcarbazepine) or intraocular treatment with siRNA targeting caspase-2. These novel approaches have relevance to the future treatment of neurodegeneration of MS, which has so far evaded treatment. PMID:24223903

Visual impairment in FOXG1-mutated individuals and mice.

PubMed

Boggio, E M; Pancrazi, L; Gennaro, M; Lo Rizzo, C; Mari, F; Meloni, I; Ariani, F; Panighini, A; Novelli, E; Biagioni, M; Strettoi, E; Hayek, J; Rufa, A; Pizzorusso, T; Renieri, A; Costa, M

2016-06-02

The Forkead Box G1 (FOXG1 in humans, Foxg1 in mice) gene encodes for a DNA-binding transcription factor, essential for the development of the telencephalon in mammalian forebrain. Mutations in FOXG1 have been reported to be involved in the onset of Rett Syndrome, for which sequence alterations of MECP2 and CDKL5 are known. While visual alterations are not classical hallmarks of Rett syndrome, an increasing body of evidence shows visual impairment in patients and in MeCP2 and CDKL5 animal models. Herein we focused on the functional role of FOXG1 in the visual system of animal models (Foxg1(+/Cre) mice) and of a cohort of subjects carrying FOXG1 mutations or deletions. Visual physiology of Foxg1(+/Cre) mice was assessed by visually evoked potentials, which revealed a significant reduction in response amplitude and visual acuity with respect to wild-type littermates. Morphological investigation showed abnormalities in the organization of excitatory/inhibitory circuits in the visual cortex. No alterations were observed in retinal structure. By examining a cohort of FOXG1-mutated individuals with a panel of neuro-ophthalmological assessments, we found that all of them exhibited visual alterations compatible with high-level visual dysfunctions. In conclusion our data show that Foxg1 haploinsufficiency results in an impairment of mouse and human visual cortical function. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Digital Museum of Retinal Ganglion Cells with Dense Anatomy and Physiology.

PubMed

Bae, J Alexander; Mu, Shang; Kim, Jinseop S; Turner, Nicholas L; Tartavull, Ignacio; Kemnitz, Nico; Jordan, Chris S; Norton, Alex D; Silversmith, William M; Prentki, Rachel; Sorek, Marissa; David, Celia; Jones, Devon L; Bland, Doug; Sterling, Amy L R; Park, Jungman; Briggman, Kevin L; Seung, H Sebastian

2018-05-17

When 3D electron microscopy and calcium imaging are used to investigate the structure and function of neural circuits, the resulting datasets pose new challenges of visualization and interpretation. Here, we present a new kind of digital resource that encompasses almost 400 ganglion cells from a single patch of mouse retina. An online "museum" provides a 3D interactive view of each cell's anatomy, as well as graphs of its visual responses. The resource reveals two aspects of the retina's inner plexiform layer: an arbor segregation principle governing structure along the light axis and a density conservation principle governing structure in the tangential plane. Structure is related to visual function; ganglion cells with arbors near the layer of ganglion cell somas are more sustained in their visual responses on average. Our methods are potentially applicable to dense maps of neuronal anatomy and physiology in other parts of the nervous system. Copyright © 2018 Elsevier Inc. All rights reserved.

VPython: Writing Real-time 3D Physics Programs

NASA Astrophysics Data System (ADS)

Chabay, Ruth

2001-06-01

VPython (http://cil.andrew.cmu.edu/projects/visual) combines the Python programming language with an innovative 3D graphics module called Visual, developed by David Scherer. Designed to make 3D physics simulations accessible to novice programmers, VPython allows the programmer to write a purely computational program without any graphics code, and produces an interactive realtime 3D graphical display. In a program 3D objects are created and their positions modified by computational algorithms. Running in a separate thread, the Visual module monitors the positions of these objects and renders them many times per second. Using the mouse, one can zoom and rotate to navigate through the scene. After one hour of instruction, students in an introductory physics course at Carnegie Mellon University, including those who have never programmed before, write programs in VPython to model the behavior of physical systems and to visualize fields in 3D. The Numeric array processing module allows the construction of more sophisticated simulations and models as well. VPython is free and open source. The Visual module is based on OpenGL, and runs on Windows, Linux, and Macintosh.

Parallel pathways from whisker and visual sensory cortices to distinct frontal regions of mouse neocortex

PubMed Central

Sreenivasan, Varun; Kyriakatos, Alexandros; Mateo, Celine; Jaeger, Dieter; Petersen, Carl C.H.

2016-01-01

Abstract. The spatial organization of mouse frontal cortex is poorly understood. Here, we used voltage-sensitive dye to image electrical activity in the dorsal cortex of awake head-restrained mice. Whisker-deflection evoked the earliest sensory response in a localized region of primary somatosensory cortex and visual stimulation evoked the earliest responses in a localized region of primary visual cortex. Over the next milliseconds, the initial sensory response spread within the respective primary sensory cortex and into the surrounding higher order sensory cortices. In addition, secondary hotspots in the frontal cortex were evoked by whisker and visual stimulation, with the frontal hotspot for whisker deflection being more anterior and lateral compared to the frontal hotspot evoked by visual stimulation. Investigating axonal projections, we found that the somatosensory whisker cortex and the visual cortex directly innervated frontal cortex, with visual cortex axons innervating a region medial and posterior to the innervation from somatosensory cortex, consistent with the location of sensory responses in frontal cortex. In turn, the axonal outputs of these two frontal cortical areas innervate distinct regions of striatum, superior colliculus, and brainstem. Sensory input, therefore, appears to map onto modality-specific regions of frontal cortex, perhaps participating in distinct sensorimotor transformations, and directing distinct motor outputs. PMID:27921067

Feature-Specific Organization of Feedback Pathways in Mouse Visual Cortex.

PubMed

Huh, Carey Y L; Peach, John P; Bennett, Corbett; Vega, Roxana M; Hestrin, Shaul

2018-01-08

Higher and lower cortical areas in the visual hierarchy are reciprocally connected [1]. Although much is known about how feedforward pathways shape receptive field properties of visual neurons, relatively little is known about the role of feedback pathways in visual processing. Feedback pathways are thought to carry top-down signals, including information about context (e.g., figure-ground segmentation and surround suppression) [2-5], and feedback has been demonstrated to sharpen orientation tuning of neurons in the primary visual cortex (V1) [6, 7]. However, the response characteristics of feedback neurons themselves and how feedback shapes V1 neurons' tuning for other features, such as spatial frequency (SF), remain largely unknown. Here, using a retrograde virus, targeted electrophysiological recordings, and optogenetic manipulations, we show that putatively feedback neurons in layer 5 (hereafter "L5 feedback") in higher visual areas, AL (anterolateral area) and PM (posteromedial area), display distinct visual properties in awake head-fixed mice. AL L5 feedback neurons prefer significantly lower SF (mean: 0.04 cycles per degree [cpd]) compared to PM L5 feedback neurons (0.15 cpd). Importantly, silencing AL L5 feedback reduced visual responses of V1 neurons preferring low SF (mean change in firing rate: -8.0%), whereas silencing PM L5 feedback suppressed responses of high-SF-preferring V1 neurons (-20.4%). These findings suggest that feedback connections from higher visual areas convey distinctly tuned visual inputs to V1 that serve to boost V1 neurons' responses to SF. Such like-to-like functional organization may represent an important feature of feedback pathways in sensory systems and in the nervous system in general. Copyright © 2017 Elsevier Ltd. All rights reserved.

The microglial fractalkine receptor is not required for activity-dependent plasticity in the mouse visual system.

PubMed

Lowery, Rebecca L; Tremblay, Marie-Eve; Hopkins, Brittany E; Majewska, Ania K

2017-11-01

Microglia have recently been implicated as key regulators of activity-dependent plasticity, where they contribute to the removal of inappropriate or excess synapses. However, the molecular mechanisms that mediate this microglial function are still not well understood. Although multiple studies have implicated fractalkine signaling as a mediator of microglia-neuron communications during synaptic plasticity, it is unclear whether this is a universal signaling mechanism or whether its role is limited to specific brain regions and stages of the lifespan. Here, we examined whether fractalkine signaling mediates microglial contributions to activity-dependent plasticity in the developing and adolescent visual system. Using genetic ablation of fractalkine's cognate receptor, CX 3 CR1, and both ex vivo characterization and in vivo imaging in mice, we examined whether fractalkine signaling is required for microglial dynamics and modulation of synapses, as well as activity-dependent plasticity in the visual system. We did not find a role for fractalkine signaling in mediating microglial properties during visual plasticity. Ablation of CX 3 CR1 had no effect on microglial density, distribution, morphology, or motility, in either adolescent or young adult mice across brain regions that include the visual cortex. Ablation of CX 3 CR1 also had no effect on baseline synaptic turnover or contact dynamics between microglia and neurons. Finally, we found that fractalkine signaling is not required for either early or late forms of activity-dependent visual system plasticity. These findings suggest that fractalkine is not a universal regulator of synaptic plasticity, but rather has heterogeneous roles in specific brain regions and life stages. © 2017 Wiley Periodicals, Inc.

Visualization of laser tattoo removal treatment effects in a mouse model by two-photon microscopy

PubMed Central

Jang, Won Hyuk; Yoon, Yeoreum; Kim, Wonjoong; Kwon, Soonjae; Lee, Seunghun; Song, Duke; Choi, Jong Woon; Kim, Ki Hean

2017-01-01

Laser tattoo removal is an effective method of eliminating tattoo particles in the skin. However, laser treatment cannot always remove the unwanted tattoo completely, and there are risks of either temporary or permanent side effects. Studies using preclinical animal models could provide detailed information on the effects of laser treatment in the skin, and might help to minimize side effects in clinical practices. In this study, two-photon microscopy (TPM) was used to visualize the laser treatment effects on tattoo particles in both phantom specimens and in vivo mouse models. Fluorescent tattoo ink was used for particle visualization by TPM, and nanosecond (ns) and picosecond (ps) lasers at 532 nm were used for treatment. In phantom specimens, TPM characterized the fragmentation of individual tattoo particles by tracking them before and after the laser treatment. These changes were confirmed by field emission scanning electron microscopy (FE-SEM). TPM was used to measure the treatment efficiency of the two lasers at different laser fluences. In the mouse model, TPM visualized clusters of tattoo particles in the skin and detected their fragmentation after the laser treatment. Longitudinal TPM imaging observed the migration of cells containing tattoo particles after the laser treatment. These results show that TPM may be useful for the assessment of laser tattoo removal treatment in preclinical studies. PMID:28856046

Targeting neuronal gap junctions in mouse retina offers neuroprotection in glaucoma

PubMed Central

Kumar, Sandeep; Ramakrishnan, Hariharasubramanian; Roy, Kaushambi; Viswanathan, Suresh; Bloomfield, Stewart A.

2017-01-01

The progressive death of retinal ganglion cells and resulting visual deficits are hallmarks of glaucoma, but the underlying mechanisms remain unclear. In many neurodegenerative diseases, cell death induced by primary insult is followed by a wave of secondary loss. Gap junctions (GJs), intercellular channels composed of subunit connexins, can play a major role in secondary cell death by forming conduits through which toxic molecules from dying cells pass to and injure coupled neighbors. Here we have shown that pharmacological blockade of GJs or genetic ablation of connexin 36 (Cx36) subunits, which are highly expressed by retinal neurons, markedly reduced loss of neurons and optic nerve axons in a mouse model of glaucoma. Further, functional parameters that are negatively affected in glaucoma, including the electroretinogram, visual evoked potential, visual spatial acuity, and contrast sensitivity, were maintained at control levels when Cx36 was ablated. Neuronal GJs may thus represent potential therapeutic targets to prevent the progressive neurodegeneration and visual impairment associated with glaucoma. PMID:28604388

A neural circuit for gamma-band coherence across the retinotopic map in mouse visual cortex

PubMed Central

Hakim, Richard; Shamardani, Kiarash

2018-01-01

Cortical gamma oscillations have been implicated in a variety of cognitive, behavioral, and circuit-level phenomena. However, the circuit mechanisms of gamma-band generation and synchronization across cortical space remain uncertain. Using optogenetic patterned illumination in acute brain slices of mouse visual cortex, we define a circuit composed of layer 2/3 (L2/3) pyramidal cells and somatostatin (SOM) interneurons that phase-locks ensembles across the retinotopic map. The network oscillations generated here emerge from non-periodic stimuli, and are stimulus size-dependent, coherent across cortical space, narrow band (30 Hz), and depend on SOM neuron but not parvalbumin (PV) neuron activity; similar to visually induced gamma oscillations observed in vivo. Gamma oscillations generated in separate cortical locations exhibited high coherence as far apart as 850 μm, and lateral gamma entrainment depended on SOM neuron activity. These data identify a circuit that is sufficient to mediate long-range gamma-band coherence in the primary visual cortex. PMID:29480803

An extended retinotopic map of mouse cortex

PubMed Central

Zhuang, Jun; Ng, Lydia; Williams, Derric; Valley, Matthew; Li, Yang; Garrett, Marina; Waters, Jack

2017-01-01

Visual perception and behavior are mediated by cortical areas that have been distinguished using architectonic and retinotopic criteria. We employed fluorescence imaging and GCaMP6 reporter mice to generate retinotopic maps, revealing additional regions of retinotopic organization that extend into barrel and retrosplenial cortices. Aligning retinotopic maps to architectonic borders, we found a mismatch in border location, indicating that architectonic borders are not aligned with the retinotopic transition at the vertical meridian. We also assessed the representation of visual space within each region, finding that four visual areas bordering V1 (LM, P, PM and RL) display complementary representations, with overlap primarily at the central hemifield. Our results extend our understanding of the organization of mouse cortex to include up to 16 distinct retinotopically organized regions. DOI: http://dx.doi.org/10.7554/eLife.18372.001 PMID:28059700

ExpTreeDB: web-based query and visualization of manually annotated gene expression profiling experiments of human and mouse from GEO.

PubMed

Ni, Ming; Ye, Fuqiang; Zhu, Juanjuan; Li, Zongwei; Yang, Shuai; Yang, Bite; Han, Lu; Wu, Yongge; Chen, Ying; Li, Fei; Wang, Shengqi; Bo, Xiaochen

2014-12-01

Numerous public microarray datasets are valuable resources for the scientific communities. Several online tools have made great steps to use these data by querying related datasets with users' own gene signatures or expression profiles. However, dataset annotation and result exhibition still need to be improved. ExpTreeDB is a database that allows for queries on human and mouse microarray experiments from Gene Expression Omnibus with gene signatures or profiles. Compared with similar applications, ExpTreeDB pays more attention to dataset annotations and result visualization. We introduced a multiple-level annotation system to depict and organize original experiments. For example, a tamoxifen-treated cell line experiment is hierarchically annotated as 'agent→drug→estrogen receptor antagonist→tamoxifen'. Consequently, retrieved results are exhibited by an interactive tree-structured graphics, which provide an overview for related experiments and might enlighten users on key items of interest. The database is freely available at http://biotech.bmi.ac.cn/ExpTreeDB. Web site is implemented in Perl, PHP, R, MySQL and Apache. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Preparation of wholemount mouse intestine for high-resolution three-dimensional imaging using two-photon microscopy.

PubMed

Appleton, P L; Quyn, A J; Swift, S; Näthke, I

2009-05-01

Visualizing overall tissue architecture in three dimensions is fundamental for validating and integrating biochemical, cell biological and visual data from less complex systems such as cultured cells. Here, we describe a method to generate high-resolution three-dimensional image data of intact mouse gut tissue. Regions of highest interest lie between 50 and 200 mum within this tissue. The quality and usefulness of three-dimensional image data of tissue with such depth is limited owing to problems associated with scattered light, photobleaching and spherical aberration. Furthermore, the highest-quality oil-immersion lenses are designed to work at a maximum distance of

Genetic background influences age-related decline in visual and nonvisual retinal responses, circadian rhythms, and sleep☆

PubMed Central

Banks, Gareth; Heise, Ines; Starbuck, Becky; Osborne, Tamzin; Wisby, Laura; Potter, Paul; Jackson, Ian J.; Foster, Russell G.; Peirson, Stuart N.; Nolan, Patrick M.

2015-01-01

The circadian system is entrained to the environmental light/dark cycle via retinal photoreceptors and regulates numerous aspects of physiology and behavior, including sleep. These processes are all key factors in healthy aging showing a gradual decline with age. Despite their importance, the exact mechanisms underlying this decline are yet to be fully understood. One of the most effective tools we have to understand the genetic factors underlying these processes are genetically inbred mouse strains. The most commonly used reference mouse strain is C57BL/6J, but recently, resources such as the International Knockout Mouse Consortium have started producing large numbers of mouse mutant lines on a pure genetic background, C57BL/6N. Considering the substantial genetic diversity between mouse strains we expect there to be phenotypic differences, including differential effects of aging, in these and other strains. Such differences need to be characterized not only to establish how different mouse strains may model the aging process but also to understand how genetic background might modify age-related phenotypes. To ascertain the effects of aging on sleep/wake behavior, circadian rhythms, and light input and whether these effects are mouse strain-dependent, we have screened C57BL/6J, C57BL/6N, C3H-HeH, and C3H-Pde6b+ mouse strains at 5 ages throughout their life span. Our data show that sleep, circadian, and light input parameters are all disrupted by the aging process. Moreover, we have cataloged a number of strain-specific aging effects, including the rate of cataract development, decline in the pupillary light response, and changes in sleep fragmentation and the proportion of time spent asleep. PMID:25179226

Genetic background influences age-related decline in visual and nonvisual retinal responses, circadian rhythms, and sleep.

PubMed

Banks, Gareth; Heise, Ines; Starbuck, Becky; Osborne, Tamzin; Wisby, Laura; Potter, Paul; Jackson, Ian J; Foster, Russell G; Peirson, Stuart N; Nolan, Patrick M

2015-01-01

The circadian system is entrained to the environmental light/dark cycle via retinal photoreceptors and regulates numerous aspects of physiology and behavior, including sleep. These processes are all key factors in healthy aging showing a gradual decline with age. Despite their importance, the exact mechanisms underlying this decline are yet to be fully understood. One of the most effective tools we have to understand the genetic factors underlying these processes are genetically inbred mouse strains. The most commonly used reference mouse strain is C57BL/6J, but recently, resources such as the International Knockout Mouse Consortium have started producing large numbers of mouse mutant lines on a pure genetic background, C57BL/6N. Considering the substantial genetic diversity between mouse strains we expect there to be phenotypic differences, including differential effects of aging, in these and other strains. Such differences need to be characterized not only to establish how different mouse strains may model the aging process but also to understand how genetic background might modify age-related phenotypes. To ascertain the effects of aging on sleep/wake behavior, circadian rhythms, and light input and whether these effects are mouse strain-dependent, we have screened C57BL/6J, C57BL/6N, C3H-HeH, and C3H-Pde6b+ mouse strains at 5 ages throughout their life span. Our data show that sleep, circadian, and light input parameters are all disrupted by the aging process. Moreover, we have cataloged a number of strain-specific aging effects, including the rate of cataract development, decline in the pupillary light response, and changes in sleep fragmentation and the proportion of time spent asleep. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Limitations of gaze transfer: without visual context, eye movements do not to help to coordinate joint action, whereas mouse movements do.

PubMed

Müller, Romy; Helmert, Jens R; Pannasch, Sebastian

2014-10-01

Remote cooperation can be improved by transferring the gaze of one participant to the other. However, based on a partner's gaze, an interpretation of his communicative intention can be difficult. Thus, gaze transfer has been inferior to mouse transfer in remote spatial referencing tasks where locations had to be pointed out explicitly. Given that eye movements serve as an indicator of visual attention, it remains to be investigated whether gaze and mouse transfer differentially affect the coordination of joint action when the situation demands an understanding of the partner's search strategies. In the present study, a gaze or mouse cursor was transferred from a searcher to an assistant in a hierarchical decision task. The assistant could use this cursor to guide his movement of a window which continuously opened up the display parts the searcher needed to find the right solution. In this context, we investigated how the ease of using gaze transfer depended on whether a link could be established between the partner's eye movements and the objects he was looking at. Therefore, in addition to the searcher's cursor, the assistant either saw the positions of these objects or only a grey background. When the objects were visible, performance and the number of spoken words were similar for gaze and mouse transfer. However, without them, gaze transfer resulted in longer solution times and more verbal effort as participants relied more strongly on speech to coordinate the window movement. Moreover, an analysis of the spatio-temporal coupling of the transmitted cursor and the window indicated that when no visual object information was available, assistants confidently followed the searcher's mouse but not his gaze cursor. Once again, the results highlight the importance of carefully considering task characteristics when applying gaze transfer in remote cooperation. Copyright © 2013 Elsevier B.V. All rights reserved.

Device- and system-independent personal touchless user interface for operating rooms : One personal UI to control all displays in an operating room.

PubMed

Ma, Meng; Fallavollita, Pascal; Habert, Séverine; Weidert, Simon; Navab, Nassir

2016-06-01

In the modern day operating room, the surgeon performs surgeries with the support of different medical systems that showcase patient information, physiological data, and medical images. It is generally accepted that numerous interactions must be performed by the surgical team to control the corresponding medical system to retrieve the desired information. Joysticks and physical keys are still present in the operating room due to the disadvantages of mouses, and surgeons often communicate instructions to the surgical team when requiring information from a specific medical system. In this paper, a novel user interface is developed that allows the surgeon to personally perform touchless interaction with the various medical systems, switch effortlessly among them, all of this without modifying the systems' software and hardware. To achieve this, a wearable RGB-D sensor is mounted on the surgeon's head for inside-out tracking of his/her finger with any of the medical systems' displays. Android devices with a special application are connected to the computers on which the medical systems are running, simulating a normal USB mouse and keyboard. When the surgeon performs interaction using pointing gestures, the desired cursor position in the targeted medical system display, and gestures, are transformed into general events and then sent to the corresponding Android device. Finally, the application running on the Android devices generates the corresponding mouse or keyboard events according to the targeted medical system. To simulate an operating room setting, our unique user interface was tested by seven medical participants who performed several interactions with the visualization of CT, MRI, and fluoroscopy images at varying distances from them. Results from the system usability scale and NASA-TLX workload index indicated a strong acceptance of our proposed user interface.

Evidence that primary visual cortex is required for image, orientation, and motion discrimination by rats.

PubMed

Petruno, Sarah K; Clark, Robert E; Reinagel, Pamela

2013-01-01

The pigmented Long-Evans rat has proven to be an excellent subject for studying visually guided behavior including quantitative visual psychophysics. This observation, together with its experimental accessibility and its close homology to the mouse, has made it an attractive model system in which to dissect the thalamic and cortical circuits underlying visual perception. Given that visually guided behavior in the absence of primary visual cortex has been described in the literature, however, it is an empirical question whether specific visual behaviors will depend on primary visual cortex in the rat. Here we tested the effects of cortical lesions on performance of two-alternative forced-choice visual discriminations by Long-Evans rats. We present data from one highly informative subject that learned several visual tasks and then received a bilateral lesion ablating >90% of primary visual cortex. After the lesion, this subject had a profound and persistent deficit in complex image discrimination, orientation discrimination, and full-field optic flow motion discrimination, compared with both pre-lesion performance and sham-lesion controls. Performance was intact, however, on another visual two-alternative forced-choice task that required approaching a salient visual target. A second highly informative subject learned several visual tasks prior to receiving a lesion ablating >90% of medial extrastriate cortex. This subject showed no impairment on any of the four task categories. Taken together, our data provide evidence that these image, orientation, and motion discrimination tasks require primary visual cortex in the Long-Evans rat, whereas approaching a salient visual target does not.

Distribution of neurons in functional areas of the mouse cerebral cortex reveals quantitatively different cortical zones

PubMed Central

Herculano-Houzel, Suzana; Watson, Charles; Paxinos, George

2013-01-01

How are neurons distributed along the cortical surface and across functional areas? Here we use the isotropic fractionator (Herculano-Houzel and Lent, 2005) to analyze the distribution of neurons across the entire isocortex of the mouse, divided into 18 functional areas defined anatomically. We find that the number of neurons underneath a surface area (the N/A ratio) varies 4.5-fold across functional areas and neuronal density varies 3.2-fold. The face area of S1 contains the most neurons, followed by motor cortex and the primary visual cortex. Remarkably, while the distribution of neurons across functional areas does not accompany the distribution of surface area, it mirrors closely the distribution of cortical volumes—with the exception of the visual areas, which hold more neurons than expected for their volume. Across the non-visual cortex, the volume of individual functional areas is a shared linear function of their number of neurons, while in the visual areas, neuronal densities are much higher than in all other areas. In contrast, the 18 functional areas cluster into three different zones according to the relationship between the N/A ratio and cortical thickness and neuronal density: these three clusters can be called visual, sensory, and, possibly, associative. These findings are remarkably similar to those in the human cerebral cortex (Ribeiro et al., 2013) and suggest that, like the human cerebral cortex, the mouse cerebral cortex comprises two zones that differ in how neurons form the cortical volume, and three zones that differ in how neurons are distributed underneath the cortical surface, possibly in relation to local differences in connectivity through the white matter. Our results suggest that beyond the developmental divide into visual and non-visual cortex, functional areas initially share a common distribution of neurons along the parenchyma that become delimited into functional areas according to the pattern of connectivity established later. PMID:24155697

Complementary Gli activity mediates early patterning of the mouse visual system.

PubMed

Furimsky, Marosh; Wallace, Valerie A

2006-03-01

The Sonic hedgehog (Shh) signaling pathway plays a key role in the development of the vertebrate central nervous system, including the eye. This pathway is mediated by the Gli transcription factors (Gli1, Gli2, and Gli3) that differentially activate and repress the expression of specific downstream target genes. In this study, we investigated the roles of the three vertebrate Glis in mediating midline Shh signaling in early ocular development. We examined the ocular phenotypes of Shh and Gli combination mutant mouse embryos and monitored proximodistal and dorsoventral patterning by the expression of specific eye development regulatory genes using in situ hybridization. We show that midline Shh signaling relieves the repressor activity of Gli3 adjacent to the midline and then promotes eye pattern formation through the nonredundant activities of all three Gli proteins. Gli3, in particular, is required to specify the dorsal optic stalk and to define the boundary between the optic stalk and the optic cup.

Semi-automated quantification and neuroanatomical mapping of heterogeneous cell populations.

PubMed

Mendez, Oscar A; Potter, Colin J; Valdez, Michael; Bello, Thomas; Trouard, Theodore P; Koshy, Anita A

2018-07-15

Our group studies the interactions between cells of the brain and the neurotropic parasite Toxoplasma gondii. Using an in vivo system that allows us to permanently mark and identify brain cells injected with Toxoplasma protein, we have identified that Toxoplasma-injected neurons (TINs) are heterogeneously distributed throughout the brain. Unfortunately, standard methods to quantify and map heterogeneous cell populations onto a reference brain atlas are time consuming and prone to user bias. We developed a novel MATLAB-based semi-automated quantification and mapping program to allow the rapid and consistent mapping of heterogeneously distributed cells on to the Allen Institute Mouse Brain Atlas. The system uses two-threshold background subtraction to identify and quantify cells of interest. We demonstrate that we reliably quantify and neuroanatomically localize TINs with low intra- or inter-observer variability. In a follow up experiment, we show that specific regions of the mouse brain are enriched with TINs. The procedure we use takes advantage of simple immunohistochemistry labeling techniques, use of a standard microscope with a motorized stage, and low cost computing that can be readily obtained at a research institute. To our knowledge there is no other program that uses such readily available techniques and equipment for mapping heterogeneous populations of cells across the whole mouse brain. The quantification method described here allows reliable visualization, quantification, and mapping of heterogeneous cell populations in immunolabeled sections across whole mouse brains. Copyright © 2018 Elsevier B.V. All rights reserved.

Multi-color fluorescence imaging of sub-cellular dynamics of cancer cells in live mice

NASA Astrophysics Data System (ADS)

Hoffman, Robert M.

2006-02-01

We have genetically engineered dual-color fluorescent cells with one color in the nucleus and the other in the cytoplasm that enables real-time nuclear-cytoplasmic dynamics to be visualized in living cells in the cytoplasm in vivo as well as in vitro. To obtain the dual-color cells, red fluorescent protein (RFP) was expressed of the cancer cells, and green fluorescent protein (GFP) linked to histone H2B was expressed in the nucleus. Mitotic cells were visualized by whole-body imaging after injection in the mouse ear. Common carotid artery or heart injection of dual-color cells and a reversible skin flap enabled the external visualization of the dual-color cells in microvessels in the mouse where extreme elongation of the cell body as well as the nucleus occurred. The migration velocities of the dual-color cancer cells in the capillaries were measured by capturing individual images of the dual-color fluorescent cells over time. Human HCT-116-GFP-RFP colon cancer and mouse mammary tumor (MMT)-GFP-RFP cells were injected in the portal vein of nude mice. Extensive clasmocytosis (destruction of the cytoplasm) of the HCT-116-GFP-RFP cells occurred within 6 hours. The data suggest rapid death of HCT-116-GFP-RFP cells in the portal vein. In contrast, MMT-GFP-RFP cells injected into the portal vein mostly survived and formed colonies in the liver. However, when the host mice were pretreated with cyclophosphamide, the HCT-116-GFP-RFP cells also survived and formed colonies in the liver after portal vein injection. These results suggest that a cyclophosphamide-sensitive host cellular system attacked the HCT-116-GFP-RFP cells but could not effectively kill the MMT-GFP-RFP cells. With the ability to continuously image cancer cells at the subcellular level in the live animal, our understanding of the complex steps of metastasis will significantly increase. In addition, new drugs can be developed to target these newly visible steps of metastasis.

In utero mouse embryonic imaging with OCT for ophthalmologic research

NASA Astrophysics Data System (ADS)

Syed, Saba H.; Larina, Irina V.; Dickinson, Mary E.; Larin, Kirill V.

2011-03-01

Live imaging of an eye during embryonic development in mammalian model is important for understanding dynamic aspects of normal and abnormal eye morphogenesis. In this study, we used Swept Source Optical Coherence Tomography (SS-OCT) for live structural imaging of mouse embryonic eye through the uterine wall. The eye structure was reconstructed in mouse embryos at 13.5 to 17.5 days post coitus (dpc). Despite the limited imaging depth of OCT in turbid tissues, we were able to visualize the whole eye globe at these stages. These results suggest that live in utero OCT imaging is a useful tool to study embryonic eye development in the mouse model.

Segregation of Visual Response Properties in the Mouse Superior Colliculus and Their Modulation during Locomotion

PubMed Central

2017-01-01

The superior colliculus (SC) receives direct input from the retina and integrates it with information about sound, touch, and state of the animal that is relayed from other parts of the brain to initiate specific behavioral outcomes. The superficial SC layers (sSC) contain cells that respond to visual stimuli, whereas the deep SC layers (dSC) contain cells that also respond to auditory and somatosensory stimuli. Here, we used a large-scale silicon probe recording system to examine the visual response properties of SC cells of head-fixed and alert male mice. We found cells with diverse response properties including: (1) orientation/direction-selective (OS/DS) cells with a firing rate that is suppressed by drifting sinusoidal gratings (negative OS/DS cells); (2) suppressed-by-contrast cells; (3) cells with complex-like spatial summation nonlinearity; and (4) cells with Y-like spatial summation nonlinearity. We also found specific response properties that are enriched in different depths of the SC. The sSC is enriched with cells with small RFs, high evoked firing rates (FRs), and sustained temporal responses, whereas the dSC is enriched with the negative OS/DS cells and with cells with large RFs, low evoked FRs, and transient temporal responses. Locomotion modulates the activity of the SC cells both additively and multiplicatively and changes the preferred spatial frequency of some SC cells. These results provide the first description of the negative OS/DS cells and demonstrate that the SC segregates cells with different response properties and that the behavioral state of a mouse affects SC activity. SIGNIFICANCE STATEMENT The superior colliculus (SC) receives visual input from the retina in its superficial layers (sSC) and induces eye/head-orientating movements and innate defensive responses in its deeper layers (dSC). Despite their importance, very little is known about the visual response properties of dSC neurons. Using high-density electrode recordings and novel model-based analysis, we found several novel visual response properties of the SC cells, including encoding of a cell's preferred orientation or direction by suppression of the firing rate. The sSC and the dSC are enriched with cells with different visual response properties. Locomotion modulates the cells in the SC. These findings contribute to our understanding of how the SC processes visual inputs, a critical step in comprehending visually guided behaviors. PMID:28760858

Segregation of feedforward and feedback projections in mouse visual cortex

PubMed Central

Berezovskii, Vladimir K.; Nassi, Jonathan J.; Born, Richard T.

2011-01-01

Hierarchical organization is a common feature of mammalian neocortex. Neurons that send their axons from lower to higher areas of the hierarchy are referred to as “feedforward” (FF) neurons, whereas those projecting in the opposite direction are called “feedback” (FB) neurons. Anatomical, functional and theoretical studies suggest that these different classes of projections play fundamentally different roles in perception. In primates, laminar differences in projection patterns often distinguish the two projection streams. In rodents, however, these differences are less clear, despite an established hierarchy of visual areas. Thus the rodent provides a strong test of the hypothesis that FF and FB neurons form distinct populations. We tested this hypothesis by injecting retrograde tracers into two different hierarchical levels of mouse visual cortex (areas 17 and AL) and then determining the relative proportions of double-labeled FB and FF neurons in an area intermediate to them (LM). Despite finding singly labeled neurons densely intermingled with no laminar segregation, we found few double-labeled neurons (~5% of each singly labeled population). We also examined the development of FF and FB connections. FF connections were present at the earliest time-point we examined (postnatal day two, P2), while FB connections were not detectable until P11. Our findings indicate that, even in cortices without laminar segregation of FF and FB neurons, the two projection systems are largely distinct at the neuronal level and also differ with respect to the timing of their outgrowth. PMID:21618232

iSyTE 2.0: a database for expression-based gene discovery in the eye

PubMed Central

Kakrana, Atul; Yang, Andrian; Anand, Deepti; Djordjevic, Djordje; Ramachandruni, Deepti; Singh, Abhyudai; Huang, Hongzhan

2018-01-01

Abstract Although successful in identifying new cataract-linked genes, the previous version of the database iSyTE (integrated Systems Tool for Eye gene discovery) was based on expression information on just three mouse lens stages and was functionally limited to visualization by only UCSC-Genome Browser tracks. To increase its efficacy, here we provide an enhanced iSyTE version 2.0 (URL: http://research.bioinformatics.udel.edu/iSyTE) based on well-curated, comprehensive genome-level lens expression data as a one-stop portal for the effective visualization and analysis of candidate genes in lens development and disease. iSyTE 2.0 includes all publicly available lens Affymetrix and Illumina microarray datasets representing a broad range of embryonic and postnatal stages from wild-type and specific gene-perturbation mouse mutants with eye defects. Further, we developed a new user-friendly web interface for direct access and cogent visualization of the curated expression data, which supports convenient searches and a range of downstream analyses. The utility of these new iSyTE 2.0 features is illustrated through examples of established genes associated with lens development and pathobiology, which serve as tutorials for its application by the end-user. iSyTE 2.0 will facilitate the prioritization of eye development and disease-linked candidate genes in studies involving transcriptomics or next-generation sequencing data, linkage analysis and GWAS approaches. PMID:29036527

Antibody-based PET imaging of amyloid beta in mouse models of Alzheimer's disease

PubMed Central

Sehlin, Dag; Fang, Xiaotian T.; Cato, Linda; Antoni, Gunnar; Lannfelt, Lars; Syvänen, Stina

2016-01-01

Owing to their specificity and high-affinity binding, monoclonal antibodies have potential as positron emission tomography (PET) radioligands and are currently used to image various targets in peripheral organs. However, in the central nervous system, antibody uptake is limited by the blood–brain barrier (BBB). Here we present a PET ligand to be used for diagnosis and evaluation of treatment effects in Alzheimer's disease. The amyloid β (Aβ) antibody mAb158 is radiolabelled and conjugated to a transferrin receptor antibody to enable receptor-mediated transcytosis across the BBB. PET imaging of two different mouse models with Aβ pathology clearly visualize Aβ in the brain. The PET signal increases with age and correlates closely with brain Aβ levels. Thus, we demonstrate that antibody-based PET ligands can be successfully used for brain imaging. PMID:26892305

Arc restores juvenile plasticity in adult mouse visual cortex

PubMed Central

Jenks, Kyle R.; Kim, Taekeun; Pastuzyn, Elissa D.; Okuno, Hiroyuki; Taibi, Andrew V.; Bear, Mark F.

2017-01-01

The molecular basis for the decline in experience-dependent neural plasticity over age remains poorly understood. In visual cortex, the robust plasticity induced in juvenile mice by brief monocular deprivation during the critical period is abrogated by genetic deletion of Arc, an activity-dependent regulator of excitatory synaptic modification. Here, we report that augmenting Arc expression in adult mice prolongs juvenile-like plasticity in visual cortex, as assessed by recordings of ocular dominance (OD) plasticity in vivo. A distinguishing characteristic of juvenile OD plasticity is the weakening of deprived-eye responses, believed to be accounted for by the mechanisms of homosynaptic long-term depression (LTD). Accordingly, we also found increased LTD in visual cortex of adult mice with augmented Arc expression and impaired LTD in visual cortex of juvenile mice that lack Arc or have been treated in vivo with a protein synthesis inhibitor. Further, we found that although activity-dependent expression of Arc mRNA does not change with age, expression of Arc protein is maximal during the critical period and declines in adulthood. Finally, we show that acute augmentation of Arc expression in wild-type adult mouse visual cortex is sufficient to restore juvenile-like plasticity. Together, our findings suggest a unifying molecular explanation for the age- and activity-dependent modulation of synaptic sensitivity to deprivation. PMID:28790183

Novel Models of Visual Topographic Map Alignment in the Superior Colliculus

PubMed Central

El-Ghazawi, Tarek A.; Triplett, Jason W.

2016-01-01

The establishment of precise neuronal connectivity during development is critical for sensing the external environment and informing appropriate behavioral responses. In the visual system, many connections are organized topographically, which preserves the spatial order of the visual scene. The superior colliculus (SC) is a midbrain nucleus that integrates visual inputs from the retina and primary visual cortex (V1) to regulate goal-directed eye movements. In the SC, topographically organized inputs from the retina and V1 must be aligned to facilitate integration. Previously, we showed that retinal input instructs the alignment of V1 inputs in the SC in a manner dependent on spontaneous neuronal activity; however, the mechanism of activity-dependent instruction remains unclear. To begin to address this gap, we developed two novel computational models of visual map alignment in the SC that incorporate distinct activity-dependent components. First, a Correlational Model assumes that V1 inputs achieve alignment with established retinal inputs through simple correlative firing mechanisms. A second Integrational Model assumes that V1 inputs contribute to the firing of SC neurons during alignment. Both models accurately replicate in vivo findings in wild type, transgenic and combination mutant mouse models, suggesting either activity-dependent mechanism is plausible. In silico experiments reveal distinct behaviors in response to weakening retinal drive, providing insight into the nature of the system governing map alignment depending on the activity-dependent strategy utilized. Overall, we describe novel computational frameworks of visual map alignment that accurately model many aspects of the in vivo process and propose experiments to test them. PMID:28027309

Enduring critical period plasticity visualized by transcranial flavoprotein imaging in mouse primary visual cortex.

PubMed

Tohmi, Manavu; Kitaura, Hiroki; Komagata, Seiji; Kudoh, Masaharu; Shibuki, Katsuei

2006-11-08

Experience-dependent plasticity in the visual cortex was investigated using transcranial flavoprotein fluorescence imaging in mice anesthetized with urethane. On- and off-responses in the primary visual cortex were elicited by visual stimuli. Fluorescence responses and field potentials elicited by grating patterns decreased similarly as contrasts of visual stimuli were reduced. Fluorescence responses also decreased as spatial frequency of grating stimuli increased. Compared with intrinsic signal imaging in the same mice, fluorescence imaging showed faster responses with approximately 10 times larger signal changes. Retinotopic maps in the primary visual cortex and area LM were constructed using fluorescence imaging. After monocular deprivation (MD) of 4 d starting from postnatal day 28 (P28), deprived eye responses were suppressed compared with nondeprived eye responses in the binocular zone but not in the monocular zone. Imaging faithfully recapitulated a critical period for plasticity with maximal effects of MD observed around P28 and not in adulthood even under urethane anesthesia. Visual responses were compared before and after MD in the same mice, in which the skull was covered with clear acrylic dental resin. Deprived eye responses decreased after MD, whereas nondeprived eye responses increased. Effects of MD during a critical period were tested 2 weeks after reopening of the deprived eye. Significant ocular dominance plasticity was observed in responses elicited by moving grating patterns, but no long-lasting effect was found in visual responses elicited by light-emitting diode light stimuli. The present results indicate that transcranial flavoprotein fluorescence imaging is a powerful tool for investigating experience-dependent plasticity in the mouse visual cortex.

H3 and H4 Lysine Acetylation Correlates with Developmental and Experimentally Induced Adult Experience-Dependent Plasticity in the Mouse Visual Cortex

PubMed Central

Vierci, Gabriela; Pannunzio, Bruno; Bornia, Natalia; Rossi, Francesco M.

2016-01-01

Histone posttranslational modifications play a fundamental role in orchestrating gene expression. In this work, we analyzed the acetylation of H3 and H4 histones (AcH3–AcH4) and its modulation by visual experience in the mouse visual cortex (VC) during normal development and in two experimental conditions that restore juvenile-like plasticity levels in adults (fluoxetine treatment and enriched environment). We found that AcH3–AcH4 declines with age and is upregulated by treatments restoring plasticity in the adult. We also found that visual experience modulates AcH3–AcH4 in young and adult plasticity-restored mice but not in untreated ones. Finally, we showed that the transporter vGAT is downregulated in adult plasticity-restored models. In summary, we identified a dynamic regulation of AcH3–AcH4, which is associated with high plasticity levels and enhanced by visual experience. These data, along with recent ones, indicate H3–H4 acetylation as a central hub in the control of experience-dependent plasticity in the VC. PMID:27891053

Dynamic changes in the distribution and time course of blood-brain barrier-permeative nitroxides in the mouse head with EPR imaging: visualization of blood flow in a mouse model of ischemia.

PubMed

Emoto, Miho C; Sato-Akaba, Hideo; Hirata, Hiroshi; Fujii, Hirotada G

2014-09-01

Electron paramagnetic resonance (EPR) imaging using nitroxides as redox-sensitive probes is a powerful, noninvasive method that can be used under various physiological conditions to visualize changes in redox status that result from oxidative damage. Two blood-brain barrier-permeative nitroxides, 3-hydroxymethyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (HMP) and 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-yloxy (MCP), have been widely used as redox-sensitive probes in the brains of small animals, but their in vivo distribution and properties have not yet been analyzed in detail. In this study, a custom-made continuous-wave three-dimensional (3D) EPR imager was used to obtain 3D EPR images of mouse heads using MCP or HMP. This EPR imager made it possible to take 3D EPR images reconstructed from data from 181 projections acquired every 60s. Using this improved EPR imager and magnetic resonance imaging, the distribution and reduction time courses of HMP and MCP were examined in mouse heads. EPR images of living mice revealed that HMP and MCP have different distributions and different time courses for entering the brain. Based on the pharmacokinetics of the reduction reactions of HMP and MCP in the mouse head, the half-lives of HMP and MCP were clearly and accurately mapped pixel by pixel. An ischemic mouse model was prepared, and the half-life of MCP was mapped in the mouse head. Compared to the half-life in control mice, the half-life of MCP in the ischemic model mouse brain was significantly increased, suggesting a shift in the redox balance. This in vivo EPR imaging method using BBB-permeative MCP is a useful noninvasive method for assessing changes in the redox status in mouse brains under oxidative stress. Copyright © 2014 Elsevier Inc. All rights reserved.

Three-photon tissue imaging using moxifloxacin.

PubMed

Lee, Seunghun; Lee, Jun Ho; Wang, Taejun; Jang, Won Hyuk; Yoon, Yeoreum; Kim, Bumju; Jun, Yong Woong; Kim, Myoung Joon; Kim, Ki Hean

2018-06-20

Moxifloxacin is an antibiotic used in clinics and has recently been used as a clinically compatible cell-labeling agent for two-photon (2P) imaging. Although 2P imaging with moxifloxacin labeling visualized cells inside tissues using enhanced fluorescence, the imaging depth was quite limited because of the relatively short excitation wavelength (<800 nm) used. In this study, the feasibility of three-photon (3P) excitation of moxifloxacin using a longer excitation wavelength and moxifloxacin-based 3P imaging were tested to increase the imaging depth. Moxifloxacin fluorescence via 3P excitation was detected at a >1000 nm excitation wavelength. After obtaining the excitation and emission spectra of moxifloxacin, moxifloxacin-based 3P imaging was applied to ex vivo mouse bladder and ex vivo mouse small intestine tissues and compared with moxifloxacin-based 2P imaging by switching the excitation wavelength of a Ti:sapphire oscillator between near 1030 and 780 nm. Both moxifloxacin-based 2P and 3P imaging visualized cellular structures in the tissues via moxifloxacin labeling, but the image contrast was better with 3P imaging than with 2P imaging at the same imaging depths. The imaging speed and imaging depth of moxifloxacin-based 3P imaging using a Ti:sapphire oscillator were limited by insufficient excitation power. Therefore, we constructed a new system for moxifloxacin-based 3P imaging using a high-energy Yb fiber laser at 1030 nm and used it for in vivo deep tissue imaging of a mouse small intestine. Moxifloxacin-based 3P imaging could be useful for clinical applications with enhanced imaging depth.

Complete method to obtain, culture, and transfer mouse blastocysts nonsurgically to study implantation and development.

PubMed

Moreno-Moya, Juan Manuel; Ramírez, Leslie; Vilella, Felipe; Martínez, Sebastián; Quiñonero, Alicia; Noguera, Inmaculada; Pellicer, Antonio; Simón, Carlos

2014-03-01

To illustrate an efficient, complete, step-by-step protocol for studying implantation in mice. Video presentation of an animal model for research in reproductive biology. Mouse (Mus musculus). A nonsurgical embryo transfer system very similar to that used for human embryo transfer. The protocols with recipient and donor mice are performed in parallel in the same week. For the donor mice: the first step is ovarian stimulation, followed by ovulation induction and mating; finally, the mice are sacrificed, and the embryos are collected and cultured. For recipient mice: first estrous synchrony is induced, followed by mating with a vasectomized male, visualization of the vaginal plug, and nonsurgical transfer of the embryos. Finally (optionally), the implantation sites can be visualized on day 7.5 of development. (All animal experiments were performed with the approval of the institutional review board.) Implantation is an essential step in human reproduction although, because of technical and ethics considerations, still relatively little is known about human implantation and early development. Conversely, mouse models are well established and can be used for preliminary experiments. However, there are various bottlenecks in the procedure for obtaining and transferring murine embryos, which makes experimentation with this model more difficult. These difficulties include pseudopregnancy, ovarian hyperstimulation, and embryo collection, culture, and transfer. We have proposed a complete, efficient method for obtaining, culturing, and transferring mouse blastocysts that can be easily applied in research. Potential applications include testing new media components that do not affect preimplantation but do affect implantation and early development. The embryo transfer method proposed here has been demonstrated to achieve embryo implantation easier and faster than, and in approximately similar rates as other traditional surgery methods. This workflow is the first set of complete step-by-step instructions available that incorporate advances such as nonsurgical mouse embryo transfer. This will facilitate research into different reproduction events such as embryo development, embryo implantation, or contraception. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

The impairment of learning and memory and synaptic loss in mouse after chronic nitrite exposure.

PubMed

Chen, Yongfang; Cui, Zhanjun; Wang, Lai; Liu, Hongliang; Fan, Wenjuan; Deng, Jinbo; Deng, Jiexin

2016-12-01

The objective of this study is to understand the impairment of learning and memory in mouse after chronic nitrite exposure. The animal model of nitrite exposure in mouse was created with the daily intubation of nitrite in adult healthy male mice for 3 months. Furthermore, the mouse's learning and memory abilities were tested with Morris water maze, and the expression of Synaptophysin and γ-Synuclein was visualized with immunocytochemistry and Western blot. Our results showed that nitrite exposure significantly prolonged the escape latency period (ELP) and decreased the values of the frequency across platform (FAP) as well as the accumulative time in target quadrant (ATITQ) compared to control, in dose-dependent manner. In addition, after nitrite exposure, synaptophysin (SYN) positive buttons in the visual cortex was reduced, in contrast the increase of γ-synuclein positive cells. The results above were supported by Western blot as well. We conclude that nitrite exposure could lead to a decline in mice's learning and memory. The overexpression of γ-synuclein contributed to the synaptic loss, which is most likely the cause of learning and memory impairment. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1720-1730, 2016. © 2015 Wiley Periodicals, Inc.

Visual deficits in a mouse model of Batten disease are the result of optic nerve degeneration and loss of dorsal lateral geniculate thalamic neurons

PubMed Central

Weimer, Jill M.; Custer, Andrew W.; Benedict, Jared W.; Alexander, Noreen A.; Kingsley, Evan; Federoff, Howard J.; Cooper, Jonathan D.; Pearce, David A.

2013-01-01

Juvenile neuronal ceroid lipofuscinosis (JNCL) is an autosomal recessive disorder of childhood caused by mutations in CLN3. Although visual deterioration is typically the first clinical sign to manifest in affected children, loss of Cln3 in a mouse model of JNCL does not recapitulate this retinal deterioration. This suggests that either the loss of CLN3 does not directly affect retinal cell survival or that nuclei involved in visual processing are affected prior to retinal degeneration. Having previously demonstrated that Cln3−/− mice have decreased optic nerve axonal density, we now demonstrate a decrease in nerve conduction. Examination of retino-recipient regions revealed a decreased number of neurons within the dorsal lateral geniculate nucleus (LGNd). We demonstrate decreased transport of amino acids from the retina to the LGN, suggesting an impediment in communication between the retina and projection nuclei. This study defines a novel path of degeneration within the LGNd, providing a mechanism for causation of JNCL visual deficits. PMID:16412658

The Importance of Visual Experience, Gender, and Emotion in the Assessment of an Assistive Tactile Mouse.

PubMed

Brayda, Luca; Campus, Claudio; Memeo, Mariacarla; Lucagrossi, Laura

2015-01-01

Tactile maps are efficient tools to improve spatial understanding and mobility skills of visually impaired people. Their limited adaptability can be compensated with haptic devices which display graphical information, but their assessment is frequently limited to performance-based metrics only which can hide potential spatial abilities in O&M protocols. We assess a low-tech tactile mouse able to deliver three-dimensional content considering how performance, mental workload, behavior, and anxiety status vary with task difficulty and gender in congenitally blind, late blind, and sighted subjects. Results show that task difficulty coherently modulates the efficiency and difficulty to build mental maps, regardless of visual experience. Although exhibiting attitudes that were similar and gender-independent, the females had lower performance and higher cognitive load, especially when congenitally blind. All groups showed a significant decrease in anxiety after using the device. Tactile graphics with our device seems therefore to be applicable with different visual experiences, with no negative emotional consequences of mentally demanding spatial tasks. Going beyond performance-based assessment, our methodology can help with better targeting technological solutions in orientation and mobility protocols.

Human Pluripotent Stem-Cell-Derived Cortical Neurons Integrate Functionally into the Lesioned Adult Murine Visual Cortex in an Area-Specific Way.

PubMed

Espuny-Camacho, Ira; Michelsen, Kimmo A; Linaro, Daniele; Bilheu, Angéline; Acosta-Verdugo, Sandra; Herpoel, Adèle; Giugliano, Michele; Gaillard, Afsaneh; Vanderhaeghen, Pierre

2018-05-29

The transplantation of pluripotent stem-cell-derived neurons constitutes a promising avenue for the treatment of several brain diseases. However, their potential for the repair of the cerebral cortex remains unclear, given its complexity and neuronal diversity. Here, we show that human visual cortical cells differentiated from embryonic stem cells can be transplanted and can integrate successfully into the lesioned mouse adult visual cortex. The transplanted human neurons expressed the appropriate repertoire of markers of six cortical layers, projected axons to specific visual cortical targets, and were synaptically active within the adult brain. Moreover, transplant maturation and integration were much less efficient following transplantation into the lesioned motor cortex, as previously observed for transplanted mouse cortical neurons. These data constitute an important milestone for the potential use of human PSC-derived cortical cells for the reassembly of cortical circuits and emphasize the importance of cortical areal identity for successful transplantation. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

In Vivo Evaluation of White Matter Integrity and Anterograde Transport in Visual System After Excitotoxic Retinal Injury With Multimodal MRI and OCT

PubMed Central

Ho, Leon C.; Wang, Bo; Conner, Ian P.; van der Merwe, Yolandi; Bilonick, Richard A.; Kim, Seong-Gi; Wu, Ed X.; Sigal, Ian A.; Wollstein, Gadi; Schuman, Joel S.; Chan, Kevin C.

2015-01-01

Purpose. Excitotoxicity has been linked to the pathogenesis of ocular diseases and injuries and may involve early degeneration of both anterior and posterior visual pathways. However, their spatiotemporal relationships remain unclear. We hypothesized that the effects of excitotoxic retinal injury (ERI) on the visual system can be revealed in vivo by diffusion tensor magnetic resonance imagining (DTI), manganese-enhanced magnetic resonance imagining (MRI), and optical coherence tomography (OCT). Methods. Diffusion tensor MRI was performed at 9.4 Tesla to monitor white matter integrity changes after unilateral N-methyl-D-aspartate (NMDA)-induced ERI in six Sprague-Dawley rats and six C57BL/6J mice. Additionally, four rats and four mice were intravitreally injected with saline to compare with NMDA-injected animals. Optical coherence tomography of the retina and manganese-enhanced MRI of anterograde transport were evaluated and correlated with DTI parameters. Results. In the rat optic nerve, the largest axial diffusivity decrease and radial diffusivity increase occurred within the first 3 and 7 days post ERI, respectively, suggestive of early axonal degeneration and delayed demyelination. The optic tract showed smaller directional diffusivity changes and weaker DTI correlations with retinal thickness compared with optic nerve, indicative of anterograde degeneration. The splenium of corpus callosum was also reorganized at 4 weeks post ERI. The DTI profiles appeared comparable between rat and mouse models. Furthermore, the NMDA-injured visual pathway showed reduced anterograde manganese transport, which correlated with diffusivity changes along but not perpendicular to optic nerve. Conclusions. Diffusion tensor MRI, manganese-enhanced MRI, and OCT provided an in vivo model system for characterizing the spatiotemporal changes in white matter integrity, the eye–brain relationships and structural–physiological relationships in the visual system after ERI. PMID:26066747

Disruption of visual circuit formation and refinement in a mouse model of autism

PubMed Central

Khanbabaei, Maryam; Murari, Kartikeya; Rho, Jong M.

2016-01-01

Aberrant connectivity is believed to contribute to the pathophysiology of autism spectrum disorder (ASD). Recent neuroimaging studies have increasingly identified such impairments in patients with ASD, including alterations in sensory systems. However, the cellular substrates and molecular underpinnings of disrupted connectivity remain poorly understood. Utilizing eye‐specific segregation in the dorsal lateral geniculate nucleus (dLGN) as a model system, we investigated the formation and refinement of precise patterning of synaptic connections in the BTBR T + tf/J (BTBR) mouse model of ASD. We found that at the neonatal stage, the shape of the dLGN occupied by retinal afferents was altered in the BTBR group compared to C57BL/6J (B6) animals. Notably, the degree of overlap between the ipsi‐ and contralateral afferents was significantly greater in the BTBR mice. Moreover, these abnormalities continued into mature stage in the BTBR animals, suggesting persistent deficits rather than delayed maturation of axonal refinement. Together, these results indicate disrupted connectivity at the synaptic patterning level in the BTBR mice, suggesting that in general, altered neural circuitry may contribute to autistic behaviours seen in this animal model. In addition, these data are consistent with the notion that lower‐level, primary processing mechanisms contribute to altered visual perception in ASD. Autism Res 2017, 10: 212–223. © 2016 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research. PMID:27529416

Combined effects of expectations and visual uncertainty upon detection and identification of a target in the fog.

PubMed

Quétard, Boris; Quinton, Jean-Charles; Colomb, Michèle; Pezzulo, Giovanni; Barca, Laura; Izaute, Marie; Appadoo, Owen Kevin; Mermillod, Martial

2015-09-01

Detecting a pedestrian while driving in the fog is one situation where the prior expectation about the target presence is integrated with the noisy visual input. We focus on how these sources of information influence the oculomotor behavior and are integrated within an underlying decision-making process. The participants had to judge whether high-/low-density fog scenes displayed on a computer screen contained a pedestrian or a deer by executing a mouse movement toward the response button (mouse-tracking). A variable road sign was added on the scene to manipulate expectations about target identity. We then analyzed the timing and amplitude of the deviation of mouse trajectories toward the incorrect response and, using an eye tracker, the detection time (before fixating the target) and the identification time (fixations on the target). Results revealed that expectation of the correct target results in earlier decisions with less deviation toward the alternative response, this effect being partially explained by the facilitation of target identification.

Diversity in spatial scope of contrast adaptation among mouse retinal ganglion cells.

PubMed

Khani, Mohammad Hossein; Gollisch, Tim

2017-12-01

Retinal ganglion cells adapt to changes in visual contrast by adjusting their response kinetics and sensitivity. While much work has focused on the time scales of these adaptation processes, less is known about the spatial scale of contrast adaptation. For example, do small, localized contrast changes affect a cell's signal processing across its entire receptive field? Previous investigations have provided conflicting evidence, suggesting that contrast adaptation occurs either locally within subregions of a ganglion cell's receptive field or globally over the receptive field in its entirety. Here, we investigated the spatial extent of contrast adaptation in ganglion cells of the isolated mouse retina through multielectrode-array recordings. We applied visual stimuli so that ganglion cell receptive fields contained regions where the average contrast level changed periodically as well as regions with constant average contrast level. This allowed us to analyze temporal stimulus integration and sensitivity separately for stimulus regions with and without contrast changes. We found that the spatial scope of contrast adaptation depends strongly on cell identity, with some ganglion cells displaying clear local adaptation, whereas others, in particular large transient ganglion cells, adapted globally to contrast changes. Thus, the spatial scope of contrast adaptation in mouse retinal ganglion cells appears to be cell-type specific. This could reflect differences in mechanisms of contrast adaptation and may contribute to the functional diversity of different ganglion cell types. NEW & NOTEWORTHY Understanding whether adaptation of a neuron in a sensory system can occur locally inside the receptive field or whether it always globally affects the entire receptive field is important for understanding how the neuron processes complex sensory stimuli. For mouse retinal ganglion cells, we here show that both local and global contrast adaptation exist and that this diversity in spatial scope can contribute to the functional diversity of retinal ganglion cell types. Copyright © 2017 the American Physiological Society.

Diversity in spatial scope of contrast adaptation among mouse retinal ganglion cells

PubMed Central

Khani, Mohammad Hossein

2017-01-01

Retinal ganglion cells adapt to changes in visual contrast by adjusting their response kinetics and sensitivity. While much work has focused on the time scales of these adaptation processes, less is known about the spatial scale of contrast adaptation. For example, do small, localized contrast changes affect a cell’s signal processing across its entire receptive field? Previous investigations have provided conflicting evidence, suggesting that contrast adaptation occurs either locally within subregions of a ganglion cell’s receptive field or globally over the receptive field in its entirety. Here, we investigated the spatial extent of contrast adaptation in ganglion cells of the isolated mouse retina through multielectrode-array recordings. We applied visual stimuli so that ganglion cell receptive fields contained regions where the average contrast level changed periodically as well as regions with constant average contrast level. This allowed us to analyze temporal stimulus integration and sensitivity separately for stimulus regions with and without contrast changes. We found that the spatial scope of contrast adaptation depends strongly on cell identity, with some ganglion cells displaying clear local adaptation, whereas others, in particular large transient ganglion cells, adapted globally to contrast changes. Thus, the spatial scope of contrast adaptation in mouse retinal ganglion cells appears to be cell-type specific. This could reflect differences in mechanisms of contrast adaptation and may contribute to the functional diversity of different ganglion cell types. NEW & NOTEWORTHY Understanding whether adaptation of a neuron in a sensory system can occur locally inside the receptive field or whether it always globally affects the entire receptive field is important for understanding how the neuron processes complex sensory stimuli. For mouse retinal ganglion cells, we here show that both local and global contrast adaptation exist and that this diversity in spatial scope can contribute to the functional diversity of retinal ganglion cell types. PMID:28904106

Ammonia Levels and Urine-Spot Characteristics as Cage-Change Indicators for High-Density Individually Ventilated Mouse Cages

PubMed Central

Washington, Ida M; Payton, Mark E

2016-01-01

Mouse cage and bedding changes are potentially stressful to mice and are also labor- and resource-intensive. These changes are often performed on a calendar-based schedule to maintain a clean microenvironment and limit the concentrations of ammonia to which mice and workers are exposed. The current study sought to establish a performance-based approach to mouse cage-changing that uses urine spot characteristics as visual indicators of intracage ammonia levels. Colorimetric ammonia indicators were used to measure ammonia levels in individually-ventilated cages (IVC) housing male or female mice (n =5 per cage) of various strains at 1 to 16 d after cage change. Urine spot characteristics were correlated with ammonia levels to create a visual indicator of the cage-change criterion of 25 ppm ammonia. Results demonstrated a consistent increase in ammonia levels with days since cage change, with cages reaching the cage-change criterion at approximately 10 d for IVC containing male mice and 16 d for those with female mice. Ammonia levels were higher for male than female mice but were not correlated with mouse age. However, urine spot diameter, color, and edge characteristics were strongly correlated with ammonia levels. Husbandry practices based on using urine spot characteristics as indicators of ammonia levels led to fewer weekly cage changes and concomitant savings in labor and resources. Therefore, urine spot characteristics can be used as visual indicators of intracage ammonia levels for use of a performance (urine spot)-based approach to cage-changing frequency that maintains animal health and wellbeing. PMID:27177558

Expression of Human Complement Factor H Prevents Age-Related Macular Degeneration–Like Retina Damage and Kidney Abnormalities in Aged Cfh Knockout Mice

PubMed Central

Ding, Jin-Dong; Kelly, Una; Landowski, Michael; Toomey, Christopher B.; Groelle, Marybeth; Miller, Chelsey; Smith, Stephanie G.; Klingeborn, Mikael; Singhapricha, Terry; Jiang, Haixiang; Frank, Michael M.; Bowes Rickman, Catherine

2016-01-01

Complement factor H (CFH) is an important regulatory protein in the alternative pathway of the complement system, and CFH polymorphisms increase the genetic risk of age-related macular degeneration dramatically. These same human CFH variants have also been associated with dense deposit disease. To mechanistically study the function of CFH in the pathogenesis of these diseases, we created transgenic mouse lines using human CFH bacterial artificial chromosomes expressing full-length human CFH variants and crossed these to Cfh knockout (Cfh−/−) mice. Human CFH protein inhibited cleavage of mouse complement component 3 and factor B in plasma and in retinal pigment epithelium/choroid/sclera, establishing that human CFH regulates activation of the mouse alternative pathway. One of the mouse lines, which express relatively higher levels of CFH, demonstrated functional and structural protection of the retina owing to the Cfh deletion. Impaired visual function, detected as a deficit in the scotopic electroretinographic response, was improved in this transgenic mouse line compared with Cfh−/− mice, and transgenics had a thicker outer nuclear layer and less sub–retinal pigment epithelium deposit accumulation. In addition, expression of human CFH also completely protected the mice from developing kidney abnormalities associated with loss of CFH. These humanized CFH mice present a valuable model for study of the molecular mechanisms of age-related macular degeneration and dense deposit disease and for testing therapeutic targets. PMID:25447048

Interactive visualization and analysis of multimodal datasets for surgical applications.

PubMed

Kirmizibayrak, Can; Yim, Yeny; Wakid, Mike; Hahn, James

2012-12-01

Surgeons use information from multiple sources when making surgical decisions. These include volumetric datasets (such as CT, PET, MRI, and their variants), 2D datasets (such as endoscopic videos), and vector-valued datasets (such as computer simulations). Presenting all the information to the user in an effective manner is a challenging problem. In this paper, we present a visualization approach that displays the information from various sources in a single coherent view. The system allows the user to explore and manipulate volumetric datasets, display analysis of dataset values in local regions, combine 2D and 3D imaging modalities and display results of vector-based computer simulations. Several interaction methods are discussed: in addition to traditional interfaces including mouse and trackers, gesture-based natural interaction methods are shown to control these visualizations with real-time performance. An example of a medical application (medialization laryngoplasty) is presented to demonstrate how the combination of different modalities can be used in a surgical setting with our approach.

Versatile functional roles of horizontal cells in the retinal circuit.

PubMed

Chaya, Taro; Matsumoto, Akihiro; Sugita, Yuko; Watanabe, Satoshi; Kuwahara, Ryusuke; Tachibana, Masao; Furukawa, Takahisa

2017-07-17

In the retinal circuit, environmental light signals are converted into electrical signals that can be decoded properly by the brain. At the first synapse of the visual system, information flow from photoreceptors to bipolar cells is modulated by horizontal cells (HCs), however, their functional contribution to retinal output and individual visual function is not fully understood. In the current study, we investigated functional roles for HCs in retinal ganglion cell (RGC) response properties and optokinetic responses by establishing a HC-depleted mouse line. We observed that HC depletion impairs the antagonistic center-surround receptive field formation of RGCs, supporting a previously reported HC function revealed by pharmacological approaches. In addition, we found that HC loss reduces both the ON and OFF response diversities of RGCs, impairs adjustment of the sensitivity to ambient light at the retinal output level, and alters spatial frequency tuning at an individual level. Taken together, our current study suggests multiple functional aspects of HCs crucial for visual processing.

Enhancement of vision by monocular deprivation in adult mice.

PubMed

Prusky, Glen T; Alam, Nazia M; Douglas, Robert M

2006-11-08

Plasticity of vision mediated through binocular interactions has been reported in mammals only during a "critical" period in juvenile life, wherein monocular deprivation (MD) causes an enduring loss of visual acuity (amblyopia) selectively through the deprived eye. Here, we report a different form of interocular plasticity of vision in adult mice in which MD leads to an enhancement of the optokinetic response (OKR) selectively through the nondeprived eye. Over 5 d of MD, the spatial frequency sensitivity of the OKR increased gradually, reaching a plateau of approximately 36% above pre-deprivation baseline. Eye opening initiated a gradual decline, but sensitivity was maintained above pre-deprivation baseline for 5-6 d. Enhanced function was restricted to the monocular visual field, notwithstanding the dependence of the plasticity on binocular interactions. Activity in visual cortex ipsilateral to the deprived eye was necessary for the characteristic induction of the enhancement, and activity in visual cortex contralateral to the deprived eye was necessary for its maintenance after MD. The plasticity also displayed distinct learning-like properties: Active testing experience was required to attain maximal enhancement and for enhancement to persist after MD, and the duration of enhanced sensitivity after MD was extended by increasing the length of MD, and by repeating MD. These data show that the adult mouse visual system maintains a form of experience-dependent plasticity in which the visual cortex can modulate the normal function of subcortical visual pathways.

A three-dimensional single-cell-resolution whole-brain atlas using CUBIC-X expansion microscopy and tissue clearing.

PubMed

Murakami, Tatsuya C; Mano, Tomoyuki; Saikawa, Shu; Horiguchi, Shuhei A; Shigeta, Daichi; Baba, Kousuke; Sekiya, Hiroshi; Shimizu, Yoshihiro; Tanaka, Kenji F; Kiyonari, Hiroshi; Iino, Masamitsu; Mochizuki, Hideki; Tainaka, Kazuki; Ueda, Hiroki R

2018-04-01

A three-dimensional single-cell-resolution mammalian brain atlas will accelerate systems-level identification and analysis of cellular circuits underlying various brain functions. However, its construction requires efficient subcellular-resolution imaging throughout the entire brain. To address this challenge, we developed a fluorescent-protein-compatible, whole-organ clearing and homogeneous expansion protocol based on an aqueous chemical solution (CUBIC-X). The expanded, well-cleared brain enabled us to construct a point-based mouse brain atlas with single-cell annotation (CUBIC-Atlas). CUBIC-Atlas reflects inhomogeneous whole-brain development, revealing a significant decrease in the cerebral visual and somatosensory cortical areas during postnatal development. Probabilistic activity mapping of pharmacologically stimulated Arc-dVenus reporter mouse brains onto CUBIC-Atlas revealed the existence of distinct functional structures in the hippocampal dentate gyrus. CUBIC-Atlas is shareable by an open-source web-based viewer, providing a new platform for whole-brain cell profiling.

Improved mutagen testing systems in mice. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roderick, T.H.

Our laboratory was the first to induce and ascertain a mammalian chromosomal inversion; we did this by searching for a high frequency of first meiotic anaphase bridges in testes of males whose fathers received post-spermatogonial radiation or mutagenesis from chromosomal breaking chemical mutagens. One test in was examined in each mouse, and those showing a high frequency were then mated to determine if the high frequency were passed on as a dominant and whether linkage analysis suggested the presence of an inversion. A very high incidence (exceeding 20% bridges in first meiotic anaphase bridges) was found in about 1 inmore » 150 males examined and this frequency was generally found to be passed on to the offspring an predicted. Later cytological banding techniques were developed elsewhere and we used them to show visually the inverted orders of the inverted chromosomal segments. Since that time we have induced inversions covering most of the mouse genome.« less

Improved mutagen testing systems in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roderick, T.H.

Our laboratory was the first to induce and ascertain a mammalian chromosomal inversion; we did this by searching for a high frequency of first meiotic anaphase bridges in testes of males whose fathers received post-spermatogonial radiation or mutagenesis from chromosomal breaking chemical mutagens. One test in was examined in each mouse, and those showing a high frequency were then mated to determine if the high frequency were passed on as a dominant and whether linkage analysis suggested the presence of an inversion. A very high incidence (exceeding 20% bridges in first meiotic anaphase bridges) was found in about 1 inmore » 150 males examined and this frequency was generally found to be passed on to the offspring an predicted. Later cytological banding techniques were developed elsewhere and we used them to show visually the inverted orders of the inverted chromosomal segments. Since that time we have induced inversions covering most of the mouse genome.« less

Allen Brain Atlas-Driven Visualizations: a web-based gene expression energy visualization tool.

PubMed

Zaldivar, Andrew; Krichmar, Jeffrey L

2014-01-01

The Allen Brain Atlas-Driven Visualizations (ABADV) is a publicly accessible web-based tool created to retrieve and visualize expression energy data from the Allen Brain Atlas (ABA) across multiple genes and brain structures. Though the ABA offers their own search engine and software for researchers to view their growing collection of online public data sets, including extensive gene expression and neuroanatomical data from human and mouse brain, many of their tools limit the amount of genes and brain structures researchers can view at once. To complement their work, ABADV generates multiple pie charts, bar charts and heat maps of expression energy values for any given set of genes and brain structures. Such a suite of free and easy-to-understand visualizations allows for easy comparison of gene expression across multiple brain areas. In addition, each visualization links back to the ABA so researchers may view a summary of the experimental detail. ABADV is currently supported on modern web browsers and is compatible with expression energy data from the Allen Mouse Brain Atlas in situ hybridization data. By creating this web application, researchers can immediately obtain and survey numerous amounts of expression energy data from the ABA, which they can then use to supplement their work or perform meta-analysis. In the future, we hope to enable ABADV across multiple data resources.

PBN (Phenyl-N-Tert-Butylnitrone)-Derivatives Are Effective in Slowing the Visual Cycle and Rhodopsin Regeneration and in Protecting the Retina from Light-Induced Damage

PubMed Central

Stiles, Megan; Moiseyev, Gennadiy P.; Budda, Madeline L.; Linens, Annette; Brush, Richard S.; Qi, Hui; White, Gary L.; Wolf, Roman F.; Ma, Jian-xing; Floyd, Robert; Anderson, Robert E.; Mandal, Nawajes A.

2015-01-01

A2E and related toxic molecules are part of lipofuscin found in the retinal pigment epithelial (RPE) cells in eyes affected by Stargardt’s disease, age-related macular degeneration (AMD), and other retinal degenerations. A novel therapeutic approach for treating such degenerations involves slowing down the visual cycle, which could reduce the amount of A2E in the RPE. This can be accomplished by inhibiting RPE65, which produces 11-cis-retinol from all-trans-retinyl esters. We recently showed that phenyl-N-tert-butylnitrone (PBN) inhibits RPE65 enzyme activity in RPE cells. In this study we show that like PBN, certain PBN-derivatives (PBNDs) such as 4-F-PBN, 4-CF3-PBN, 3,4-di-F-PBN, and 4-CH3-PBN can inhibit RPE65 and synthesis of 11-cis-retinol in in vitro assays using bovine RPE microsomes. We further demonstrate that systemic (intraperitoneal, IP) administration of these PBNDs protect the rat retina from light damage. Electroretinography (ERG) and histological analysis showed that rats treated with PBNDs retained ~90% of their photoreceptor cells compared to a complete loss of function and 90% loss of photoreceptors in the central retina in rats treated with vehicle/control injections. Topically applied PBN and PBNDs also significantly slowed the rate of the visual cycle in mouse and baboon eyes. One hour dark adaptation resulted in 75–80% recovery of bleachable rhodopsin in control/vehicle treated mice. Eye drops of 5% 4-CH3-PBN were most effective, inhibiting the regeneration of bleachable rhodopsin significantly (60% compared to vehicle control). In addition, a 10% concentration of PBN and 5% concentration of 4-CH3-PBN in baboon eyes inhibited the visual cycle by 60% and by 30%, respectively. We have identified a group of PBN related nitrones that can reach the target tissue (RPE) by systemic and topical application and slow the rate of rhodopsin regeneration and therefore the visual cycle in mouse and baboon eyes. PBNDs can also protect the rat retina from light damage. There is potential in developing these compounds as preventative therapeutics for the treatment of human retinal degenerations in which the accumulation of lipofuscin may be pathogenic. PMID:26694648

PBN (Phenyl-N-Tert-Butylnitrone)-Derivatives Are Effective in Slowing the Visual Cycle and Rhodopsin Regeneration and in Protecting the Retina from Light-Induced Damage.

PubMed

Stiles, Megan; Moiseyev, Gennadiy P; Budda, Madeline L; Linens, Annette; Brush, Richard S; Qi, Hui; White, Gary L; Wolf, Roman F; Ma, Jian-Xing; Floyd, Robert; Anderson, Robert E; Mandal, Nawajes A

2015-01-01

A2E and related toxic molecules are part of lipofuscin found in the retinal pigment epithelial (RPE) cells in eyes affected by Stargardt's disease, age-related macular degeneration (AMD), and other retinal degenerations. A novel therapeutic approach for treating such degenerations involves slowing down the visual cycle, which could reduce the amount of A2E in the RPE. This can be accomplished by inhibiting RPE65, which produces 11-cis-retinol from all-trans-retinyl esters. We recently showed that phenyl-N-tert-butylnitrone (PBN) inhibits RPE65 enzyme activity in RPE cells. In this study we show that like PBN, certain PBN-derivatives (PBNDs) such as 4-F-PBN, 4-CF3-PBN, 3,4-di-F-PBN, and 4-CH3-PBN can inhibit RPE65 and synthesis of 11-cis-retinol in in vitro assays using bovine RPE microsomes. We further demonstrate that systemic (intraperitoneal, IP) administration of these PBNDs protect the rat retina from light damage. Electroretinography (ERG) and histological analysis showed that rats treated with PBNDs retained ~90% of their photoreceptor cells compared to a complete loss of function and 90% loss of photoreceptors in the central retina in rats treated with vehicle/control injections. Topically applied PBN and PBNDs also significantly slowed the rate of the visual cycle in mouse and baboon eyes. One hour dark adaptation resulted in 75-80% recovery of bleachable rhodopsin in control/vehicle treated mice. Eye drops of 5% 4-CH3-PBN were most effective, inhibiting the regeneration of bleachable rhodopsin significantly (60% compared to vehicle control). In addition, a 10% concentration of PBN and 5% concentration of 4-CH3-PBN in baboon eyes inhibited the visual cycle by 60% and by 30%, respectively. We have identified a group of PBN related nitrones that can reach the target tissue (RPE) by systemic and topical application and slow the rate of rhodopsin regeneration and therefore the visual cycle in mouse and baboon eyes. PBNDs can also protect the rat retina from light damage. There is potential in developing these compounds as preventative therapeutics for the treatment of human retinal degenerations in which the accumulation of lipofuscin may be pathogenic.

Expression pattern of cadherins in the naked mole rat (Heterocephalus glaber) suggests innate cortical diversification of the cerebrum.

PubMed

Matsunaga, Eiji; Nambu, Sanae; Iriki, Atsushi; Okanoya, Kazuo

2011-06-15

The cerebral cortex is an indispensable region for higher cognitive function that is remarkably diverse among mammalian species. Although previous research has shown that the cortical area map in the mammalian cerebral cortex is formed by innate and activity-dependent mechanisms, it remains unknown how these mechanisms contribute to the evolution and diversification of the functional cortical areas in various species. The naked mole rat (Heterocephalus glaber) is a subterranean, eusocial rodent. Physiological and anatomical studies have revealed that the visual system is regressed and the somatosensory system is enlarged. To examine whether species differences in cortical area development are caused by intrinsic factors or environmental factors, we performed comparative gene expression analysis of neonatal naked mole rat and mouse brains. The expression domain of cadherin-6, a somatosensory marker, was expanded caudally and shifted dorsally in the cortex, whereas the expression domain of cadherin-8, a visual marker, was reduced caudally in the neonatal naked mole rat cortex. The expression domain of cadherin-8 was also reduced in other visual areas, such as the lateral geniculate nucleus and superior colliculus. Immunohistochemical analysis of thalamocortical fibers further suggested that somatosensory input did not affect cortical gene expression in the neonatal naked mole rat brain. These results suggest that the development of the somatosensory system and the regression of the visual system in the naked mole rat cortex are due to intrinsic genetic mechanisms as well as sensory input-dependent mechanisms. Intrinsic genetic mechanisms thus appear to contribute to species diversity in cortical area formation. Copyright © 2011 Wiley-Liss, Inc.

Visualization of tumor vascular reactivity in response to respiratory challenges by optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kim, Hoon Sup; Lee, Songhyun; Lee, Kiri; Eom, Tae Joong; Kim, Jae G.

2016-02-01

We previously reported the potential of using vascular reactivity during respiratory challenges as a marker to predict the response of breast tumor to chemotherapy in a rat model by using a continuous wave near-infrared spectroscopy. However, it cannot visualize how the vascular reactivity from tumor vessel can predict the tumor response to its treatment. In this study, we utilized a spectral domain optical coherence tomography (SD-OCT) system to visualize vascular reactivity of both tumor and normal vasculature during respiratory challenges in a mouse model. We adapted intensity based Doppler variance algorithm to draw angiogram from the ear of mouse (8-week-old Balb/c nu/nu). Animals were anesthetized using 1.5% isoflurane, and the body temperature was maintained by a heating pad. Inhalational gas was switched from air (10min) to 100% oxygen (10min), and a pulse oximeter was used to monitor arterial oxygen saturation and heart rate. OCT angiograms were acquired 5 min after the onset of each gas. The vasoconstriction effect of hyperoxic gas on vasculature was shown by subtracting an en-face image acquired during 100% oxygen from the image acquired during air inhalation. The quantitative change in the vessel diameter was measured from the en-face OCT images of the individual blood vessels. The percentage of blood vessel diameter reduction varied from 1% to 12% depending on arterial, capillary, or venous blood vessel. The vascular reactivity change during breast tumor progression and post chemotherapy will be monitored by OCT angiography.

Roles of ON Cone Bipolar Cell Subtypes in Temporal Coding in the Mouse Retina

PubMed Central

Fyk-Kolodziej, Bozena; Cohn, Jesse

2014-01-01

In the visual system, diverse image processing starts with bipolar cells, which are the second-order neurons of the retina. Thirteen subtypes of bipolar cells have been identified, which are thought to encode different features of image signaling and to initiate distinct signal-processing streams. Although morphologically identified, the functional roles of each bipolar cell subtype in visual signal encoding are not fully understood. Here, we investigated how ON cone bipolar cells of the mouse retina encode diverse temporal image signaling. We recorded bipolar cell voltage changes in response to two different input functions: sinusoidal light and step light stimuli. Temporal tuning in ON cone bipolar cells was diverse and occurred in a subtype-dependent manner. Subtypes 5s and 8 exhibited low-pass filtering property in response to a sinusoidal light stimulus, and responded with sustained fashion to step-light stimulation. Conversely, subtypes 5f, 6, 7, and XBC exhibited bandpass filtering property in response to sinusoidal light stimuli, and responded transiently to step-light stimuli. In particular, subtypes 7 and XBC were high-temporal tuning cells. We recorded responses in different ways to further examine the underlying mechanisms of temporal tuning. Current injection evoked low-pass filtering, whereas light responses in voltage-clamp mode produced bandpass filtering in all ON bipolar cells. These findings suggest that cone photoreceptor inputs shape bandpass filtering in bipolar cells, whereas intrinsic properties of bipolar cells shape low-pass filtering. Together, our results demonstrate that ON bipolar cells encode diverse temporal image signaling in a subtype-dependent manner to initiate temporal visual information-processing pathways. PMID:24966376

High-Speed and Scalable Whole-Brain Imaging in Rodents and Primates.

PubMed

Seiriki, Kaoru; Kasai, Atsushi; Hashimoto, Takeshi; Schulze, Wiebke; Niu, Misaki; Yamaguchi, Shun; Nakazawa, Takanobu; Inoue, Ken-Ichi; Uezono, Shiori; Takada, Masahiko; Naka, Yuichiro; Igarashi, Hisato; Tanuma, Masato; Waschek, James A; Ago, Yukio; Tanaka, Kenji F; Hayata-Takano, Atsuko; Nagayasu, Kazuki; Shintani, Norihito; Hashimoto, Ryota; Kunii, Yasuto; Hino, Mizuki; Matsumoto, Junya; Yabe, Hirooki; Nagai, Takeharu; Fujita, Katsumasa; Matsuda, Toshio; Takuma, Kazuhiro; Baba, Akemichi; Hashimoto, Hitoshi

2017-06-21

Subcellular resolution imaging of the whole brain and subsequent image analysis are prerequisites for understanding anatomical and functional brain networks. Here, we have developed a very high-speed serial-sectioning imaging system named FAST (block-face serial microscopy tomography), which acquires high-resolution images of a whole mouse brain in a speed range comparable to that of light-sheet fluorescence microscopy. FAST enables complete visualization of the brain at a resolution sufficient to resolve all cells and their subcellular structures. FAST renders unbiased quantitative group comparisons of normal and disease model brain cells for the whole brain at a high spatial resolution. Furthermore, FAST is highly scalable to non-human primate brains and human postmortem brain tissues, and can visualize neuronal projections in a whole adult marmoset brain. Thus, FAST provides new opportunities for global approaches that will allow for a better understanding of brain systems in multiple animal models and in human diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

Spatial cell firing during virtual navigation of open arenas by head-restrained mice.

PubMed

Chen, Guifen; King, John Andrew; Lu, Yi; Cacucci, Francesca; Burgess, Neil

2018-06-18

We present a mouse virtual reality (VR) system which restrains head-movements to horizontal rotations, compatible with multi-photon imaging. This system allows expression of the spatial navigation and neuronal firing patterns characteristic of real open arenas (R). Comparing VR to R: place and grid, but not head-direction, cell firing had broader spatial tuning; place, but not grid, cell firing was more directional; theta frequency increased less with running speed; whereas increases in firing rates with running speed and place and grid cells' theta phase precession were similar. These results suggest that the omni-directional place cell firing in R may require local-cues unavailable in VR, and that the scale of grid and place cell firing patterns, and theta frequency, reflect translational motion inferred from both virtual (visual and proprioceptive) and real (vestibular translation and extra-maze) cues. By contrast, firing rates and theta phase precession appear to reflect visual and proprioceptive cues alone. © 2018, Chen et al.

CardioTF, a database of deconstructing transcriptional circuits in the heart system

PubMed Central

2016-01-01

Background: Information on cardiovascular gene transcription is fragmented and far behind the present requirements of the systems biology field. To create a comprehensive source of data for cardiovascular gene regulation and to facilitate a deeper understanding of genomic data, the CardioTF database was constructed. The purpose of this database is to collate information on cardiovascular transcription factors (TFs), position weight matrices (PWMs), and enhancer sequences discovered using the ChIP-seq method. Methods: The Naïve-Bayes algorithm was used to classify literature and identify all PubMed abstracts on cardiovascular development. The natural language learning tool GNAT was then used to identify corresponding gene names embedded within these abstracts. Local Perl scripts were used to integrate and dump data from public databases into the MariaDB management system (MySQL). In-house R scripts were written to analyze and visualize the results. Results: Known cardiovascular TFs from humans and human homologs from fly, Ciona, zebrafish, frog, chicken, and mouse were identified and deposited in the database. PWMs from Jaspar, hPDI, and UniPROBE databases were deposited in the database and can be retrieved using their corresponding TF names. Gene enhancer regions from various sources of ChIP-seq data were deposited into the database and were able to be visualized by graphical output. Besides biocuration, mouse homologs of the 81 core cardiac TFs were selected using a Naïve-Bayes approach and then by intersecting four independent data sources: RNA profiling, expert annotation, PubMed abstracts and phenotype. Discussion: The CardioTF database can be used as a portal to construct transcriptional network of cardiac development. Availability and Implementation: Database URL: http://www.cardiosignal.org/database/cardiotf.html. PMID:27635320

CardioTF, a database of deconstructing transcriptional circuits in the heart system.

PubMed

Zhen, Yisong

2016-01-01

Information on cardiovascular gene transcription is fragmented and far behind the present requirements of the systems biology field. To create a comprehensive source of data for cardiovascular gene regulation and to facilitate a deeper understanding of genomic data, the CardioTF database was constructed. The purpose of this database is to collate information on cardiovascular transcription factors (TFs), position weight matrices (PWMs), and enhancer sequences discovered using the ChIP-seq method. The Naïve-Bayes algorithm was used to classify literature and identify all PubMed abstracts on cardiovascular development. The natural language learning tool GNAT was then used to identify corresponding gene names embedded within these abstracts. Local Perl scripts were used to integrate and dump data from public databases into the MariaDB management system (MySQL). In-house R scripts were written to analyze and visualize the results. Known cardiovascular TFs from humans and human homologs from fly, Ciona, zebrafish, frog, chicken, and mouse were identified and deposited in the database. PWMs from Jaspar, hPDI, and UniPROBE databases were deposited in the database and can be retrieved using their corresponding TF names. Gene enhancer regions from various sources of ChIP-seq data were deposited into the database and were able to be visualized by graphical output. Besides biocuration, mouse homologs of the 81 core cardiac TFs were selected using a Naïve-Bayes approach and then by intersecting four independent data sources: RNA profiling, expert annotation, PubMed abstracts and phenotype. The CardioTF database can be used as a portal to construct transcriptional network of cardiac development. Database URL: http://www.cardiosignal.org/database/cardiotf.html.

Single-Cell Analysis of Experience-Dependent Transcriptomic States in Mouse Visual Cortex

PubMed Central

Hrvatin, Sinisa; Hochbaum, Daniel R.; Nagy, M. Aurel; Cicconet, Marcelo; Robertson, Keiramarie; Cheadle, Lucas; Zilionis, Rapolas; Ratner, Alex; Borges-Monroy, Rebeca; Klein, Allon M.; Sabatini, Bernardo L.; Greenberg, Michael E.

2017-01-01

Activity-dependent transcriptional responses shape cortical function. However, we lack a comprehensive understanding of the diversity of these responses across the full range of cortical cell types, and how these changes contribute to neuronal plasticity and disease. Here we applied high-throughput single-cell RNA-sequencing to investigate the breadth of transcriptional changes that occur across cell types in mouse visual cortex following exposure to light. We identified significant and divergent transcriptional responses to stimulation in each of the 30 cell types characterized, revealing 611 stimulus-responsive genes. Excitatory pyramidal neurons exhibit inter- and intra-laminar heterogeneity in the induction of stimulus responsive genes. Non-neuronal cells demonstrated clear transcriptional responses that may regulate experience-dependent changes in neurovascular coupling and myelination. Together, these results reveal the dynamic landscape of stimulus-dependent transcriptional changes that occur across cell types in visual cortex, which are likely critical for cortical function and may be sites of de-regulation in developmental brain disorders. PMID:29230054

A method to visualize transdermal nickel permeation in mouse skin using a nickel allergy patch

PubMed Central

Sugiyama, Tomoko; Uo, Motohiro; Wada, Takahiro; Hongo, Toshio; Omagari, Daisuke; Komiyama, Kazuo; Oikawa, Masakazu; Kusama, Mikio; Mori, Yoshiyuki

2015-01-01

Metal patch test is often used in clinical settings when metal-induced contact dermatitis is suspected. However, the transdermal permeation behavior of metal ions from the patch test remains unclear. Current patch tests using high concentrations of metal salt solutions have some side effects, e.g. acute skin reactions to high concentrations of metal salt. To resolve these, estimating metal ion transdermal permeation is wished. In this study, synchrotron radiation X-ray fluorescence (SR-XRF) and micro-focused particle-induced X-ray emission (micro-PIXE) were used to visualize the time-dependent Ni permeation in mouse skin. The cross-sectional diffusion of Ni was visualized in a time-dependent manner. Our results indicate that maximum Ni permeation occurs after 24 h of patch treatment, and the permeated Ni content was high in the epidermis and spread into the dermis beyond the basal layer. This method may be useful to determine the appropriate solution concentration and duration of administration for the patch test. PMID:26484550

Parallel Computations in Insect and Mammalian Visual Motion Processing

PubMed Central

Clark, Damon A.; Demb, Jonathan B.

2016-01-01

Sensory systems use receptors to extract information from the environment and neural circuits to perform subsequent computations. These computations may be described as algorithms composed of sequential mathematical operations. Comparing these operations across taxa reveals how different neural circuits have evolved to solve the same problem, even when using different mechanisms to implement the underlying math. In this review, we compare how insect and mammalian neural circuits have solved the problem of motion estimation, focusing on the fruit fly Drosophila and the mouse retina. Although the two systems implement computations with grossly different anatomy and molecular mechanisms, the underlying circuits transform light into motion signals with strikingly similar processing steps. These similarities run from photoreceptor gain control and spatiotemporal tuning to ON and OFF pathway structures, motion detection, and computed motion signals. The parallels between the two systems suggest that a limited set of algorithms for estimating motion satisfies both the needs of sighted creatures and the constraints imposed on them by metabolism, anatomy, and the structure and regularities of the visual world. PMID:27780048

Parallel Computations in Insect and Mammalian Visual Motion Processing.

PubMed

Clark, Damon A; Demb, Jonathan B

2016-10-24

Sensory systems use receptors to extract information from the environment and neural circuits to perform subsequent computations. These computations may be described as algorithms composed of sequential mathematical operations. Comparing these operations across taxa reveals how different neural circuits have evolved to solve the same problem, even when using different mechanisms to implement the underlying math. In this review, we compare how insect and mammalian neural circuits have solved the problem of motion estimation, focusing on the fruit fly Drosophila and the mouse retina. Although the two systems implement computations with grossly different anatomy and molecular mechanisms, the underlying circuits transform light into motion signals with strikingly similar processing steps. These similarities run from photoreceptor gain control and spatiotemporal tuning to ON and OFF pathway structures, motion detection, and computed motion signals. The parallels between the two systems suggest that a limited set of algorithms for estimating motion satisfies both the needs of sighted creatures and the constraints imposed on them by metabolism, anatomy, and the structure and regularities of the visual world. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multimodality animal rotation imaging system (Mars) for in vivo detection of intraperitoneal tumors.

PubMed

Pizzonia, John; Holmberg, Jennie; Orton, Sean; Alvero, Ayesha; Viteri, Oscar; McLaughlin, William; Feke, Gil; Mor, Gil

2012-01-01

PROBLEM Ovarian cancer stem cells (OCSCs) have been postulated as the potential source of recurrence and chemoresistance. Therefore identification of OvCSC and their complete removal is a pivotal stage for the treatment of ovarian cancer. The objective of the following study was to develop a new in vivo imaging model that allows for the detection and monitoring of OCSCs. METHOD OF STUDY  OCSCs were labeled with X-Sight 761 Nanospheres and injected intra-peritoneally (i.p.) and sub-cutaneously (s.c.) to Athymic nude mice. The Carestream In-Vivo Imaging System FX was used to obtain X-ray and, concurrently, near-infrared fluorescence images. Tumor images in the mouse were observed from different angles by automatic rotation of the mouse. RESULTS  X-Sight 761 Nanospheres labeled almost 100% of the cells. No difference on growth rate was observed between labeled and unlabeled cells. Tumors were observed and monitoring revealed strong signaling up to 21 days. CONCLUSION  We describe the use of near-infrared nanoparticle probes for in vivo imaging of metastatic ovarian cancer models. Visualization of multiple sites around the animals was enhanced with the use of the Carestream Multimodal Animal Rotation System. © 2011 John Wiley & Sons A/S.

PTEN is a potent suppressor of small cell lung cancer.

PubMed

Cui, Min; Augert, Arnaud; Rongione, Michael; Conkrite, Karina; Parazzoli, Susan; Nikitin, Alexander Yu; Ingolia, Nicholas; MacPherson, David

2014-05-01

Small cell lung carcinoma (SCLC) is a highly metastatic tumor type with neuroendocrine features and a dismal prognosis. PTEN mutations and PIK3CA activating mutations have been reported in SCLC but the functional relevance of this pathway is unknown. The PTEN/PIK3CA pathway was interrogated using an AdenoCre-driven mouse model of SCLC harboring inactivated Rb and p53. Inactivation of one allele of PTEN in Rb/p53-deleted mice led to accelerated SCLC with frequent metastasis to the liver. In contrast with the high mutation burden reported in human SCLC, exome analyses revealed a low number of protein-altering mutations in mouse SCLC. Inactivation of both alleles of PTEN in the Rb/p53-deleted system led to nonmetastatic adenocarcinoma with neuroendocrine differentiation. This study reveals a critical role for the PTEN/PI3K pathway in both SCLC and lung adenocarcinoma and provides an ideal system to test the phosphoinositide 3-kinase (PI3K) pathway inhibitors as targeted therapy for subsets of patients with SCLC. The ability of PTEN inactivation to accelerate SCLC in a genetic mouse model suggests that targeting the PTEN pathway is a therapeutic option for a subset of human patients with SCLC. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/early/2014/04/28/1541-7786.MCR-13-0554/F1.large.jpg. ©2014 AACR.

An Advanced Preclinical Mouse Model for Acute Myeloid Leukemia Using Patients' Cells of Various Genetic Subgroups and In Vivo Bioluminescence Imaging

PubMed Central

Vick, Binje; Rothenberg, Maja; Sandhöfer, Nadine; Carlet, Michela; Finkenzeller, Cornelia; Krupka, Christina; Grunert, Michaela; Trumpp, Andreas; Corbacioglu, Selim; Ebinger, Martin; André, Maya C.; Hiddemann, Wolfgang; Schneider, Stephanie; Subklewe, Marion; Metzeler, Klaus H.; Spiekermann, Karsten; Jeremias, Irmela

2015-01-01

Acute myeloid leukemia (AML) is a clinically and molecularly heterogeneous disease with poor outcome. Adequate model systems are required for preclinical studies to improve understanding of AML biology and to develop novel, rational treatment approaches. Xenografts in immunodeficient mice allow performing functional studies on patient-derived AML cells. We have established an improved model system that integrates serial retransplantation of patient-derived xenograft (PDX) cells in mice, genetic manipulation by lentiviral transduction, and essential quality controls by immunophenotyping and targeted resequencing of driver genes. 17/29 samples showed primary engraftment, 10/17 samples could be retransplanted and some of them allowed virtually indefinite serial transplantation. 5/6 samples were successfully transduced using lentiviruses. Neither serial transplantation nor genetic engineering markedly altered sample characteristics analyzed. Transgene expression was stable in PDX AML cells. Example given, recombinant luciferase enabled bioluminescence in vivo imaging and highly sensitive and reliable disease monitoring; imaging visualized minimal disease at 1 PDX cell in 10000 mouse bone marrow cells and facilitated quantifying leukemia initiating cells. We conclude that serial expansion, genetic engineering and imaging represent valuable tools to improve the individualized xenograft mouse model of AML. Prospectively, these advancements enable repetitive, clinically relevant studies on AML biology and preclinical treatment trials on genetically defined and heterogeneous subgroups. PMID:25793878

Visual Information Present in Infragranular Layers of Mouse Auditory Cortex.

PubMed

Morrill, Ryan J; Hasenstaub, Andrea R

2018-03-14

The cerebral cortex is a major hub for the convergence and integration of signals from across the sensory modalities; sensory cortices, including primary regions, are no exception. Here we show that visual stimuli influence neural firing in the auditory cortex of awake male and female mice, using multisite probes to sample single units across multiple cortical layers. We demonstrate that visual stimuli influence firing in both primary and secondary auditory cortex. We then determine the laminar location of recording sites through electrode track tracing with fluorescent dye and optogenetic identification using layer-specific markers. Spiking responses to visual stimulation occur deep in auditory cortex and are particularly prominent in layer 6. Visual modulation of firing rate occurs more frequently at areas with secondary-like auditory responses than those with primary-like responses. Auditory cortical responses to drifting visual gratings are not orientation-tuned, unlike visual cortex responses. The deepest cortical layers thus appear to be an important locus for cross-modal integration in auditory cortex. SIGNIFICANCE STATEMENT The deepest layers of the auditory cortex are often considered its most enigmatic, possessing a wide range of cell morphologies and atypical sensory responses. Here we show that, in mouse auditory cortex, these layers represent a locus of cross-modal convergence, containing many units responsive to visual stimuli. Our results suggest that this visual signal conveys the presence and timing of a stimulus rather than specifics about that stimulus, such as its orientation. These results shed light on both how and what types of cross-modal information is integrated at the earliest stages of sensory cortical processing. Copyright © 2018 the authors 0270-6474/18/382854-09$15.00/0.

Sub-Chronic Neuropathological and Biochemical Changes in Mouse Visual System after Repetitive Mild Traumatic Brain Injury

PubMed Central

Tzekov, Radouil; Dawson, Clint; Orlando, Megan; Mouzon, Benoit; Reed, Jon; Evans, James; Crynen, Gogce; Mullan, Michael; Crawford, Fiona

2016-01-01

Repetitive mild traumatic brain injury (r-mTBI) results in neuropathological and biochemical consequences in the human visual system. Using a recently developed mouse model of r-mTBI, with control mice receiving repetitive anesthesia alone (r-sham) we assessed the effects on the retina and optic nerve using histology, immunohistochemistry, proteomic and lipidomic analyses at 3 weeks post injury. Retina tissue was used to determine retinal ganglion cell (RGC) number, while optic nerve tissue was examined for cellularity, myelin content, protein and lipid changes. Increased cellularity and areas of demyelination were clearly detectable in optic nerves in r-mTBI, but not in r-sham. These changes were accompanied by a ~25% decrease in the total number of Brn3a-positive RGCs. Proteomic analysis of the optic nerves demonstrated various changes consistent with a negative effect of r-mTBI on major cellular processes like depolymerization of microtubules, disassembly of filaments and loss of neurons, manifested by decrease of several proteins, including neurofilaments (NEFH, NEFM, NEFL), tubulin (TUBB2A, TUBA4A), microtubule-associated proteins (MAP1A, MAP1B), collagen (COL6A1, COL6A3) and increased expression of other proteins, including heat shock proteins (HSP90B1, HSPB1), APOE and cathepsin D. Lipidomic analysis showed quantitative changes in a number of phospholipid species, including a significant increase in the total amount of lysophosphatidylcholine (LPC), including the molecular species 16:0, a known demyelinating agent. The overall amount of some ether phospholipids, like ether LPC, ether phosphatidylcholine and ether lysophosphatidylethanolamine were also increased, while the majority of individual molecular species of ester phospholipids, like phosphatidylcholine and phosphatidylethanolamine, were decreased. Results from the biochemical analysis correlate well with changes detected by histological and immunohistochemical methods and indicate the involvement of several important molecular pathways. This will allow future identification of therapeutic targets for improving the visual consequences of r-mTBI. PMID:27088355

Axial elongation in mouse embryos involves mediolateral cell intercalation behavior in the paraxial mesoderm

NASA Astrophysics Data System (ADS)

Yen, WeiWei; Burdsal, Carol; Periasamy, Ammasi; Sutherland, Ann E.

2006-02-01

The cell mechanical and signaling pathways involved in gastrulation have been studied extensively in invertebrates and amphibians, such as Xenopus, and more recently in non-mammalian vertebrates such as zebrafish and chick. However, because culturing mouse embryos extra-utero is very difficult, this fundamental process has been least characterized in the mouse. As the primary mammalian model for genetics, biochemistry, and the study of human disease and birth defects, it is important to investigate how gastrulation proceeds in murine embryos. We have developed a method of using 4D multiphoton excitation microscopy and extra-utero culture to visualize and characterize the morphogenetic movements in mouse embryos dissected at 8.5 days of gestation. Cells are labeled by expression of an X chromosome-linked enhanced green fluorescent protein (EGFP) transgene. This method has provided a unique approach, where, for the first time, patterns of cell behavior in the notochord and surrounding paraxial mesoderm can be visualized and traced quantitatively. Our observations of mouse embryos reveal both distinct differences as well as striking similarities in patterned cell motility relative to other vertebrate models such as Xenopus, where axial extension is driven primarily by mediolateral oriented cell behaviors in the notochord and paraxial somitic mesoderm. Unlike Xenopus, the width of the mouse notochord remains the same between 4-somite stage and 8-somite stage embryos. This implies the mouse notochord plays a lesser role in driving axial extension compared to Xenopus, although intercalation may occur where the anterior region of the node becomes notochordal plate. In contrast, the width of mouse paraxial mesoderm narrows significantly during this period and cells within the paraxial mesoderm are both elongated and aligned perpendicular to the midline. In addition, these cells are observed to intercalate, consistent with a role for paraxial mesoderm in driving convergence and extension. These cell behaviors are similar to those characterized in the axial mesoderm of frog embryos during convergence and extension[1], and suggests that tissues may play different roles in axial elongation between the frog and the mouse.

Biomarkers for PTSD

DTIC Science & Technology

2014-07-01

Molecular evidence of stress- induced acute heart injury in a mouse model simulating posttraumatic stress disorder. Proc Natl Acad Sci U S A. 2014 Feb...obtaining measures aligned with the core neurocognitive domains: IQ, working memory ( auditory /visual), processing speed, verbal memory (immediate...in the test sample and combined sample with a similar pattern for the validation sample. Similarly, performance on tests of auditory and visual

Localization of peroxisome proliferator-activated receptor in mouse and rat-tissues and demonstration of its nuclear translocation in transfected cv-1 cells.

PubMed

Huang, Q; Yeldandi, A; Alvares, K; Ide, H; Reddy, J; Rao, M

1995-02-01

Hepatocarcinogenesis in rodents induced by nongenotoxic peroxisome proliferators is postulated to be a receptor-mediated process. The peroxisome proliferator-activated receptors (PPAR) are members of the steroid hormone receptor superfamily, which participate in ligand-dependent transcriptional activation of peroxisomal fatty acid beta oxidation enzyme system genes in liver parenchymal cells of rats and mice. In order to study the tissue distribution and cellular localization of PPAR, we raised polyclonal antibodies against PPAR using a recombinant rat PPAR (rPPAR) expressed as a glutathione-S-transferase-rPPAR fusion protein. On immunoblot analysis the antibodies specifically recognized a 55 kDa PPAR protein in rat, mouse and human liver homogenates. Immunoblotting also showed that in the mouse and rat, PPAR is expressed in liver, kidney and heart, and only weakly in brain and testis. Immunohistochemical localization in the rat and mouse revealed that PPAR is highly expressed in perivenular (i.e., those surrounding hepatic vein) hepatocytes and very weakly in the cytoplasm of remaining hepatocytes. In the kidney, PPAR was visualized predominantly in the p(3) segments of proximal convoluted tubular epithelium. CV-1 cells transiently transfected with rPPAR cDNA construct showed predominant cytoplasmic fluorescence; treatment of these cells with ciprofibrate, a peroxisome proliferator, resulted in the nuclear translocation of PPAR signal.

Oral recombinant human or mouse lactoferrin reduces Mycobacterium tuberculosis TDM induced granulomatous lung pathology.

PubMed

Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

2017-02-01

Trehalose 6'6-dimycolate (TDM) is the most abundant glycolipid on the cell wall of Mycobacterium tuberculosis (MTB). TDM is capable of inducing granulomatous pathology in mouse models that resembles those induced by MTB infection. Using the acute TDM model, this work investigates the effect of recombinant human and mouse lactoferrin to reduce granulomatous pathology. C57BL/6 mice were injected intravenously with TDM at a dose of 25 μg·mouse -1 . At day 4 and 6, recombinant human or mouse lactoferrin (1 mg·(100 μL) -1 ·mouse -1 ) were delivered by gavage. At day 7 after TDM injection, mice were evaluated for lung pathology, cytokine production, and leukocyte populations. Mice given human or mouse lactoferrin had reduced production of IL-12p40 in their lungs. Mouse lactoferrin increased IL-6 and KC (CXCL1) in lung tissue. Increased numbers of macrophages were observed in TDM-injected mice given human or mouse lactoferrin. Granulomatous pathology, composed of mainly migrated leukocytes, was visually reduced in mice that received human or mouse lactoferrin. Quantitation of granulomatous pathology demonstrated a significant decrease in mice given human or mouse lactoferrin compared with TDM control mice. This report is the first to directly compare the immune modulatory effects of both heterologous recombinant human and homologous mouse lactoferrin on the development of TDM-induced granulomas.

Preservation of three-dimensional spatial structure in the gut microbiome.

PubMed

Hasegawa, Yuko; Mark Welch, Jessica L; Rossetti, Blair J; Borisy, Gary G

2017-01-01

Preservation of three-dimensional structure in the gut is necessary in order to analyze the spatial organization of the gut microbiota and gut luminal contents. In this study, we evaluated preparation methods for mouse gut with the goal of preserving micron-scale spatial structure while performing fluorescence imaging assays. Our evaluation of embedding methods showed that commonly used media such as Tissue-Tek Optimal Cutting Temperature (OCT) compound, paraffin, and polyester waxes resulted in redistribution of luminal contents. By contrast, a hydrophilic methacrylate resin, Technovit H8100, preserved three-dimensional organization. Our mouse intestinal preparation protocol optimized using the Technovit H8100 embedding method was compatible with microbial fluorescence in situ hybridization (FISH) and other labeling techniques, including immunostaining and staining with both wheat germ agglutinin (WGA) and 4', 6-diamidino-2-phenylindole (DAPI). Mucus could be visualized whether the sample was fixed with paraformaldehyde (PFA) or with Carnoy's fixative. The protocol optimized in this study enabled simultaneous visualization of micron-scale spatial patterns formed by microbial cells in the mouse intestines along with biogeographical landmarks such as host-derived mucus and food particles.

In vivo microscopy of the mouse brain using multiphoton laser scanning techniques

NASA Astrophysics Data System (ADS)

Yoder, Elizabeth J.

2002-06-01

The use of multiphoton microscopy for imaging mouse brain in vivo offers several advantages and poses several challenges. This tutorial begins by briefly comparing multiphoton microscopy with other imaging modalities used to visualize the brain and its activity. Next, an overview of the techniques for introducing fluorescence into whole animals to generate contrast for in vivo microscopy using two-photon excitation is presented. Two different schemes of surgically preparing mice for brain imaging with multiphoton microscopy are reviewed. Then, several issues and problems with in vivo microscopy - including motion artifact, respiratory and cardiac rhythms, maintenance of animal health, anesthesia, and the use of fiducial markers - are discussed. Finally, examples of how these techniques have been applied to visualize the cerebral vasculature and its response to hypercapnic stimulation are provided.

Experience-dependent development of perineuronal nets and chondroitin sulfate proteoglycan receptors in mouse visual cortex.

PubMed

Ye, Qian; Miao, Qing-Long

2013-08-08

Perineuronal nets (PNNs) are extracellular matrix structures consisting of chondroitin sulfate proteoglycans (CSPGs), hyaluronan, link proteins and tenascin-R (Tn-R). They enwrap a subset of GABAergic inhibitory interneurons in the cerebral cortex and restrict experience-dependent cortical plasticity. While the expression profile of PNN components has been widely studied in many areas of the central nervous system of various animal species, it remains unclear how these components are expressed during the postnatal development of mouse primary visual cortex (V1). In the present study, we characterized the developmental time course of the formation of PNNs in the mouse primary visual cortex, using the specific antibodies against the two PNN component proteins aggrecan and tenascin-R, or the lectin Wisteria floribunda agglutinin (WFA) that directly binds to glycosaminoglycan chains of chondroitin sulfate proteoglycans (CSPGs). We found that the fluorescence staining signals of both the WFA staining and the antibody against aggrecan rapidly increased in cortical neurons across layers 2-6 during postnatal days (PD) 10-28 and reached a plateau around PD42, suggesting a full construction of PNNs by the end of the critical period. Co-staining with antibodies to Ca(2+) binding protein parvalbumin (PV) demonstrated that the majority of PNN-surrounding cortical neurons are immunoreactive to PV. Similar expression profile of another PNN component tenascin-R was observed in the development of V1. Dark rearing of mice from birth significantly reduced the density of PNN-surrounding neurons. In addition, the expression of two recently identified CSPG receptors - Nogo receptor (NgR) and leukocyte common antigen-related phosphatase (LAR), showed significant increases from PD14 to PD70 in layer 2-6 of cortical PV-positive interneurons in normal reared mice, but decreased significantly in dark-reared ones. Taken together, these results suggest that PNNs form preferentially in cortical PV-positive interneurons in an experience-dependent manner, and reach full maturation around the end of the critical period of V1 development. © Elsevier B.V. All rights reserved.

Dissection of the Mouse Pancreas for Histological Analysis and Metabolic Profiling.

PubMed

Veite-Schmahl, Michelle J; Regan, Daniel P; Rivers, Adam C; Nowatzke, Joseph F; Kennedy, Michael A

2017-08-19

We have been investigating the pancreas specific transcription factor, 1a cre-recombinase; lox-stop-lox- Kristen rat sarcoma, glycine to aspartic acid at the 12 codon (Ptf1a cre/+ ;LSL-Kras G12D/+ ) mouse strain as a model of human pancreatic cancer. The goal of our current studies is to identify novel metabolic biomarkers of pancreatic cancer progression. We have performed metabolic profiling of urine, feces, blood, and pancreas tissue extracts, as well as histological analyses of the pancreas to stage the cancer progression. The mouse pancreas is not a well-defined solid organ like in humans, but rather is a diffusely distributed soft tissue that is not easily identified by individuals unfamiliar with mouse internal anatomy or by individuals that have little or no experience performing mouse organ dissections. The purpose of this article is to provide a detailed step-wise visual demonstration to guide novices in the removal of the mouse pancreas by dissection. This article should be especially valuable to students and investigators new to research that requires harvesting of the mouse pancreas by dissection for metabolic profiling or histological analyses.

Mouse Tumor Biology (MTB): a database of mouse models for human cancer.

PubMed

Bult, Carol J; Krupke, Debra M; Begley, Dale A; Richardson, Joel E; Neuhauser, Steven B; Sundberg, John P; Eppig, Janan T

2015-01-01

The Mouse Tumor Biology (MTB; http://tumor.informatics.jax.org) database is a unique online compendium of mouse models for human cancer. MTB provides online access to expertly curated information on diverse mouse models for human cancer and interfaces for searching and visualizing data associated with these models. The information in MTB is designed to facilitate the selection of strains for cancer research and is a platform for mining data on tumor development and patterns of metastases. MTB curators acquire data through manual curation of peer-reviewed scientific literature and from direct submissions by researchers. Data in MTB are also obtained from other bioinformatics resources including PathBase, the Gene Expression Omnibus and ArrayExpress. Recent enhancements to MTB improve the association between mouse models and human genes commonly mutated in a variety of cancers as identified in large-scale cancer genomics studies, provide new interfaces for exploring regions of the mouse genome associated with cancer phenotypes and incorporate data and information related to Patient-Derived Xenograft models of human cancers. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Autophagy as a melanocytic self-defense mechanism.

PubMed

Setaluri, Vijayasaradhi

2015-05-01

Defects in autophagy have implications for melanocyte survival and manifestations of skin pigmentary disorders. Zhang et al. (2015) show that mouse melanocytes lacking the autophagy protein Atg7 undergo premature senescence in vitro and accumulate products of oxidative damage, despite activation of the redox response. Interestingly, contrary to previous findings, the melanocyte-specific deficiency in autophagy did not cause major defects in melanosome biogenesis, nor did it produce visually striking changes in mouse coat color.

A head movement image (HMI)-controlled computer mouse for people with disabilities.

PubMed

Chen, Yu-Luen; Chen, Weoi-Luen; Kuo, Te-Son; Lai, Jin-Shin

2003-02-04

This study proposes image processing and microprocessor technology for use in developing a head movement image (HMI)-controlled computer mouse system for the spinal cord injured (SCI). The system controls the movement and direction of the mouse cursor by capturing head movement images using a marker installed on the user's headset. In the clinical trial, this new mouse system was compared with an infrared-controlled mouse system on various tasks with nine subjects with SCI. The results were favourable to the new mouse system. The differences between the new mouse system and the infrared-controlled mouse were reaching statistical significance in each of the test situations (p<0.05). The HMI-controlled computer mouse improves the input speed. People with disabilities need only wear the headset and move their heads to freely control the movement of the mouse cursor.

Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice.

PubMed

Hosang, Leon; Yusifov, Rashad; Löwel, Siegrid

2018-01-01

For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward nonrewarded stimuli. Indeed, and in contrast to old mice raised in a generally enriched environment (Greifzu et al., 2016), long-term VWT training increased visual acuity (VA) on average by more than 30% to 0.82 cycles per degree (cyc/deg). In an individual animal, VA even increased to 1.49 cyc/deg, i.e., beyond the rat range of VAs. Since visual experience enhances the spatial frequency threshold of the optomotor (OPT) reflex of the open eye after monocular deprivation (MD), we also quantified monocular vision after VWT training. Monocular VA did not increase reliably, and eye reopening did not initiate a decline to pre-MD values as observed by optomotry; VA values rather increased by continued VWT training. Thus, optomotry and VWT measure different parameters of mouse spatial vision. Finally, we tested whether long-term MD induced ocular dominance (OD) plasticity in the visual cortex of adult [postnatal day (P)162-P182] SC-raised mice. This was indeed the case: 40-50 days of MD induced OD shifts toward the open eye in both VWT-trained and, surprisingly, also in age-matched mice without VWT training. These data indicate that (1) long-term VWT training increases adult mouse VA, and (2) long-term MD induces OD shifts also in adult SC-raised mice.

Visual defects in a mouse model of fetal alcohol spectrum disorder.

PubMed

Lantz, Crystal L; Pulimood, Nisha S; Rodrigues-Junior, Wandilson S; Chen, Ching-Kang; Manhaes, Alex C; Kalatsky, Valery A; Medina, Alexandre Esteves

2014-01-01

Alcohol consumption during pregnancy can lead to a multitude of neurological problems in offspring, varying from subtle behavioral changes to severe mental retardation. These alterations are collectively referred to as Fetal Alcohol Spectrum Disorders (FASD). Early alcohol exposure can strongly affect the visual system and children with FASD can exhibit an amblyopia-like pattern of visual acuity deficits even in the absence of optical and oculomotor disruption. Here, we test whether early alcohol exposure can lead to a disruption in visual acuity, using a model of FASD to mimic alcohol consumption in the last months of human gestation. To accomplish this, mice were exposed to ethanol (5 g/kg i.p.) or saline on postnatal days (P) 5, 7, and 9. Two to three weeks later we recorded visually evoked potentials to assess spatial frequency detection and contrast sensitivity, conducted electroretinography (ERG) to further assess visual function and imaged retinotopy using optical imaging of intrinsic signals. We observed that animals exposed to ethanol displayed spatial frequency acuity curves similar to controls. However, ethanol-treated animals showed a significant deficit in contrast sensitivity. Moreover, ERGs revealed a market decrease in both a- and b-waves amplitudes, and optical imaging suggest that both elevation and azimuth maps in ethanol-treated animals have a 10-20° greater map tilt compared to saline-treated controls. Overall, our findings suggest that binge alcohol drinking restricted to the last months of gestation in humans can lead to marked deficits in visual function.

MotionExplorer: exploratory search in human motion capture data based on hierarchical aggregation.

PubMed

Bernard, Jürgen; Wilhelm, Nils; Krüger, Björn; May, Thorsten; Schreck, Tobias; Kohlhammer, Jörn

2013-12-01

We present MotionExplorer, an exploratory search and analysis system for sequences of human motion in large motion capture data collections. This special type of multivariate time series data is relevant in many research fields including medicine, sports and animation. Key tasks in working with motion data include analysis of motion states and transitions, and synthesis of motion vectors by interpolation and combination. In the practice of research and application of human motion data, challenges exist in providing visual summaries and drill-down functionality for handling large motion data collections. We find that this domain can benefit from appropriate visual retrieval and analysis support to handle these tasks in presence of large motion data. To address this need, we developed MotionExplorer together with domain experts as an exploratory search system based on interactive aggregation and visualization of motion states as a basis for data navigation, exploration, and search. Based on an overview-first type visualization, users are able to search for interesting sub-sequences of motion based on a query-by-example metaphor, and explore search results by details on demand. We developed MotionExplorer in close collaboration with the targeted users who are researchers working on human motion synthesis and analysis, including a summative field study. Additionally, we conducted a laboratory design study to substantially improve MotionExplorer towards an intuitive, usable and robust design. MotionExplorer enables the search in human motion capture data with only a few mouse clicks. The researchers unanimously confirm that the system can efficiently support their work.

Mars @ ASDC

NASA Astrophysics Data System (ADS)

Carraro, Francesco

"Mars @ ASDC" is a project born with the goal of using the new web technologies to assist researches involved in the study of Mars. This project employs Mars map and javascript APIs provided by Google to visualize data acquired by space missions on the planet. So far, visualization of tracks acquired by MARSIS and regions observed by VIRTIS-Rosetta has been implemented. The main reason for the creation of this kind of tool is the difficulty in handling hundreds or thousands of acquisitions, like the ones from MARSIS, and the consequent difficulty in finding observations related to a particular region. This led to the development of a tool which allows to search for acquisitions either by defining the region of interest through a set of geometrical parameters or by manually selecting the region on the map through a few mouse clicks The system allows the visualization of tracks (acquired by MARSIS) or regions (acquired by VIRTIS-Rosetta) which intersect the user defined region. MARSIS tracks can be visualized both in Mercator and polar projections while the regions observed by VIRTIS can presently be visualized only in Mercator projection. The Mercator projection is the standard map provided by Google. The polar projections are provided by NASA and have been developed to be used in combination with APIs provided by Google The whole project has been developed following the "open source" philosophy: the client-side code which handles the functioning of the web page is written in javascript; the server-side code which executes the searches for tracks or regions is written in PHP and the DB which undergoes the system is MySQL.

3D reconstruction of internal structure of animal body using near-infrared light

NASA Astrophysics Data System (ADS)

Tran, Trung Nghia; Yamamoto, Kohei; Namita, Takeshi; Kato, Yuji; Shimizu, Koichi

2014-03-01

To realize three-dimensional (3D) optical imaging of the internal structure of animal body, we have developed a new technique to reconstruct CT images from two-dimensional (2D) transillumination images. In transillumination imaging, the image is blurred due to the strong scattering in the tissue. We had developed a scattering suppression technique using the point spread function (PSF) for a fluorescent light source in the body. In this study, we have newly proposed a technique to apply this PSF for a light source to the image of unknown light-absorbing structure. The effectiveness of the proposed technique was examined in the experiments with a model phantom and a mouse. In the phantom experiment, the absorbers were placed in the tissue-equivalent medium to simulate the light-absorbing organs in mouse body. Near-infrared light was illuminated from one side of the phantom and the image was recorded with CMOS camera from another side. Using the proposed techniques, the scattering effect was efficiently suppressed and the absorbing structure can be visualized in the 2D transillumination image. Using the 2D images obtained in many different orientations, we could reconstruct the 3D image. In the mouse experiment, an anesthetized mouse was held in an acrylic cylindrical holder. We can visualize the internal organs such as kidneys through mouse's abdomen using the proposed technique. The 3D image of the kidneys and a part of the liver were reconstructed. Through these experimental studies, the feasibility of practical 3D imaging of the internal light-absorbing structure of a small animal was verified.

EMPReSS: European mouse phenotyping resource for standardized screens.

PubMed

Green, Eain C J; Gkoutos, Georgios V; Lad, Heena V; Blake, Andrew; Weekes, Joseph; Hancock, John M

2005-06-15

Standardized phenotyping protocols are essential for the characterization of phenotypes so that results are comparable between different laboratories and phenotypic data can be related to ontological descriptions in an automated manner. We describe a web-based resource for the visualization, searching and downloading of standard operating procedures and other documents, the European Mouse Phenotyping Resource for Standardized Screens-EMPReSS. Direct access: http://www.empress.har.mrc.ac.uk e.green@har.mrc.ac.uk.

Corneal Biofilms: From Planktonic to Microcolony Formation in an Experimental Keratitis Infection with Pseudomonas Aeruginosa.

PubMed

Saraswathi, Padmanabhan; Beuerman, Roger W

2015-10-01

Microbial biofilms commonly comprise part of the infectious scenario, complicating the therapeutic approach. The purpose of this study was to determine in a mouse model of corneal infection if mature biofilms formed and to visualize the stages of biofilm formation. A bacterial keratitis model was established using Pseudomonas aeruginosa ATCC 9027 (1 × 10(8) CFU/ml) to infect the cornea of C57BL/6 black mouse. Eyes were examined post-infection (PI) on days 1, 2, 3, 5, and 7, and imaged by slit lamp microscopy, and light, confocal, and electron microscopy to identify the stages of biofilm formation and the time of appearance. On PI day 1, Gram staining showed rod-shaped bacteria adherent on the corneal surface. On PI days 2 and 3, bacteria were seen within webs of extracellular polymeric substance (EPS) and glycocalyx secretion, imaged by confocal microscopy. Scanning electron microscopy demonstrated microcolonies of active infectious cells bound with thick fibrous material. Transmission electron microscopy substantiated the formation of classical biofilm architecture with P. aeruginosa densely packed within the extracellular polymeric substances on PI days 5 and 7. Direct visual evidence showed that biofilms routinely developed on the biotic surface of the mouse cornea. The mouse model can be used to develop new approaches to deal therapeutically with biofilms in corneal infections. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Vision in laboratory rodents-Tools to measure it and implications for behavioral research.

PubMed

Leinonen, Henri; Tanila, Heikki

2017-07-29

Mice and rats are nocturnal mammals and their vision is specialized for detection of motion and contrast in dim light conditions. These species possess a large proportion of UV-sensitive cones in their retinas and the majority of their optic nerve axons target superior colliculus rather than visual cortex. Therefore, it was a widely held belief that laboratory rodents hardly utilize vision during day-time behavior. This dogma is being questioned as accumulating evidence suggests that laboratory rodents are able to perform complex visual functions, such as perceiving subjective contours, and that declined vision may affect their performance in many behavioral tasks. For instance, genetic engineering may have unexpected consequences on vision as mouse models of Alzheimer's and Huntington's diseases have declined visual function. Rodent vision can be tested in numerous ways using operant training or reflex-based behavioral tasks, or alternatively using electrophysiological recordings. In this article, we will first provide a summary of visual system and explain its characteristics unique to rodents. Then, we present well-established techniques to test rodent vision, with an emphasis on pattern vision: visual water test, optomotor reflex test, pattern electroretinography and pattern visual evoked potentials. Finally, we highlight the importance of visual phenotyping in rodents. As the number of genetically engineered rodent models and volume of behavioral testing increase simultaneously, the possibility of visual dysfunctions needs to be addressed. Neglect in this matter potentially leads to crude biases in the field of neuroscience and beyond. Copyright © 2017 Elsevier B.V. All rights reserved.

Molecular imaging with bioconjugates in mouse models of cancer.

PubMed

Mather, Stephen

2009-04-01

The definition of molecular imaging provided by the Society of Nuclear Medicine is "the visualization, characterization and measurement of biological processes at the molecular and cellular levels in humans and other living systems". This review gives an overview of the technologies available for and the potential benefits from molecular imaging at the preclinical stage. It focuses on the use of imaging probes based on bioconjugates and for reasons of brevity confines itself to discussion of applications in the field of oncology, although molecular imaging can be equally useful in many fields including cardiovascular medicine, neurosciences, infection, and others.

An autism-associated serotonin transporter variant disrupts multisensory processing.

PubMed

Siemann, J K; Muller, C L; Forsberg, C G; Blakely, R D; Veenstra-VanderWeele, J; Wallace, M T

2017-03-21

Altered sensory processing is observed in many children with autism spectrum disorder (ASD), with growing evidence that these impairments extend to the integration of information across the different senses (that is, multisensory function). The serotonin system has an important role in sensory development and function, and alterations of serotonergic signaling have been suggested to have a role in ASD. A gain-of-function coding variant in the serotonin transporter (SERT) associates with sensory aversion in humans, and when expressed in mice produces traits associated with ASD, including disruptions in social and communicative function and repetitive behaviors. The current study set out to test whether these mice also exhibit changes in multisensory function when compared with wild-type (WT) animals on the same genetic background. Mice were trained to respond to auditory and visual stimuli independently before being tested under visual, auditory and paired audiovisual (multisensory) conditions. WT mice exhibited significant gains in response accuracy under audiovisual conditions. In contrast, although the SERT mutant animals learned the auditory and visual tasks comparably to WT littermates, they failed to show behavioral gains under multisensory conditions. We believe these results provide the first behavioral evidence of multisensory deficits in a genetic mouse model related to ASD and implicate the serotonin system in multisensory processing and in the multisensory changes seen in ASD.

Multispectral photoacoustic tomography for detection of small tumors inside biological tissues

NASA Astrophysics Data System (ADS)

Hirasawa, Takeshi; Okawa, Shinpei; Tsujita, Kazuhiro; Kushibiki, Toshihiro; Fujita, Masanori; Urano, Yasuteru; Ishihara, Miya

2018-02-01

Visualization of small tumors inside biological tissue is important in cancer treatment because that promotes accurate surgical resection and enables therapeutic effect monitoring. For sensitive detection of tumor, we have been developing photoacoustic (PA) imaging technique to visualize tumor-specific contrast agents, and have already succeeded to image a subcutaneous tumor of a mouse using the contrast agents. To image tumors inside biological tissues, extension of imaging depth and improvement of sensitivity were required. In this study, to extend imaging depth, we developed a PA tomography (PAT) system that can image entire cross section of mice. To improve sensitivity, we discussed the use of the P(VDF-TrFE) linear array acoustic sensor that can detect PA signals with wide ranges of frequencies. Because PA signals produced from low absorbance optical absorbers shifts to low frequency, we hypothesized that the detection of low frequency PA signals improves sensitivity to low absorbance optical absorbers. We developed a PAT system with both a PZT linear array acoustic sensor and the P(VDF-TrFE) sensor, and performed experiment using tissue-mimicking phantoms to evaluate lower detection limits of absorbance. As a result, PAT images calculated from low frequency components of PA signals detected by the P(VDF-TrFE) sensor could visualize optical absorbers with lower absorbance.

Photochemical restoration of visual responses in blind mice

PubMed Central

Polosukhina, Aleksandra; Litt, Jeffrey; Tochitsky, Ivan; Nemargut, Joseph; Sychev, Yivgeny; De Kouchkovsky, Ivan; Huang, Tracy; Borges, Katharine; Trauner, Dirk; Van Gelder, Russell N.; Kramer, Richard H.

2012-01-01

Summary Retinitis pigmentosa (RP) and age-related macular degeneration (AMD) are degenerative blinding diseases caused by the death of rods and cones, leaving the remainder of the visual system intact but largely unable to respond to light. Here we show that, AAQ, a synthetic small molecule photoswitch, can restore light sensitivity to the retina and behavioral responses in vivo in mouse models of RP without exogenous gene delivery. Brief application of AAQ bestows prolonged light sensitivity on multiple types of retinal neurons, resulting in synaptically amplified responses and center-surround antagonism in arrays of retinal ganglion cells (RGCs). Intraocular injection of AAQ restores the pupillary light reflex and locomotory light avoidance responses in mice lacking retinal photoreceptors, indicating reconstitution of light signaling to brain circuits. AAQ and related photoswitch molecules present a new drug strategy for restoring retinal function in degenerative blinding diseases. PMID:22841312

A multimodal interface device for online board games designed for sight-impaired people.

PubMed

Caporusso, Nicholas; Mkrtchyan, Lusine; Badia, Leonardo

2010-03-01

Online games between remote opponents playing over computer networks are becoming a common activity of everyday life. However, computer interfaces for board games are usually based on the visual channel. For example, they require players to check their moves on a video display and interact by using pointing devices such as a mouse. Hence, they are not suitable for visually impaired people. The present paper discusses a multipurpose system that allows especially blind and deafblind people playing chess or other board games over a network, therefore reducing their disability barrier. We describe and benchmark a prototype of a special interactive haptic device for online gaming providing a dual tactile feedback. The novel interface of this proposed device is able to guarantee not only a better game experience for everyone but also an improved quality of life for sight-impaired people.

Simultaneous two-photon imaging and two-photon optogenetics of cortical circuits in three dimensions

PubMed Central

Carrillo-Reid, Luis; Bando, Yuki; Peterka, Darcy S

2018-01-01

The simultaneous imaging and manipulating of neural activity could enable the functional dissection of neural circuits. Here we have combined two-photon optogenetics with simultaneous volumetric two-photon calcium imaging to measure and manipulate neural activity in mouse neocortex in vivo in three-dimensions (3D) with cellular resolution. Using a hybrid holographic approach, we simultaneously photostimulate more than 80 neurons over 150 μm in depth in layer 2/3 of the mouse visual cortex, while simultaneously imaging the activity of the surrounding neurons. We validate the usefulness of the method by photoactivating in 3D selected groups of interneurons, suppressing the response of nearby pyramidal neurons to visual stimuli in awake animals. Our all-optical approach could be used as a general platform to read and write neuronal activity. PMID:29412138

Mouse cones require an arrestin for normal inactivation of phototransduction.

PubMed

Nikonov, Sergei S; Brown, Bruce M; Davis, Jason A; Zuniga, Freddi I; Bragin, Alvina; Pugh, Edward N; Craft, Cheryl M

2008-08-14

Arrestins are proteins that arrest the activity of G protein-coupled receptors (GPCRs). While it is well established that normal inactivation of photoexcited rhodopsin, the GPCR of rod phototransduction, requires arrestin (Arr1), it has been controversial whether the same requirement holds for cone opsin inactivation. Mouse cone photoreceptors express two distinct visual arrestins: Arr1 and Arr4. By means of recordings from cones of mice with one or both arrestins knocked out, this investigation establishes that a visual arrestin is required for normal cone inactivation. Arrestin-independent inactivation is 70-fold more rapid in cones than in rods, however. Dual arrestin expression in cones could be a holdover from ancient genome duplication events that led to multiple isoforms of arrestin, allowing evolutionary specialization of one form while the other maintains the basic function.

Comparing the Microsoft Kinect to a traditional mouse for adjusting the viewed tissue densities of three-dimensional anatomical structures

NASA Astrophysics Data System (ADS)

Juhnke, Bethany; Berron, Monica; Philip, Adriana; Williams, Jordan; Holub, Joseph; Winer, Eliot

2013-03-01

Advancements in medical image visualization in recent years have enabled three-dimensional (3D) medical images to be volume-rendered from magnetic resonance imaging (MRI) and computed tomography (CT) scans. Medical data is crucial for patient diagnosis and medical education, and analyzing these three-dimensional models rather than two-dimensional (2D) slices would enable more efficient analysis by surgeons and physicians, especially non-radiologists. An interaction device that is intuitive, robust, and easily learned is necessary to integrate 3D modeling software into the medical community. The keyboard and mouse configuration does not readily manipulate 3D models because these traditional interface devices function within two degrees of freedom, not the six degrees of freedom presented in three dimensions. Using a familiar, commercial-off-the-shelf (COTS) device for interaction would minimize training time and enable maximum usability with 3D medical images. Multiple techniques are available to manipulate 3D medical images and provide doctors more innovative ways of visualizing patient data. One such example is windowing. Windowing is used to adjust the viewed tissue density of digital medical data. A software platform available at the Virtual Reality Applications Center (VRAC), named Isis, was used to visualize and interact with the 3D representations of medical data. In this paper, we present the methodology and results of a user study that examined the usability of windowing 3D medical imaging using a Kinect™ device compared to a traditional mouse.

IMGT/GeneInfo: enhancing V(D)J recombination database accessibility

PubMed Central

Baum, Thierry-Pascal; Pasqual, Nicolas; Thuderoz, Florence; Hierle, Vivien; Chaume, Denys; Lefranc, Marie-Paule; Jouvin-Marche, Evelyne; Marche, Patrice-Noël; Demongeot, Jacques

2004-01-01

IMGT/GeneInfo is a user-friendly online information system that provides information on data resulting from the complex mechanisms of immunoglobulin (IG) and T cell receptor (TR) V(D)J recombinations. For the first time, it is possible to visualize all the rearrangement parameters on a single page. IMGT/GeneInfo is part of the international ImMunoGeneTics information system® (IMGT), a high-quality integrated knowledge resource specializing in IG, TR, major histocompatibility complex (MHC), and related proteins of the immune system of human and other vertebrate species. The IMGT/GeneInfo system was developed by the TIMC and ICH laboratories (with the collaboration of LIGM), and is the first example of an external system being incorporated into IMGT. In this paper, we report the first part of this work. IMGT/GeneInfo_TR deals with the human and mouse TRA/TRD and TRB loci of the TR. Data handling and visualization are complementary to the current data and tools in IMGT, and will subsequently allow the modelling of V(D)J gene use, and thus, to predict non-standard recombination profiles which may eventually be found in conditions such as leukaemias or lymphomas. Access to IMGT/GeneInfo is free and can be found at http://imgt.cines.fr/GeneInfo. PMID:14681357

Visualization of Oxidative Stress Induced by Experimental Periodontitis in Keap1-Dependent Oxidative Stress Detector-Luciferase Mice.

PubMed

Kataoka, Kota; Ekuni, Daisuke; Tomofuji, Takaaki; Irie, Koichiro; Kunitomo, Muneyoshi; Uchida, Yoko; Fukuhara, Daiki; Morita, Manabu

2016-11-16

The aim of this study was to investigate whether a Keap1-dependent oxidative stress detector-luciferase (OKD-LUC) mouse model would be useful for the visualization of oxidative stress induced by experimental periodontitis. A ligature was placed around the mandibular first molars for seven days to induce periodontitis. Luciferase activity was measured with an intraperitoneal injection of d-luciferin on days 0, 1, and 7. The luciferase activity in the periodontitis group was significantly greater than that in the control group at seven days. The expressions of heme oxygenase-1 (HO-1) and malondialdehyde in periodontal tissue were significantly higher in the periodontitis group than in the control group. Immunofluorescent analysis confirmed that the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) occurred more frequently in the periodontitis group than in the control group. This study found that under oxidative stress induced by experimental periodontitis, the Nrf2/antioxidant defense pathway was activated and could be visualized from the luciferase activity in the OKD-LUC model. Thus, the OKD-LUC mouse model may be useful for exploring the mechanism underlying the relationship between the Nrf2/antioxidant defense pathway and periodontitis by enabling the visualization of oxidative stress over time.

Pharmacotherapy of retinal disease with visual cycle modulators.

PubMed

Hussain, Rehan M; Gregori, Ninel Z; Ciulla, Thomas A; Lam, Byron L

2018-04-01

Pharmacotherapy with visual cycle modulators (VCMs) is under investigation for retinitis pigmentosa (RP), Leber congenital amaurosis (LCA), Stargardt macular dystrophy (SMD) and nonexudative age-related macular degeneration (AMD), all blinding diseases that lack effective treatment options. Areas covered: The authors review investigational VCMs, including oral retinoids, 9-cis-retinyl-acetate (zuretinol) and 9-cis-β-carotene, which restore 11-cis-retinal levels in RP and LCA caused by LRAT and RPE65 gene mutations, and may improve visual acuity and visual fields. Therapies for SMD aiming to decrease accumulation of toxic Vitamin A dimers and lipofuscin in the retina and retinal pigment epithelium (RPE) include C20-D3-vitamin A (ALK-001), isotretinoin, VM200, emixustat, and A1120. Mouse models of SMD show promising data for these treatments, though proof of efficacy in humans is currently lacking. Fenretinide and emixustat are investigational VCMs for dry AMD, though neither has been shown to reduce geographic atrophy or improve vision in human trials. A1120 prevents retinol transport into the RPE and may spare the side effects typically seen in VCMs (nyctalopia and chromatopsia) per mouse studies. Expert opinion: Oral VCMs may be feasible treatment options for degenerative retinal diseases based on pre-clinical and some early clinical studies. Further trials are warranted to assess their efficacy and safety in humans.

AUTONOMIC AXONS IN THE HUMAN ENDOCRINE PANCREAS SHOW UNIQUE INNERVATION PATTERNS

PubMed Central

Rodriguez-Diaz, Rayner; Abdulreda, Midhat H.; Formoso, Alexander L.; Gans, Itai; Ricordi, Camillo; Berggren, Per-Olof; Caicedo, Alejandro

2011-01-01

SUMMARY The autonomic nervous system regulates hormone secretion from the endocrine pancreas, the islets of Langerhans, and thus impacts glucose metabolism. The parasympathetic and sympathetic nerves innervate the pancreatic islet, but the precise innervation patterns are not known, particularly in human islets. Here we demonstrate that the innervation of human islets is different from that of mouse islets and that it does not conform to existing models of autonomic control of islet function. By visualizing axons in three dimensions and quantifying axonal densities and contacts within pancreatic islets, we found that, in contrast to mouse endocrine cells, human endocrine cells are sparsely contacted by autonomic axons. Few parasympathetic cholinergic axons penetrate the human islet and the invading sympathetic fibers preferentially innervate smooth muscle cells of blood vessels located within the islet. Thus, rather than modulating endocrine cell function directly, sympathetic nerves may regulate hormone secretion in human islets by controlling local blood flow or by acting on islet regions located downstream. PMID:21723503

Mouse rods signal through gap junctions with cones.

PubMed

Asteriti, Sabrina; Gargini, Claudia; Cangiano, Lorenzo

2014-01-01

Rod and cone photoreceptors are coupled by gap junctions (GJs), relatively large channels able to mediate both electrical and molecular communication. Despite their critical location in our visual system and evidence that they are dynamically gated for dark/light adaptation, the full impact that rod-cone GJs can have on cone function is not known. We recorded the photovoltage of mouse cones and found that the initial level of rod input increased spontaneously after obtaining intracellular access. This process allowed us to explore the underlying coupling capacity to rods, revealing that fully coupled cones acquire a striking rod-like phenotype. Calcium, a candidate mediator of the coupling process, does not appear to be involved on the cone side of the junctional channels. Our findings show that the anatomical substrate is adequate for rod-cone coupling to play an important role in vision and, possibly, in biochemical signaling among photoreceptors. DOI: http://dx.doi.org/10.7554/eLife.01386.001.

Mouse rods signal through gap junctions with cones

PubMed Central

Asteriti, Sabrina; Gargini, Claudia; Cangiano, Lorenzo

2014-01-01

Rod and cone photoreceptors are coupled by gap junctions (GJs), relatively large channels able to mediate both electrical and molecular communication. Despite their critical location in our visual system and evidence that they are dynamically gated for dark/light adaptation, the full impact that rod–cone GJs can have on cone function is not known. We recorded the photovoltage of mouse cones and found that the initial level of rod input increased spontaneously after obtaining intracellular access. This process allowed us to explore the underlying coupling capacity to rods, revealing that fully coupled cones acquire a striking rod-like phenotype. Calcium, a candidate mediator of the coupling process, does not appear to be involved on the cone side of the junctional channels. Our findings show that the anatomical substrate is adequate for rod–cone coupling to play an important role in vision and, possibly, in biochemical signaling among photoreceptors. DOI: http://dx.doi.org/10.7554/eLife.01386.001 PMID:24399457

Ex vivo mouse brain microscopy at 15T with loop-gap RF coil.

PubMed

Cohen, Ouri; Ackerman, Jerome L

2018-04-18

The design of a loop-gap-resonator RF coil optimized for ex vivo mouse brain microscopy at ultra high fields is described and its properties characterized using simulations, phantoms and experimental scans of mouse brains fixed in 10% formalin containing 4 mM Magnevist™. The RF (B 1 ) and magnetic field (B 0 ) homogeneities are experimentally quantified and compared to electromagnetic simulations of the coil. The coil's performance is also compared to a similarly sized surface coil and found to yield double the sensitivity. A three-dimensional gradient-echo (GRE) sequence is used to acquire high resolution mouse brain scans at (47 μm) 3 resolution in 1.8 h and a 20 × 20 × 19 μm 3 resolution in 27 h. The high resolution obtained permitted clear visualization and identification of multiple structures in the ex vivo mouse brain and represents, to our knowledge, the highest resolution ever achieved for a whole mouse brain. Importantly, the coil design is simple and easy to construct. Copyright © 2018 Elsevier Inc. All rights reserved.

Non-invasive detection of matrix-metalloproteinase activity in a mouse model of cerebral ischemia using multispectral optoacoustic tomography

NASA Astrophysics Data System (ADS)

Ni, Ruiqing; Vaas, Markus; Ren, Wuwei; Klohs, Jan

2018-02-01

Matrix metalloproteinases (MMPs) play important roles in the pathophysiology of cerebral ischemia. Here we visualized in vivo MMP activity in the transient middle cerebral artery occlusion (tMCAO) mouse model using multispectral optoacoustic imaging (MSOT) with a MMP-activatable probe. MSOT data was co-registered with structural magnetic resonance imaging (MRI) obtained at 7 T for localization of signal distribution. We demonstrated upregulated MMP signal within the focal ischemic lesion in the tMCAO mouse model using MSOT/MRI multimodal imaging. This convenient non-invasive method will allow repetitive measurement following the time course of MMP-lesion development in ischemic stroke animal model.

Adult mouse brain gene expression patterns bear an embryologic imprint

PubMed Central

Zapala, Matthew A.; Hovatta, Iiris; Ellison, Julie A.; Wodicka, Lisa; Del Rio, Jo A.; Tennant, Richard; Tynan, Wendy; Broide, Ron S.; Helton, Rob; Stoveken, Barbara S.; Winrow, Christopher; Lockhart, Daniel J.; Reilly, John F.; Young, Warren G.; Bloom, Floyd E.; Lockhart, David J.; Barlow, Carrolee

2005-01-01

The current model to explain the organization of the mammalian nervous system is based on studies of anatomy, embryology, and evolution. To further investigate the molecular organization of the adult mammalian brain, we have built a gene expression-based brain map. We measured gene expression patterns for 24 neural tissues covering the mouse central nervous system and found, surprisingly, that the adult brain bears a transcriptional “imprint” consistent with both embryological origins and classic evolutionary relationships. Embryonic cellular position along the anterior–posterior axis of the neural tube was shown to be closely associated with, and possibly a determinant of, the gene expression patterns in adult structures. We also observed a significant number of embryonic patterning and homeobox genes with region-specific expression in the adult nervous system. The relationships between global expression patterns for different anatomical regions and the nature of the observed region-specific genes suggest that the adult brain retains a degree of overall gene expression established during embryogenesis that is important for regional specificity and the functional relationships between regions in the adult. The complete collection of extensively annotated gene expression data along with data mining and visualization tools have been made available on a publicly accessible web site (www.barlow-lockhart-brainmapnimhgrant.org). PMID:16002470

A Role for Mouse Primary Visual Cortex in Motion Perception.

PubMed

Marques, Tiago; Summers, Mathew T; Fioreze, Gabriela; Fridman, Marina; Dias, Rodrigo F; Feller, Marla B; Petreanu, Leopoldo

2018-06-04

Visual motion is an ethologically important stimulus throughout the animal kingdom. In primates, motion perception relies on specific higher-order cortical regions. Although mouse primary visual cortex (V1) and higher-order visual areas show direction-selective (DS) responses, their role in motion perception remains unknown. Here, we tested whether V1 is involved in motion perception in mice. We developed a head-fixed discrimination task in which mice must report their perceived direction of motion from random dot kinematograms (RDKs). After training, mice made around 90% correct choices for stimuli with high coherence and performed significantly above chance for 16% coherent RDKs. Accuracy increased with both stimulus duration and visual field coverage of the stimulus, suggesting that mice in this task integrate motion information in time and space. Retinal recordings showed that thalamically projecting On-Off DS ganglion cells display DS responses when stimulated with RDKs. Two-photon calcium imaging revealed that neurons in layer (L) 2/3 of V1 display strong DS tuning in response to this stimulus. Thus, RDKs engage motion-sensitive retinal circuits as well as downstream visual cortical areas. Contralateral V1 activity played a key role in this motion direction discrimination task because its reversible inactivation with muscimol led to a significant reduction in performance. Neurometric-psychometric comparisons showed that an ideal observer could solve the task with the information encoded in DS L2/3 neurons. Motion discrimination of RDKs presents a powerful behavioral tool for dissecting the role of retino-forebrain circuits in motion processing. Copyright © 2018 Elsevier Ltd. All rights reserved.

Social modulation of associative fear learning by pheromone communication

PubMed Central

Bredy, Timothy W.; Barad, Mark

2009-01-01

Mice communicate through visual, vocal, and olfactory cues that influence innate, nonassociative behavior. We here report that exposure to a recently fear-conditioned familiar mouse impairs acquisition of conditioned fear and facilitates fear extinction, effects mimicked by both an olfactory chemosignal emitted by a recently fear-conditioned familiar mouse and by the putative stress-related anxiogenic pheromone β-phenylethylamine (β-PEA). Together, these findings suggest social modulation of higher-order cognitive processing through pheromone communication and support the concurrent excitor hypothesis of extinction learning. PMID:19117912

Social modulation of associative fear learning by pheromone communication.

PubMed

Bredy, Timothy W; Barad, Mark

2009-01-01

Mice communicate through visual, vocal, and olfactory cues that influence innate, nonassociative behavior. We here report that exposure to a recently fear-conditioned familiar mouse impairs acquisition of conditioned fear and facilitates fear extinction, effects mimicked by both an olfactory chemosignal emitted by a recently fear-conditioned familiar mouse and by the putative stress-related anxiogenic pheromone beta-phenylethylamine (beta-PEA). Together, these findings suggest social modulation of higher-order cognitive processing through pheromone communication and support the concurrent excitor hypothesis of extinction learning.

Potentiometric Dye Imaging for Pheochromocytoma and Cortical Neurons with a Novel Measurement System Using an Integrated Complementary Metal-Oxide-Semiconductor Imaging Device

NASA Astrophysics Data System (ADS)

Kobayashi, Takuma; Tagawa, Ayato; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Hatanaka, Yumiko; Tamura, Hideki; Ishikawa, Yasuyuki; Shiosaka, Sadao; Ohta, Jun

2010-11-01

The combination of optical imaging with voltage-sensitive dyes is a powerful tool for studying the spatiotemporal patterns of neural activity and understanding the neural networks of the brain. To visualize the potential status of multiple neurons simultaneously using a compact instrument with high density and a wide range, we present a novel measurement system using an implantable biomedical photonic LSI device with a red absorptive light filter for voltage-sensitive dye imaging (BpLSI-red). The BpLSI-red was developed for sensing fluorescence by the on-chip LSI, which was designed by using complementary metal-oxide-semiconductor (CMOS) technology. A micro-electro-mechanical system (MEMS) microfabrication technique was used to postprocess the CMOS sensor chip; light-emitting diodes (LEDs) were integrated for illumination and to enable long-term cell culture. Using the device, we succeeded in visualizing the membrane potential of 2000-3000 cells and the process of depolarization of pheochromocytoma cells (PC12 cells) and mouse cerebral cortical neurons in a primary culture with cellular resolution. Therefore, our measurement application enables the detection of multiple neural activities simultaneously.

Live dynamic imaging and analysis of developmental cardiac defects in mouse models with optical coherence tomography

NASA Astrophysics Data System (ADS)

Lopez, Andrew L.; Wang, Shang; Garcia, Monica; Valladolid, Christian; Larin, Kirill V.; Larina, Irina V.

2015-03-01

Understanding mouse embryonic development is an invaluable resource for our interpretation of normal human embryology and congenital defects. Our research focuses on developing methods for live imaging and dynamic characterization of early embryonic development in mouse models of human diseases. Using multidisciplinary methods: optical coherence tomography (OCT), live mouse embryo manipulations and static embryo culture, molecular biology, advanced image processing and computational modeling we aim to understand developmental processes. We have developed an OCT based approach to image live early mouse embryos (E8.5 - E9.5) cultured on an imaging stage and visualize developmental events with a spatial resolution of a few micrometers (less than the size of an individual cell) and a frame rate of up to hundreds of frames per second and reconstruct cardiodynamics in 4D (3D+time). We are now using these methods to study how specific embryonic lethal mutations affect cardiac morphology and function during early development.

Morphological phenotyping of mouse hearts using optical coherence tomography

NASA Astrophysics Data System (ADS)

Cua, Michelle; Lin, Eric; Lee, Ling; Sheng, Xiaoye; Wong, Kevin S. K.; Tibbits, Glen F.; Beg, Mirza Faisal; Sarunic, Marinko V.

2014-11-01

Transgenic mouse models have been instrumental in the elucidation of the molecular mechanisms behind many genetically based cardiovascular diseases such as Marfan syndrome (MFS). However, the characterization of their cardiac morphology has been hampered by the small size of the mouse heart. In this report, we adapted optical coherence tomography (OCT) for imaging fixed adult mouse hearts, and applied tools from computational anatomy to perform morphometric analyses. The hearts were first optically cleared and imaged from multiple perspectives. The acquired volumes were then corrected for refractive distortions, and registered and stitched together to form a single, high-resolution OCT volume of the whole heart. From this volume, various structures such as the valves and myofibril bundles were visualized. The volumetric nature of our dataset also allowed parameters such as wall thickness, ventricular wall masses, and luminal volumes to be extracted. Finally, we applied the entire acquisition and processing pipeline in a preliminary study comparing the cardiac morphology of wild-type mice and a transgenic mouse model of MFS.

CDKL5 protein substitution therapy rescues neurological phenotypes of a mouse model of CDKL5 disorder.

PubMed

Trazzi, Stefania; De Franceschi, Marianna; Fuchs, Claudia; Bastianini, Stefano; Viggiano, Rocchina; Lupori, Leonardo; Mazziotti, Raffaele; Medici, Giorgio; Lo Martire, Viviana; Ren, Elisa; Rimondini, Roberto; Zoccoli, Giovanna; Bartesaghi, Renata; Pizzorusso, Tommaso; Ciani, Elisabetta

2018-05-01

Cyclin-dependent kinase like-5 (CDKL5) disorder is a rare neurodevelopmental disease caused by mutations in the CDKL5 gene. The consequent misexpression of the CDKL5 protein in the nervous system leads to a severe phenotype characterized by intellectual disability, motor impairment, visual deficits and early-onset epilepsy. No therapy is available for CDKL5 disorder. It has been reported that a protein transduction domain (TAT) is able to deliver macromolecules into cells and even into the brain when fused to a given protein. We demonstrate that TAT-CDKL5 fusion protein is efficiently internalized by target cells and retains CDKL5 activity. Intracerebroventricular infusion of TAT-CDKL5 restored hippocampal development, hippocampus-dependent memory and breathing pattern in Cdkl5-null mice. Notably, systemically administered TAT-CDKL5 protein passed the blood-brain-barrier, reached the CNS, and rescued various neuroanatomical and behavioral defects, including breathing pattern and visual responses. Our results suggest that CDKL5 protein therapy may be an effective clinical tool for the treatment of CDKL5 disorder.

Automatic Visual Tracking and Social Behaviour Analysis with Multiple Mice

PubMed Central

Giancardo, Luca; Sona, Diego; Huang, Huiping; Sannino, Sara; Managò, Francesca; Scheggia, Diego; Papaleo, Francesco; Murino, Vittorio

2013-01-01

Social interactions are made of complex behavioural actions that might be found in all mammalians, including humans and rodents. Recently, mouse models are increasingly being used in preclinical research to understand the biological basis of social-related pathologies or abnormalities. However, reliable and flexible automatic systems able to precisely quantify social behavioural interactions of multiple mice are still missing. Here, we present a system built on two components. A module able to accurately track the position of multiple interacting mice from videos, regardless of their fur colour or light settings, and a module that automatically characterise social and non-social behaviours. The behavioural analysis is obtained by deriving a new set of specialised spatio-temporal features from the tracker output. These features are further employed by a learning-by-example classifier, which predicts for each frame and for each mouse in the cage one of the behaviours learnt from the examples given by the experimenters. The system is validated on an extensive set of experimental trials involving multiple mice in an open arena. In a first evaluation we compare the classifier output with the independent evaluation of two human graders, obtaining comparable results. Then, we show the applicability of our technique to multiple mice settings, using up to four interacting mice. The system is also compared with a solution recently proposed in the literature that, similarly to us, addresses the problem with a learning-by-examples approach. Finally, we further validated our automatic system to differentiate between C57B/6J (a commonly used reference inbred strain) and BTBR T+tf/J (a mouse model for autism spectrum disorders). Overall, these data demonstrate the validity and effectiveness of this new machine learning system in the detection of social and non-social behaviours in multiple (>2) interacting mice, and its versatility to deal with different experimental settings and scenarios. PMID:24066146

In vivo metabolic labeling of sialoglycans in the mouse brain by using a liposome-assisted bioorthogonal reporter strategy

PubMed Central

Xie, Ran; Dong, Lu; Du, Yifei; Zhu, Yuntao; Hua, Rui; Zhang, Chen; Chen, Xing

2016-01-01

Mammalian brains are highly enriched with sialoglycans, which have been implicated in brain development and disease progression. However, in vivo labeling and visualization of sialoglycans in the mouse brain remain a challenge because of the blood−brain barrier. Here we introduce a liposome-assisted bioorthogonal reporter (LABOR) strategy for shuttling 9-azido sialic acid (9AzSia), a sialic acid reporter, into the brain to metabolically label sialoglycoconjugates, including sialylated glycoproteins and glycolipids. Subsequent bioorthogonal conjugation of the incorporated 9AzSia with fluorescent probes via click chemistry enabled fluorescence imaging of brain sialoglycans in living animals and in brain sections. Newly synthesized sialoglycans were found to widely distribute on neuronal cell surfaces, in particular at synaptic sites. Furthermore, large-scale proteomic profiling identified 140 brain sialylated glycoproteins, including a wealth of synapse-associated proteins. Finally, by performing a pulse−chase experiment, we showed that dynamic sialylation is spatially regulated, and that turnover of sialoglycans in the hippocampus is significantly slower than that in other brain regions. The LABOR strategy provides a means to directly visualize and monitor the sialoglycan biosynthesis in the mouse brain and will facilitate elucidating the functional role of brain sialylation. PMID:27125855

Disturbed Processing of Contextual Information in HCN3 Channel Deficient Mice

PubMed Central

Stieglitz, Marc S.; Fenske, Stefanie; Hammelmann, Verena; Becirovic, Elvir; Schöttle, Verena; Delorme, James E.; Schöll-Weidinger, Martha; Mader, Robert; Deussing, Jan; Wolfer, David P.; Seeliger, Mathias W.; Albrecht, Urs; Wotjak, Carsten T.; Biel, Martin; Michalakis, Stylianos; Wahl-Schott, Christian

2018-01-01

Hyperpolarization-activated cyclic nucleotide-gated channels (HCNs) in the nervous system are implicated in a variety of neuronal functions including learning and memory, regulation of vigilance states and pain. Dysfunctions or genetic loss of these channels have been shown to cause human diseases such as epilepsy, depression, schizophrenia, and Parkinson's disease. The physiological functions of HCN1 and HCN2 channels in the nervous system have been analyzed using genetic knockout mouse models. By contrast, there are no such genetic studies for HCN3 channels so far. Here, we use a HCN3-deficient (HCN3−/−) mouse line, which has been previously generated in our group to examine the expression and function of this channel in the CNS. Specifically, we investigate the role of HCN3 channels for the regulation of circadian rhythm and for the determination of behavior. Contrary to previous suggestions we find that HCN3−/− mice show normal visual, photic, and non-photic circadian function. In addition, HCN3−/− mice are impaired in processing contextual information, which is characterized by attenuated long-term extinction of contextual fear and increased fear to a neutral context upon repeated exposure. PMID:29375299

Absence of Vsx1 expression in the normal and damaged mouse cornea

PubMed Central

Chow, Robert L.

2011-01-01

Purpose To examine the expression of visual system homeobox 1 (Vsx1) in the mouse cornea and its potential role in the corneal wound response pathway. Methods Expression of Vsx1 was examined by quantitative reverse-transcription PCR (qRT–PCR) in corneal tissue from developing and adult mice and from mice that had undergone alkali-burn corneal wounding. Immunolabeling and Vsx1 knock-in reporter gene expression in wild type and Vsx1 null-mice were used to confirm the qRT–PCR data. Results Using qRT–PCR, Vsx1 expression was not detected in either the postnatal or adult mouse cornea or in corneas following wounding. This qRT–PCR data was supported by the absence of specific Vsx1 immunolabeling and Vsx1 knock-in reporter expression in untreated and wounded corneas. Conclusions In mice, Vsx1 mRNA, protein or reporter gene expression is not detected in the normal or damaged cornea. These results make it uncertain what role VSX1/Vsx1 plays in corneal biology. Future experiments examining the pathogenicity of VSX1 mutations associated with corneal dystrophy are required to rule out species differences and possible non-cell autonomous roles for VSX1 in the cornea. PMID:21437200

Association between sociability and diffusion tensor imaging in BALB/cJ mice.

PubMed

Kim, Sungheon; Pickup, Stephen; Fairless, Andrew H; Ittyerah, Ranjit; Dow, Holly C; Abel, Ted; Brodkin, Edward S; Poptani, Harish

2012-01-01

The purpose of this study was to use high-resolution diffusion tensor imaging (DTI) to investigate the association between DTI metrics and sociability in BALB/c inbred mice. The sociability of prepubescent (30-day-old) BALB/cJ mice was operationally defined as the time that the mice spent sniffing a stimulus mouse in a social choice test. High-resolution ex vivo DTI data on 12 BALB/cJ mouse brains were acquired using a 9.4-T vertical-bore magnet. Regression analysis was conducted to investigate the association between DTI metrics and sociability. Significant positive regression (p < 0.001) between social sniffing time and fractional anisotropy was found in 10 regions located in the thalamic nuclei, zona incerta/substantia nigra, visual/orbital/somatosensory cortices and entorhinal cortex. In addition, significant negative regression (p < 0.001) between social sniffing time and mean diffusivity was found in five areas located in the sensory cortex, motor cortex, external capsule and amygdaloid region. In all regions showing significant regression with either the mean diffusivity or fractional anisotropy, the tertiary eigenvalue correlated negatively with the social sniffing time. This study demonstrates the feasibility of using DTI to detect brain regions associated with sociability in a mouse model system. Copyright © 2011 John Wiley & Sons, Ltd.

Synthesis of nanostructured barium phosphate and its application in micro-computed tomography of mouse brain vessels in ex vivo

NASA Astrophysics Data System (ADS)

Zhu, Bangshang; Yuan, Falei; Yuan, Xiaoya; Bo, Yang; Wang, Yongting; Yang, Guo-Yuan; Drummen, Gregor P. C.; Zhu, Xinyuan

2014-02-01

Micro-computed tomography (micro-CT) is a powerful tool for visualizing the vascular systems of tissues, organs, or entire small animals. Vascular contrast agents play a vital role in micro-CT imaging in order to obtain clear and high-quality images. In this study, a new kind of nanostructured barium phosphate was fabricated and used as a contrast agent for ex vivo micro-CT imaging of blood vessels in the mouse brain. Nanostructured barium phosphate was synthesized through a simple wet precipitation method using Ba(NO3)2, and (NH4)2HPO4 as starting materials. The physiochemical properties of barium phosphate were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermal analysis. Furthermore, the impact of the produced nanostructures on cell viability was evaluated via the MTT assay, which generally showed low to moderate cytotoxicity. Finally, the animal test images demonstrated that the use of nanostructured barium phosphate as a contrast agent in Micro-CT imaging produced sharp images with excellent contrast. Both major vessels and the microvasculature were clearly observable in the imaged mouse brain. Overall, the results indicate that nanostructured barium phosphate is a potential and useful vascular contrast agent for micro-CT imaging.

A Real-Time Magnetoencephalography Brain-Computer Interface Using Interactive 3D Visualization and the Hadoop Ecosystem.

PubMed

McClay, Wilbert A; Yadav, Nancy; Ozbek, Yusuf; Haas, Andy; Attias, Hagaii T; Nagarajan, Srikantan S

2015-09-30

Ecumenically, the fastest growing segment of Big Data is human biology-related data and the annual data creation is on the order of zetabytes. The implications are global across industries, of which the treatment of brain related illnesses and trauma could see the most significant and immediate effects. The next generation of health care IT and sensory devices are acquiring and storing massive amounts of patient related data. An innovative Brain-Computer Interface (BCI) for interactive 3D visualization is presented utilizing the Hadoop Ecosystem for data analysis and storage. The BCI is an implementation of Bayesian factor analysis algorithms that can distinguish distinct thought actions using magneto encephalographic (MEG) brain signals. We have collected data on five subjects yielding 90% positive performance in MEG mid- and post-movement activity. We describe a driver that substitutes the actions of the BCI as mouse button presses for real-time use in visual simulations. This process has been added into a flight visualization demonstration. By thinking left or right, the user experiences the aircraft turning in the chosen direction. The driver components of the BCI can be compiled into any software and substitute a user's intent for specific keyboard strikes or mouse button presses. The BCI's data analytics OPEN ACCESS Brain. Sci. 2015, 5 420 of a subject's MEG brainwaves and flight visualization performance are stored and analyzed using the Hadoop Ecosystem as a quick retrieval data warehouse.

A Real-Time Magnetoencephalography Brain-Computer Interface Using Interactive 3D Visualization and the Hadoop Ecosystem

PubMed Central

McClay, Wilbert A.; Yadav, Nancy; Ozbek, Yusuf; Haas, Andy; Attias, Hagaii T.; Nagarajan, Srikantan S.

2015-01-01

Ecumenically, the fastest growing segment of Big Data is human biology-related data and the annual data creation is on the order of zetabytes. The implications are global across industries, of which the treatment of brain related illnesses and trauma could see the most significant and immediate effects. The next generation of health care IT and sensory devices are acquiring and storing massive amounts of patient related data. An innovative Brain-Computer Interface (BCI) for interactive 3D visualization is presented utilizing the Hadoop Ecosystem for data analysis and storage. The BCI is an implementation of Bayesian factor analysis algorithms that can distinguish distinct thought actions using magneto encephalographic (MEG) brain signals. We have collected data on five subjects yielding 90% positive performance in MEG mid- and post-movement activity. We describe a driver that substitutes the actions of the BCI as mouse button presses for real-time use in visual simulations. This process has been added into a flight visualization demonstration. By thinking left or right, the user experiences the aircraft turning in the chosen direction. The driver components of the BCI can be compiled into any software and substitute a user’s intent for specific keyboard strikes or mouse button presses. The BCI’s data analytics of a subject’s MEG brainwaves and flight visualization performance are stored and analyzed using the Hadoop Ecosystem as a quick retrieval data warehouse. PMID:26437432

Study on choroidal neovascularization with anti-VEGF treatment in the mouse retina using optical coherence tomography angiography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Park, Jang Ryul; Choi, WooJhon; Kim, Jaeryung; Hong, Hye Kyong; Kim, Yongjoo; Hwang, Yoonha; Park, Sang Jun; Woo, Se Joon; Kim, Pilhan; Park, Kyu Hyung; Koh, Gou Young; Oh, Wang-Yuhl

2017-02-01

To understand the pathogenesis of ophthalmic disease, utilizing small animal models such as mouse is necessary because of their ease of maintenance and availability. For identifying pathophysiology and drug development of retinal diseases in mouse model, optical coherence tomography angiography (OCTA) is promising imaging modality visualizing not only microstructure but also microvasculature. In this study, we serially imaged 3D structure and angiography of laser-induced choroidal neovascularization (CNV) in the mouse retina with/without anti-VEGF treatment. Also, the volume changes of CNV and avascular region in choroid layer are measured for identifying effects of anti-VEGF. A lab-built high-speed OCTA prototype using the wavelength-swept laser centered at 1040 nm with 230 kHz A-scan rate acquired 3-D volumetric data consisted of 1024 x 1024 x 3 A-scans. The OCTA scanned 1.7 mm x 1.7 mm area around ONH. For obtaining angiography, amplitude decorrelation from 3 consecutive B-scans at each position was generated. Seven days after the laser photocoagulation at mouse retina for generation of the laser-induced CNV, intravitreal administration of Fc and VEGF-Trap was given in the therapeutic arm. The OCTA were performed at 6, 14, 21 and 35 days after laser photocoagulation. Vasculatures of inner retina, outer retina and choroid layers were separately visualized after RPE flattening and layer segmentation. To investigate therapeutic effects of anti-VEGF treatment, the relative area and volume of CNV in outer retina layer is measured. Also, total volume of avascular zone surrounding the laser injury site in choroid layer is also analyzed.

Analysis of Alternative Pre-RNA Splicing in the Mouse Retina Using a Fluorescent Reporter.

PubMed

Murphy, Daniel; Kolandaivelu, Saravanan; Ramamurthy, Visvanathan; Stoilov, Peter

2016-01-01

In vivo alternative splicing is controlled in a tissue and cell type specific manner. Often individual cellular components of complex tissues will express different splicing programs. Thus, when studying splicing in multicellular organisms it is critical to determine the exon inclusion levels in individual cells positioned in the context of their native tissue or organ. Here we describe how a fluorescent splicing reporter in combination with in vivo electroporation can be used to visualize alternative splicing in individual cells within mature tissues. In a test case we show how the splicing of a photoreceptor specific exon can be visualized within the mouse retina. The retina was chosen as an example of a complex tissue that is fragile and whose cells cannot be studied in culture. With minor modifications to the injection and electroporation procedure, the protocol we outline can be applied to other tissues and organs.

In-vivo visualization of melanoma tumor microvessels and blood flow velocity changes accompanying tumor growth

NASA Astrophysics Data System (ADS)

Ishida, Hiroki; Hachiga, Tadashi; Andoh, Tsugunobu; Akiguchi, Shunsuke

2012-11-01

We demonstrate that using micro multipoint laser Doppler velocimetry (μ-MLDV) for noninvasive in-vivo imaging of blood vessels is useful for diagnosing malignant melanomas by comparison with visual diagnosis by dermoscopy. The blood flow velocity in microvessels varied during growth of melanomas transplanted in mouse ears. Mouse ears were observed by μ-MLDV up to 16 days after transplantation. The blood flow velocity in the tumor increased with increasing time and reached maximum of 4.5 mm/s at 9 days, which is more than twice that prior to transplantation. After 12 days, when the lesion had grown to an area of 6.6 mm2, we observed the formation of new blood vessels in the tumor. Finally, when the lesion had an area of 18 mm2 after 16 days, the flow velocity in the tumor decreased to approximately 3.2 mm/s.

A Comparison of Rapid-Scanning X-Ray Fluorescence Mapping And Magnetic Resonance Imaging to Localize Brain Iron Distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCrea, R.P.E.; Harder, S.L.; Martin, M.

2009-05-26

The clinical diagnosis of many neurodegenerative disorders relies primarily or exclusively on observed behaviors rather than measurable physical tests. One of the hallmarks of Alzheimer disease (AD) is the presence of amyloid-containing plaques associated with deposits of iron, copper and/or zinc. Work in other laboratories has shown that iron-rich plaques can be seen in the mouse brain in vivo with magnetic resonance imaging (MRI) using a high-field strength magnet but this iron cannot be visualized in humans using clinical magnets. To improve the interpretation of MRI, we correlated iron accumulation visualized by X-ray fluorescence spectroscopy, an element-specific technique with T1,more » T2, and susceptibility weighted MR (SWI) in a mouse model of AD. We show that SWI best shows areas of increased iron accumulation when compared to standard sequences.« less

New generation of 3D desktop computer interfaces

NASA Astrophysics Data System (ADS)

Skerjanc, Robert; Pastoor, Siegmund

1997-05-01

Today's computer interfaces use 2-D displays showing windows, icons and menus and support mouse interactions for handling programs and data files. The interface metaphor is that of a writing desk with (partly) overlapping sheets of documents placed on its top. Recent advances in the development of 3-D display technology give the opportunity to take the interface concept a radical stage further by breaking the design limits of the desktop metaphor. The major advantage of the envisioned 'application space' is, that it offers an additional, immediately perceptible dimension to clearly and constantly visualize the structure and current state of interrelations between documents, videos, application programs and networked systems. In this context, we describe the development of a visual operating system (VOS). Under VOS, applications appear as objects in 3-D space. Users can (graphically connect selected objects to enable communication between the respective applications. VOS includes a general concept of visual and object oriented programming for tasks ranging from, e.g., low-level programming up to high-level application configuration. In order to enable practical operation in an office or at home for many hours, the system should be very comfortable to use. Since typical 3-D equipment used, e.g., in virtual-reality applications (head-mounted displays, data gloves) is rather cumbersome and straining, we suggest to use off-head displays and contact-free interaction techniques. In this article, we introduce an autostereoscopic 3-D display and connected video based interaction techniques which allow viewpoint-depending imaging (by head tracking) and visually controlled modification of data objects and links (by gaze tracking, e.g., to pick, 3-D objects just by looking at them).

In vivo three-photon microscopy of subcortical structures within an intact mouse brain

NASA Astrophysics Data System (ADS)

Horton, Nicholas G.; Wang, Ke; Kobat, Demirhan; Clark, Catharine G.; Wise, Frank W.; Schaffer, Chris B.; Xu, Chris

2013-03-01

Two-photon fluorescence microscopy enables scientists in various fields including neuroscience, embryology and oncology to visualize in vivo and ex vivo tissue morphology and physiology at a cellular level deep within scattering tissue. However, tissue scattering limits the maximum imaging depth of two-photon fluorescence microscopy to the cortical layer within mouse brain, and imaging subcortical structures currently requires the removal of overlying brain tissue or the insertion of optical probes. Here, we demonstrate non-invasive, high-resolution, in vivo imaging of subcortical structures within an intact mouse brain using three-photon fluorescence microscopy at a spectral excitation window of 1,700 nm. Vascular structures as well as red fluorescent protein-labelled neurons within the mouse hippocampus are imaged. The combination of the long excitation wavelength and the higher-order nonlinear excitation overcomes the limitations of two-photon fluorescence microscopy, enabling biological investigations to take place at a greater depth within tissue.

In vivo visualization and ex vivo quantification of murine breast cancer cells in the mouse brain using MRI cell tracking and electron paramagnetic resonance.

PubMed

Danhier, Pierre; Magat, Julie; Levêque, Philippe; De Preter, Géraldine; Porporato, Paolo E; Bouzin, Caroline; Jordan, Bénédicte F; Demeur, Gladys; Haufroid, Vincent; Feron, Olivier; Sonveaux, Pierre; Gallez, Bernard

2015-03-01

Cell tracking could be useful to elucidate fundamental processes of cancer biology such as metastasis. The aim of this study was to visualize, using MRI, and to quantify, using electron paramagnetic resonance (EPR), the entrapment of murine breast cancer cells labeled with superparamagnetic iron oxide particles (SPIOs) in the mouse brain after intracardiac injection. For this purpose, luciferase-expressing murine 4 T1-luc breast cancer cells were labeled with fluorescent Molday ION Rhodamine B SPIOs. Following intracardiac injection, SPIO-labeled 4 T1-luc cells were imaged using multiple gradient-echo sequences. Ex vivo iron oxide quantification in the mouse brain was performed using EPR (9 GHz). The long-term fate of 4 T1-luc cells after injection was characterized using bioluminescence imaging (BLI), brain MRI and immunofluorescence. We observed hypointense spots due to SPIO-labeled cells in the mouse brain 4 h after injection on T2 *-weighted images. Histology studies showed that SPIO-labeled cancer cells were localized within blood vessels shortly after delivery. Ex vivo quantification of SPIOs showed that less than 1% of the injected cells were taken up by the mouse brain after injection. MRI experiments did not reveal the development of macrometastases in the mouse brain several days after injection, but immunofluorescence studies demonstrated that these cells found in the brain established micrometastases. Concerning the metastatic patterns of 4 T1-luc cells, an EPR biodistribution study demonstrated that SPIO-labeled 4 T1-luc cells were also entrapped in the lungs of mice after intracardiac injection. BLI performed 6 days after injection of 4 T1-luc cells showed that this cell line formed macrometastases in the lungs and in the bones. Conclusively, EPR and MRI were found to be complementary for cell tracking applications. MRI cell tracking at 11.7 T allowed sensitive detection of isolated SPIO-labeled cells in the mouse brain, whereas EPR allowed the assessment of the number of SPIO-labeled cells in organs shortly after injection. Copyright © 2015 John Wiley & Sons, Ltd.

Dynamic two-photon imaging of the immune response to Toxoplasma gondii infection.

PubMed

Luu, L; Coombes, J L

2015-03-01

Toxoplasma gondii is a highly successful parasite that can manipulate host immune responses to optimize its persistence and spread. As a result, a highly complex relationship exists between T. gondii and the immune system of the host. Advances in imaging techniques, and in particular, the application of two-photon microscopy to mouse infection models, have made it possible to directly visualize interactions between parasites and the host immune system as they occur in living tissues. Here, we will discuss how dynamic imaging techniques have provided unexpected new insight into (i) how immune responses are dynamically regulated by cells and structures in the local tissue environment, (ii) how protective responses to T. gondii are generated and (iii) how the parasite exploits the immune system for its own benefit. © 2014 John Wiley & Sons Ltd.

Fast frame rate rodent cardiac x-ray imaging using scintillator lens coupled to CMOS camera

NASA Astrophysics Data System (ADS)

Swathi Lakshmi, B.; Sai Varsha, M. K. N.; Kumar, N. Ashwin; Dixit, Madhulika; Krishnamurthi, Ganapathy

2017-03-01

Micro-Computed Tomography (MCT) systems for small animal imaging plays a critical role for monitoring disease progression and therapy evaluation. In this work, an in-house built micro-CT system equipped with a X-ray scintillator lens coupled to a commercial CMOS camera was used to test the feasibility of its application to Digital Subtraction Angiography (DSA). Literature has reported such studies being done with clinical X-ray tubes that can be pulsed rapidly or with rotating gantry systems, thus increasing the cost and infrastructural requirements.The feasibility of DSA was evaluated by injected Iodinated contrast agent (ICA) through the tail vein of a mouse. Projection images of the heart were acquired pre and post contrast using the high frame rate X-ray detector and processing done to visualize transit of ICA through the heart.

Long-Term Visual Training Increases Visual Acuity and Long-Term Monocular Deprivation Promotes Ocular Dominance Plasticity in Adult Standard Cage-Raised Mice

PubMed Central

Yusifov, Rashad

2018-01-01

Abstract For routine behavioral tasks, mice predominantly rely on olfactory cues and tactile information. In contrast, their visual capabilities appear rather restricted, raising the question whether they can improve if vision gets more behaviorally relevant. We therefore performed long-term training using the visual water task (VWT): adult standard cage (SC)-raised mice were trained to swim toward a rewarded grating stimulus so that using visual information avoided excessive swimming toward nonrewarded stimuli. Indeed, and in contrast to old mice raised in a generally enriched environment (Greifzu et al., 2016), long-term VWT training increased visual acuity (VA) on average by more than 30% to 0.82 cycles per degree (cyc/deg). In an individual animal, VA even increased to 1.49 cyc/deg, i.e., beyond the rat range of VAs. Since visual experience enhances the spatial frequency threshold of the optomotor (OPT) reflex of the open eye after monocular deprivation (MD), we also quantified monocular vision after VWT training. Monocular VA did not increase reliably, and eye reopening did not initiate a decline to pre-MD values as observed by optomotry; VA values rather increased by continued VWT training. Thus, optomotry and VWT measure different parameters of mouse spatial vision. Finally, we tested whether long-term MD induced ocular dominance (OD) plasticity in the visual cortex of adult [postnatal day (P)162–P182] SC-raised mice. This was indeed the case: 40–50 days of MD induced OD shifts toward the open eye in both VWT-trained and, surprisingly, also in age-matched mice without VWT training. These data indicate that (1) long-term VWT training increases adult mouse VA, and (2) long-term MD induces OD shifts also in adult SC-raised mice. PMID:29379877

Following the ontogeny of retinal waves: pan-retinal recordings of population dynamics in the neonatal mouse

PubMed Central

Maccione, Alessandro; Hennig, Matthias H; Gandolfo, Mauro; Muthmann, Oliver; van Coppenhagen, James; Eglen, Stephen J; Berdondini, Luca; Sernagor, Evelyne

2014-01-01

The immature retina generates spontaneous waves of spiking activity that sweep across the ganglion cell layer during a limited period of development before the onset of visual experience. The spatiotemporal patterns encoded in the waves are believed to be instructive for the wiring of functional connections throughout the visual system. However, the ontogeny of retinal waves is still poorly documented as a result of the relatively low resolution of conventional recording techniques. Here, we characterize the spatiotemporal features of mouse retinal waves from birth until eye opening in unprecedented detail using a large-scale, dense, 4096-channel multielectrode array that allowed us to record from the entire neonatal retina at near cellular resolution. We found that early cholinergic waves propagate with random trajectories over large areas with low ganglion cell recruitment. They become slower, smaller and denser when GABAA signalling matures, as occurs beyond postnatal day (P) 7. Glutamatergic influences dominate from P10, coinciding with profound changes in activity dynamics. At this time, waves cease to be random and begin to show repetitive trajectories confined to a few localized hotspots. These hotspots gradually tile the retina with time, and disappear after eye opening. Our observations demonstrate that retinal waves undergo major spatiotemporal changes during ontogeny. Our results support the hypotheses that cholinergic waves guide the refinement of retinal targets and that glutamatergic waves may also support the wiring of retinal receptive fields. PMID:24366261

LCFM - LIVING COLOR FRAME MAKER: PC GRAPHICS GENERATION AND MANAGEMENT TOOL FOR REAL-TIME APPLICATIONS

NASA Technical Reports Server (NTRS)

Truong, L. V.

1994-01-01

Computer graphics are often applied for better understanding and interpretation of data under observation. These graphics become more complicated when animation is required during "run-time", as found in many typical modern artificial intelligence and expert systems. Living Color Frame Maker is a solution to many of these real-time graphics problems. Living Color Frame Maker (LCFM) is a graphics generation and management tool for IBM or IBM compatible personal computers. To eliminate graphics programming, the graphic designer can use LCFM to generate computer graphics frames. The graphical frames are then saved as text files, in a readable and disclosed format, which can be easily accessed and manipulated by user programs for a wide range of "real-time" visual information applications. For example, LCFM can be implemented in a frame-based expert system for visual aids in management of systems. For monitoring, diagnosis, and/or controlling purposes, circuit or systems diagrams can be brought to "life" by using designated video colors and intensities to symbolize the status of hardware components (via real-time feedback from sensors). Thus status of the system itself can be displayed. The Living Color Frame Maker is user friendly with graphical interfaces, and provides on-line help instructions. All options are executed using mouse commands and are displayed on a single menu for fast and easy operation. LCFM is written in C++ using the Borland C++ 2.0 compiler for IBM PC series computers and compatible computers running MS-DOS. The program requires a mouse and an EGA/VGA display. A minimum of 77K of RAM is also required for execution. The documentation is provided in electronic form on the distribution medium in WordPerfect format. A sample MS-DOS executable is provided on the distribution medium. The standard distribution medium for this program is one 5.25 inch 360K MS-DOS format diskette. The contents of the diskette are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. The Living Color Frame Maker tool was developed in 1992.

Age-related slowing of response selection and production in a visual choice reaction time task

PubMed Central

Woods, David L.; Wyma, John M.; Yund, E. William; Herron, Timothy J.; Reed, Bruce

2015-01-01

Aging is associated with delayed processing in choice reaction time (CRT) tasks, but the processing stages most impacted by aging have not been clearly identified. Here, we analyzed CRT latencies in a computerized serial visual feature-conjunction task. Participants responded to a target letter (probability 40%) by pressing one mouse button, and responded to distractor letters differing either in color, shape, or both features from the target (probabilities 20% each) by pressing the other mouse button. Stimuli were presented randomly to the left and right visual fields and stimulus onset asynchronies (SOAs) were adaptively reduced following correct responses using a staircase procedure. In Experiment 1, we tested 1466 participants who ranged in age from 18 to 65 years. CRT latencies increased significantly with age (r = 0.47, 2.80 ms/year). Central processing time (CPT), isolated by subtracting simple reaction times (SRT) (obtained in a companion experiment performed on the same day) from CRT latencies, accounted for more than 80% of age-related CRT slowing, with most of the remaining increase in latency due to slowed motor responses. Participants were faster and more accurate when the stimulus location was spatially compatible with the mouse button used for responding, and this effect increased slightly with age. Participants took longer to respond to distractors with target color or shape than to distractors with no target features. However, the additional time needed to discriminate the more target-like distractors did not increase with age. In Experiment 2, we replicated the findings of Experiment 1 in a second population of 178 participants (ages 18–82 years). CRT latencies did not differ significantly in the two experiments, and similar effects of age, distractor similarity, and stimulus-response spatial compatibility were found. The results suggest that the age-related slowing in visual CRT latencies is largely due to delays in response selection and production. PMID:25954175

Reduction in spontaneous firing of mouse excitatory layer 4 cortical neurons following visual classical conditioning

NASA Astrophysics Data System (ADS)

Bekisz, Marek; Shendye, Ninad; Raciborska, Ida; Wróbel, Andrzej; Waleszczyk, Wioletta J.

2017-08-01

The process of learning induces plastic changes in neuronal network of the brain. Our earlier studies on mice showed that classical conditioning in which monocular visual stimulation was paired with an electric shock to the tail enhanced GABA immunoreactivity within layer 4 of the monocular part of the primary visual cortex (V1), contralaterally to the stimulated eye. In the present experiment we investigated whether the same classical conditioning paradigm induces changes of neuronal excitability in this cortical area. Two experimental groups were used: mice that underwent 7-day visual classical conditioning and controls. Patch-clamp whole-cell recordings were performed from ex vivo slices of mouse V1. The slices were perfused with the modified artificial cerebrospinal fluid, the composition of which better mimics the brain interstitial fluid in situ and induces spontaneous activity. The neuronal excitability was characterized by measuring the frequency of spontaneous action potentials. We found that layer 4 star pyramidal cells located in the monocular representation of the "trained" eye in V1 had lower frequency of spontaneous activity in comparison with neurons from the same cortical region of control animals. Weaker spontaneous firing indicates decreased general excitability of star pyramidal neurons within layer 4 of the monocular representation of the "trained" eye in V1. Such effect could result from enhanced inhibitory processes accompanying learning in this cortical area.

Visual Tuning Properties of Genetically Identified Layer 2/3 Neuronal Types in the Primary Visual Cortex of Cre-Transgenic Mice

PubMed Central

Zariwala, Hatim A.; Madisen, Linda; Ahrens, Kurt F.; Bernard, Amy; Lein, Edward S.; Jones, Allan R.; Zeng, Hongkui

2011-01-01

The putative excitatory and inhibitory cell classes within the mouse primary visual cortex V1 have different functional properties as studied using recording microelectrode. Excitatory neurons show high selectivity for the orientation angle of moving gratings while the putative inhibitory neurons show poor selectivity. However, the study of selectivity of the genetically identified interneurons and their subtypes remain controversial. Here we use novel Cre-driver and reporter mice to identify genetic subpopulations in vivo for two-photon calcium dye imaging: Wfs1(+)/Gad1(−) mice that labels layer 2/3 excitatory cell population and Pvalb(+)/Gad1(+) mice that labels a genetic subpopulation of inhibitory neurons. The cells in both mice were identically labeled with a tdTomato protein, visible in vivo, using a Cre-reporter line. We found that the Wfs1(+) cells exhibited visual tuning properties comparable to the excitatory population, i.e., high selectivity and tuning to the angle, direction, and spatial frequency of oriented moving gratings. The functional tuning of Pvalb(+) neurons was consistent with previously reported narrow-spiking interneurons in microelectrode studies, exhibiting poorer selectivity than the excitatory neurons. This study demonstrates the utility of Cre-transgenic mouse technology in selective targeting of subpopulations of neurons and makes them amenable to structural, functional, and connectivity studies. PMID:21283555

Pharmacological Amelioration of Cone Survival and Vision in a Mouse Model for Leber Congenital Amaurosis

PubMed Central

Li, Songhua; Samardzija, Marijana; Yang, Zhihui; Grimm, Christian

2016-01-01

RPE65, an abundant membrane-associate protein in the retinal pigment epithelium (RPE), is a key retinoid isomerase of the visual cycle necessary for generating 11-cis-retinal that functions not only as a molecular switch for activating cone and rod visual pigments in response to light stimulation, but also as a chaperone for normal trafficking of cone opsins to the outer segments. Many mutations in RPE65 are associated with Leber congenital amaurosis (LCA). A R91W substitution, the most frequent LCA-associated mutation, results in a severe decrease in protein level and enzymatic activity of RPE65, causing cone opsin mislocalization and early cone degeneration in the mutation knock-in mouse model of LCA. Here we show that R91W RPE65 undergoes ubiquitination-dependent proteasomal degradation in the knock-in mouse RPE due to misfolding. The 26S proteasome non-ATPase regulatory subunit 13 mediated degradation specifically of misfolded R91W RPE65. The mutation disrupted membrane-association and colocalization of RPE65 with lecithin:retinol acyltransferase (LRAT) that provides the hydrophobic substrate for RPE65. Systemic administration of sodium 4-phenylbutyrate (PBA), a chemical chaperone, increased protein stability, enzymatic activity, membrane-association, and colocalization of R91W RPE65 with LRAT. This rescue effect increased synthesis of 11-cis-retinal and 9-cis-retinal, a functional iso-chromophore of the visual pigments, led to alleviation of S-opsin mislocalization and cone degeneration in the knock-in mice. Importantly, PBA-treatment also improved cone-mediated vision in the mutant mice. These results indicate that PBA, a U.S. Food and Drug Administration-approved safe oral medication, may provide a noninvasive therapeutic intervention that delays daylight vision loss in patients with RPE65 mutations. SIGNIFICANCE STATEMENT LCA is a severe early onset retinal dystrophy. Recent clinical trials of gene therapy have implicated the need of an alternative or combination therapy to improve cone survival and function in patients with LCA caused by RPE65 mutations. Using a mouse model carrying the most frequent LCA-associated mutation (R91W), we found that the mutant RPE65 underwent ubiquitination-dependent proteasomal degradation due to misfolding. Treatment of the mice with a chemical chaperone partially corrected stability, enzymatic activity, and subcellular localization of R91W RPE65, which was also accompanied by improvement of cone survival and vision. These findings identify an in vivo molecular pathogenic mechanism for R91W mutation and provide a feasible pharmacological approach that can delay vision loss in patients with RPE65 mutations. PMID:27225770

The role of whiskers in compensation of visual deficit in a mouse model of retinal degeneration.

PubMed

Voller, Jaroslav; Potužáková, Barbora; Šimeček, Vojtěch; Vožeh, František

2014-01-13

Sensory deprivation in one modality can enhance the development of the remaining modalities via mechanisms of synaptic plasticity. Mice of the C3H strain suffer from RD1 retinal degeneration that leads to visual impairment at weaning age. We examined a role of whiskers in compensation of the visual deficit. In order to differentiate the contribution of the whiskers from other mechanisms that can take part in the compensation, we investigated the effect of both chronic and acute tactile deprivation. Three-month-old mice were used. We examined motor skills (rotarod, beam walking test), gait control (CatWalk system), spontaneous motor activity (open field) and CNS excitability to an acoustic stimulus for assessment of compensatory changes in auditory system (audiogenic epilepsy). In the sighted mice, the only effect was a decline in their rotarod test performance after acute whisker removal. In the blind animals, chronic tactile deprivation caused changes in their gait and impaired the performance in motor tests. Some other compensatory mechanisms were involved but the whiskers are essential for the compensation as it emerged from more marked change of gait and the worsening of the motor performance after the acute whisker removal. Both chronic and acute tactile deprivation induced anxiety-like behaviour. Only a combination of blindness and chronic tactile deprivation led to an increased sense of hearing. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Computational genetic neuroanatomy of the developing mouse brain: dimensionality reduction, visualization, and clustering.

PubMed

Ji, Shuiwang

2013-07-11

The structured organization of cells in the brain plays a key role in its functional efficiency. This delicate organization is the consequence of unique molecular identity of each cell gradually established by precise spatiotemporal gene expression control during development. Currently, studies on the molecular-structural association are beginning to reveal how the spatiotemporal gene expression patterns are related to cellular differentiation and structural development. In this article, we aim at a global, data-driven study of the relationship between gene expressions and neuroanatomy in the developing mouse brain. To enable visual explorations of the high-dimensional data, we map the in situ hybridization gene expression data to a two-dimensional space by preserving both the global and the local structures. Our results show that the developing brain anatomy is largely preserved in the reduced gene expression space. To provide a quantitative analysis, we cluster the reduced data into groups and measure the consistency with neuroanatomy at multiple levels. Our results show that the clusters in the low-dimensional space are more consistent with neuroanatomy than those in the original space. Gene expression patterns and developing brain anatomy are closely related. Dimensionality reduction and visual exploration facilitate the study of this relationship.

A new method for in vivo visualization of vessel remodeling using a near-infrared dye

PubMed Central

Billaud, Marie; Ross, Jeremy A; Greyson, Mark A; Bruce, Anthony C; Seaman, Scott A; Heberlein, Katherine R; Han, Jenny; Best, Angela K; Peirce, Shayn M; Isakson, Brant E

2011-01-01

Intro Vascular obstructive events can be partially compensated for by remodeling processes that increase vessel diameter and collateral tortuosity. However, methods for visualizing remodeling events in vivo and with temporal comparisons from the same animal remain elusive. Methods Using a novel infrared conjugated polyethylene glycol dye, we investigated the possibility of intravital vascular imaging of the mouse ear before and after ligation of the primary feeder artery. For comparison, we used two different mouse models known to have impaired vascular remodeling post ligation (i.e. aged and PAI-1−/− mice). The results obtained with the infrared dye were confirmed using immunofluorescence labeling of the ear microvasculature with confocal microscopy. Results After ligation, increases in vessel diameter (between 10% and 60%) and tortuosity (approximately 15%) were observed in C57Bl/6 mice using both the infrared dye and the immunofluorescence technique. However, aged C57Bl/6 and PAI-1−/− mice did not show vascular remodeling following ligation. Conclusion Vascular remodeling can be visualized and accurately quantified using a new infrared dye in vivo. This analysis technique could be generally employed for quantitative investigations of changes in vascular remodeling. PMID:21418375

Causal evidence for retina dependent and independent visual motion computations in mouse cortex

PubMed Central

Hillier, Daniel; Fiscella, Michele; Drinnenberg, Antonia; Trenholm, Stuart; Rompani, Santiago B.; Raics, Zoltan; Katona, Gergely; Juettner, Josephine; Hierlemann, Andreas; Rozsa, Balazs; Roska, Botond

2017-01-01

How neuronal computations in the sensory periphery contribute to computations in the cortex is not well understood. We examined this question in the context of visual-motion processing in the retina and primary visual cortex (V1) of mice. We disrupted retinal direction selectivity – either exclusively along the horizontal axis using FRMD7 mutants or along all directions by ablating starburst amacrine cells – and monitored neuronal activity in layer 2/3 of V1 during stimulation with visual motion. In control mice, we found an overrepresentation of cortical cells preferring posterior visual motion, the dominant motion direction an animal experiences when it moves forward. In mice with disrupted retinal direction selectivity, the overrepresentation of posterior-motion-preferring cortical cells disappeared, and their response at higher stimulus speeds was reduced. This work reveals the existence of two functionally distinct, sensory-periphery-dependent and -independent computations of visual motion in the cortex. PMID:28530661

Deficient plasticity in the primary visual cortex of alpha-calcium/calmodulin-dependent protein kinase II mutant mice.

PubMed

Gordon, J A; Cioffi, D; Silva, A J; Stryker, M P

1996-09-01

The recent characterization of plasticity in the mouse visual cortex permits the use of mutant mice to investigate the cellular mechanisms underlying activity-dependent development. As calcium-dependent signaling pathways have been implicated in neuronal plasticity, we examined visual cortical plasticity in mice lacking the alpha-isoform of calcium/calmodulin-dependent protein kinase II (alpha CaMKII). In wild-type mice, brief occlusion of vision in one eye during a critical period reduces responses in the visual cortex. In half of the alpha CaMKII-deficient mice, visual cortical responses developed normally, but visual cortical plasticity was greatly diminished. After intensive training, spatial learning in the Morris water maze was severely impaired in a similar fraction of mutant animals. These data indicate that loss of alpha CaMKII results in a severe but variable defect in neuronal plasticity.

Fiber optic label-free biophotonic diagnostic tool for cardiovascular disease

NASA Astrophysics Data System (ADS)

Rius, Cristina; Ackermann, Tobias N.; Dorado, Beatriz; Muñoz-Berbel, Xavier; Andrés, Vicente; Llobera, Andreu

2015-06-01

A label-free compact method for performing photonic characterization of "healthy" versus "diseased" arteries has been developed. It permits the detection of atherosclerotic lesion in living mouse arteries. Using this prototype, we observed that the spectral response (photonic fingerprint, PIN) obtained from aortas of wild-type mice differs from the response of ApoE-KO mice fed with high-fat diet (an atheroprone mouse model). Benchmark of the results against gold standard was performed by staining the aortas with Oil-Red-O to visualize atherosclerotic plaques.

Investigating Visual Alerting in Maritime Command and Control

DTIC Science & Technology

2008-12-01

were: “ qwe ” for neutral or “asd” for hostile. The final step in the categorization task was to confirm their decision by clicking the mouse on a box...the Report display was active. As in Experiment 1, participants typed “ qwe ” or “asd” into the textbox to report their classification. An example of...button, and enter your answer in the text box on the right screen. To enter your answer type " qwe "=neutral or "asd"=hostile. Use the mouse to

A transgenic approach to study argininosuccinate synthetase gene expression

PubMed Central

2014-01-01

Background Argininosuccinate synthetase (ASS) participates in urea, nitric oxide and arginine production. Besides transcriptional regulation, a post-transcriptional regulation affecting nuclear precursor RNA stability has been reported. To study whether such post-transcriptional regulation underlines particular temporal and spatial ASS expression, and to investigate how human ASS gene behaves in a mouse background, a transgenic mouse system using a modified bacterial artificial chromosome carrying the human ASS gene tagged with EGFP was employed. Results Two lines of ASS-EGFP transgenic mice were generated: one with EGFP under transcriptional control similar to that of the endogenous ASS gene, another with EGFP under both transcriptional and post-transcriptional regulation as that of the endogenous ASS mRNA. EGFP expression in the liver, the organ for urea production, and in the intestine and kidney that are responsible for arginine biosynthesis, was examined. Organs taken from embryos E14.5 stage to young adult were examined under a fluorescence microscope either directly or after cryosectioning. The levels of EGFP and endogenous mouse Ass mRNAs were also quantified by S1 nuclease mapping. EGFP fluorescence and EGFP mRNA levels in both the liver and kidney were found to increase progressively from embryonic stage toward birth. In contrast, EGFP expression in the intestine was higher in neonates and started to decline at about 3 weeks after birth. Comparison between the EGFP profiles of the two transgenic lines indicated the developmental and tissue-specific regulation was mainly controlled at the transcriptional level. The ASS transgene was of human origin. EGFP expression in the liver followed essentially the mouse Ass pattern as evidenced by zonation distribution of fluorescence and the level of EGFP mRNA at birth. However, in the small intestine, Ass mRNA level declined sharply at 3 week of age, and yet substantial EGFP mRNA was still detectable at this stage. Thus, the time course of EGFP expression in the transgenic mice resembled that of the human ASS gene. Conclusions We demonstrate that the transgenic mouse system reported here has the merit of sensitivity and direct visualization advantage, and is ideal for annotating temporal and spatial expression profiles and the regulation mode of the ASS gene. PMID:24884799

In vitro three-dimensional coculturing poly3-hydroxybutyrate-co-3-hydroxyhexanoate with mouse-induced pluripotent stem cells for myocardial patch application.

PubMed

Shijun, Xu; Junsheng, Mu; Jianqun, Zhang; Ping, Bo

2016-03-01

Identifying a suitable polymeric biomaterial for myocardial patch repair following myocardial infarction, cerebral infarction, and cartilage injury is essential. This study aimed to investigate the effect of the novel polymer material, poly3-hydroxybutyrate-co-3-hydroxyhexanoate, on the adhesion, proliferation, and differentiation of mouse-induced pluripotent stem cells in vitro. Mouse-induced pluripotent stem cells were isolated, expanded, and cultured on either two-dimensional or three-dimensional poly3-hydroxybutyrate-co-3-hydroxyhexanoate films (membranes were perforated to imitate three-dimensional space). Following attachment onto the films, mouse-induced pluripotent stem cell morphology was visualized using scanning electron microscopy. Cell vitality was detected using the Cell Counting Kit-8 assay and cell proliferation was observed using fluorescent 4',6-diamidino-2-phenylindole (DAPI) staining. Mouse-induced pluripotent stem cells were induced into cardiomyocytes by differentiation medium containing vitamin C. A control group in the absence of an inducer was included. Mouse-induced pluripotent stem cell survival and differentiation were observed using immunofluorescence and flow cytometry, respectively. Mouse-induced pluripotent stem cells growth, proliferation, and differentiation were observed on both two-dimensional and three-dimensional poly3-hydroxybutyrate-co-3-hydroxyhexanoate films. Vitamin C markedly improved the efficiency of mouse-induced pluripotent stem cells differentiation into cardiomyocytes on poly3-hydroxybutyrate-co-3-hydroxyhexanoate films. Three-dimensional culture was better at promoting mouse-induced pluripotent stem cell proliferation and differentiation compared with two-dimensional culture. © The Author(s) 2016.

A Mouse Model for Conditional Secretion of Specific Single-Chain Antibodies Provides Genetic Evidence for Regulation of Cortical Plasticity by a Non-cell Autonomous Homeoprotein Transcription Factor.

PubMed

Bernard, Clémence; Vincent, Clémentine; Testa, Damien; Bertini, Eva; Ribot, Jérôme; Di Nardo, Ariel A; Volovitch, Michel; Prochiantz, Alain

2016-05-01

During postnatal life the cerebral cortex passes through critical periods of plasticity allowing its physiological adaptation to the environment. In the visual cortex, critical period onset and closure are influenced by the non-cell autonomous activity of the Otx2 homeoprotein transcription factor, which regulates the maturation of parvalbumin-expressing inhibitory interneurons (PV cells). In adult mice, the maintenance of a non-plastic adult state requires continuous Otx2 import by PV cells. An important source of extra-cortical Otx2 is the choroid plexus, which secretes Otx2 into the cerebrospinal fluid. Otx2 secretion and internalization requires two small peptidic domains that are part of the DNA-binding domain. Thus, mutating these "transfer" sequences also modifies cell autonomous transcription, precluding this approach to obtain a cell autonomous-only mouse. Here, we develop a mouse model with inducible secretion of an anti-Otx2 single-chain antibody to trap Otx2 in the extracellular milieu. Postnatal secretion of this single-chain antibody by PV cells delays PV maturation and reduces plasticity gene expression. Induced adult expression of this single-chain antibody in cerebrospinal fluid decreases Otx2 internalization by PV cells, strongly induces plasticity gene expression and reopens physiological plasticity. We provide the first mammalian genetic evidence for a signaling mechanism involving intercellular transfer of a homeoprotein transcription factor. Our single-chain antibody mouse model is a valid strategy for extracellular neutralization that could be applied to other homeoproteins and signaling molecules within and beyond the nervous system.

New animal models to study the role of tyrosinase in normal retinal development.

PubMed

Lavado, Alfonso; Montoliu, Lluis

2006-01-01

Albino animals display a hypopigmented phenotype associated with several visual abnormalities, including rod photoreceptor cell deficits, abnormal patterns of connections between the eye and the brain and a general underdevelopment of central retina. Oculocutaneous albinism type I, a common form of albinism, is caused by mutations in the tyrosinase gene. In mice, the albino phenotype can be corrected by functional tyrosinase transgenes. Tyrosinase transgenic animals not only show normal pigmentation but the correction of all visual abnormalities associated with albinism, confirming a role of tyrosinase, a key enzyme in melanin biosynthesis, in normal retinal development. Here, we will discuss recent work carried out with new tyrosinase transgenic mouse models, to further analyse the role of tyrosinase in retinal development. We will first report a transgenic model with inducible tyrosinase expression that has been used to address the regulated activation of this gene and its associated effects on the development of the visual system. Second, we will comment on an interesting yeast artificial chromosome (YAC)-tyrosinase transgene, lacking important regulatory elements, that has highlighted the significance of local interactions between the retinal pigment epithelium (RPE) and developing neural retina.

Visualizing epithelial expression of EGFR in vivo with distal scanning side-viewing confocal endomicroscope

NASA Astrophysics Data System (ADS)

Duan, Xiyu; Li, Haijun; Zhou, Juan; Zhou, Quan; Oldham, Kenn R.; Wang, Thomas D.

2016-11-01

Confocal endomicroscopy is an emerging imaging technology that has recently been introduced into the clinic to instantaneously collect “optical biopsies” in vivo with histology-like quality. Here, we demonstrate a fast scanner located in the distal end of a side-viewing instrument using a compact lens assembly with numerical aperture of 0.5 to achieve a working distance of 100 μm and field-of-view of 300 × 400 μm2. The microelectromechanical systems (MEMS) mirror was designed based on the principle of parametric resonance and images at 5 frames per second. The instrument has a 4.2 mm outer diameter and 3 cm rigid length, and can pass through the biopsy channel of a medical endoscope. We achieved real time optical sections of NIR fluorescence with 0.87 μm lateral resolution, and were able to visualize in vivo binding of a Cy5.5-labeled peptide specific for EGFR to the cell surface of pre-cancerous colonocytes within the epithelium of dysplastic crypts in mouse colon. By performing targeted imaging with endomicroscopy, we can visualize molecular expression patterns in vivo that provide a biological basis for disease detection.

Four alpha ganglion cell types in mouse retina: Function, structure, and molecular signatures

PubMed Central

Sanes, Joshua R.

2017-01-01

The retina communicates with the brain using ≥30 parallel channels, each carried by axons of distinct types of retinal ganglion cells. In every mammalian retina one finds so-called "alpha" ganglion cells (αRGCs), identified by their large cell bodies, stout axons, wide and mono-stratified dendritic fields, and high levels of neurofilament protein. In the mouse, three αRGC types have been described based on responses to light steps: On-sustained, Off-sustained, and Off-transient. Here we employed a transgenic mouse line that labels αRGCs in the live retina, allowing systematic targeted recordings. We characterize the three known types and identify a fourth, with On-transient responses. All four αRGC types share basic aspects of visual signaling, including a large receptive field center, a weak antagonistic surround, and absence of any direction selectivity. They also share a distinctive waveform of the action potential, faster than that of other RGC types. Morphologically, they differ in the level of dendritic stratification within the IPL, which accounts for their response properties. Molecularly, each type has a distinct signature. A comparison across mammals suggests a common theme, in which four large-bodied ganglion cell types split the visual signal into four channels arranged symmetrically with respect to polarity and kinetics. PMID:28753612

Specimen preparation, imaging, and analysis protocols for knife-edge scanning microscopy.

PubMed

Choe, Yoonsuck; Mayerich, David; Kwon, Jaerock; Miller, Daniel E; Sung, Chul; Chung, Ji Ryang; Huffman, Todd; Keyser, John; Abbott, Louise C

2011-12-09

Major advances in high-throughput, high-resolution, 3D microscopy techniques have enabled the acquisition of large volumes of neuroanatomical data at submicrometer resolution. One of the first such instruments producing whole-brain-scale data is the Knife-Edge Scanning Microscope (KESM), developed and hosted in the authors' lab. KESM has been used to section and image whole mouse brains at submicrometer resolution, revealing the intricate details of the neuronal networks (Golgi), vascular networks (India ink), and cell body distribution (Nissl). The use of KESM is not restricted to the mouse nor the brain. We have successfully imaged the octopus brain, mouse lung, and rat brain. We are currently working on whole zebra fish embryos. Data like these can greatly contribute to connectomics research; to microcirculation and hemodynamic research; and to stereology research by providing an exact ground-truth. In this article, we will describe the pipeline, including specimen preparation (fixing, staining, and embedding), KESM configuration and setup, sectioning and imaging with the KESM, image processing, data preparation, and data visualization and analysis. The emphasis will be on specimen preparation and visualization/analysis of obtained KESM data. We expect the detailed protocol presented in this article to help broaden the access to KESM and increase its utilization.

Fluorescence-based surface magnifying chromoendoscopy and optical coherence tomography endoscope

NASA Astrophysics Data System (ADS)

Wall, R. Andrew; Barton, Jennifer K.

2012-02-01

A side-viewing, 2 mm diameter, surface magnifying chromoendoscopy (SMC)-optical coherence tomography (OCT) endoscope has been designed for simultaneous, non-destructive surface fluorescence visualization and cross-sectional imaging. We apply this endoscope to in vivo examination of mouse colon. A 30,000 element fiber bundle is combined with single mode fibers. The distal optics consist of a gradient-index lens and spacer to provide a magnification of 1 at a working distance of 1.58 mm in air, necessary to image the sample through a 0.23 mm thick outer glass envelope, and an aluminized right-angle prism fixed to the distal end of the GRIN lens assembly. The resulting 1:1 imaging system is capable of 3.9 μm lateral and 2.3 μm axial resolution in the OCT channel, and 125 lp/mm resolution across a 0.70 mm field of view in the SMC channel. The endoscope can perform high contrast crypt visualization, molecular imaging, and cross-sectional imaging of colon microstructure.

Visualization of aging-associated chromatin alterations with an engineered TALE system

PubMed Central

Ren, Ruotong; Deng, Liping; Xue, Yanhong; Suzuki, Keiichiro; Zhang, Weiqi; Yu, Yang; Wu, Jun; Sun, Liang; Gong, Xiaojun; Luan, Huiqin; Yang, Fan; Ju, Zhenyu; Ren, Xiaoqing; Wang, Si; Tang, Hong; Geng, Lingling; Zhang, Weizhou; Li, Jian; Qiao, Jie; Xu, Tao; Qu, Jing; Liu, Guang-Hui

2017-01-01

Visualization of specific genomic loci in live cells is a prerequisite for the investigation of dynamic changes in chromatin architecture during diverse biological processes, such as cellular aging. However, current precision genomic imaging methods are hampered by the lack of fluorescent probes with high specificity and signal-to-noise contrast. We find that conventional transcription activator-like effectors (TALEs) tend to form protein aggregates, thereby compromising their performance in imaging applications. Through screening, we found that fusing thioredoxin with TALEs prevented aggregate formation, unlocking the full power of TALE-based genomic imaging. Using thioredoxin-fused TALEs (TTALEs), we achieved high-quality imaging at various genomic loci and observed aging-associated (epi) genomic alterations at telomeres and centromeres in human and mouse premature aging models. Importantly, we identified attrition of ribosomal DNA repeats as a molecular marker for human aging. Our study establishes a simple and robust imaging method for precisely monitoring chromatin dynamics in vitro and in vivo. PMID:28139645

Integrative Analysis of Disease Signatures Shows Inflammation Disrupts Juvenile Experience-Dependent Cortical Plasticity

PubMed Central

Smith, Milo R.; Burman, Poromendro

2016-01-01

Throughout childhood and adolescence, periods of heightened neuroplasticity are critical for the development of healthy brain function and behavior. Given the high prevalence of neurodevelopmental disorders, such as autism, identifying disruptors of developmental plasticity represents an essential step for developing strategies for prevention and intervention. Applying a novel computational approach that systematically assessed connections between 436 transcriptional signatures of disease and multiple signatures of neuroplasticity, we identified inflammation as a common pathological process central to a diverse set of diseases predicted to dysregulate plasticity signatures. We tested the hypothesis that inflammation disrupts developmental cortical plasticity in vivo using the mouse ocular dominance model of experience-dependent plasticity in primary visual cortex. We found that the administration of systemic lipopolysaccharide suppressed plasticity during juvenile critical period with accompanying transcriptional changes in a particular set of molecular regulators within primary visual cortex. These findings suggest that inflammation may have unrecognized adverse consequences on the postnatal developmental trajectory and indicate that treating inflammation may reduce the burden of neurodevelopmental disorders. PMID:28101530

Increased visual sensitivity following periods of dim illumination.

PubMed

McKeown, Alex S; Kraft, Timothy W; Loop, Michael S

2015-02-19

We measured changes in the sensitivity of the human rod pathway by testing visual reaction times before and after light adaptation. We targeted a specific range of conditioning light intensities to see if a physiological adaptation recently discovered in mouse rods is observable at the perceptual level in humans. We also measured the noise spectrum of single mouse rods due to the importance of the signal-to-noise ratio in rod to rod bipolar cell signal transfer. Using the well-defined relationship between stimulus intensity and reaction time (Piéron's law), we measured the reaction times of eight human subjects (ages 24-66) to scotopic test flashes of a single intensity before and after the presentation of a 3-minute background. We also made recordings from single mouse rods and processed the cellular noise spectrum before and after similar conditioning exposures. Subject reaction times to a fixed-strength stimulus were fastest 5 seconds after conditioning background exposure (79% ± 1% of the preconditioning mean, in darkness) and were significantly faster for the first 12 seconds after background exposure (P < 0.01). During the period of increased rod sensitivity, the continuous noise spectrum of individual mouse rods was not significantly increased. A decrease in human reaction times to a dim flash after conditioning background exposure may originate in rod photoreceptors through a transient increase in the sensitivity of the phototransduction cascade. There is no accompanying increase in rod cellular noise, allowing for reliable transmission of larger rod signals after conditioning exposures and the observed increase in perceptual sensitivity. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

System parameters for erythropoiesis control model: Comparison of normal values in human and mouse model

NASA Technical Reports Server (NTRS)

1979-01-01

The computer model for erythropoietic control was adapted to the mouse system by altering system parameters originally given for the human to those which more realistically represent the mouse. Parameter values were obtained from a variety of literature sources. Using the mouse model, the mouse was studied as a potential experimental model for spaceflight. Simulation studies of dehydration and hypoxia were performed. A comparison of system parameters for the mouse and human models is presented. Aside from the obvious differences expected in fluid volumes, blood flows and metabolic rates, larger differences were observed in the following: erythrocyte life span, erythropoietin half-life, and normal arterial pO2.

HSV-1 interaction to 3-O-sulfated heparan sulfate in mouse-derived DRG explant and profiles of inflammatory markers during virus infection.

PubMed

Sharthiya, Harsh; Seng, Chanmoly; Van Kuppevelt, T H; Tiwari, Vaibhav; Fornaro, Michele

2017-06-01

The molecular mechanism of herpes simplex virus (HSV) entry and the associated inflammatory response in the nervous system remain poorly understood. Using mouse-derived ex vivo dorsal root ganglia (DRG) explant model and single cell neurons (SCNs), in this study, we provided a visual evidence for the expression of heparan sulfate (HS) and 3-O-sulfated heparan sulfate (3-OS HS) followed by their interactions with HSV-1 glycoprotein B (gB) and glycoprotein D (gD) during cell entry. Upon heparanase treatment of DRG-derived SCN, a significant inhibition of HSV-1 entry was observed suggesting the involvement of HS role during viral entry. Finally, a cytokine array profile generated during HSV-1 infection in DRG explant indicated an enhanced expression of chemokines (LIX, TIMP-2, and M-CSF)-known regulators of HS. Taken together, these results highlight the significance of HS during HSV-1 entry in DRG explant. Further investigation is needed to understand which isoforms of 3-O-sulfotransferase (3-OST)-generated HS contributed during HSV-1 infection and associated cell damage.

Establishment of pseudovirus infection mouse models for in vivo pharmacodynamics evaluation of filovirus entry inhibitors.

PubMed

Chen, Qing; Tang, Ke; Zhang, Xiaoyu; Chen, Panpan; Guo, Ying

2018-03-01

Filoviruses cause severe and fatal viral hemorrhagic fever in humans. Filovirus research has been extensive since the 2014 Ebola outbreak. Due to their high pathogenicity and mortality, live filoviruses require Biosafety Level-4 (BSL-4) facilities, which have restricted the development of anti-filovirus vaccines and drugs. An HIV-based pseudovirus cell infection assay is widely used for viral entry studies in BSL-2 conditions. Here, we successfully constructed nine in vitro pseudo-filovirus models covering all filovirus genera and three in vivo pseudo-filovirus-infection mouse models using Ebola virus, Marburg virus, and Lloviu virus as representative viruses. The pseudo-filovirus-infected mice showed visualizing bioluminescence in a dose-dependent manner. A bioluminescence peak in mice was reached on day 5 post-infection for Ebola virus and Marburg virus and on day 4 post-infection for Lloviu virus. Two known filovirus entry inhibitors, clomiphene and toremiphene, were used to validate the model. Collectively, our study shows that all genera of filoviruses can be well-pseudotyped and are infectious in vitro . The pseudo-filovirus-infection mouse models can be used for in vivo activity evaluation of anti-filovirus drugs. This sequential in vitro and in vivo evaluation system of filovirus entry inhibitors provides a secure and efficient platform for screening and assessing anti-filovirus agents in BSL-2 facilities.

Fluorescent and scattering contrast agents in a mouse model of colorectal cancer

NASA Astrophysics Data System (ADS)

Winkler, Amy M.; Rice, Photini F. S.; Troutman, Timothy S.; Backer, Marina V.; Backer, Joseph M.; Drezek, Rebekah A.; Romanowski, Marek; Barton, Jennifer K.

2008-02-01

In previous work we have demonstrated the utility of laser-induced fluorescence (LIF) and optical coherence tomography (OCT) to identify adenoma in mouse models of colorectal cancer with high sensitivity and specificity. However, improved sensitivity to early disease, as well as the ability to distinguish confounders (e.g. fecal contamination, natural variations in mucosal thickness), is desired. In this study, we investigated the signal enhancement of fluorescent and scattering contrast agents in the colons of AOM-treated mice. The fluorescent tracer scVEGF/Cy, targeted to receptors for vascular endothelial growth factor, was visualized on a dual modality OCT/LIF endoscopic system with 1300-nm center wavelength OCT source and 635-nm LIF excitation. Scattering agents were tested with an 890-nm center wavelength endoscopic OCT system. Agents included nanoshells, 120-nm in diameter, and nanorods, 20-nm in diameter by 80-nm in length. Following imaging, colons were excised. Tissue treated with fluorophore was imaged on an epifluorescence microscope. Histological sections were obtained and stained with H&E and silver enhancer to verify disease and identify regions of gold uptake, respectively. Non-specific signal enhancement was observed with the scattering contrast agents. Specificity for adenoma was seen with the scVEGF/Cy dye.

Development of a miniature autofluorescence device for the early diagnosis of squamous cell carcinoma

NASA Astrophysics Data System (ADS)

Patil, Ajeetkumar; Rao K., Swati; V. K., Unnikrishnan; Pai, Keerthilatha M.; Kartha, V. B.; Chidangil, Santhosh

2017-07-01

Autofluorescence spectroscopy offer noninvasive and promising tools for the detection of alternations biochemical compositions of tissues and cells, in presence of disease. They have the added advantage of being highly objective due to the fact that diagnostic evaluation is by statistical methods, eliminating errors from lack of experience, fatigue factor, and subjectivity of visual perceptions. The present research work involves in designing and assembling of a low cost, miniature oral cancer screening device with for routine clinical applications. A miniature system was designed and assembled with much smaller and cost-effective components like compact light source and miniature spectrometer, in a hand-held unit configuration. The performance of the system was evaluated using animal -mouse- SCC model. The current system can be used in handheld operation, which makes it very useful for many applications like, screening of squamous cell carcinoma susceptible population.

Murmer, a message generator and reporter for Unix, VMS, and VxWorks

NASA Astrophysics Data System (ADS)

Oleynik, G.; Appleton, B.; Moore, C.; Sergey, G.; Udumula, L.

1994-02-01

Murmer is a Unix based message generation, reporting, display, and logging system that we have developed for use in data acquisition systems at Fermilab. Murmer is a tool for the production and management of message reporting. Its usefulness ranges from software product development and maintenance to system level shakedown and diagnostics. Murmer provides a VMS MESSAGE-like function code generation utility, a client routine package for sending these codes over the network to a central server, and a server which translates the codes into meaningful visual information, writes the information to a logfile, and display it on B&W or color X windows. Because Murmer stores message information in keyed access files, it can provide advanced features such as popping up help when a displayed message is clicked on by the mouse and executing 'action' shell scripts when selected messages are received by the server.

Deletion of Ten-m3 Induces the Formation of Eye Dominance Domains in Mouse Visual Cortex

PubMed Central

Merlin, Sam; Horng, Sam; Marotte, Lauren R.; Sur, Mriganka; Sawatari, Atomu

2013-01-01

The visual system is characterized by precise retinotopic mapping of each eye, together with exquisitely matched binocular projections. In many species, the inputs that represent the eyes are segregated into ocular dominance columns in primary visual cortex (V1), whereas in rodents, this does not occur. Ten-m3, a member of the Ten-m/Odz/Teneurin family, regulates axonal guidance in the retinogeniculate pathway. Significantly, ipsilateral projections are expanded in the dorsal lateral geniculate nucleus and are not aligned with contralateral projections in Ten-m3 knockout (KO) mice. Here, we demonstrate the impact of altered retinogeniculate mapping on the organization and function of V1. Transneuronal tracing and c-fos immunohistochemistry demonstrate that the subcortical expansion of ipsilateral input is conveyed to V1 in Ten-m3 KOs: Ipsilateral inputs are widely distributed across V1 and are interdigitated with contralateral inputs into eye dominance domains. Segregation is confirmed by optical imaging of intrinsic signals. Single-unit recording shows ipsilateral, and contralateral inputs are mismatched at the level of single V1 neurons, and binocular stimulation leads to functional suppression of these cells. These findings indicate that the medial expansion of the binocular zone together with an interocular mismatch is sufficient to induce novel structural features, such as eye dominance domains in rodent visual cortex. PMID:22499796

Surface-based atlases of cerebellar cortex in the human, macaque, and mouse.

PubMed

Van Essen, David C

2002-12-01

This study describes surface reconstructions and associated flat maps that represent the highly convoluted shape of cerebellar cortex in three species: human, macaque, and mouse. The reconstructions were based on high-resolution structural MRI data obtained from other laboratories. The surface areas determined for the fiducial reconstructions are about 600 cm(2) for the human, 60 cm(2) for the macaque, and 0.8 cm(2) for the mouse. As expected from the ribbon-like pattern of cerebellar folding, the cerebellar flat maps are elongated along the axis parallel to the midline. However, the degree of elongation varies markedly across species. The macaque flat map is many times longer than its mean width, whereas the mouse flat map is only slightly elongated and the human map is intermediate in its aspect ratio. These cerebellar atlases, along with associated software for visualization and for mapping experimental data onto the atlas, are freely available to the neuroscience community (see http:/brainmap.wustl.edu).

Primary amines protect against retinal degeneration in mouse models of retinopathies

PubMed Central

Maeda, Akiko; Golczak, Marcin; Chen, Yu; Okano, Kiichiro; Kohno, Hideo; Shiose, Satomi; Ishikawa, Kaede; Harte, William; Palczewska, Grazyna; Maeda, Tadao; Palczewski, Krzysztof

2011-01-01

Vertebrate vision is initiated by photoisomerization of the visual pigment chromophore, 11-cis-retinal, and is maintained by continuous regeneration of this retinoid through a series of reactions termed the retinoid cycle. However, toxic side reaction products, especially those involving reactive aldehyde groups of the photoisomered product, all-trans-retinal, can cause severe retinal pathology. Here we lowered peak concentrations of free all-trans-retinal with primary amine-containing FDA-approved drugs that did not inhibit chromophore regeneration in mouse models of retinal degeneration. Schiff base adducts between all-trans-retinal and these amines were identified by mass spectrometry. Adducts were observed in mouse eyes only when an experimental drug protected the retina from degeneration in both short-term and long-term treatment experiments. This study demonstrates a molecular basis of all-trans-retinal-induced retinal pathology and identifies an assemblage of FDA-approved compounds with protective effects against this pathology in a mouse model that displays features of Stargardt’s and age-related retinal degeneration. PMID:22198730

Surface-based atlases of cerebellar cortex in the human, macaque, and mouse

NASA Technical Reports Server (NTRS)

Van Essen, David C.

2002-01-01

This study describes surface reconstructions and associated flat maps that represent the highly convoluted shape of cerebellar cortex in three species: human, macaque, and mouse. The reconstructions were based on high-resolution structural MRI data obtained from other laboratories. The surface areas determined for the fiducial reconstructions are about 600 cm(2) for the human, 60 cm(2) for the macaque, and 0.8 cm(2) for the mouse. As expected from the ribbon-like pattern of cerebellar folding, the cerebellar flat maps are elongated along the axis parallel to the midline. However, the degree of elongation varies markedly across species. The macaque flat map is many times longer than its mean width, whereas the mouse flat map is only slightly elongated and the human map is intermediate in its aspect ratio. These cerebellar atlases, along with associated software for visualization and for mapping experimental data onto the atlas, are freely available to the neuroscience community (see http:/brainmap.wustl.edu).

VisiOmatic: Celestial image viewer

NASA Astrophysics Data System (ADS)

Bertin, Emmanuel; Marmo, Chiara; Pillay, Ruven

2014-08-01

VisiOmatic is a web client for IIPImage (ascl:1408.009) and is used to visualize and navigate through large science images from remote locations. It requires STIFF (ascl:1110.006), is based on the Leaflet Javascript library, and works on both touch-based and mouse-based devices.

Dynamic Imaging of Mouse Embryos and Cardiodynamics in Static Culture.

PubMed

Lopez, Andrew L; Larina, Irina V

2018-01-01

The heart is a dynamic organ that quickly undergoes morphological and mechanical changes through early embryonic development. Characterizing these early moments is important for our understanding of proper embryonic development and the treatment of heart disease. Traditionally, tomographic imaging modalities and fluorescence-based microscopy are excellent approaches to visualize structural features and gene expression patterns, respectively, and connect aberrant gene programs to pathological phenotypes. However, these approaches usually require static samples or fluorescent markers, which can limit how much information we can derive from the dynamic and mechanical changes that regulate heart development. Optical coherence tomography (OCT) is unique in this circumstance because it allows for the acquisition of three-dimensional structural and four-dimensional (3D + time) functional images of living mouse embryos without fixation or contrast reagents. In this chapter, we focus on how OCT can visualize heart morphology at different stages of development and provide cardiodynamic information to reveal mechanical properties of the developing heart.

Hunger-Dependent Enhancement of Food Cue Responses in Mouse Postrhinal Cortex and Lateral Amygdala.

PubMed

Burgess, Christian R; Ramesh, Rohan N; Sugden, Arthur U; Levandowski, Kirsten M; Minnig, Margaret A; Fenselau, Henning; Lowell, Bradford B; Andermann, Mark L

2016-09-07

The needs of the body can direct behavioral and neural processing toward motivationally relevant sensory cues. For example, human imaging studies have consistently found specific cortical areas with biased responses to food-associated visual cues in hungry subjects, but not in sated subjects. To obtain a cellular-level understanding of these hunger-dependent cortical response biases, we performed chronic two-photon calcium imaging in postrhinal association cortex (POR) and primary visual cortex (V1) of behaving mice. As in humans, neurons in mouse POR, but not V1, exhibited biases toward food-associated cues that were abolished by satiety. This emergent bias was mirrored by the innervation pattern of amygdalo-cortical feedback axons. Strikingly, these axons exhibited even stronger food cue biases and sensitivity to hunger state and trial history. These findings highlight a direct pathway by which the lateral amygdala may contribute to state-dependent cortical processing of motivationally relevant sensory cues. Published by Elsevier Inc.

Platelets are responsible for the accumulation of β-amyloid in blood clots inside and around blood vessels in mouse brain after thrombosis.

PubMed

Kucheryavykh, Lilia Y; Dávila-Rodríguez, Josué; Rivera-Aponte, David E; Zueva, Lidia V; Washington, A Valance; Sanabria, Priscilla; Inyushin, Mikhail Y

2017-01-01

Platelets contain beta-amyloid precursor protein (APP) as well as Aβ peptide (Aβ) that can be released upon activation. During thrombosis, platelets are concentrated in clots and activated. We used in vivo fluorescent analysis and electron microscopy in mice to determine to what degree platelets are concentrated in clots. We used immunostaining to visualize Aβ after photothrombosis in mouse brains. Both in vivo results and electron microscopy revealed that platelets were 300-500 times more concentrated in clots than in non-clotted blood. After thrombosis in control mice, but not in thrombocytopenic animals, Aβ immunofluorescence was present inside blood vessels in the visual cortex and around capillaries in the entorhinal cortex. The increased concentration of platelets allows enhanced release of Aβ during thrombosis, suggesting an additional source of Aβ in the brains of Alzheimer's patients that may arise if frequent micro-thrombosis events occur in their brains. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Evans blue dye-enhanced imaging of the brain microvessels using spectral focusing coherent anti-Stokes Raman scattering microscopy

PubMed Central

Lee, Bo-Ram; Joo, Kyung-Il; Choi, Eun Sook; Jahng, Junghoon; Kim, Hyunmin

2017-01-01

We performed dye-enhanced imaging of mouse brain microvessels using spectral focusing coherent anti-Stokes Raman scattering (SF-CARS) microscopy. The resonant signals from C-H stretching in forward CARS usually show high background intensity in tissues, which makes CARS imaging of microvessels difficult. In this study, epi-detection of back-scattered SF-CARS signals showed a negligible background, but the overall intensity of resonant CARS signals was too low to observe the network of brain microvessels. Therefore, Evans blue (EB) dye was used as contrasting agent to enhance the back-scattered SF-CARS signals. Breakdown of brain microvessels by inducing hemorrhage in a mouse was clearly visualized using backward SF-CARS signals, following intravenous injection of EB. The improved visualization of brain microvessels with EB enhanced the sensitivity of SF-CARS, detecting not only the blood vessels themselves but their integrity as well in the brain vasculature. PMID:29049299

Predicting successful tactile mapping of virtual objects.

PubMed

Brayda, Luca; Campus, Claudio; Gori, Monica

2013-01-01

Improving spatial ability of blind and visually impaired people is the main target of orientation and mobility (O&M) programs. In this study, we use a minimalistic mouse-shaped haptic device to show a new approach aimed at evaluating devices providing tactile representations of virtual objects. We consider psychophysical, behavioral, and subjective parameters to clarify under which circumstances mental representations of spaces (cognitive maps) can be efficiently constructed with touch by blindfolded sighted subjects. We study two complementary processes that determine map construction: low-level perception (in a passive stimulation task) and high-level information integration (in an active exploration task). We show that jointly considering a behavioral measure of information acquisition and a subjective measure of cognitive load can give an accurate prediction and a practical interpretation of mapping performance. Our simple TActile MOuse (TAMO) uses haptics to assess spatial ability: this may help individuals who are blind or visually impaired to be better evaluated by O&M practitioners or to evaluate their own performance.

Visual Cone Arrestin 4 Contributes to Visual Function and Cone Health.

PubMed

Deming, Janise D; Pak, Joseph S; Brown, Bruce M; Kim, Moon K; Aung, Moe H; Eom, Yun Sung; Shin, Jung-A; Lee, Eun-Jin; Pardue, Machelle T; Craft, Cheryl Mae

2015-08-01

Visual arrestins (ARR) play a critical role in shutoff of rod and cone phototransduction. When electrophysiological responses are measured for a single mouse cone photoreceptor, ARR1 expression can substitute for ARR4 in cone pigment desensitization; however, each arrestin may also contribute its own, unique role to modulate other cellular functions. A combination of ERG, optokinetic tracking, immunohistochemistry, and immunoblot analysis was used to investigate the retinal phenotypes of Arr4 null mice (Arr4-/-) compared with age-matched control, wild-type mice. When 2-month-old Arr4-/- mice were compared with wild-type mice, they had diminished visual acuity and contrast sensitivity, yet enhanced ERG flicker response and higher photopic ERG b-wave amplitudes. In contrast, in older Arr4-/- mice, all ERG amplitudes were significantly reduced in magnitude compared with age-matched controls. Furthermore, in older Arr4-/- mice, the total cone numbers decreased and cone opsin protein immunoreactive expression levels were significantly reduced, while overall photoreceptor outer nuclear layer thickness was unchanged. Our study demonstrates that Arr4-/- mice display distinct phenotypic differences when compared to controls, suggesting that ARR4 modulates essential functions in high acuity vision and downstream cellular signaling pathways that are not fulfilled or substituted by the coexpression of ARR1, despite its high expression levels in all mouse cones. Without normal ARR4 expression levels, cones slowly degenerate with increasing age, making this a new model to study age-related cone dystrophy.

Effects of isoflurane anesthesia on ensemble patterns of Ca2+ activity in mouse v1: reduced direction selectivity independent of increased correlations in cellular activity.

PubMed

Goltstein, Pieter M; Montijn, Jorrit S; Pennartz, Cyriel M A

2015-01-01

Anesthesia affects brain activity at the molecular, neuronal and network level, but it is not well-understood how tuning properties of sensory neurons and network connectivity change under its influence. Using in vivo two-photon calcium imaging we matched neuron identity across episodes of wakefulness and anesthesia in the same mouse and recorded spontaneous and visually evoked activity patterns of neuronal ensembles in these two states. Correlations in spontaneous patterns of calcium activity between pairs of neurons were increased under anesthesia. While orientation selectivity remained unaffected by anesthesia, this treatment reduced direction selectivity, which was attributable to an increased response to the null-direction. As compared to anesthesia, populations of V1 neurons coded more mutual information on opposite stimulus directions during wakefulness, whereas information on stimulus orientation differences was lower. Increases in correlations of calcium activity during visual stimulation were correlated with poorer population coding, which raised the hypothesis that the anesthesia-induced increase in correlations may be causal to degrading directional coding. Visual stimulation under anesthesia, however, decorrelated ongoing activity patterns to a level comparable to wakefulness. Because visual stimulation thus appears to 'break' the strength of pairwise correlations normally found in spontaneous activity under anesthesia, the changes in correlational structure cannot explain the awake-anesthesia difference in direction coding. The population-wide decrease in coding for stimulus direction thus occurs independently of anesthesia-induced increments in correlations of spontaneous activity.

Effects of Isoflurane Anesthesia on Ensemble Patterns of Ca2+ Activity in Mouse V1: Reduced Direction Selectivity Independent of Increased Correlations in Cellular Activity

PubMed Central

Goltstein, Pieter M.; Montijn, Jorrit S.; Pennartz, Cyriel M. A.

2015-01-01

Anesthesia affects brain activity at the molecular, neuronal and network level, but it is not well-understood how tuning properties of sensory neurons and network connectivity change under its influence. Using in vivo two-photon calcium imaging we matched neuron identity across episodes of wakefulness and anesthesia in the same mouse and recorded spontaneous and visually evoked activity patterns of neuronal ensembles in these two states. Correlations in spontaneous patterns of calcium activity between pairs of neurons were increased under anesthesia. While orientation selectivity remained unaffected by anesthesia, this treatment reduced direction selectivity, which was attributable to an increased response to the null-direction. As compared to anesthesia, populations of V1 neurons coded more mutual information on opposite stimulus directions during wakefulness, whereas information on stimulus orientation differences was lower. Increases in correlations of calcium activity during visual stimulation were correlated with poorer population coding, which raised the hypothesis that the anesthesia-induced increase in correlations may be causal to degrading directional coding. Visual stimulation under anesthesia, however, decorrelated ongoing activity patterns to a level comparable to wakefulness. Because visual stimulation thus appears to ‘break’ the strength of pairwise correlations normally found in spontaneous activity under anesthesia, the changes in correlational structure cannot explain the awake-anesthesia difference in direction coding. The population-wide decrease in coding for stimulus direction thus occurs independently of anesthesia-induced increments in correlations of spontaneous activity. PMID:25706867

Diffusion fMRI detects white-matter dysfunction in mice with acute optic neuritis

PubMed Central

Lin, Tsen-Hsuan; Spees, William M.; Chiang, Chia-Wen; Trinkaus, Kathryn; Cross, Anne H.; Song, Sheng-Kwei

2014-01-01

Optic neuritis is a frequent and early symptom of multiple sclerosis (MS). Conventional magnetic resonance (MR) techniques provide means to assess multiple MS-related pathologies, including axonal injury, demyelination, and inflammation. A method to directly and non-invasively probe white-matter function could further elucidate the interplay of underlying pathologies and functional impairments. Previously, we demonstrated a significant 27% activation-associated decrease in the apparent diffusion coefficient of water perpendicular to the axonal fibers (ADC⊥) in normal C57BL/6 mouse optic nerve with visual stimulation using diffusion fMRI. Here we apply this approach to explore the relationship between visual acuity, optic nerve pathology, and diffusion fMRI in the experimental autoimmune encephalomyelitis (EAE) mouse model of optic neuritis. Visual stimulation produced a significant 25% (vs. baseline) ADC⊥ decrease in sham EAE optic nerves, while only a 7% (vs. baseline) ADC⊥ decrease was seen in EAE mice with acute optic neuritis. The reduced activation-associated ADC⊥ response correlated with post-MRI immunohistochemistry determined pathologies (including inflammation, demyelination, and axonal injury). The negative correlation between activation-associated ADC⊥ response and visual acuity was also found when pooling EAE-affected and sham groups under our experimental criteria. Results suggest that reduction in diffusion fMRI directly reflects impaired axonal-activation in EAE mice with optic neuritis. Diffusion fMRI holds promise for directly gauging in vivo white-matter dysfunction or therapeutic responses in MS patients. PMID:24632420

Eye movements and manual interception of ballistic trajectories: effects of law of motion perturbations and occlusions.

PubMed

Delle Monache, Sergio; Lacquaniti, Francesco; Bosco, Gianfranco

2015-02-01

Manual interceptions are known to depend critically on integration of visual feedback information and experience-based predictions of the interceptive event. Within this framework, coupling between gaze and limb movements might also contribute to the interceptive outcome, since eye movements afford acquisition of high-resolution visual information. We investigated this issue by analyzing subjects' head-fixed oculomotor behavior during manual interceptions. Subjects moved a mouse cursor to intercept computer-generated ballistic trajectories either congruent with Earth's gravity or perturbed with weightlessness (0 g) or hypergravity (2 g) effects. In separate sessions, trajectories were either fully visible or occluded before interception to enforce visual prediction. Subjects' oculomotor behavior was classified in terms of amounts of time they gazed at different visual targets and of overall number of saccades. Then, by way of multivariate analyses, we assessed the following: (1) whether eye movement patterns depended on targets' laws of motion and occlusions; and (2) whether interceptive performance was related to the oculomotor behavior. First, we found that eye movement patterns depended significantly on targets' laws of motion and occlusion, suggesting predictive mechanisms. Second, subjects coupled differently oculomotor and interceptive behavior depending on whether targets were visible or occluded. With visible targets, subjects made smaller interceptive errors if they gazed longer at the mouse cursor. Instead, with occluded targets, they achieved better performance by increasing the target's tracking accuracy and by avoiding gaze shifts near interception, suggesting that precise ocular tracking provided better trajectory predictions for the interceptive response.

Intravital imaging of a spheroid-based orthotopic model of melanoma in the mouse ear skin

PubMed Central

Chan, Keefe T.; Jones, Stephen W.; Brighton, Hailey E.; Bo, Tao; Cochran, Shelly D.; Sharpless, Norman E.; Bear, James E.

2017-01-01

Multiphoton microscopy is a powerful tool that enables the visualization of fluorescently tagged tumor cells and their stromal interactions within tissues in vivo. We have developed an orthotopic model of implanting multicellular melanoma tumor spheroids into the dermis of the mouse ear skin without the requirement for invasive surgery. Here, we demonstrate the utility of this approach to observe the primary tumor, single cell actin dynamics, and tumor-associated vasculature. These methods can be broadly applied to investigate an array of biological questions regarding tumor cell behavior in vivo. PMID:28748125

Adult Mouse Cortical Cell Taxonomy by Single Cell Transcriptomics

PubMed Central

Tasic, Bosiljka; Menon, Vilas; Nguyen, Thuc Nghi; Kim, Tae Kyung; Jarsky, Tim; Yao, Zizhen; Levi, Boaz; Gray, Lucas T.; Sorensen, Staci A.; Dolbeare, Tim; Bertagnolli, Darren; Goldy, Jeff; Shapovalova, Nadiya; Parry, Sheana; Lee, Changkyu; Smith, Kimberly; Bernard, Amy; Madisen, Linda; Sunkin, Susan M.; Hawrylycz, Michael; Koch, Christof; Zeng, Hongkui

2016-01-01

Nervous systems are composed of various cell types, but the extent of cell type diversity is poorly understood. Here, we construct a cellular taxonomy of one cortical region, primary visual cortex, in adult mice based on single cell RNA-sequencing. We identify 49 transcriptomic cell types including 23 GABAergic, 19 glutamatergic and seven non-neuronal types. We also analyze cell-type specific mRNA processing and characterize genetic access to these transcriptomic types by many transgenic Cre lines. Finally, we show that some of our transcriptomic cell types display specific and differential electrophysiological and axon projection properties, thereby confirming that the single cell transcriptomic signatures can be associated with specific cellular properties. PMID:26727548

Effect of visual distraction and auditory feedback on patient effort during robot-assisted movement training after stroke

PubMed Central

2011-01-01

Background Practicing arm and gait movements with robotic assistance after neurologic injury can help patients improve their movement ability, but patients sometimes reduce their effort during training in response to the assistance. Reduced effort has been hypothesized to diminish clinical outcomes of robotic training. To better understand patient slacking, we studied the role of visual distraction and auditory feedback in modulating patient effort during a common robot-assisted tracking task. Methods Fourteen participants with chronic left hemiparesis from stroke, five control participants with chronic right hemiparesis and fourteen non-impaired healthy control participants, tracked a visual target with their arms while receiving adaptive assistance from a robotic arm exoskeleton. We compared four practice conditions: the baseline tracking task alone; tracking while also performing a visual distracter task; tracking with the visual distracter and sound feedback; and tracking with sound feedback. For the distracter task, symbols were randomly displayed in the corners of the computer screen, and the participants were instructed to click a mouse button when a target symbol appeared. The sound feedback consisted of a repeating beep, with the frequency of repetition made to increase with increasing tracking error. Results Participants with stroke halved their effort and doubled their tracking error when performing the visual distracter task with their left hemiparetic arm. With sound feedback, however, these participants increased their effort and decreased their tracking error close to their baseline levels, while also performing the distracter task successfully. These effects were significantly smaller for the participants who used their non-paretic arm and for the participants without stroke. Conclusions Visual distraction decreased participants effort during a standard robot-assisted movement training task. This effect was greater for the hemiparetic arm, suggesting that the increased demands associated with controlling an affected arm make the motor system more prone to slack when distracted. Providing an alternate sensory channel for feedback, i.e., auditory feedback of tracking error, enabled the participants to simultaneously perform the tracking task and distracter task effectively. Thus, incorporating real-time auditory feedback of performance errors might improve clinical outcomes of robotic therapy systems. PMID:21513561

Nogo Receptor 1 Confines a Disinhibitory Microcircuit to the Critical Period in Visual Cortex.

PubMed

Stephany, Céleste-Élise; Ikrar, Taruna; Nguyen, Collins; Xu, Xiangmin; McGee, Aaron W

2016-10-26

A characteristic of the developing mammalian visual system is a brief interval of plasticity, termed the "critical period," when the circuitry of primary visual cortex is most sensitive to perturbation of visual experience. Depriving one eye of vision (monocular deprivation [MD]) during the critical period alters ocular dominance (OD) by shifting the responsiveness of neurons in visual cortex to favor the nondeprived eye. A disinhibitory microcircuit involving parvalbumin-expressing (PV) interneurons initiates this OD plasticity. The gene encoding the neuronal nogo-66-receptor 1 (ngr1/rtn4r) is required to close the critical period. Here we combined mouse genetics, electrophysiology, and circuit mapping with laser-scanning photostimulation to investigate whether disinhibition is confined to the critical period by ngr1 We demonstrate that ngr1 mutant mice retain plasticity characteristic of the critical period as adults, and that ngr1 operates within PV interneurons to restrict the loss of intracortical excitatory synaptic input following MD in adult mice, and this disinhibition induces a "lower PV network configuration" in both critical-period wild-type mice and adult ngr1 -/- mice. We propose that ngr1 limits disinhibition to close the critical period for OD plasticity and that a decrease in PV expression levels reports the diminished recent cumulative activity of these interneurons. Life experience refines brain circuits throughout development during specified critical periods. Abnormal experience during these critical periods can yield enduring maladaptive changes in neural circuits that impair brain function. In the developing visual system, visual deprivation early in life can result in amblyopia (lazy-eye), a prevalent childhood disorder comprising permanent deficits in spatial vision. Here we identify that the nogo-66 receptor 1 gene restricts an early and essential step in OD plasticity to the critical period. These findings link the emerging circuit-level description of OD plasticity to the genetic regulation of the critical period. Understanding how plasticity is confined to critical periods may provide clues how to better treat amblyopia. Copyright © 2016 the authors 0270-6474/16/3611006-07$15.00/0.

High-resolution synchrotron radiation-based phase tomography of the healthy and epileptic brain

NASA Astrophysics Data System (ADS)

Bikis, Christos; Janz, Philipp; Schulz, Georg; Schweighauser, Gabriel; Hench, Jürgen; Thalmann, Peter; Deyhle, Hans; Chicherova, Natalia; Rack, Alexander; Khimchenko, Anna; Hieber, Simone E.; Mariani, Luigi; Haas, Carola A.; Müller, Bert

2016-10-01

Phase-contrast micro-tomography using synchrotron radiation has yielded superior soft tissue visualization down to the sub-cellular level. The isotropic spatial resolution down to about one micron is comparable to the one of histology. The methods, however, provide different physical quantities and are thus complementary, also allowing for the extension of histology into the third dimension. To prepare for cross-sectional animal studies on epilepsy, we have standardized the specimen's preparation and scanning procedure for mouse brains, so that subsequent histology remains entirely unaffected and scanning of all samples (n = 28) is possible in a realistic time frame. For that, we have scanned five healthy and epileptic mouse brains at the ID19 beamline, ESRF, Grenoble, France, using grating- and propagation-based phase contrast micro-tomography. The resulting datasets clearly show the cortex, ventricular system, thalamus, hypothalamus, and hippocampus. Our focus is on the latter, having planned kainate-induced epilepsy experiments. The cell density and organization in the dentate gyrus and Ammon's horn region were clearly visualized in control animals. This proof of principle was required to initiate experiment. The resulting three-dimensional data have been correlated to histology. The goal is a brain-wide quantification of cell death or structural reorganization associated with epilepsy as opposed to histology alone that represents small volumes of the total brain only. Thus, the proposed technique bears the potential to correlate the gold standard in analysis with independently obtained data sets. Such an achievement also fuels interest for other groups in neuroscience research to closely collaborate with experts in phase micro-tomography.

The LIM protein complex establishes a retinal circuitry of visual adaptation by regulating Pax6 α-enhancer activity

PubMed Central

Kim, Yeha; Lim, Soyeon; Ha, Taejeong; Song, You-Hyang; Sohn, Young-In; Park, Dae-Jin; Paik, Sun-Sook; Kim-Kaneyama, Joo-ri; Song, Mi-Ryoung; Leung, Amanda; Levine, Edward M; Kim, In-Beom; Goo, Yong Sook; Lee, Seung-Hee; Kang, Kyung Hwa; Kim, Jin Woo

2017-01-01

The visual responses of vertebrates are sensitive to the overall composition of retinal interneurons including amacrine cells, which tune the activity of the retinal circuitry. The expression of Paired-homeobox 6 (PAX6) is regulated by multiple cis-DNA elements including the intronic α-enhancer, which is active in GABAergic amacrine cell subsets. Here, we report that the transforming growth factor ß1-induced transcript 1 protein (Tgfb1i1) interacts with the LIM domain transcription factors Lhx3 and Isl1 to inhibit the α-enhancer in the post-natal mouse retina. Tgfb1i1-/- mice show elevated α-enhancer activity leading to overproduction of Pax6ΔPD isoform that supports the GABAergic amacrine cell fate maintenance. Consequently, the Tgfb1i1-/- mouse retinas show a sustained light response, which becomes more transient in mice with the auto-stimulation-defective Pax6ΔPBS/ΔPBS mutation. Together, we show the antagonistic regulation of the α-enhancer activity by Pax6 and the LIM protein complex is necessary for the establishment of an inner retinal circuitry, which controls visual adaptation. DOI: http://dx.doi.org/10.7554/eLife.21303.001 PMID:28139974

Computational genetic neuroanatomy of the developing mouse brain: dimensionality reduction, visualization, and clustering

PubMed Central

2013-01-01

Background The structured organization of cells in the brain plays a key role in its functional efficiency. This delicate organization is the consequence of unique molecular identity of each cell gradually established by precise spatiotemporal gene expression control during development. Currently, studies on the molecular-structural association are beginning to reveal how the spatiotemporal gene expression patterns are related to cellular differentiation and structural development. Results In this article, we aim at a global, data-driven study of the relationship between gene expressions and neuroanatomy in the developing mouse brain. To enable visual explorations of the high-dimensional data, we map the in situ hybridization gene expression data to a two-dimensional space by preserving both the global and the local structures. Our results show that the developing brain anatomy is largely preserved in the reduced gene expression space. To provide a quantitative analysis, we cluster the reduced data into groups and measure the consistency with neuroanatomy at multiple levels. Our results show that the clusters in the low-dimensional space are more consistent with neuroanatomy than those in the original space. Conclusions Gene expression patterns and developing brain anatomy are closely related. Dimensionality reduction and visual exploration facilitate the study of this relationship. PMID:23845024

Novel mouse model of colitis characterized by hapten-protein visualization.

PubMed

Ishiguro, Kazuhiro; Ando, Takafumi; Maeda, Osamu; Watanabe, Osamu; Goto, Hidemi

2010-09-01

Trinitrobenzene sulfonic acid (TNBS) and oxazolone are used to induce colitis for the investigation of inflammatory reactions in the colon. Although these chemicals are presumed to bind proteins in the colonic mucosa and then induce colitis as haptens, hapten-protein formation has not yet been confirmed in the colonic mucosa. We developed a mouse model of colitis characterized by hapten-protein visualization, using 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl), which emits fluorescence after binding to proteins. The enema of 1 mg/mL NBD-Cl induced severe diarrhea, rectal bleeding, and body weight reductions in BALB/c mice. Mucosal signs indicative of colitis, such as redness and swelling observed under stereomicroscopy or inflammatory cell infiltration and crypt-epithelium destruction under microscopy, were manifested around NBD-proteins visualized with fluorescence. Fluorescence microscopy showed the infiltration of F4/80+ cells around areas of NBD-proteins, and flow cytometry indicated the uptake of NBD-proteins by CD11b+ cells. We also found critical roles for T cells and interleukin-6 in colitis induction with NBD-proteins. NBD-Cl-induced colitis presents a unique model to study the relevance between hapten-protein formation and inflammatory reactions and offers a method to assess experimental interventions on colitis induction in the mucosa, where hapten-protein formation is confirmed.

Tau pathology does not affect experience-driven single-neuron and network-wide Arc/Arg3.1 responses.

PubMed

Rudinskiy, Nikita; Hawkes, Jonathan M; Wegmann, Susanne; Kuchibhotla, Kishore V; Muzikansky, Alona; Betensky, Rebecca A; Spires-Jones, Tara L; Hyman, Bradley T

2014-06-10

Intraneuronal neurofibrillary tangles (NFTs) - a characteristic pathological feature of Alzheimer's and several other neurodegenerative diseases - are considered a major target for drug development. Tangle load correlates well with the severity of cognitive symptoms and mouse models of tauopathy are behaviorally impaired. However, there is little evidence that NFTs directly impact physiological properties of host neurons. Here we used a transgenic mouse model of tauopathy to study how advanced tau pathology in different brain regions affects activity-driven expression of immediate-early gene Arc required for experience-dependent consolidation of long-term memories. We demonstrate in vivo that visual cortex neurons with tangles are as likely to express comparable amounts of Arc in response to structured visual stimulation as their neighbors without tangles. Probability of experience-dependent Arc response was not affected by tau tangles in both visual cortex and hippocampal pyramidal neurons as determined postmortem. Moreover, whole brain analysis showed that network-wide activity-driven Arc expression was not affected by tau pathology in any of the brain regions, including brain areas with the highest tangle load. Our findings suggest that intraneuronal NFTs do not affect signaling cascades leading to experience-dependent gene expression required for long-term synaptic plasticity.

Model-based analysis of pattern motion processing in mouse primary visual cortex

PubMed Central

Muir, Dylan R.; Roth, Morgane M.; Helmchen, Fritjof; Kampa, Björn M.

2015-01-01

Neurons in sensory areas of neocortex exhibit responses tuned to specific features of the environment. In visual cortex, information about features such as edges or textures with particular orientations must be integrated to recognize a visual scene or object. Connectivity studies in rodent cortex have revealed that neurons make specific connections within sub-networks sharing common input tuning. In principle, this sub-network architecture enables local cortical circuits to integrate sensory information. However, whether feature integration indeed occurs locally in rodent primary sensory areas has not been examined directly. We studied local integration of sensory features in primary visual cortex (V1) of the mouse by presenting drifting grating and plaid stimuli, while recording the activity of neuronal populations with two-photon calcium imaging. Using a Bayesian model-based analysis framework, we classified single-cell responses as being selective for either individual grating components or for moving plaid patterns. Rather than relying on trial-averaged responses, our model-based framework takes into account single-trial responses and can easily be extended to consider any number of arbitrary predictive models. Our analysis method was able to successfully classify significantly more responses than traditional partial correlation (PC) analysis, and provides a rigorous statistical framework to rank any number of models and reject poorly performing models. We also found a large proportion of cells that respond strongly to only one stimulus class. In addition, a quarter of selectively responding neurons had more complex responses that could not be explained by any simple integration model. Our results show that a broad range of pattern integration processes already take place at the level of V1. This diversity of integration is consistent with processing of visual inputs by local sub-networks within V1 that are tuned to combinations of sensory features. PMID:26300738

An open-source Java-based Toolbox for environmental model evaluation: The MOUSE Software Application

USDA-ARS?s Scientific Manuscript database

A consequence of environmental model complexity is that the task of understanding how environmental models work and identifying their sensitivities/uncertainties, etc. becomes progressively more difficult. Comprehensive numerical and visual evaluation tools have been developed such as the Monte Carl...

Virtual reality in the operating room of the future.

PubMed

Müller, W; Grosskopf, S; Hildebrand, A; Malkewitz, R; Ziegler, R

1997-01-01

In cooperation with the Max-Delbrück-Centrum/Robert-Rössle-Klinik (MDC/RRK) in Berlin, the Fraunhofer Institute for Computer Graphics is currently designing and developing a scenario for the operating room of the future. The goal of this project is to integrate new analysis, visualization and interaction tools in order to optimize and refine tumor diagnostics and therapy in combination with laser technology and remote stereoscopic video transfer. Hence, a human 3-D reference model is reconstructed using CT, MR, and anatomical cryosection images from the National Library of Medicine's Visible Human Project. Applying segmentation algorithms and surface-polygonization methods a 3-D representation is obtained. In addition, a "fly-through" the virtual patient is realized using 3-D input devices (data glove, tracking system, 6-DOF mouse). In this way, the surgeon can experience really new perspectives of the human anatomy. Moreover, using a virtual cutting plane any cut of the CT volume can be interactively placed and visualized in realtime. In conclusion, this project delivers visions for the application of effective visualization and VR systems. Commonly known as Virtual Prototyping and applied by the automotive industry long ago, this project shows, that the use of VR techniques can also prototype an operating room. After evaluating design and functionality of the virtual operating room, MDC plans to build real ORs in the near future. The use of VR techniques provides a more natural interface for the surgeon in the OR (e.g., controlling interactions by voice input). Besides preoperative planning future work will focus on supporting the surgeon in performing surgical interventions. An optimal synthesis of real and synthetic data, and the inclusion of visual, aural, and tactile senses in virtual environments can meet these requirements. This Augmented Reality could represent the environment for the surgeons of tomorrow.

Evaluation of state-of-the-art imaging systems for in vivo monitoring of retinal structure in mice: current capabilities and limitations

NASA Astrophysics Data System (ADS)

Zhang, Pengfei; Zam, Azhar; Pugh, Edward N.; Zawadzki, Robert J.

2014-02-01

Animal models of human diseases play an important role in studying and advancing our understanding of these conditions, allowing molecular level studies of pathogenesis as well as testing of new therapies. Recently several non-invasive imaging modalities including Fundus Camera, Scanning Laser Ophthalmoscopy (SLO) and Optical Coherence Tomography (OCT) have been successfully applied to monitor changes in the retinas of the living animals in experiments in which a single animal is followed over a portion of its lifespan. Here we evaluate the capabilities and limitations of these three imaging modalities for visualization of specific structures in the mouse eye. Example images acquired from different types of mice are presented. Future directions of development for these instruments and potential advantages of multi-modal imaging systems are discussed as well.

High-frequency spectral ultrasound imaging (SUSI) visualizes early post-traumatic heterotopic ossification (HO) in a mouse model.

PubMed

Ranganathan, Kavitha; Hong, Xiaowei; Cholok, David; Habbouche, Joe; Priest, Caitlin; Breuler, Christopher; Chung, Michael; Li, John; Kaura, Arminder; Hsieh, Hsiao Hsin Sung; Butts, Jonathan; Ucer, Serra; Schwartz, Ean; Buchman, Steven R; Stegemann, Jan P; Deng, Cheri X; Levi, Benjamin

2018-04-01

Early treatment of heterotopic ossification (HO) is currently limited by delayed diagnosis due to limited visualization at early time points. In this study, we validate the use of spectral ultrasound imaging (SUSI) in an animal model to detect HO as early as one week after burn tenotomy. Concurrent SUSI, micro CT, and histology at 1, 2, 4, and 9weeks post-injury were used to follow the progression of HO after an Achilles tenotomy and 30% total body surface area burn (n=3-5 limbs per time point). To compare the use of SUSI in different types of injury models, mice (n=5 per group) underwent either burn/tenotomy or skin incision injury and were imaged using a 55MHz probe on VisualSonics VEVO 770 system at one week post injury to evaluate the ability of SUSI to distinguish between edema and HO. Average acoustic concentration (AAC) and average scatterer diameter (ASD) were calculated for each ultrasound image frame. Micro CT was used to calculate the total volume of HO. Histology was used to confirm bone formation. Using SUSI, HO was visualized as early as 1week after injury. HO was visualized earliest by 4weeks after injury by micro CT. The average acoustic concentration of HO was 33% more than that of the control limb (n=5). Spectroscopic foci of HO present at 1week that persisted throughout all time points correlated with the HO present at 9weeks on micro CT imaging. SUSI visualizes HO as early as one week after injury in an animal model. SUSI represents a new imaging modality with promise for early diagnosis of HO. Copyright © 2018 Elsevier Inc. All rights reserved.

Cryo-Imaging and Software Platform for Analysis of Molecular MR Imaging of Micrometastases

PubMed Central

Qutaish, Mohammed Q.; Zhou, Zhuxian; Prabhu, David; Liu, Yiqiao; Busso, Mallory R.; Izadnegahdar, Donna; Gargesha, Madhusudhana; Lu, Hong; Lu, Zheng-Rong

2018-01-01

We created and evaluated a preclinical, multimodality imaging, and software platform to assess molecular imaging of small metastases. This included experimental methods (e.g., GFP-labeled tumor and high resolution multispectral cryo-imaging), nonrigid image registration, and interactive visualization of imaging agent targeting. We describe technological details earlier applied to GFP-labeled metastatic tumor targeting by molecular MR (CREKA-Gd) and red fluorescent (CREKA-Cy5) imaging agents. Optimized nonrigid cryo-MRI registration enabled nonambiguous association of MR signals to GFP tumors. Interactive visualization of out-of-RAM volumetric image data allowed one to zoom to a GFP-labeled micrometastasis, determine its anatomical location from color cryo-images, and establish the presence/absence of targeted CREKA-Gd and CREKA-Cy5. In a mouse with >160 GFP-labeled tumors, we determined that in the MR images every tumor in the lung >0.3 mm2 had visible signal and that some metastases as small as 0.1 mm2 were also visible. More tumors were visible in CREKA-Cy5 than in CREKA-Gd MRI. Tape transfer method and nonrigid registration allowed accurate (<11 μm error) registration of whole mouse histology to corresponding cryo-images. Histology showed inflammation and necrotic regions not labeled by imaging agents. This mouse-to-cells multiscale and multimodality platform should uniquely enable more informative and accurate studies of metastatic cancer imaging and therapy. PMID:29805438

Cryo-image Analysis of Tumor Cell Migration, Invasion, and Dispersal in a Mouse Xenograft Model of Human Glioblastoma Multiforme

PubMed Central

Qutaish, Mohammed Q.; Sullivant, Kristin E.; Burden-Gulley, Susan M.; Lu, Hong; Roy, Debashish; Wang, Jing; Basilion, James P.; Brady-Kalnay, Susann M.; Wilson, David L.

2012-01-01

Purpose The goals of this study were to create cryo-imaging methods to quantify characteristics (size, dispersal, and blood vessel density) of mouse orthotopic models of glioblastoma multiforme (GBM) and to enable studies of tumor biology, targeted imaging agents, and theranostic nanoparticles. Procedures Green fluorescent protein-labeled, human glioma LN-229 cells were implanted into mouse brain. At 20–38 days, cryo-imaging gave whole brain, 4-GB, 3D microscopic images of bright field anatomy, including vasculature, and fluorescent tumor. Image analysis/visualization methods were developed. Results Vessel visualization and segmentation methods successfully enabled analyses. The main tumor mass volume, the number of dispersed clusters, the number of cells/cluster, and the percent dispersed volume all increase with age of the tumor. Histograms of dispersal distance give a mean and median of 63 and 56 μm, respectively, averaged over all brains. Dispersal distance tends to increase with age of the tumors. Dispersal tends to occur along blood vessels. Blood vessel density did not appear to increase in and around the tumor with this cell line. Conclusion Cryo-imaging and software allow, for the first time, 3D, whole brain, microscopic characterization of a tumor from a particular cell line. LN-229 exhibits considerable dispersal along blood vessels, a characteristic of human tumors that limits treatment success. PMID:22125093

Autoradiographic visualization of the mouse egg's sperm receptor bound to sperm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bleil, J.D.; Wassarman, P.M.

1986-04-01

The extracellular coat, or zona pellucida, of mammalian eggs contains species-specific receptors to which sperm bind as a prelude to fertilization. In mice, ZP3, one of only three zona pellucida glycoproteins, serves as sperm receptor. Acrosome-intact, but not acrosome-reacted, mouse sperm recognize and interact with specific O-linked oligosaccharides of ZP3 resulting in sperm-egg binding. Binding, in turn, causes sperm to undergo the acrosome reaction; a membrane fusion event that results in loss of plasma membrane at the anterior region of the head and exposure of inner acrosomal membrane with its associated acrosomal contents. Bound, acrosome-reacted sperm are able to penetratemore » the zona pellucida and fuse with the egg's plasma membrane (fertilization). In the present report, we examined binding of radioiodinated, purified, egg ZP3 to both acrosome intact and acrosome reacted sperm by whole-mount autoradiography. Silver grains due to bound 125I-ZP3 were found localized to the acrosomal cap region of heads of acrosome-reacted sperm. Under the same conditions, 125I-fetuin bound at only background levels to heads of both acrosome-intact and -reacted sperm, and 125I-ZP2, another zona pellucida glycoprotein, bound preferentially to acrosome-reacted sperm. These results provide visual evidence that ZP3 binds preferentially and specifically to heads of acrosome intact sperm; properties expected of the mouse egg's sperm receptor.« less

Localized CT-Guided Irradiation Inhibits Neurogenesis in Specific Regions of the Adult Mouse Brain

PubMed Central

Ford, E. C.; Achanta, P.; Purger, D.; Armour, M.; Reyes, J.; Fong, J.; Kleinberg, L.; Redmond, K.; Wong, J.; Jang, M. H.; Jun, H.; Song, H-J.; Quinones-Hinojosa, A.

2011-01-01

Radiation is used in the study of neurogenesis in the adult mouse both as a model for patients undergoing radiation therapy for CNS malignancies and as a tool to interrupt neurogenesis. We describe the use of a dedicated CT-guided precision device to irradiate specific sub-regions of the adult mouse brain. Improved CT visualization was accomplished with intrathecal injection of iodinated contrast agent, which enhances the lateral ventricles. T2-weighted MRI images were also used for target localization. Visualization of delivered beams (10 Gy) in tissue was accomplished with immunohistochemical staining for the protein γ-H2AX, a marker of DNA double-strand breaks. γ-H2AX stains showed that the lateral ventricle wall could be targeted with an accuracy of 0.19 mm (n = 10). In the hippocampus, γ-H2AX staining showed that the dentate gyrus can be irradiated unilaterally with a localized arc treatment. This resulted in a significant decrease of proliferative neural progenitor cells as measured by Ki-67 staining (P < 0.001) while leaving the contralateral side intact. Two months after localized irradiation, neurogenesis was significantly inhibited in the irradiated region as seen with EdU/NeuN double labeling (P < 0.001). Localized radiation in the rodent brain is a promising new tool for the study of neurogenesis. PMID:21449714

Environmental enrichment decreases GABAergic inhibition and improves cognitive abilities, synaptic plasticity, and visual functions in a mouse model of Down syndrome

PubMed Central

Begenisic, Tatjana; Spolidoro, Maria; Braschi, Chiara; Baroncelli, Laura; Milanese, Marco; Pietra, Gianluca; Fabbri, Maria E.; Bonanno, Giambattista; Cioni, Giovanni; Maffei, Lamberto; Sale, Alessandro

2011-01-01

Down syndrome (DS) is the most common genetic disorder associated with mental retardation. It has been repeatedly shown that Ts65Dn mice, the prime animal model for DS, have severe cognitive and neural plasticity defects due to excessive inhibition. We report that increasing sensory-motor stimulation in adulthood through environmental enrichment (EE) reduces brain inhibition levels and promotes recovery of spatial memory abilities, hippocampal synaptic plasticity, and visual functions in adult Ts65Dn mice. PMID:22207837

Critical period revisited: impact on vision.

PubMed

Morishita, Hirofumi; Hensch, Takao K

2008-02-01

Neural circuits are shaped by experience in early postnatal life. The permanent loss of visual acuity (amblyopia) and anatomical remodeling within primary visual cortex following monocular deprivation is a classic example of critical period development from mouse to man. Recent work in rodents reveals a residual subthreshold potentiation of open eye response throughout life. Resetting excitatory-inhibitory balance or removing molecular 'brakes' on structural plasticity may unmask the potential for recovery of function in adulthood. Novel pharmacological or environmental interventions now hold great therapeutic promise based on a deeper understanding of critical period mechanisms.

Strain differences of the effect of enucleation and anophthalmia on the size and growth of sensory cortices in mice.

PubMed

Massé, Ian O; Guillemette, Sonia; Laramée, Marie-Eve; Bronchti, Gilles; Boire, Denis

2014-11-07

Anophthalmia is a condition in which the eye does not develop from the early embryonic period. Early blindness induces cross-modal plastic modifications in the brain such as auditory and haptic activations of the visual cortex and also leads to a greater solicitation of the somatosensory and auditory cortices. The visual cortex is activated by auditory stimuli in anophthalmic mice and activity is known to alter the growth pattern of the cerebral cortex. The size of the primary visual, auditory and somatosensory cortices and of the corresponding specific sensory thalamic nuclei were measured in intact and enucleated C57Bl/6J mice and in ZRDCT anophthalmic mice (ZRDCT/An) to evaluate the contribution of cross-modal activity on the growth of the cerebral cortex. In addition, the size of these structures were compared in intact, enucleated and anophthalmic fourth generation backcrossed hybrid C57Bl/6J×ZRDCT/An mice to parse out the effects of mouse strains and of the different visual deprivations. The visual cortex was smaller in the anophthalmic ZRDCT/An than in the intact and enucleated C57Bl/6J mice. Also the auditory cortex was larger and the somatosensory cortex smaller in the ZRDCT/An than in the intact and enucleated C57Bl/6J mice. The size differences of sensory cortices between the enucleated and anophthalmic mice were no longer present in the hybrid mice, showing specific genetic differences between C57Bl/6J and ZRDCT mice. The post natal size increase of the visual cortex was less in the enucleated than in the anophthalmic and intact hybrid mice. This suggests differences in the activity of the visual cortex between enucleated and anophthalmic mice and that early in-utero spontaneous neural activity in the visual system contributes to the shaping of functional properties of cortical networks. Copyright © 2014 Elsevier B.V. All rights reserved.

In vivo biometry in the mouse eye with low coherence interferometry.

PubMed

Schmucker, Christine; Schaeffel, Frank

2004-01-01

A major drawback of the mouse model of myopia is that the ocular dimensions cannot be measured in vivo, and that histological techniques post-mortem suffer from limited resolution. We have tested the potential of a newly developed technique, optical low coherence interferometry (OLCI), adapted for short measurement distances by Meditec, Carl Zeiss, Jena, Germany (the "ACMaster"). Using this technique, ocular biometry was performed in mice with normal vision and after deprivation of form vision. Axial eye length, corneal thickness and anterior chamber depth were measured in 23 mice, aged 25-53 days, and standard deviations from repeated measurements in the same eyes, as well as intra-individual and inter-individual variability were determined in different age groups. The data were compared to those from a preceding study in which biometrical data were obtained from frozen sections [Vision Res. 44 (2004) 1857]. Refractions were measured by automated infrared photorefraction. Mice had either normal visual exposure or were monocularly deprived of form vision for 14 days. Using OLCI, axial length could be determined with an average standard deviation of 8.0 +/- 2.9 microm, corneal thickness with 3.5 +/- 2.1 microm, and anterior chamber depth with 10.6 +/- 12.3 microm. Neither axial length, nor corneal thickness, nor anterior chamber depth were significantly different in left and right eyes of individual mice that had normal visual experience (mean absolute difference between axial lengths: 17 +/- 18 microm, between corneal thickness 5.1 +/- 4.8 microm, and between anterior chamber depths 16.7 +/- 14.8 microm). Compared to the variability that was previously found in frozen sections, the variability of axial length measurements with OLCI was 2.7 times less. After two weeks of form deprivation, OLCI revealed a significant axial elongation in the occluded eyes, compared to the contralateral fellow eyes (+38 +/- 36 microm or 1.16%, p = 0.045, n = 7, paired t-test). In this sample, no accompanying myopic shift was observed in the occluded eyes but this observation is not unexpected given the inherently variable responses of mouse eye growth to visual deprivation. OLCI had sufficient resolution in living mice to detect axial length changes in vivo that were equivalent to a dioptric change of 2 D. Using this technique, it was confirmed that mouse eyes respond to form deprivation by axial elongation, similar to the eyes of other animal models. The lack of a myopic shift in this sample, despite the axial elongation, demonstrates that biometric data are particularly important when the mouse eye is used as a model to study myopia.

cis Retinol oxidation regulates photoreceptor access to the retina visual cycle and cone pigment regeneration

PubMed Central

Sato, Shinya

2016-01-01

Key points This study explores the nature of the cis retinol that Müller cells in the retina provide to cones for the regeneration of their visual pigment.We report that the retina visual cycle provides cones exclusively with 11‐cis chromophore in both salamander and mouse and show that this selectivity is dependent on the 11‐cis‐specific cellular retinaldehyde binding protein (CRALBP) present in Müller cells.Even though salamander blue cones and green rods share the same visual pigment, only blue cones but not green rods are able to dark‐adapt in the retina following a bleach and to use exogenous 9‐cis retinol for pigment regeneration, suggesting that access to the retina visual cycle is cone‐specific and pigment‐independent.Our results show that the retina produces 11‐cis retinol that can be oxidized and used for pigment regeneration and dark adaptation selectively in cones and not in rods. Abstract Chromophore supply by the retinal Müller cells (retina visual cycle) supports the efficient pigment regeneration required for cone photoreceptor function in bright light. Surprisingly, a large fraction of the chromophore produced by dihydroceramide desaturase‐1, the putative all‐trans retinol isomerase in Müller cells, appears to be 9‐cis retinol. In contrast, the canonical retinal pigment epithelium (RPE) visual cycle produces exclusively 11‐cis retinal. Here, we used the different absorption spectra of 9‐cis and 11‐cis pigments to identify the isoform of the chromophore produced by the visual cycle of the intact retina. We found that the spectral sensitivity of salamander and mouse cones dark‐adapted in the isolated retina (with only the retina visual cycle) was similar to that of cones dark‐adapted in the intact eye (with both the RPE and retina visual cycles) and consistent with pure 11‐cis pigment composition. However, in mice lacking the cellular retinaldehyde binding protein (CRALBP), cone spectral sensitivity contained a substantial 9‐cis component. Thus, the retina visual cycle provides cones exclusively with 11‐cis chromophore and this process is mediated by the 11‐cis selective CRALBP in Müller cells. Finally, despite sharing the same pigment, salamander blue cones, but not green rods, recovered their sensitivity in the isolated retina. Exogenous 9‐cis retinol produced robust sensitivity recovery in bleached red and blue cones but not in red and green rods, suggesting that cis retinol oxidation restricts access to the retina visual cycle to cones. PMID:27385534

A novel histochemical method for the visualization of thrombin activity in the nervous system.

PubMed

Bushi, D; Gera, O; Kostenich, G; Shavit-Stein, E; Weiss, R; Chapman, J; Tanne, D

2016-04-21

Although thrombin has an important role in both central and peripheral nerve diseases, characterization of the anatomical distribution of its proteolytic activity has been limited by available methods. This study presents the development, challenges, validation and implementation of a novel histochemical method for visualization of thrombin activity in the nervous system. The method is based on the cleavage of the substrate, Boc-Asp(OBzl)-Pro-Arg-4MβNA by thrombin to liberate free 4-methoxy-2-naphthylamine (4MβNA). In the presence of 5-nitrosalicylaldehyde, free 4MβNA is captured, yielding an insoluble yellow fluorescent precipitate which marks the site of thrombin activity. The sensitivity of the method was determined in vitro using known concentrations of thrombin while the specificity was verified using a highly specific thrombin inhibitor. Using this method we determined the spatial distribution of thrombin activity in mouse brain following transient middle cerebral artery occlusion (tMCAo) and in mouse sciatic nerve following crush injury. Fluorescence microscopy revealed well-defined thrombin activity localized to the right ischemic hemisphere in cortical areas and in the striatum compared to negligible thrombin activity contralaterally. The histochemical localization of thrombin activity following tMCAo was in good correlation with the infarct areas per triphenyltetrazolium chloride staining and to thrombin activity measured biochemically in tissue punches (85 ± 35 and 20 ± 3 mU/ml, in the cortical and striatum areas respectively, compared to 7 ± 2 and 13 ± 2 mU/ml, in the corresponding contralateral areas; mean ± SEM; p<0.05). In addition, 24 h following crush injury, focal areas of highly elevated thrombin activity were detected in teased sciatic fibers. This observation was supported by the biochemical assay and western blot technique. The histochemical method developed in this study can serve as an important tool for studying the role of thrombin in physiological and pathological conditions. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Social Modulation of Associative Fear Learning by Pheromone Communication

ERIC Educational Resources Information Center

Bredy, Timothy W.; Barad, Mark

2009-01-01

Mice communicate through visual, vocal, and olfactory cues that influence innate, nonassociative behavior. We here report that exposure to a recently fear-conditioned familiar mouse impairs acquisition of conditioned fear and facilitates fear extinction, effects mimicked by both an olfactory chemosignal emitted by a recently fear-conditioned…

Visualizing estrogen receptor-a-expressing neurons using a new ERa-ZsGreen reporter mouse line

USDA-ARS?s Scientific Manuscript database

A variety of biological functions of estrogens, including regulation of energy metabolism, are mediated by neurons expressingestrogen receptor-a (ERa) in the brain. However, complex intracellular processes in these ERa-expressing neurons are difficult to unravel, due to the lack of strategy to visua...

Visual Neuroscience: A Retinal Ganglion Cell to Report Image Focus?

PubMed

Baden, Tom; Schaeffel, Frank; Berens, Philipp

2017-02-20

A recent study describes a mouse neuron projecting from the retina to the brain that exhibits exquisitely high sensitivity to high spatial frequency patterns presented over an unusually large receptive field: could this cell be a (de)focus detector? Copyright © 2017 Elsevier Ltd. All rights reserved.

CerebralWeb: a Cytoscape.js plug-in to visualize networks stratified by subcellular localization.

PubMed

Frias, Silvia; Bryan, Kenneth; Brinkman, Fiona S L; Lynn, David J

2015-01-01

CerebralWeb is a light-weight JavaScript plug-in that extends Cytoscape.js to enable fast and interactive visualization of molecular interaction networks stratified based on subcellular localization or other user-supplied annotation. The application is designed to be easily integrated into any website and is configurable to support customized network visualization. CerebralWeb also supports the automatic retrieval of Cerebral-compatible localizations for human, mouse and bovine genes via a web service and enables the automated parsing of Cytoscape compatible XGMML network files. CerebralWeb currently supports embedded network visualization on the InnateDB (www.innatedb.com) and Allergy and Asthma Portal (allergen.innatedb.com) database and analysis resources. Database tool URL: http://www.innatedb.com/CerebralWeb © The Author(s) 2015. Published by Oxford University Press.

Age-Dependent Ocular Dominance Plasticity in Adult Mice

PubMed Central

Lehmann, Konrad; Löwel, Siegrid

2008-01-01

Background Short monocular deprivation (4 days) induces a shift in the ocular dominance of binocular neurons in the juvenile mouse visual cortex but is ineffective in adults. Recently, it has been shown that an ocular dominance shift can still be elicited in young adults (around 90 days of age) by longer periods of deprivation (7 days). Whether the same is true also for fully mature animals is not yet known. Methodology/Principal Findings We therefore studied the effects of different periods of monocular deprivation (4, 7, 14 days) on ocular dominance in C57Bl/6 mice of different ages (25 days, 90–100 days, 109–158 days, 208–230 days) using optical imaging of intrinsic signals. In addition, we used a virtual optomotor system to monitor visual acuity of the open eye in the same animals during deprivation. We observed that ocular dominance plasticity after 7 days of monocular deprivation was pronounced in young adult mice (90–100 days) but significantly weaker already in the next age group (109–158 days). In animals older than 208 days, ocular dominance plasticity was absent even after 14 days of monocular deprivation. Visual acuity of the open eye increased in all age groups, but this interocular plasticity also declined with age, although to a much lesser degree than the optically detected ocular dominance shift. Conclusions/Significance These data indicate that there is an age-dependence of both ocular dominance plasticity and the enhancement of vision after monocular deprivation in mice: ocular dominance plasticity in binocular visual cortex is most pronounced in young animals, reduced but present in adolescence and absent in fully mature animals older than 110 days of age. Mice are thus not basically different in ocular dominance plasticity from cats and monkeys which is an absolutely essential prerequisite for their use as valid model systems of human visual disorders. PMID:18769674

Visual Cone Arrestin 4 Contributes to Visual Function and Cone Health

PubMed Central

Deming, Janise D.; Pak, Joseph S.; Brown, Bruce M.; Kim, Moon K.; Aung, Moe H.; Eom, Yun Sung; Shin, Jung-a; Lee, Eun-Jin; Pardue, Machelle T.; Craft, Cheryl Mae

2015-01-01

Purpose Visual arrestins (ARR) play a critical role in shutoff of rod and cone phototransduction. When electrophysiological responses are measured for a single mouse cone photoreceptor, ARR1 expression can substitute for ARR4 in cone pigment desensitization; however, each arrestin may also contribute its own, unique role to modulate other cellular functions. Methods A combination of ERG, optokinetic tracking, immunohistochemistry, and immunoblot analysis was used to investigate the retinal phenotypes of Arr4 null mice (Arr4−/−) compared with age-matched control, wild-type mice. Results When 2-month-old Arr4−/− mice were compared with wild-type mice, they had diminished visual acuity and contrast sensitivity, yet enhanced ERG flicker response and higher photopic ERG b-wave amplitudes. In contrast, in older Arr4−/− mice, all ERG amplitudes were significantly reduced in magnitude compared with age-matched controls. Furthermore, in older Arr4−/− mice, the total cone numbers decreased and cone opsin protein immunoreactive expression levels were significantly reduced, while overall photoreceptor outer nuclear layer thickness was unchanged. Conclusions Our study demonstrates that Arr4−/− mice display distinct phenotypic differences when compared to controls, suggesting that ARR4 modulates essential functions in high acuity vision and downstream cellular signaling pathways that are not fulfilled or substituted by the coexpression of ARR1, despite its high expression levels in all mouse cones. Without normal ARR4 expression levels, cones slowly degenerate with increasing age, making this a new model to study age-related cone dystrophy. PMID:26284544

Therapeutic Cell-Cycle-Decoy Efficacy of a Telomerase-Dependent Adenovirus in an Orthotopic Model of Chemotherapy-Resistant Human Stomach Carcinomatosis Peritonitis Visualized With FUCCI Imaging.

PubMed

Yano, Shuya; Takehara, Kiyoto; Tazawa, Hiroshi; Kishimoto, Hiroyuki; Urata, Yasuo; Kagawa, Shunsuke; Fujiwara, Toshiyoshi; Hoffman, Robert M

2017-11-01

We have established an orthotopic nude-mouse model of gastric cancer carcinomatosis peritonitis, a recalcitrant disease in human patients. Human MKN45 poorly-differentiated human gastric cancer cells developed carcinomatosis peritonitis upon orthotopic transplantation in nude mice. The MKN45 cells expressed the fluorescent ubiquitination-based cell cycle indicator (FUCCI) that color codes the phases of the cell cycle. The intra-peritoneal tumors and ascites contained mostly quiescent G 1 /G o cancer cells visualized as red by FUCCI imaging. Cisplatinum (CDDP) treatment did not reduce bloody ascites, and larger tumors formed in the peritoneal cavity after CDDP treatment in an early-stage carcinomatosis peritonitis orthotopic mouse model. Paclitaxel-treated mice had reduced ascites, but also had large tumor masses in the peritonium after treatment with cancer cells mostly in G 0 /G 1 , visualized by FUCCI red. In contrast, OBP-301 telomerase-dependent adenovirus-treated mice had no ascites and only small tumor nodules consisting of cancer cells mostly in S/G 2 phases in the early-stage carcinomatosis peritonitis model, visualized by FUCCI green. Furthermore, OBP-301 significantly reduced the size of tumors (P < 0.01) and ascites even in a late-stage carcinomatosis peritonitis model. These results suggest that quiescent peritoneally-disseminated gastric cancer cells are resistant to conventional chemotherapy, but OBP-301 significantly reduced the weight of the tumors and increased survival, suggesting clinical potential. J. Cell. Biochem. 118: 3635-3642, 2017. © 2016 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Sensory-driven and spontaneous gamma oscillations engage distinct cortical circuitry

PubMed Central

2015-01-01

Gamma oscillations are a robust component of sensory responses but are also part of the background spontaneous activity of the brain. To determine whether the properties of gamma oscillations in cortex are specific to their mechanism of generation, we compared in mouse visual cortex in vivo the laminar geometry and single-neuron rhythmicity of oscillations produced during sensory representation with those occurring spontaneously in the absence of stimulation. In mouse visual cortex under anesthesia (isoflurane and xylazine), visual stimulation triggered oscillations mainly between 20 and 50 Hz, which, because of their similar functional significance to gamma oscillations in higher mammals, we define here as gamma range. Sensory representation in visual cortex specifically increased gamma oscillation amplitude in the supragranular (L2/3) and granular (L4) layers and strongly entrained putative excitatory and inhibitory neurons in infragranular layers, while spontaneous gamma oscillations were distributed evenly through the cortical depth and primarily entrained putative inhibitory neurons in the infragranular (L5/6) cortical layers. The difference in laminar distribution of gamma oscillations during the two different conditions may result from differences in the source of excitatory input to the cortex. In addition, modulation of superficial gamma oscillation amplitude did not result in a corresponding change in deep-layer oscillations, suggesting that superficial and deep layers of cortex may utilize independent but related networks for gamma generation. These results demonstrate that stimulus-driven gamma oscillations engage cortical circuitry in a manner distinct from spontaneous oscillations and suggest multiple networks for the generation of gamma oscillations in cortex. PMID:26719085

The Role of the Oculomotor System in Updating Visual-Spatial Working Memory across Saccades.

PubMed

Boon, Paul J; Belopolsky, Artem V; Theeuwes, Jan

2016-01-01

Visual-spatial working memory (VSWM) helps us to maintain and manipulate visual information in the absence of sensory input. It has been proposed that VSWM is an emergent property of the oculomotor system. In the present study we investigated the role of the oculomotor system in updating of spatial working memory representations across saccades. Participants had to maintain a location in memory while making a saccade to a different location. During the saccade the target was displaced, which went unnoticed by the participants. After executing the saccade, participants had to indicate the memorized location. If memory updating fully relies on cancellation driven by extraretinal oculomotor signals, the displacement should have no effect on the perceived location of the memorized stimulus. However, if postsaccadic retinal information about the location of the saccade target is used, the perceived location will be shifted according to the target displacement. As it has been suggested that maintenance of accurate spatial representations across saccades is especially important for action control, we used different ways of reporting the location held in memory; a match-to-sample task, a mouse click or by making another saccade. The results showed a small systematic target displacement bias in all response modalities. Parametric manipulation of the distance between the to-be-memorized stimulus and saccade target revealed that target displacement bias increased over time and changed its spatial profile from being initially centered on locations around the saccade target to becoming spatially global. Taken together results suggest that we neither rely exclusively on extraretinal nor on retinal information in updating working memory representations across saccades. The relative contribution of retinal signals is not fixed but depends on both the time available to integrate these signals as well as the distance between the saccade target and the remembered location.

Direct visualization of membrane architecture of myelinating cells in transgenic mice expressing membrane-anchored EGFP.

PubMed

Deng, Yaqi; Kim, BongWoo; He, Xuelian; Kim, Sunja; Lu, Changqing; Wang, Haibo; Cho, Ssang-Goo; Hou, Yiping; Li, Jianrong; Zhao, Xianghui; Lu, Q Richard

2014-04-01

Myelinogenesis is a complex process that involves substantial and dynamic changes in plasma membrane architecture and myelin interaction with axons. Highly ramified processes of oligodendrocytes in the central nervous system (CNS) make axonal contact and then extrapolate to wrap around axons and form multilayer compact myelin sheathes. Currently, the mechanisms governing myelin sheath assembly and axon selection by myelinating cells are not fully understood. Here, we generated a transgenic mouse line expressing the membrane-anchored green fluorescent protein (mEGFP) in myelinating cells, which allow live imaging of details of myelinogenesis and cellular behaviors in the nervous systems. mEGFP expression is driven by the promoter of 2'-3'-cyclic nucleotide 3'-phosphodiesterase (CNP) that is expressed in the myelinating cell lineage. Robust mEGFP signals appear in the membrane processes of oligodendrocytes in the CNS and Schwann cells in the peripheral nervous system (PNS), wherein mEGFP expression defines the inner layers of myelin sheaths and Schmidt-Lanterman incisures in adult sciatic nerves. In addition, mEGFP expression can be used to track the extent of remyelination after demyelinating injury in a toxin-induced demyelination animal model. Taken together, the membrane-anchored mEGFP expression in the new transgenic line would facilitate direct visualization of dynamic myelin membrane formation and assembly during development and process remodeling during remyelination after various demyelinating injuries.

Partial corrosion casting to assess cochlear vasculature in mouse models of presbycusis and CMV infection.

PubMed

Carraro, Mattia; Park, Albert H; Harrison, Robert V

2016-02-01

Some forms of sensorineural hearing loss involve damage or degenerative changes to the stria vascularis and/or other vascular structures in the cochlea. In animal models, many methods for anatomical assessment of cochlear vasculature exist, each with advantages and limitations. One methodology, corrosion casting, has proved useful in some species, however in the mouse model this technique is difficult to achieve because digestion of non vascular tissue results in collapse of the delicate cast specimen. We have developed a partial corrosion cast method that allows visualization of vasculature along much of the cochlear length but maintains some structural integrity of the specimen. We provide a detailed step-by-step description of this novel technique. We give some illustrative examples of the use of the method in mouse models of presbycusis and cytomegalovirus (CMV) infection. Copyright © 2015 Elsevier B.V. All rights reserved.

Progressive Recruitment of Mesenchymal Progenitors Reveals a Time-Dependent Process of Cell Fate Acquisition in Mouse and Human Nephrogenesis.

PubMed

Lindström, Nils O; De Sena Brandine, Guilherme; Tran, Tracy; Ransick, Andrew; Suh, Gio; Guo, Jinjin; Kim, Albert D; Parvez, Riana K; Ruffins, Seth W; Rutledge, Elisabeth A; Thornton, Matthew E; Grubbs, Brendan; McMahon, Jill A; Smith, Andrew D; McMahon, Andrew P

2018-06-04

Mammalian nephrons arise from a limited nephron progenitor pool through a reiterative inductive process extending over days (mouse) or weeks (human) of kidney development. Here, we present evidence that human nephron patterning reflects a time-dependent process of recruitment of mesenchymal progenitors into an epithelial nephron precursor. Progressive recruitment predicted from high-resolution image analysis and three-dimensional reconstruction of human nephrogenesis was confirmed through direct visualization and cell fate analysis of mouse kidney organ cultures. Single-cell RNA sequencing of the human nephrogenic niche provided molecular insights into these early patterning processes and predicted developmental trajectories adopted by nephron progenitor cells in forming segment-specific domains of the human nephron. The temporal-recruitment model for nephron polarity and patterning suggested by direct analysis of human kidney development provides a framework for integrating signaling pathways driving mammalian nephrogenesis. Copyright © 2018 Elsevier Inc. All rights reserved.

Multi-modality optical imaging of ovarian cancer in a post-menopausal mouse model

NASA Astrophysics Data System (ADS)

Watson, Jennifer M.; Rice, Photini Faith; Marion, Samuel L.; Bentley, David L.; Brewer, Molly A.; Utzinger, Urs; Hoyer, Patricia B.; Barton, Jennifer K.

2011-03-01

Our goal is to use optical imaging to detect cancer development on the sub cellular scale. By determining the microscopic changes that precede ovarian cancer we hope to develop a minimally invasive screening test for high risk patients. A mouse ovarian cancer model has been developed by treating mice with 4-Vinylcyclohexene Diepoxide to induce ovarian failure and 7, 12-Dimethylbenz[a]anthracene (DMBA) to induce ovarian cancer. Using optical coherence tomography (OCT) and multiphoton microscopy (MPM) we have obtained co-registered en face images of sixty-seven mouse ovaries ex vivo and forty-two ovaries in vivo. Preliminary analysis indicates that OCT and MPM can visualize ovarian microstructure. During the next year we will be completing a long term survival study using post-menopausal mice that have been treated with DMBA to induce cancer and imaged in vivo at time points before and after treatment.

Mouse Phenome Database

PubMed Central

Grubb, Stephen C.; Bult, Carol J.; Bogue, Molly A.

2014-01-01

The Mouse Phenome Database (MPD; phenome.jax.org) was launched in 2001 as the data coordination center for the international Mouse Phenome Project. MPD integrates quantitative phenotype, gene expression and genotype data into a common annotated framework to facilitate query and analysis. MPD contains >3500 phenotype measurements or traits relevant to human health, including cancer, aging, cardiovascular disorders, obesity, infectious disease susceptibility, blood disorders, neurosensory disorders, drug addiction and toxicity. Since our 2012 NAR report, we have added >70 new data sets, including data from Collaborative Cross lines and Diversity Outbred mice. During this time we have completely revamped our homepage, improved search and navigational aspects of the MPD application, developed several web-enabled data analysis and visualization tools, annotated phenotype data to public ontologies, developed an ontology browser and released new single nucleotide polymorphism query functionality with much higher density coverage than before. Here, we summarize recent data acquisitions and describe our latest improvements. PMID:24243846

Application of Thinned-Skull Cranial Window to Mouse Cerebral Blood Flow Imaging Using Optical Microangiography

PubMed Central

Wang, Ruikang K.

2014-01-01

In vivo imaging of mouse brain vasculature typically requires applying skull window opening techniques: open-skull cranial window or thinned-skull cranial window. We report non-invasive 3D in vivo cerebral blood flow imaging of C57/BL mouse by the use of ultra-high sensitive optical microangiography (UHS-OMAG) and Doppler optical microangiography (DOMAG) techniques to evaluate two cranial window types based on their procedures and ability to visualize surface pial vessel dynamics. Application of the thinned-skull technique is found to be effective in achieving high quality images for pial vessels for short-term imaging, and has advantages over the open-skull technique in available imaging area, surgical efficiency, and cerebral environment preservation. In summary, thinned-skull cranial window serves as a promising tool in studying hemodynamics in pial microvasculature using OMAG or other OCT blood flow imaging modalities. PMID:25426632

Application of laser speckle contrast image in the evaluation of arthritis animal model

NASA Astrophysics Data System (ADS)

Son, Taeyoon; Jang, Won Hyuk; Park, Jihoon; Yoon, Hyung-Ju; Lee, Jeon; Kim, Wan-Uk; Jung, Byungjo

2013-03-01

Arthritis is a chronic inflammatory disease that induces potentially damaging and commonly disabling. Various imaging modalities have been used for the evaluation of arthritis. This study aimed to investigate the feasibility of laser speckle contrast image (LSCI) in the evaluation of the severity and early stage of arthritis in animal model. Arthritis was induced on mouse foot and evaluated by a trained expert and the LSCI. The arthritis severity was quantitatively evaluated by speckle index (SI) computed from LSCI. In visual inspection by an expert, it was difficult to evaluate the arthritis because there was no noticeable different between control mouse group (CMG) and arthritis mouse group (AMG) in erythema. However, arthritis was easily evaluated by significant SI different between the CMG and AMG. In addition, the LSCI also successfully evaluated the early stage of arthritis, presenting different SI distribution depending on lesion.

Cutaneous Surgical Denervation: A Method for Testing the Requirement for Nerves in Mouse Models of Skin Disease.

PubMed

Peterson, Shelby C; Brownell, Isaac; Wong, Sunny Y

2016-06-26

Cutaneous somatosensory nerves function to detect diverse stimuli that act upon the skin. In addition to their established sensory roles, recent studies have suggested that nerves may also modulate skin disorders including atopic dermatitis, psoriasis and cancer. Here, we describe protocols for testing the requirement for nerves in maintaining a cutaneous mechanosensory organ, the touch dome (TD). Specifically, we discuss methods for genetically labeling, harvesting and visualizing TDs by whole-mount staining, and for performing unilateral surgical denervation on mouse dorsal back skin. Together, these approaches can be used to directly compare TD morphology and gene expression in denervated as well as sham-operated skin from the same animal. These methods can also be readily adapted to examine the requirement for nerves in mouse models of skin pathology. Finally, the ability to repeatedly sample the skin provides an opportunity to monitor disease progression at different stages and times after initiation.

Using the Scroll Wheel on a Wireless Mouse as a Motion Sensor

NASA Astrophysics Data System (ADS)

Taylor, Richard S.; Wilson, William R.

2010-12-01

Since its inception in the mid-80s, the computer mouse has undergone several design changes. As the mouse has evolved, physicists have found new ways to utilize it as a motion sensor. For example, the rollers in a mechanical mouse have been used as pulleys to study the motion of a magnet moving through a copper tube as a quantitative demonstration of Lenz's law and to study mechanical oscillators (e.g., mass-spring system and compound pendulum).1-3 Additionally, the optical system in an optical mouse has been used to study a mechanical oscillator (e.g., mass-spring system).4 The argument for using a mouse as a motion sensor has been and continues to be availability and cost. This paper continues this tradition by detailing the use of the scroll wheel on a wireless mouse as a motion sensor.

Synchrotron phase-contrast X-ray imaging reveals fluid dosing dynamics for gene transfer into mouse airways.

PubMed

Donnelley, M; Siu, K K W; Jamison, R A; Parsons, D W

2012-01-01

Although airway gene transfer research in mouse models relies on bolus fluid dosing into the nose or trachea, the dynamics and immediate fate of delivered gene transfer agents are poorly understood. In particular, this is because there are no in vivo methods able to accurately visualize the movement of fluid in small airways of intact animals. Using synchrotron phase-contrast X-ray imaging, we show that the fate of surrogate fluid doses delivered into live mouse airways can now be accurately and non-invasively monitored with high spatial and temporal resolution. This new imaging approach can help explain the non-homogenous distributions of gene expression observed in nasal airway gene transfer studies, suggests that substantial dose losses may occur at deliver into mouse trachea via immediate retrograde fluid motion and shows the influence of the speed of bolus delivery on the relative targeting of conducting and deeper lung airways. These findings provide insight into some of the factors that can influence gene expression in vivo, and this method provides a new approach to documenting and analyzing dose delivery in small-animal models.

Application of Synchrotron Radiation Imaging for Non-destructive Monitoring of Mouse Rheumatoid Arthritis Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Chang-Hyuk; Kim, Hong-Tae; Choe, Jung-Yoon

This study was performed to observe microstructures of the rheumatoid arthritis induced mouse feet using a synchrotron radiation beam and to compare findings with histological observations. X-ray refraction images from ex-vivo rheumatoid arthritis induced mouse feet were obtained with an 8KeV white (unmonochromatic) beam and 20 micron thick CsI(Tl) scintillation crystal. The visual image was magnified using a x 10 microscope objective and captured using digital CCD camera. Experiments were performed at 1B2 bending magnet beamline of the Pohang Accelerator Laboratory (PAL) in Korea. Obtained images were compared with histopathologic findings from same sample. Cartilage destruction and thickened joint capsulemore » with joint space narrowing were clearly identified at each grade of rheumatoid model with spatial resolution of as much as 1.2 micron and these findings were directly correlated with histopathologic findings. The results suggest that x-ray microscopy study of the rheumatoid arthritis model using synchrotron radiation demonstrates the potential for clinically relevant micro structure of mouse feet without sectioning and fixation.« less

Imaging mouse cerebellum with serial optical coherence scanner (Conference Presentation)

NASA Astrophysics Data System (ADS)

Liu, Chao J.; Williams, Kristen; Orr, Harry; Taner, Akkin

2017-02-01

We present the serial optical coherence scanner (SOCS), which consists of a polarization sensitive optical coherence tomography and a vibratome with associated controls for serial imaging, to visualize the cerebellum and adjacent brainstem of mouse. The cerebellar cortical layers and white matter are distinguished by using intrinsic optical contrasts. Images from serial scans reveal the large-scale anatomy in detail and map the nerve fiber pathways in the cerebellum and adjacent brainstem. The optical system, which has 5.5 μm axial resolution, utilizes a scan lens or a water-immersion microscope objective resulting in 10 μm or 4 μm lateral resolution, respectively. The large-scale brain imaging at high resolution requires an efficient way to collect large datasets. It is important to improve the SOCS system to deal with large-scale and large number of samples in a reasonable time. The imaging and slicing procedure for a section took about 4 minutes due to a low speed of the vibratome blade to maintain slicing quality. SOCS has potential to investigate pathological changes and monitor the effects of therapeutic drugs in cerebellar diseases such as spinocerebellar ataxia 1 (SCA1). The SCA1 is a neurodegenerative disease characterized by atrophy and eventual loss of Purkinje cells from the cerebellar cortex, and the optical contrasts provided by SOCS is being evaluated for biomarkers of the disease.

State of the field: An informatics-based systematic review of the SOD1-G93A amyotrophic lateral sclerosis transgenic mouse model

PubMed Central

Kim, Renaid B.; Irvin, Cameron W.; Tilva, Keval R.; Mitchell, Cassie S.

2016-01-01

Numerous sub-cellular through system-level disturbances have been identified in over 1300 articles examining the superoxide dismutase-1 guanine 93 to alanine (SOD1-G93A) transgenic mouse amyotrophic lateral sclerosis (ALS) pathophysiology. Manual assessment of such a broad literature base is daunting. We performed a comprehensive informatics-based systematic review or ‘field analysis’ to agnostically compute and map the current state of the field. Text mining of recaptured articles was used to quantify published data topic breadth and frequency. We constructed a nine-category pathophysiological function-based ontology to systematically organize and quantify the field's primary data. Results demonstrated that the distribution of primary research belonging to each category is: systemic measures an motor function, 59%; inflammation, 46%; cellular energetics, 37%; proteomics, 31%; neural excitability, 22%; apoptosis, 20%; oxidative stress, 18%; aberrant cellular chemistry, 14%; axonal transport, 10%. We constructed a SOD1-G93A field map that visually illustrates and categorizes the 85% most frequently assessed sub-topics. Finally, we present the literature-cited significance of frequently published terms and uncover thinly investigated areas. In conclusion, most articles individually examine at least two categories, which is indicative of the numerous underlying pathophysiological interrelationships. An essential future path is examination of cross-category pathophysiological interrelationships and their co-correspondence to homeostatic regulation and disease progression. PMID:25998063

Quantification and visualization of injury and regeneration in the developing ciliated epithelium using quantitative flow imaging and speckle variance optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Gamm, Ute A.; Huang, Brendan K.; Mis, Emily K.; Khokha, Mustafa K.; Choma, Michael A.

2017-02-01

Premature infants are at a high risk for respiratory diseases owing to an underdeveloped respiratory system that is very susceptible to infection and inflammation. One aspect of respiratory health is the state of the ciliated respiratory epithelium which lines the trachea and bronchi. The ciliated epithelium is responsible for trapping and removing pathogens and pollutants from the lungs and an impairment of ciliary functionality can lead to recurring respiratory infections and subsequent lung damage. Mechanisms of cilia-driven fluid flow itself but also factors influenced by development like ciliary density and flow generation are incompletely understood. Furthermore, medical interventions like intubation and accidental aspiration can lead to focal or diffuse loss of cilia and disruption of flow. In this study we use two animal models, Xenopus embryo and ex vivo mouse trachea, to analyze flow defects in the injured ciliated epithelium. Injury is generated either mechanically with a scalpel or chemically by calcium chloride (CaCl2) shock, which efficiently but reversibly deciliates the embryo skin. In this study we used optical coherence tomography (OCT) and particle tracking velocimetry (PTV) to quantify cilia driven fluid flow over the surface of the Xenopus embryo. We additionally visualized damage to the ciliated epithelium by capturing 3D speckle variance images that highlight beating cilia. Mechanical injury disrupted cilia-driven fluid flow over the injured site, which led to a reduction in cilia-driven fluid flow over the whole surface of the embryo (n=7). The calcium chloride shock protocol proved to be highly effective in deciliating embryos (n=6). 3D speckle variance images visualized a loss of cilia and cilia-driven flow was halted immediately after application. We also applied CaCl2-shock to cultured ex vivo mouse trachea (n=8) and found, similarly to effects in Xenopus embryo, an extensive loss of cilia with resulting cessation of flow. We investigated the regeneration of the ciliated epithelium after an 8 day incubation period, and found that cilia had regrown and flow was completely restored. In conclusion, OCT is a valuable tool to visualize injury of the ciliated epithelium and to quantify reduction of generated flow. This method allows for systematic investigation of focal and diffuse injury of the ciliated epithelium and the assessment of mechanisms to compensate for loss of flow.

In vivo fluorescence imaging of hepatocellular carcinoma xenograft using near-infrared labeled epidermal growth factor receptor (EGFR) peptide

PubMed Central

Li, Z.; Zhou, Q.; Zhou, J.; Duan, X.; Zhu, J.; Wang, T. D.

2016-01-01

Minimally-invasive surgery of hepatocellular carcinoma (HCC) can be limited by poor tumor visualization with white light. We demonstrate systemic administration of a Cy5.5-labeled peptide specific for epidermal growth factor receptor (EGFR) to target HCC in vivo in a mouse xenograft model. We attached a compact imaging module to the proximal end of a medical laparoscope to collect near-infrared fluorescence and reflectance images concurrently at 15 frames/sec. We measured a mean target-to-background ratio of 2.99 ± 0.22 from 13 surgically exposed subcutaneous human HCC tumors in vivo in 5 mice. This integrated imaging methodology is promising to guide laparoscopic resection of HCC. PMID:27699089

Gene Therapy for Color Blindness.

PubMed

Hassall, Mark M; Barnard, Alun R; MacLaren, Robert E

2017-12-01

Achromatopsia is a rare congenital cause of vision loss due to isolated cone photoreceptor dysfunction. The most common underlying genetic mutations are autosomal recessive changes in CNGA3 , CNGB3 , GNAT2 , PDE6H , PDE6C , or ATF6 . Animal models of Cnga3 , Cngb3 , and Gnat2 have been rescued using AAV gene therapy; showing partial restoration of cone electrophysiology and integration of this new photopic vision in reflexive and behavioral visual tests. Three gene therapy phase I/II trials are currently being conducted in human patients in the USA, the UK, and Germany. This review details the AAV gene therapy treatments of achromatopsia to date. We also present novel data showing rescue of a Cnga3 -/- mouse model using an rAAV.CBA.CNGA3 vector. We conclude by synthesizing the implications of this animal work for ongoing human trials, particularly, the challenge of restoring integrated cone retinofugal pathways in an adult visual system. The evidence to date suggests that gene therapy for achromatopsia will need to be applied early in childhood to be effective.

Fluorescence-based surface magnifying chromoendoscopy and optical coherence tomography endoscope

NASA Astrophysics Data System (ADS)

Wall, R. Andrew; Barton, Jennifer K.

2012-08-01

A side-viewing, 2.3-mm diameter, surface magnifying chromoendoscopy-optical coherence tomography (SMC-OCT) endoscope has been designed for simultaneous, nondestructive surface fluorescence visualization and cross-sectional imaging. We apply this endoscope to in vivo examination of the mouse colon. A 30,000 element fiber bundle is combined with single mode fibers, for SMC and OCT imaging, respectively. The distal optics consist of a gradient-index lens and spacer to provide a 1× magnification at a working distance of 1.58 mm in air, necessary to image the sample through a 0.23-mm thick outer glass envelope, and an aluminized right-angle prism fixed to the distal end of the gradient-index lens assembly. The resulting 1∶1 imaging system is capable of 3.9-μm lateral and 2.3-μm axial resolution in the OCT channel, and 125-lp/mm resolution across a 0.70-mm field of view in the SMC channel. The endoscope can perform high contrast crypt visualization, molecular imaging, and cross-sectional imaging of colon microstructure.

Fluorescence-based surface magnifying chromoendoscopy and optical coherence tomography endoscope

PubMed Central

Wall, R. Andrew

2012-01-01

Abstract. A side-viewing, 2.3-mm diameter, surface magnifying chromoendoscopy-optical coherence tomography (SMC-OCT) endoscope has been designed for simultaneous, nondestructive surface fluorescence visualization and cross-sectional imaging. We apply this endoscope to in vivo examination of the mouse colon. A 30,000 element fiber bundle is combined with single mode fibers, for SMC and OCT imaging, respectively. The distal optics consist of a gradient-index lens and spacer to provide a 1× magnification at a working distance of 1.58 mm in air, necessary to image the sample through a 0.23-mm thick outer glass envelope, and an aluminized right-angle prism fixed to the distal end of the gradient-index lens assembly. The resulting 1∶1 imaging system is capable of 3.9-µm lateral and 2.3-µm axial resolution in the OCT channel, and 125-lp/mm resolution across a 0.70-mm field of view in the SMC channel. The endoscope can perform high contrast crypt visualization, molecular imaging, and cross-sectional imaging of colon microstructure. PMID:23224190

Intravital phosphorescence lifetime imaging of the renal cortex accurately measures renal hypoxia.

PubMed

Hirakawa, Yosuke; Mizukami, Kiichi; Yoshihara, Toshitada; Takahashi, Ippei; Khulan, Purevsuren; Honda, Tomoko; Mimura, Imari; Tanaka, Tetsuhiro; Tobita, Seiji; Nangaku, Masaomi

2018-06-01

Renal tubulointerstitial hypoxia is recognized as a final common pathway of chronic kidney disease and is considered a promising drug target. However, hypoxia in the tubules is not well examined because of limited detection methods. Here, we devised a method to visualize renal tubular oxygen tension with spatial resolution at a cellular level using the cell-penetrating phosphorescent probe, BTPDM1 (an iridium-based cationic lipophilic dye), and confocal phosphorescence lifetime imaging microscopy to precisely assess renal hypoxia. Imaging with BTPDM1 revealed an oxygen gradient between S1 and S2 segments in mouse kidney. We also demonstrated that our microscopy system can detect subtle changes of hypoxemia and reoxygenation, and the acquired phosphorescence lifetime can be converted to partial pressure of oxygen. This new method allows, for the first time, visualization of intravital oxygen gradients at the renal surface with high spatial resolution. Thus, the confocal phosphorescence lifetime imaging microscopy platform, combined with BTPDM1, will promote an accurate understanding of tissue hypoxia, including renal hypoxia. Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Defective pigment granule biogenesis and aberrant behavior caused by mutations in the Drosophila AP-3beta adaptin gene ruby.

PubMed Central

Kretzschmar, D; Poeck, B; Roth, H; Ernst, R; Keller, A; Porsch, M; Strauss, R; Pflugfelder, G O

2000-01-01

Lysosomal protein trafficking is a fundamental process conserved from yeast to humans. This conservation extends to lysosome-like organelles such as mammalian melanosomes and insect eye pigment granules. Recently, eye and coat color mutations in mouse (mocha and pearl) and Drosophila (garnet and carmine) were shown to affect subunits of the heterotetrameric adaptor protein complex AP-3 involved in vesicle trafficking. Here we demonstrate that the Drosophila eye color mutant ruby is defective in the AP-3beta subunit gene. ruby expression was found in retinal pigment and photoreceptor cells and in the developing central nervous system. ruby mutations lead to a decreased number and altered size of pigment granules in various cell types in and adjacent to the retina. Humans with lesions in the related AP-3betaA gene suffer from Hermansky-Pudlak syndrome, which is caused by defects in a number of lysosome-related organelles. Hermansky-Pudlak patients have a reduced skin pigmentation and suffer from internal bleeding, pulmonary fibrosis, and visual system malfunction. The Drosophila AP-3beta adaptin also appears to be involved in processes other than eye pigment granule biogenesis because all ruby allele combinations tested exhibited defective behavior in a visual fixation paradigm. PMID:10790396

An automatic eye detection and tracking technique for stereo video sequences

NASA Astrophysics Data System (ADS)

Paduru, Anirudh; Charalampidis, Dimitrios; Fouts, Brandon; Jovanovich, Kim

2009-05-01

Human-computer interfacing (HCI) describes a system or process with which two information processors, namely a human and a computer, attempt to exchange information. Computer-to-human (CtH) information transfer has been relatively effective through visual displays and sound devices. On the other hand, the human-tocomputer (HtC) interfacing avenue has yet to reach its full potential. For instance, the most common HtC communication means are the keyboard and mouse, which are already becoming a bottleneck in the effective transfer of information. The solution to the problem is the development of algorithms that allow the computer to understand human intentions based on their facial expressions, head motion patterns, and speech. In this work, we are investigating the feasibility of a stereo system to effectively determine the head position, including the head rotation angles, based on the detection of eye pupils.

A retinal code for motion along the gravitational and body axes

PubMed Central

Sabbah, Shai; Gemmer, John A.; Bhatia-Lin, Ananya; Manoff, Gabrielle; Castro, Gabriel; Siegel, Jesse K.; Jeffery, Nathan; Berson, David M.

2017-01-01

Summary Self-motion triggers complementary visual and vestibular reflexes supporting image-stabilization and balance. Translation through space produces one global pattern of retinal image motion (optic flow), rotation another. We show that each subtype of direction-selective ganglion cell (DSGC) adjusts its direction preference topographically to align with specific translatory optic flow fields, creating a neural ensemble tuned for a specific direction of motion through space. Four cardinal translatory directions are represented, aligned with two axes of high adaptive relevance: the body and gravitational axes. One subtype maximizes its output when the mouse advances, others when it retreats, rises, or falls. ON-DSGCs and ON-OFF-DSGCs share the same spatial geometry but weight the four channels differently. Each subtype ensemble is also tuned for rotation. The relative activation of DSGC channels uniquely encodes every translation and rotation. Though retinal and vestibular systems both encode translatory and rotatory self-motion, their coordinate systems differ. PMID:28607486

The Rise of the Graphical User Interface.

ERIC Educational Resources Information Center

Edwards, Alastair D. N.

1996-01-01

Discusses the history of the graphical user interface (GUI) and the growing realization that adaptations must be made to it lest its visual nature discriminate against nonsighted or sight-impaired users. One of the most popular commercially developed adaptations is to develop sounds that signal the location of icons or menus to mouse users.…

Accumulation of phosphorylated alpha-synuclein (p129S) and retinal pathology in a mouse model of Parkinson's disease

USDA-ARS?s Scientific Manuscript database

Aims: Parkinson's disease (PD) is a neurodegenerative disorder characterized by accumulation of misfolded alpha-synuclein within the CNS. Although non-motor clinical phenotypes of PD such as visual dysfunction have become increasingly apparent, retinal pathology associated with PD is not well under...

ESCAPE: database for integrating high-content published data collected from human and mouse embryonic stem cells.

PubMed

Xu, Huilei; Baroukh, Caroline; Dannenfelser, Ruth; Chen, Edward Y; Tan, Christopher M; Kou, Yan; Kim, Yujin E; Lemischka, Ihor R; Ma'ayan, Avi

2013-01-01

High content studies that profile mouse and human embryonic stem cells (m/hESCs) using various genome-wide technologies such as transcriptomics and proteomics are constantly being published. However, efforts to integrate such data to obtain a global view of the molecular circuitry in m/hESCs are lagging behind. Here, we present an m/hESC-centered database called Embryonic Stem Cell Atlas from Pluripotency Evidence integrating data from many recent diverse high-throughput studies including chromatin immunoprecipitation followed by deep sequencing, genome-wide inhibitory RNA screens, gene expression microarrays or RNA-seq after knockdown (KD) or overexpression of critical factors, immunoprecipitation followed by mass spectrometry proteomics and phosphoproteomics. The database provides web-based interactive search and visualization tools that can be used to build subnetworks and to identify known and novel regulatory interactions across various regulatory layers. The web-interface also includes tools to predict the effects of combinatorial KDs by additive effects controlled by sliders, or through simulation software implemented in MATLAB. Overall, the Embryonic Stem Cell Atlas from Pluripotency Evidence database is a comprehensive resource for the stem cell systems biology community. Database URL: http://www.maayanlab.net/ESCAPE

Clinical and experimental advances in congenital and paediatric cataracts

PubMed Central

Churchill, Amanda; Graw, Jochen

2011-01-01

Cataracts (opacities of the lens) are frequent in the elderly, but rare in paediatric practice. Congenital cataracts (in industrialized countries) are mainly caused by mutations affecting lens development. Much of our knowledge about the underlying mechanisms of cataractogenesis has come from the genetic analysis of affected families: there are contributions from genes coding for transcription factors (such as FoxE3, Maf, Pitx3) and structural proteins such as crystallins or connexins. In addition, there are contributions from enzymes affecting sugar pathways (particularly the galactose pathway) and from a quite unexpected area: axon guidance molecules like ephrins and their receptors. Cataractous mouse lenses can be identified easily by visual inspection, and a remarkable number of mutant lines have now been characterized. Generally, most of the mouse mutants show a similar phenotype to their human counterparts; however, there are some remarkable differences. It should be noted that many mutations affect genes that are expressed not only in the lens, but also in tissues and organs outside the eye. There is increasing evidence for pleiotropic effects of these genes, and increasing consideration that cataracts may act as early and readily detectable biomarkers for a number of systemic syndromes. PMID:21402583

Enabling Disabled Persons to Gain Access to Digital Media

NASA Technical Reports Server (NTRS)

Beach, Glenn; OGrady, Ryan

2011-01-01

A report describes the first phase in an effort to enhance the NaviGaze software to enable profoundly disabled persons to operate computers. (Running on a Windows-based computer equipped with a video camera aimed at the user s head, the original NaviGaze software processes the user's head movements and eye blinks into cursor movements and mouse clicks to enable hands-free control of the computer.) To accommodate large variations in movement capabilities among disabled individuals, one of the enhancements was the addition of a graphical user interface for selection of parameters that affect the way the software interacts with the computer and tracks the user s movements. Tracking algorithms were improved to reduce sensitivity to rotations and reduce the likelihood of tracking the wrong features. Visual feedback to the user was improved to provide an indication of the state of the computer system. It was found that users can quickly learn to use the enhanced software, performing single clicks, double clicks, and drags within minutes of first use. Available programs that could increase the usability of NaviGaze were identified. One of these enables entry of text by using NaviGaze as a mouse to select keys on a virtual keyboard.

Gene therapy augments the efficacy of hematopoietic cell transplantation and fully corrects mucopolysaccharidosis type I phenotype in the mouse model

PubMed Central

Visigalli, Ilaria; Delai, Stefania; Politi, Letterio S.; Di Domenico, Carmela; Cerri, Federica; Mrak, Emanuela; D'Isa, Raffaele; Ungaro, Daniela; Stok, Merel; Sanvito, Francesca; Mariani, Elisabetta; Staszewsky, Lidia; Godi, Claudia; Russo, Ilaria; Cecere, Francesca; del Carro, Ubaldo; Rubinacci, Alessandro; Brambilla, Riccardo; Quattrini, Angelo; Di Natale, Paola; Ponder, Katherine; Naldini, Luigi

2010-01-01

Type I mucopolysaccharidosis (MPS I) is a lysosomal storage disorder caused by the deficiency of α-L-iduronidase, which results in glycosaminoglycan accumulation in tissues. Clinical manifestations include skeletal dysplasia, joint stiffness, visual and auditory defects, cardiac insufficiency, hepatosplenomegaly, and mental retardation (the last being present exclusively in the severe Hurler variant). The available treatments, enzyme-replacement therapy and hematopoietic stem cell (HSC) transplantation, can ameliorate most disease manifestations, but their outcome on skeletal and brain disease could be further improved. We demonstrate here that HSC gene therapy, based on lentiviral vectors, completely corrects disease manifestations in the mouse model. Of note, the therapeutic benefit provided by gene therapy on critical MPS I manifestations, such as neurologic and skeletal disease, greatly exceeds that exerted by HSC transplantation, the standard of care treatment for Hurler patients. Interestingly, therapeutic efficacy of HSC gene therapy is strictly dependent on the achievement of supranormal enzyme activity in the hematopoietic system of transplanted mice, which allows enzyme delivery to the brain and skeleton for disease correction. Overall, our data provide evidence of an efficacious treatment for MPS I Hurler patients, warranting future development toward clinical testing. PMID:20847202

Mouse strain and injection site are crucial for detecting linked suppression in transplant recipients by trans-vivo DTH assay.

PubMed

Burlingham, W J; Jankowska-Gan, E

2007-02-01

Chemokine-driven accumulation of lymphocytes, mononuclear and polymorphonuclear proinflammatory cells in antigenic tissue sites is a key feature of several types of T-cell-dependent autoimmunity and transplant rejection pathology. It is now clear that the immune system expends considerable energy to control this process, exemplified by the sequential layers of regulatory cell input, both innate and adaptive, designed to prevent a classical Type IV or 'delayed-type' hypersensitivity (DTH) reaction from occurring in the visual field of the eye. Yet, despite an abundance of in vitro assays currently available to the human T-cell immunologist, none of them adequately models the human DTH response and its various control features. The theme of this article is that it is relatively easy to model the effector side of the human DTH response with xenogeneic adoptive transfer models. However, we show that in order to detect inhibition of a recall DTH in response to colocalized donor antigen (linked suppression)--a characteristic feature of peripheral tolerance to an organ transplant--both the challenge site and the immunocompetence of the mouse adoptive host are critical factors limiting the sensitivity of the trans-vivo DTH test.

A novel multistep mechanism for initial lymphangiogenesis in mouse embryos based on ultramicroscopy

PubMed Central

Hägerling, René; Pollmann, Cathrin; Andreas, Martin; Schmidt, Christian; Nurmi, Harri; Adams, Ralf H; Alitalo, Kari; Andresen, Volker; Schulte-Merker, Stefan; Kiefer, Friedemann

2013-01-01

During mammalian development, a subpopulation of endothelial cells in the cardinal vein (CV) expresses lymphatic-specific genes and subsequently develops into the first lymphatic structures, collectively termed as lymph sacs. Budding, sprouting and ballooning of lymphatic endothelial cells (LECs) have been proposed to underlie the emergence of LECs from the CV, but the exact mechanisms of lymph vessel formation remain poorly understood. Applying selective plane illumination-based ultramicroscopy to entire wholemount-immunostained mouse embryos, we visualized the complete developing vascular system with cellular resolution. Here, we report emergence of the earliest detectable LECs as strings of loosely connected cells between the CV and superficial venous plexus. Subsequent aggregation of LECs resulted in formation of two distinct, previously unidentified lymphatic structures, the dorsal peripheral longitudinal lymphatic vessel (PLLV) and the ventral primordial thoracic duct (pTD), which at later stages formed a direct contact with the CV. Providing new insights into their function, we found vascular endothelial growth factor C (VEGF-C) and the matrix component CCBE1 indispensable for LEC budding and migration. Altogether, we present a significantly more detailed view and novel model of early lymphatic development. PMID:23299940

Molecular basis of tactile specialization in the duck bill.

PubMed

Schneider, Eve R; Anderson, Evan O; Mastrotto, Marco; Matson, Jon D; Schulz, Vincent P; Gallagher, Patrick G; LaMotte, Robert H; Gracheva, Elena O; Bagriantsev, Sviatoslav N

2017-12-05

Tactile-foraging ducks are specialist birds known for their touch-dependent feeding behavior. They use dabbling, straining, and filtering to find edible matter in murky water, relying on the sense of touch in their bill. Here, we present the molecular characterization of embryonic duck bill, which we show contains a high density of mechanosensory corpuscles innervated by functional rapidly adapting trigeminal afferents. In contrast to chicken, a visually foraging bird, the majority of duck trigeminal neurons are mechanoreceptors that express the Piezo2 ion channel and produce slowly inactivating mechano-current before hatching. Furthermore, duck neurons have a significantly reduced mechano-activation threshold and elevated mechano-current amplitude. Cloning and electrophysiological characterization of duck Piezo2 in a heterologous expression system shows that duck Piezo2 is functionally similar to the mouse ortholog but with prolonged inactivation kinetics, particularly at positive potentials. Knockdown of Piezo2 in duck trigeminal neurons attenuates mechano current with intermediate and slow inactivation kinetics. This suggests that Piezo2 is capable of contributing to a larger range of mechano-activated currents in duck trigeminal ganglia than in mouse trigeminal ganglia. Our results provide insights into the molecular basis of mechanotransduction in a tactile-specialist vertebrate.

Molecular basis of tactile specialization in the duck bill

PubMed Central

Anderson, Evan O.; Mastrotto, Marco; Matson, Jon D.; Schulz, Vincent P.; Gallagher, Patrick G.; LaMotte, Robert H.; Gracheva, Elena O.; Bagriantsev, Sviatoslav N.

2017-01-01

Tactile-foraging ducks are specialist birds known for their touch-dependent feeding behavior. They use dabbling, straining, and filtering to find edible matter in murky water, relying on the sense of touch in their bill. Here, we present the molecular characterization of embryonic duck bill, which we show contains a high density of mechanosensory corpuscles innervated by functional rapidly adapting trigeminal afferents. In contrast to chicken, a visually foraging bird, the majority of duck trigeminal neurons are mechanoreceptors that express the Piezo2 ion channel and produce slowly inactivating mechano-current before hatching. Furthermore, duck neurons have a significantly reduced mechano-activation threshold and elevated mechano-current amplitude. Cloning and electrophysiological characterization of duck Piezo2 in a heterologous expression system shows that duck Piezo2 is functionally similar to the mouse ortholog but with prolonged inactivation kinetics, particularly at positive potentials. Knockdown of Piezo2 in duck trigeminal neurons attenuates mechano current with intermediate and slow inactivation kinetics. This suggests that Piezo2 is capable of contributing to a larger range of mechano-activated currents in duck trigeminal ganglia than in mouse trigeminal ganglia. Our results provide insights into the molecular basis of mechanotransduction in a tactile-specialist vertebrate. PMID:29109250

Pre-existing periodontitis exacerbates experimental arthritis in a mouse model.

PubMed

Cantley, Melissa D; Haynes, David R; Marino, Victor; Bartold, P Mark

2011-06-01

Previous studies have shown a higher incidence of alveolar bone loss in patients with rheumatoid arthritis (RA) and that patients with periodontitis are at a greater risk of developing RA. The aim of this study was to develop an animal model to assess the relationship between pre-existing periodontitis and experimental arthritis (EA). Periodontitis was first induced in mice by oral gavage with Porphyromonas gingivalis followed by EA using the collagen antibody-induced arthritis model. These animals were compared with animals with periodontitis alone, EA alone and no disease (controls). Visual changes in paw swelling were assessed to determine clinical development of EA. Alveolar bone and joint changes were assessed using micro-CT, histological analyses and immunohistochemistry. Serum levels of C-reactive protein were used to monitor systemic inflammation. Mice with pre-existing periodontitis developed more severe arthritis, which developed at a faster rate. Mice with periodontitis only also showed evidence of loss of bone within the radiocarpal joint. There was also evidence of alveolar bone loss in mice with EA alone. The results of this study indicate that pre-existing periodontitis exacerbated experimental arthritis in a mouse model. © 2011 John Wiley & Sons A/S.

MultiMap: A Tool to Automatically Extract and Analyse Spatial Microscopic Data From Large Stacks of Confocal Microscopy Images

PubMed Central

Varando, Gherardo; Benavides-Piccione, Ruth; Muñoz, Alberto; Kastanauskaite, Asta; Bielza, Concha; Larrañaga, Pedro; DeFelipe, Javier

2018-01-01

The development of 3D visualization and reconstruction methods to analyse microscopic structures at different levels of resolutions is of great importance to define brain microorganization and connectivity. MultiMap is a new tool that allows the visualization, 3D segmentation and quantification of fluorescent structures selectively in the neuropil from large stacks of confocal microscopy images. The major contribution of this tool is the posibility to easily navigate and create regions of interest of any shape and size within a large brain area that will be automatically 3D segmented and quantified to determine the density of puncta in the neuropil. As a proof of concept, we focused on the analysis of glutamatergic and GABAergic presynaptic axon terminals in the mouse hippocampal region to demonstrate its use as a tool to provide putative excitatory and inhibitory synaptic maps. The segmentation and quantification method has been validated over expert labeled images of the mouse hippocampus and over two benchmark datasets, obtaining comparable results to the expert detections. PMID:29875639

MultiMap: A Tool to Automatically Extract and Analyse Spatial Microscopic Data From Large Stacks of Confocal Microscopy Images.

PubMed

Varando, Gherardo; Benavides-Piccione, Ruth; Muñoz, Alberto; Kastanauskaite, Asta; Bielza, Concha; Larrañaga, Pedro; DeFelipe, Javier

2018-01-01

The development of 3D visualization and reconstruction methods to analyse microscopic structures at different levels of resolutions is of great importance to define brain microorganization and connectivity. MultiMap is a new tool that allows the visualization, 3D segmentation and quantification of fluorescent structures selectively in the neuropil from large stacks of confocal microscopy images. The major contribution of this tool is the posibility to easily navigate and create regions of interest of any shape and size within a large brain area that will be automatically 3D segmented and quantified to determine the density of puncta in the neuropil. As a proof of concept, we focused on the analysis of glutamatergic and GABAergic presynaptic axon terminals in the mouse hippocampal region to demonstrate its use as a tool to provide putative excitatory and inhibitory synaptic maps. The segmentation and quantification method has been validated over expert labeled images of the mouse hippocampus and over two benchmark datasets, obtaining comparable results to the expert detections.

Fluorescence-based visualization of autophagic activity predicts mouse embryo viability

NASA Astrophysics Data System (ADS)

Tsukamoto, Satoshi; Hara, Taichi; Yamamoto, Atsushi; Kito, Seiji; Minami, Naojiro; Kubota, Toshiro; Sato, Ken; Kokubo, Toshiaki

2014-03-01

Embryo quality is a critical parameter in assisted reproductive technologies. Although embryo quality can be evaluated morphologically, embryo morphology does not correlate perfectly with embryo viability. To improve this, it is important to understand which molecular mechanisms are involved in embryo quality control. Autophagy is an evolutionarily conserved catabolic process in which cytoplasmic materials sequestered by autophagosomes are degraded in lysosomes. We previously demonstrated that autophagy is highly activated after fertilization and is essential for further embryonic development. Here, we developed a simple fluorescence-based method for visualizing autophagic activity in live mouse embryos. Our method is based on imaging of the fluorescence intensity of GFP-LC3, a versatile marker for autophagy, which is microinjected into the embryos. Using this method, we show that embryonic autophagic activity declines with advancing maternal age, probably due to a decline in the activity of lysosomal hydrolases. We also demonstrate that embryonic autophagic activity is associated with the developmental viability of the embryo. Our results suggest that embryonic autophagic activity can be utilized as a novel indicator of embryo quality.

New GABA modulators protect photoreceptor cells from light-induced degeneration in mouse models.

PubMed

Schur, Rebecca M; Gao, Songqi; Yu, Guanping; Chen, Yu; Maeda, Akiko; Palczewski, Krzysztof; Lu, Zheng-Rong

2018-01-24

No clinically approved therapies are currently available that prevent the onset of photoreceptor death in retinal degeneration. Signaling between retinal neurons is regulated by the release and uptake of neurotransmitters, wherein GABA is the main inhibitory neurotransmitter. In this work, novel 3-chloropropiophenone derivatives and the clinical anticonvulsants tiagabine and vigabatrin were tested to modulate GABA signaling and protect against light-induced retinal degeneration. Abca4 -/- Rdh8 -/- mice, an accelerated model of retinal degeneration, were exposed to intense light after prophylactic injections of one of these compounds. Imaging and functional assessments of the retina indicated that these compounds successfully protected photoreceptor cells from degeneration to maintain a full-visual-field response. Furthermore, these compounds demonstrated a strong safety profile in wild-type mice and did not compromise visual function or damage the retina, despite repeated administration. These results indicate that modulating inhibitory GABA signaling can offer prophylactic protection against light-induced retinal degeneration.-Schur, R. M., Gao, S., Yu, G., Chen, Y., Maeda, A., Palczewski, K., Lu, Z.-R. New GABA modulators protect photoreceptor cells from light-induced degeneration in mouse models.

Reduced dimethylaminoethanol in [(18)F]fluoromethylcholine: an important step towards enhanced tumour visualization.

PubMed

Slaets, Dominique; De Bruyne, Sylvie; Dumolyn, Caroline; Moerman, Lieselotte; Mertens, Koen; De Vos, Filip

2010-11-01

[(18)F]Fluoromethylcholine ([(18)F]FCho) is a radiotracer generally used for tumour visualization in patients. Due to high levels of dimethylaminoethanol (DMAE) remaining in [(18)F]FCho solutions synthesized by currently available methods, tumour visualization might be compromised. An improved purification method involving an optimized purification step for reducing the levels of DMAE was conceived. The physiological explanation for the interference of residual DMAE in [(18)F]FCho pharmacokinetics was further elaborated in a xenograft mouse model. The use of a series of polymer solid-phase extraction cartridges (Oasis HLB/WCX), instead of the commonly used combination of tC18 and Accell CM cartridges, reduced DMAE levels from 402.2±49.6 ppm to 3.0±0.5 ppm. Subsequent in vitro tests proved that (1) [(18)F]FCho uptake was reduced in the presence of DMAE at concentrations above 0.5 µM and (2) DMAE is a competitive inhibitor of [(18)F]FCho transport. In vivo experiments in xenograft mouse models corroborated reduced tumour uptake at DMAE plasma levels of about 2.5 µM as found in patients injected with contaminated [(18)F]FCho. Residual DMAE, even at levels below choline plasma concentrations found during fasting, compromises [(18)F]FCho uptake in vivo and care should be taken to avoid its interference in molecular imaging with [(18)F]FCho.

Fluorescence in vivo imaging of live tumor cells with pH-activatable targeted probes via receptor-mediated endocytosis

NASA Astrophysics Data System (ADS)

Asanuma, Daisuke; Urano, Yasuteru; Nagano, Tetsuo; Hama, Yukihiro; Koyama, Yoshinori; Kobayashi, Hisataka

2009-02-01

One goal of molecular imaging is to establish a widely applicable technique for specific detection of tumors with minimal background. Here, we achieve specific in vivo tumor visualization with a newly-designed "activatable" targeted fluorescence probe. This agent is activated after cellular internalization by sensing the pH change in the lysosome. Novel acidic pH-activatable probes based on the BODIPY fluorophore were synthesized, and then conjugated to a cancer-targeting monoclonal antibody, Trastuzumab, or galactosyl serum albumin (GSA). As proof of concept, ex and in vivo imaging of two different tumor mouse models was performed: HER2-overexpressed lung metastasis tumor with Trastuzumab-pH probe conjugates and lectin-overexpressed i.p. disseminated tumor with GSA-pH probe conjugates. These pH-activatable targeted probes were highly specific for tumors with minimal background signal. Because the acidic pH in lysosomes is maintained by the energy-consuming proton pump, only viable cancer cells were successfully visualized. Furthermore, this strategy was also applied to fluorescence endoscopy in tumor mouse models, resulting in specific visualization of tumors as small as submillimeter in size that could hardly detected by naked eyes because of their poor contrast against normal tissues. The design concept can be widely adapted to cancer-specific cell-surface-targeting molecules that result in cellular internalization.

Implicit visual learning and the expression of learning.

PubMed

Haider, Hilde; Eberhardt, Katharina; Kunde, Alexander; Rose, Michael

2013-03-01

Although the existence of implicit motor learning is now widely accepted, the findings concerning perceptual implicit learning are ambiguous. Some researchers have observed perceptual learning whereas other authors have not. The review of the literature provides different reasons to explain this ambiguous picture, such as differences in the underlying learning processes, selective attention, or differences in the difficulty to express this knowledge. In three experiments, we investigated implicit visual learning within the original serial reaction time task. We used different response devices (keyboard vs. mouse) in order to manipulate selective attention towards response dimensions. Results showed that visual and motor sequence learning differed in terms of RT-benefits, but not in terms of the amount of knowledge assessed after training. Furthermore, visual sequence learning was modulated by selective attention. However, the findings of all three experiments suggest that selective attention did not alter implicit but rather explicit learning processes. Copyright © 2012 Elsevier Inc. All rights reserved.

Color-coded Imaging Enables Fluorescence-guided Surgery to Resect the Tumor Along with the Tumor Microenvironment in a Syngeneic Mouse Model of EL-4 Lymphoma.

PubMed

Hasegawa, Kosuke; Suetsugu, Atsushi; Nakamura, Miki; Matsumoto, Takuro; Kunisada, Takahiro; Shimizu, Masahito; Saji, Shigetoyo; Moriwaki, Hisataka; Bouvet, Michael; Hoffman, Robert M

2016-09-01

Fluorescence-guided surgery (FGS) of cancer is an emerging technology. We have previously shown the importance of resecting both the tumor and the tumor microenvironment (TME) for curative FGS. We also previously developed a syngeneic model using the mouse lymphoma cell line EL-4, expressing red fluorescent protein (EL-4-RFP), growing in green fluorescent protein (GFP) transgenic mice, which we have used in the present report to develop FGS of the tumor microenvironment. EL-4-RFP lymphoma cells were injected subcutaneously in C57/BL6 GFP transgenic mice. EL-4-RFP cells subsequently formed tumors by 35 days after cell transplantation. Using the portable hand-held Dino-Lite digital imaging system, subcutaneous tumors were resected by FGS. Resected tumor tissues were visualized with the Olympus FV1000 confocal microscope. Using the Dino-Lite, subcutaneous tumors and the tumor microenvironment were clearly visualized and resected. In the resected tumor, host stromal cells, including adipocyte-like cells and blood vessels with lymphocytes, were observed by confocal microscopy in addition to cancer cells by color-coded confocal imaging. The cancer cells and stromal cells in the TME were deeply intermingled in a highly-complex pattern. Color-coded FGS is an effective method to completely resect cancer cells along with the stromal cells in the TME which interact in a highly-complex pattern. Microscopically, cancer cells invade the TME and vice versa. To prevent tumor recurrence, it is necessary to resect the TME along with the tumor. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

In vivo analysis of THz wave irradiation induced acute inflammatory response in skin by laser-scanning confocal microscopy.

PubMed

Hwang, Yoonha; Ahn, Jinhyo; Mun, Jungho; Bae, Sangyoon; Jeong, Young Uk; Vinokurov, Nikolay A; Kim, Pilhan

2014-05-19

The recent development of THz sources in a wide range of THz frequencies and power levels has led to greatly increased interest in potential biomedical applications such as cancer and burn wound diagnosis. However, despite its importance in realizing THz wave based applications, our knowledge of how THz wave irradiation can affect a live tissue at the cellular level is very limited. In this study, an acute inflammatory response caused by pulsed THz wave irradiation on the skin of a live mouse was analyzed at the cellular level using intravital laser-scanning confocal microscopy. Pulsed THz wave (2.7 THz, 4 μs pulsewidth, 61.4 μJ per pulse, 3Hz repetition), generated using compact FEL, was used to irradiate an anesthetized mouse's ear skin with an average power of 260 mW/cm(2) for 30 minutes using a high-precision focused THz wave irradiation setup. In contrast to in vitro analysis using cultured cells at similar power levels of CW THz wave irradiation, no temperature change at the surface of the ear skin was observed when skin was examined with an IR camera. To monitor any potential inflammatory response, resident neutrophils in the same area of ear skin were repeatedly visualized before and after THz wave irradiation using a custom-built laser-scanning confocal microscopy system optimized for in vivo visualization. While non-irradiated control skin area showed no changes in the number of resident neutrophils, a massive recruitment of newly infiltrated neutrophils was observed in the THz wave irradiated skin area after 6 hours, which suggests an induction of acute inflammatory response by the pulsed THz wave irradiation on the skin via a non-thermal process.

Stand-alone front-end system for high- frequency, high-frame-rate coded excitation ultrasonic imaging.

PubMed

Park, Jinhyoung; Hu, Changhong; Shung, K Kirk

2011-12-01

A stand-alone front-end system for high-frequency coded excitation imaging was implemented to achieve a wider dynamic range. The system included an arbitrary waveform amplifier, an arbitrary waveform generator, an analog receiver, a motor position interpreter, a motor controller and power supplies. The digitized arbitrary waveforms at a sampling rate of 150 MHz could be programmed and converted to an analog signal. The pulse was subsequently amplified to excite an ultrasound transducer, and the maximum output voltage level achieved was 120 V(pp). The bandwidth of the arbitrary waveform amplifier was from 1 to 70 MHz. The noise figure of the preamplifier was less than 7.7 dB and the bandwidth was 95 MHz. Phantoms and biological tissues were imaged at a frame rate as high as 68 frames per second (fps) to evaluate the performance of the system. During the measurement, 40-MHz lithium niobate (LiNbO(3)) single-element lightweight (<;0.28 g) transducers were utilized. The wire target measure- ment showed that the -6-dB axial resolution of a chirp-coded excitation was 50 μm and lateral resolution was 120 μm. The echo signal-to-noise ratios were found to be 54 and 65 dB for the short burst and coded excitation, respectively. The contrast resolution in a sphere phantom study was estimated to be 24 dB for the chirp-coded excitation and 15 dB for the short burst modes. In an in vivo study, zebrafish and mouse hearts were imaged. Boundaries of the zebrafish heart in the image could be differentiated because of the low-noise operation of the implemented system. In mouse heart images, valves and chambers could be readily visualized with the coded excitation.

Skin test sensitivity to mouse predicts allergic symptoms to nasal challenge in urban adults.

PubMed

Chong, Laura K; Ong, Mary Jane; Curtin-Brosnan, Jean; Matsui, Elizabeth C

2010-01-01

Epidemiologic studies have shown an association between mouse allergen exposure and asthma morbidity among urban populations, but confirmatory challenge studies in community populations have not been performed. This study was designed to examine the clinical relevance of mouse sensitization using a nasal challenge model. Forty-nine urban adults with asthma underwent skin-prick testing (SPT) and intradermal testing (IDT) with mouse epithelia extract. A positive SPT was defined as a net wheal size ≥3 mm and a positive IDT was defined as a net wheal size ≥6 mm using a 1:100 dilution of extract (1:10 w/v was obtained from Greer Laboratories (Lenoir, NC) as a single lot [Mus m 1 concentration = 2130 ng/mL]). Mouse-specific IgE (m-IgE) was measured by ImmunoCAP (Phadia, Uppsala, Sweden). Nasal challenge was performed with increasing concentrations of mouse epithelia extract and symptoms were assessed by visual analog scale. A positive challenge was defined as a 20-mm increase in the scale. The age range of the 49 participants was 18-50 years; 41% were men and 86% were black. Fourteen participants were SPT(+) to mouse, 15 participants were SPT(-) but (IDT(+)), and 20 participants were negative on both SPT(-) and IDT(-) (SPT(-)/IDT(-)). Sixty-four percent of the SPT(+) group, 40% of the IDT(+) group, and 20% of the SPT(-)/IDT(-) group had a positive nasal challenge. Sixty-seven percent (10/15) of those who were either SPT(+) or m-IgE(+) had a positive nasal challenge. SPT or the combination of SPT plus m-IgE performed best in diagnosing mouse allergy. The great majority of mouse-sensitized urban adults with asthma appear to have clinically relevant sensitization. Urban adults with asthma should be evaluated for mouse sensitization using SPT or SPT plus m-IgE testing.

Whole-Mount Adult Ear Skin Imaging Reveals Defective Neuro-Vascular Branching Morphogenesis in Obese and Type 2 Diabetic Mouse Models.

PubMed

Yamazaki, Tomoko; Li, Wenling; Yang, Ling; Li, Ping; Cao, Haiming; Motegi, Sei-Ichiro; Udey, Mark C; Bernhard, Elise; Nakamura, Takahisa; Mukouyama, Yoh-Suke

2018-01-11

Obesity and type 2 diabetes are frequently associated with peripheral neuropathy. Though there are multiple methods for diagnosis and analysis of morphological changes of peripheral nerves and blood vessels, three-dimensional high-resolution imaging is necessary to appreciate the pathogenesis with an anatomically recognizable branching morphogenesis and patterning. Here we established a novel technique for whole-mount imaging of adult mouse ear skin to visualize branching morphogenesis and patterning of peripheral nerves and blood vessels. Whole-mount immunostaining of adult mouse ear skin showed that peripheral sensory and sympathetic nerves align with large-diameter blood vessels. Diet-induced obesity (DIO) mice exhibit defective vascular smooth muscle cells (VSMCs) coverage, while there is no significant change in the amount of peripheral nerves. The leptin receptor-deficient db/db mice, a severe obese and type 2 diabetic mouse model, exhibit defective VSMC coverage and a large increase in the amount of smaller-diameter nerve bundles with myelin sheath and unmyelinated nerve fibers. Interestingly, an increase in the amount of myeloid immune cells was observed in the DIO but not db/db mouse skin. These data suggest that our whole-mount imaging method enables us to investigate the neuro-vascular and neuro-immune phenotypes in the animal models of obesity and diabetes.

Publisher Correction: Single-cell analysis of experience-dependent transcriptomic states in the mouse visual cortex.

PubMed

Hrvatin, Sinisa; Hochbaum, Daniel R; Nagy, M Aurel; Cicconet, Marcelo; Robertson, Keiramarie; Cheadle, Lucas; Zilionis, Rapolas; Ratner, Alex; Borges-Monroy, Rebeca; Klein, Allon M; Sabatini, Bernardo L; Greenberg, Michael E

2018-05-11

In the version of this article initially published, the x-axis labels in Fig. 3c read Vglut, Gad1/2, Aldh1l1 and Pecam1; they should have read Vglut + , Gad1/2 + , Aldh1l1 + and Pecam1 + . In Fig. 4, the range values were missing from the color scales; they are, from left to right, 4-15, 0-15, 4-15 and 0-15 in Fig. 4a and 4-15, 4-15 and 4-8 in Fig. 4h. In the third paragraph of the main text, the phrase reading "Previous approaches have analyzed a limited number of inhibitory cell types, thus masking the full diversity of excitatory populations" should have read "Previous approaches have analyzed a limited number of inhibitory cell types and masked the full diversity of excitatory populations." In the second paragraph of Results section "Diversity of experience-regulated ERGs," the phrase reading "thus suggesting considerable divergence within the gene expression program responding to early stimuli" should have read "thus suggesting considerable divergence within the early stimulus-responsive gene expression program." In the fourth paragraph of Results section "Excitatory neuronal LRGs," the sentence reading "The anatomical organization of these cell types into sublayers, coupled with divergent transcriptional responses to a sensory stimulus, suggested previously unappreciated functional subdivisions located within the laminae of the mouse visual cortex and resembling the cytoarchitecture in higher mammals" should have read "The anatomical organization of these cell types into sublayers, coupled with divergent transcriptional responses to a sensory stimulus, suggests previously unappreciated functional subdivisions located within the laminae of the mouse visual cortex, resembling the cytoarchitecture in higher mammals." In the last sentence of the Results, "sensory-responsive genes" should have read "sensory-stimulus-responsive genes." The errors have been corrected in the HTML and PDF versions of the article.

Testing of visual field with virtual reality goggles in manual and visual grasp modes.

PubMed

Wroblewski, Dariusz; Francis, Brian A; Sadun, Alfredo; Vakili, Ghazal; Chopra, Vikas

2014-01-01

Automated perimetry is used for the assessment of visual function in a variety of ophthalmic and neurologic diseases. We report development and clinical testing of a compact, head-mounted, and eye-tracking perimeter (VirtualEye) that provides a more comfortable test environment than the standard instrumentation. VirtualEye performs the equivalent of a full threshold 24-2 visual field in two modes: (1) manual, with patient response registered with a mouse click, and (2) visual grasp, where the eye tracker senses change in gaze direction as evidence of target acquisition. 59 patients successfully completed the test in manual mode and 40 in visual grasp mode, with 59 undergoing the standard Humphrey field analyzer (HFA) testing. Large visual field defects were reliably detected by VirtualEye. Point-by-point comparison between the results obtained with the different modalities indicates: (1) minimal systematic differences between measurements taken in visual grasp and manual modes, (2) the average standard deviation of the difference distributions of about 5 dB, and (3) a systematic shift (of 4-6 dB) to lower sensitivities for VirtualEye device, observed mostly in high dB range. The usability survey suggested patients' acceptance of the head-mounted device. The study appears to validate the concepts of a head-mounted perimeter and the visual grasp mode.

Retinal ganglion cell responses to voltage and current stimulation in wild-type and rd1 mouse retinas

NASA Astrophysics Data System (ADS)

Goo, Yong Sook; Ye, Jang Hee; Lee, Seokyoung; Nam, Yoonkey; Ryu, Sang Baek; Kim, Kyung Hwan

2011-06-01

Retinal prostheses are being developed to restore vision for those with retinal diseases such as retinitis pigmentosa or age-related macular degeneration. Since neural prostheses depend upon electrical stimulation to control neural activity, optimal stimulation parameters for successful encoding of visual information are one of the most important requirements to enable visual perception. In this paper, we focused on retinal ganglion cell (RGC) responses to different stimulation parameters and compared threshold charge densities in wild-type and rd1 mice. For this purpose, we used in vitro retinal preparations of wild-type and rd1 mice. When the neural network was stimulated with voltage- and current-controlled pulses, RGCs from both wild-type and rd1 mice responded; however the temporal pattern of RGC response is very different. In wild-type RGCs, a single peak within 100 ms appears, while multiple peaks (approximately four peaks) with ~10 Hz rhythm within 400 ms appear in RGCs in the degenerated retina of rd1 mice. We find that an anodic phase-first biphasic voltage-controlled pulse is more efficient for stimulation than a biphasic current-controlled pulse based on lower threshold charge density. The threshold charge densities for activation of RGCs both with voltage- and current-controlled pulses are overall more elevated for the rd1 mouse than the wild-type mouse. Here, we propose the stimulus range for wild-type and rd1 retinas when the optimal modulation of a RGC response is possible.

Glucagon-related peptides in the mouse retina and the effects of deprivation of form vision.

PubMed

Mathis, Ute; Schaeffel, Frank

2007-02-01

In chickens, retinal glucagon amacrine cells play an important role in emmetropization, since they express the transcription factor ZENK (also known as NGFI-A, zif268, tis8, cef5, Krox24) in correlation with the sign of imposed image defocus. Pharmacological studies have shown that glucagon can act as a stop signal for axial eye growth, making it a promising target for pharmacological intervention of myopia. Unfortunately, in mammalian retina, glucagon itself has not yet been detected by immunohistochemical staining. To learn more about its possible role in emmetropization in mammals, we studied the expression of different members of the glucagon hormone family in mouse retina, and whether their abundance is regulated by visual experience. Black wildtype C57BL/6 mice, raised under a 12/12 h light/dark cycle, were studied at postnatal ages between P29 and P40. Frosted hemispherical thin plastic shells (diffusers) were placed in front of the right eyes to impose visual conditions that are known to induce myopia. The left eyes remained uncovered and served as controls. Transversal retinal cryostat sections were single- or double-labeled by indirect immunofluorescence for early growth response protein 1 (Egr-1, the mammalian ortholog of ZENK), glucagon, glucagon-like peptide-2 (GLP-2), glucose-dependent insulinotropic polypeptide (GIP), peptide histidine isoleucine (PHI), growth hormone-releasing hormone (GHRH), pituitary adenylate cyclase-activating polypeptide (PACAP), secretin, and vasoactive intestinal polypeptide (VIP). In total, retinas of 45 mice were studied, 28 treated with diffusers, and 17 serving as controls. Glucagon itself was not detected in mouse retina. VIP, PHI, PACAP and GIP were localized. VIP was co-localized with PHI and Egr-1, which itself was strongly regulated by retinal illumination. Diffusers, applied for various durations (1, 2, 6, and 24 h) had no effect on the expression of VIP, PHI, PACAP, and GIP, at least at the protein level. Similarly, even if the analysis was confined to cells that also expressed Egr-1, no difference was found between VIP expression in eyes with diffusers and in eyes with normal vision. Several members of the glucagon super family are expressed in mouse retina (although not glucagon itself), but their expression pattern does not seem to be regulated by visual experience.

Excitation-resolved wide-field fluorescence imaging of indocyanine green visualizes the microenvironment properties in vivo via solvatochromic shift (Conference Presentation)

NASA Astrophysics Data System (ADS)

Cho, Jaedu; Kim, Chang-Seok; Gulsen, Gultekin

2016-03-01

Near-infrared fluorescence imaging (NIRF) is a powerful wide-field optical imaging tool that has a potential to visualize molecular-specific exogenous fluorescence agents, such as FDA approved Indocyanine Green (ICG), in thick tissue. Indeed, ICG is sensitive to biochemical environment such that it can be used to detect micro- or macroscopic environmental changes in tissue by solvatochromic shift that is defined by the dependence of absorption and emission spectra with the solvent polarity. For example, dimethyl sulfoxide (DMSO) is a very powerful drug carrier that can penetrate biological barriers such as the skin, the membranes, and the blood-brain-barrier. In presence of DMSO, ICG in tissue shows the excitation blue shift. However, NIRF imaging of microenvironment dependent changes of ICG has been challenging for the following reasons. First, the Stoke's shift of ICG is too small to separate the excitation and emission spectra easily. Second, the solvatochromic shift of ICG is too small to be detected by conventional NIRF techniques. Last but not least, the multiple scattering in tissue degrades not only the spatial information but also the spectral contents by the red-shift. We developed a wavelength-swept laser-based NIRF system that can resolve the excitation shift of ICG in tissue such that DMSO can be indirectly visualized. We plan to conduct an in-vivo lymph-node drug-delivery study in a mouse model to show feasibility of the indirect imaging of the drug-carrier with the wavelength-swept-laser based NIRF system.

Progressive alterations of central nervous system structure and function are caused by charged particle radiation

NASA Astrophysics Data System (ADS)

Nelson, G. A.; Cns Nscor Team

A new NASA-sponsored program project (NSCOR) has been organized to conduct the first comprehensive investigation of the response of a mammalian brain structure (mouse hippocampus) to charged-particle radiation. The NSCOR collaboration has three main goals. The first goal is to quantify the time- and dose-dependent changes in cellular composition and architecture. By using stereology on preserved brains, subsets of cells (neurons, glia, endothelia and stem cells) will be quantified out to 2 years after irradiation with accelerated protons and iron ions. To further characterize changes in vasculature architecture a polymer infusion technique will be used to produce a three-dimensional vasculature cast that then will be mapped by x-ray tomography to determine topological changes, and microscopic infarcts associated with amyloid protein deposits. The 2nd goal is to quantify hippocampal function(s). The primary measurement of function will be extracellular electrical recordings from hippocampal ``brain slices'' that reflect underlying functions such as connectivity, action potential generation & conduction, and neurotransmitter formation, secretion, and uptake. Individual nerve membrane properties will be assessed by ``patch clamp'' recordings. Two non-invasive methods will evaluate brain function and the evolution of changes with time. Electroencephalograms will map macroscopic spontaneous electrical activity while two state-of-the-art MRI magnetization sequences will visualize and quantify local oxygen utilization and white matter fiber tracts structural integrity. To quantify the brains' overall performance under stress, animals will receive a systemic shock mediated by the immune system in the form of a reaction to lipopolysaccharide. A second strategy will employ the APP23 transgenic mouse that develops the pathological changes associated with Alzheimer's disease. Measurements of irradiated mice will determine whether radiation exposure affects the latency and severity of the disease-associated pathological changes. The third goal is to quantify molecular markers that underly cellular and system changes. The team will quantify the frequency and structural spectrum of mutations in hippocampal samples using the E. coli β -galactosidase gene present in a transgenic mouse's tissues. Finally, by using transcription profiling hybridization, the status of a set of 96 genes involved in cytokine signaling during inflammation will be assessed.

Progressive thalamocortical neuron loss in Cln5 deficient mice: distinct effects in Finnish variant late infantile NCL

PubMed Central

von Schantz, Carina; Kielar, Catherine; Hansen, Stine N; Pontikis, Charlie C; Alexander, Noreen A; Kopra, Outi; Jalanko, Anu; Cooper, Jonathan D

2009-01-01

Finnish variant LINCL (vLINCLFin) is the result of mutations in the CLN5 gene. To gain insights into the pathological staging of this fatal pediatric disorder, we have undertaken a stereological analysis of the CNS of Cln5 deficient mice (Cln5-/-) at different stages of disease progression. Consistent with human vLINCLFin, these Cln5-/- mice displayed a relatively late onset regional atrophy and generalized cortical thinning and synaptic pathology, preceded by early and localized glial responses within the thalamocortical system. However, in marked contrast to other forms of NCL, neuron loss in Cln5-/- mice began in the cortex and only subsequently occurred within thalamic relay nuclei. Nevertheless, as in other NCL mouse models, this progressive thalamocortical neuron loss was still most pronounced within the visual system. These data provide unexpected evidence for a distinctive sequence of neuron loss in the thalamocortical system of Cln5-/- mice, diametrically opposed to that seen in other forms of NCL. PMID:19385065

Progressive thalamocortical neuron loss in Cln5 deficient mice: Distinct effects in Finnish variant late infantile NCL.

PubMed

von Schantz, Carina; Kielar, Catherine; Hansen, Stine N; Pontikis, Charlie C; Alexander, Noreen A; Kopra, Outi; Jalanko, Anu; Cooper, Jonathan D

2009-05-01

Finnish variant LINCL (vLINCL(Fin)) is the result of mutations in the CLN5 gene. To gain insights into the pathological staging of this fatal pediatric disorder, we have undertaken a stereological analysis of the CNS of Cln5 deficient mice (Cln5-/-) at different stages of disease progression. Consistent with human vLINCL(Fin), these Cln5-/- mice displayed a relatively late onset regional atrophy and generalized cortical thinning and synaptic pathology, preceded by early and localized glial responses within the thalamocortical system. However, in marked contrast to other forms of NCL, neuron loss in Cln5-/- mice began in the cortex and only subsequently occurred within thalamic relay nuclei. Nevertheless, as in other NCL mouse models, this progressive thalamocortical neuron loss was still most pronounced within the visual system. These data provide unexpected evidence for a distinctive sequence of neuron loss in the thalamocortical system of Cln5-/- mice, diametrically opposed to that seen in other forms of NCL.

Photopic visual input is necessary for emmetropization in mice

PubMed Central

Tkatchenko, Tatiana V.; Shen, Yimin; Braun, Rod D.; Bawa, Gurinder; Kumar, Pradeep; Avrutsky, Ivan; Tkatchenko, Andrei V.

2013-01-01

It was recently demonstrated that refractive errors in mice stabilize around emmetropic values during early postnatal development, and that they develop experimental myopia in response to both visual form deprivation and imposed optical defocus similar to other vertebrate species. Animal studies also suggest that photopic vision plays critical role in emmetropization in diurnal species; however, it is unknown whether refractive eye development is guided by photopic vision in the mouse, which is a nocturnal species. We used an infrared mouse photorefractor and a high-resolution MRI to clarify the role of photopic visual input in refractive eye development in the mouse. Refractive eye development and form-deprivation myopia in P21-P89 C57BL/6J mice were analyzed under 12:12 h light-dark cycle, constant light and constant darkness regimens. Animals in all experimental groups were myopic at P21 (-13.2 ± 1.6 D, light-dark cycle; -12.5 ± 0.9 D, constant light; -12.5 ± 2.0 D, constant dark). The mean refractive error in the light-dark-cycle-reared animals was -0.5 ± 1.3 D at P32 and, and did not change significantly until P40 (+0.3 ± 0.6 D, P40). Animals in this group became progressively hyperopic between P40 and P89 (+2.2 ± 0.6, P67; +3.7 ± 2.0, P89). The mean refractive error in the constant-light-reared mice was -1.0 ± 0.7 D at P32 and remained stable until P89 (+0.1 ± 0.6, P40; +0.3 ± 0.6, P67; 0.0 ± 0.4, P89). Dark-reared animals exhibited highly hyperopic refractive errors at P32 (+5.2 ± 1.8) and became progressively more hyperopic with age (+8.7 ± 1.9, P40; +11.2 ± 1.4, P67). MRI analysis revealed that emmetropization in the P40-P89 constant-light-reared animals was associated with larger eyes, a longer axial length and a larger vitreous chamber compared to the light-dark-cycle-reared mice. Constant-light-reared mice also developed 4 times higher degrees of form-deprivation myopia on average compared to light-dark-cycle-reared animals (-12.0 ± 1.4, constant light; -2.7 ± 0.7, light-dark cycle). Dark-rearing completely prevented the development of form-deprivation myopia (-0.3 ± 0.5). Thus, photopic vision plays important role in normal refractive eye development and ocular response to visual form deprivation in the mouse. PMID:23838522

Dopamine receptor D4 internalization requires a beta-arrestin and a visual arrestin.

PubMed

Deming, Janise D; Shin, Jung-A; Lim, Kayleen; Lee, Eun-Jin; Van Craenenbroeck, Kathleen; Craft, Cheryl Mae

2015-10-01

The G-protein coupled receptor (GPCR) Dopamine Receptor D4 (DRD4) plays an essential role in cAMP regulation and gap junctional coupling in the photoreceptors, where DRD4 expression is under circadian control. Previous in vitro transfection studies of human DRD4 desensitization have reported that DRD4 is not internalized upon dopamine stimulation when beta-arrestin is co-transfected with DRD4. We hypothesized that the visual arrestins, ARR1 and ARR4, play a modulatory role in DRD4 desensitization in the photoreceptors. To test this hypothesis, immunohistochemistry analysis of mouse retinas was used to determine the cellular localization of beta-arrestins and DRD4 in photoreceptors. In vitro studies were performed in HEK293T cells transiently transfected with human DRD4 and arrestins. First, co-immunoprecipitation experiments were executed to test protein-protein interactions and to investigate the effect of dopamine stimulation. Second, immunohistochemistry analysis was implemented to study DRD4 internalization and translocation of ARR4. Immunohistochemistry studies of mouse retinas confirmed the expression of beta-arrestin 2, ARR1 and ARR4, as well as DRD4 in mouse cone photoreceptor inner segments. Co-immunoprecipitation experiments revealed a dopamine-dependent protein-protein interaction between human DRD4 and ARR4. In vitro internalization experiments showed that no detectable internalization of DRD4 was observed with any single arrestin co-transfected. However, a dopamine-dependent internalization of DRD4 was observed with three out of six sets of two arrestins co-transfected with DRD4. Each of these pairs of arrestins contained one visual arrestin and one beta-arrestin, and no internalization was observed with either two visual arrestins or two beta-arrestins. Additional time-course experiments revealed that in vitro, ARR4 translocates to co-localize with DRD4 at the plasma membrane in response to 30min of dopamine stimulation. The results have functional implications and we hypothesize that the desensitization and internalization of DRD4 in photoreceptors are synergistically mediated by both visual and beta-arrestins. These results are additionally unique because they demonstrate for the first time that at least one G-protein coupled receptor, DRD4, requires two arrestins for desensitization and internalization, and opens up the possibility that other G-protein coupled receptors may require more than one arrestin for desensitization and/or internalization. Copyright © 2015 Elsevier Inc. All rights reserved.

Machine Learning Model Analysis and Data Visualization with Small Molecules Tested in a Mouse Model of Mycobacterium tuberculosis Infection (2014–2015)

PubMed Central

2016-01-01

The renewed urgency to develop new treatments for Mycobacterium tuberculosis (Mtb) infection has resulted in large-scale phenotypic screening and thousands of new active compounds in vitro. The next challenge is to identify candidates to pursue in a mouse in vivo efficacy model as a step to predicting clinical efficacy. We previously analyzed over 70 years of this mouse in vivo efficacy data, which we used to generate and validate machine learning models. Curation of 60 additional small molecules with in vivo data published in 2014 and 2015 was undertaken to further test these models. This represents a much larger test set than for the previous models. Several computational approaches have now been applied to analyze these molecules and compare their molecular properties beyond those attempted previously. Our previous machine learning models have been updated, and a novel aspect has been added in the form of mouse liver microsomal half-life (MLM t1/2) and in vitro-based Mtb models incorporating cytotoxicity data that were used to predict in vivo activity for comparison. Our best Mtbin vivo models possess fivefold ROC values > 0.7, sensitivity > 80%, and concordance > 60%, while the best specificity value is >40%. Use of an MLM t1/2 Bayesian model affords comparable results for scoring the 60 compounds tested. Combining MLM stability and in vitroMtb models in a novel consensus workflow in the best cases has a positive predicted value (hit rate) > 77%. Our results indicate that Bayesian models constructed with literature in vivoMtb data generated by different laboratories in various mouse models can have predictive value and may be used alongside MLM t1/2 and in vitro-based Mtb models to assist in selecting antitubercular compounds with desirable in vivo efficacy. We demonstrate for the first time that consensus models of any kind can be used to predict in vivo activity for Mtb. In addition, we describe a new clustering method for data visualization and apply this to the in vivo training and test data, ultimately making the method accessible in a mobile app. PMID:27335215

Mutagenicity testing with transgenic mice. Part I: Comparison with the mouse bone marrow micronucleus test

PubMed Central

Wahnschaffe, U; Bitsch, A; Kielhorn, J; Mangelsdorf, I

2005-01-01

As part of a larger literature study on transgenic animals in mutagenicity testing, test results from the transgenic mutagenicity assays (lacI model; commercially available as the Big Blue® mouse, and the lacZ model; commercially available as the Muta™Mouse), were compared with the results on the same substances in the more traditional mouse bone marrow micronucleus test. 39 substances were found which had been tested in the micronucleus assay and in the above transgenic mouse systems. Although, the transgenic animal mutation assay is not directly comparable with the micronucleus test, because different genetic endpoints are examined: chromosome aberration versus gene mutation, the results for the majority of substances were in agreement. Both test systems, the transgenic mouse assay and the mouse bone marrow micronucleus test, have advantages and they complement each other. However, the transgenic animal assay has some distinct advantages over the micronucleus test: it is not restricted to one target organ and detects systemic as well as local mutagenic effects. PMID:15655069

Timing-dependent LTP and LTD in mouse primary visual cortex following different visual deprivation models

PubMed Central

Chen, Xia; Fu, Junhong; Cheng, Wenbo; Song, Desheng; Qu, Xiaolei; Yang, Zhuo; Zhao, Kanxing

2017-01-01

Visual deprivation during the critical period induces long-lasting changes in cortical circuitry by adaptively modifying neuro-transmission and synaptic connectivity at synapses. Spike timing-dependent plasticity (STDP) is considered a strong candidate for experience-dependent changes. However, the visual deprivation forms that affect timing-dependent long-term potentiation(LTP) and long-term depression(LTD) remain unclear. Here, we demonstrated the temporal window changes of tLTP and tLTD, elicited by coincidental pre- and post-synaptic firing, following different modes of 6-day visual deprivation. Markedly broader temporal windows were found in robust tLTP and tLTD in the V1M of the deprived visual cortex in mice after 6-day MD and DE. The underlying mechanism for the changes seen with visual deprivation in juvenile mice using 6 days of dark exposure or monocular lid suture involves an increased fraction of NR2b-containing NMDAR and the consequent prolongation of NMDAR-mediated response duration. Moreover, a decrease in NR2A protein expression at the synapse is attributable to the reduction of the NR2A/2B ratio in the deprived cortex. PMID:28520739

Quiz Making Activities Using the Multi-Mouse Quiz System in an Elementary School

ERIC Educational Resources Information Center

Zhou, Juan; Mori, Mikihiko; Ueda, Hiroshi; Kita, Hajime

2013-01-01

The Multi-Mouse Quiz System is an application used to treat quizzes in a classroom or other learning environment. The system comprises the Multi Mouse Quiz (MMQ) and MMQEditor. The MMQ is an application of Single Display Groupware (SDG), which enables multiple users to answer quizzes by connecting several mice to an ordinary computer. The…

MouseNet database: digital management of a large-scale mutagenesis project.

PubMed

Pargent, W; Heffner, S; Schäble, K F; Soewarto, D; Fuchs, H; Hrabé de Angelis, M

2000-07-01

The Munich ENU Mouse Mutagenesis Screen is a large-scale mutant production, phenotyping, and mapping project. It encompasses two animal breeding facilities and a number of screening groups located in the general area of Munich. A central database is required to manage and process the immense amount of data generated by the mutagenesis project. This database, which we named MouseNet(c), runs on a Sybase platform and will finally store and process all data from the entire project. In addition, the system comprises a portfolio of functions needed to support the workflow management of the core facility and the screening groups. MouseNet(c) will make all of the data available to the participating screening groups, and later to the international scientific community. MouseNet(c) will consist of three major software components:* Animal Management System (AMS)* Sample Tracking System (STS)* Result Documentation System (RDS)MouseNet(c) provides the following major advantages:* being accessible from different client platforms via the Internet* being a full-featured multi-user system (including access restriction and data locking mechanisms)* relying on a professional RDBMS (relational database management system) which runs on a UNIX server platform* supplying workflow functions and a variety of plausibility checks.

Java 3D Interactive Visualization for Astrophysics

NASA Astrophysics Data System (ADS)

Chae, K.; Edirisinghe, D.; Lingerfelt, E. J.; Guidry, M. W.

2003-05-01

We are developing a series of interactive 3D visualization tools that employ the Java 3D API. We have applied this approach initially to a simple 3-dimensional galaxy collision model (restricted 3-body approximation), with quite satisfactory results. Running either as an applet under Web browser control, or as a Java standalone application, this program permits real-time zooming, panning, and 3-dimensional rotation of the galaxy collision simulation under user mouse and keyboard control. We shall also discuss applications of this technology to 3-dimensional visualization for other problems of astrophysical interest such as neutron star mergers and the time evolution of element/energy production networks in X-ray bursts. *Managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

A New Species of Sucking Louse (Phthiraptera: Anoplura: Polyplacidae) From the Gray Mouse Lemur, Microcebus murinus (Primates: Cheirogaleidae), in Madagascar.

PubMed

Durden, Lance A; Kessler, Sharon E; Radespiel, Ute; Zimmermann, Elke; Hasiniaina, Alida F; Zohdy, Sarah

2018-04-12

Lemurpediculus madagascariensis sp. nov. (Phthiraptera: Anoplura: Polyplacidae) is described from the Gray Mouse lemur, Microcebus murinus (J. F. Miller) (Primates: Cheirogaleidae), from Ankarafantsika National Park, Madagascar. Lemurs were trapped using Sherman Live Traps and visually inspected for lice, which were preserved in 90% ethanol. Adults of both sexes and the third-instar nymph of the new species are illustrated and distinguished from the four previously known species of Lemurpediculus: L. verruculosus (Ward); L. petterorum Paulian; L. claytoni Durden, Blanco, and Seabolt; and L. robbinsi Durden, Blanco, and Seabolt. It is not known if the new species of louse is a vector of any pathogens or parasites.

An evaluation of touchscreen versus keyboard/mouse interaction for large screen process control displays.

PubMed

Noah, Benjamin; Li, Jingwen; Rothrock, Ling

2017-10-01

The objectives of this study were to test the effect of interaction device on performance in a process control task (managing a tank farm). The study compared the following two conditions: a) 4K-resolution 55" screen with a 21" touchscreen versus b) 4K-resolution 55″ screen with keyboard/mouse. The touchscreen acted both as an interaction device for data entry and navigation and as an additional source of information. A within-subject experiment was conducted among 20 college engineering students. A primary task of preventing tanks from overfilling as well as a secondary task of manual logging with situation awareness questions were designed for the study. Primary Task performance (including tank level at discharge, number of tank discharged and performance score), Secondary Task Performance (including Tank log count, performance score), system interaction times, subjective workload, situation awareness questionnaire, user experience survey regarding usability and condition comparison were used as the measures. Parametric data resulted in two metrics statistically different means between the two conditions: The 4K-keyboard condition resulted in faster Detection + Navigation time compared to the 4K-touchscreen condition, by about 2 s, while participants within the 4K-touchscreen condition were about 2 s faster in data entry than in the 4K-keyboard condition. No significant results were found for: performance on the secondary task, situation awareness, and workload. Additionally, no clear significant differences were found in the non-parametric data analysis. However, participants showed a slight preference for the 4K-touchscreen condition compared to the 4K-keyboard condition in subjective responses in comparing the conditions. Introducing the touchscreen as an additional/alternative input device showed to have an effect in interaction times, which suggests that proper design considerations need to be made. While having values shown on the interaction device provides value, a potential issue of visual distraction exists when having an additional visual display. The allocation of visual attention between primary displays and the touchscreen should be further investigated. Copyright © 2017 Elsevier Ltd. All rights reserved.

PyMOL mControl: Manipulating Molecular Visualization with Mobile Devices

ERIC Educational Resources Information Center

Lam, Wendy W. T.; Siu, Shirley W. I.

2017-01-01

Viewing and manipulating three-dimensional (3D) structures in molecular graphics software are essential tasks for researchers and students to understand the functions of molecules. Currently, the way to manipulate a 3D molecular object is mainly based on mouse-and-keyboard control that is usually difficult and tedious to learn. While gesture-based…

Adenosine transport systems on dissociated brain cells from mouse, guinea-pig, and rat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnston, M.E.; Geiger, J.D.

1990-09-01

The kinetics and sodium dependence of adenosine transport were determined using an inhibitor-stop method on dissociated cell body preparations obtained from mouse, guinea-pig and rat brain. Transport affinity (KT) values for the high affinity adenosine transport systems KT(H) were significantly different between these three species; mean +/- SEM values were 0.34 +/- 0.1 in mouse, 0.9 +/- 0.2 in rat, and 1.5 +/- 0.5 microM in guinea-pig. The KT values for the low affinity transport system KT(L) were not different between the three species. Brain cells from rat displayed a significantly greater maximal capacity to accumulate (3H)adenosine (Vmax) than didmore » mouse or guinea-pig for the high affinity system, or than did mouse for the low affinity system. When sodium chloride was replaced in the transport medium with choline chloride, the KT(H) values for guinea-pig and rat were both increased by approximately 100%; only in rat did the change reach statistical significance. The sodium-dependence of adenosine transport in mouse brain was clearly absent. The differences between KT(H) values in mouse and those in guinea-pig or rat were accentuated in the absence of sodium. The differences in kinetic values, ionic requirements, and pharmacological characteristics between adenosine transporters in CNS tissues of mouse, guinea-pig and rat may help account for some of the variability noted among species in terms of their physiological responses to adenosine.« less

In Vivo Voltage-Sensitive Dye Study of Lateral Spreading of Cortical Activity in Mouse Primary Visual Cortex Induced by a Current Impulse

PubMed Central

Fehérvári, Tamás Dávid; Sawai, Hajime; Yagi, Tetsuya

2015-01-01

In the mammalian primary visual cortex (V1), lateral spreading of excitatory potentials is believed to be involved in spatial integrative functions, but the underlying cortical mechanism is not well understood. Visually-evoked population-level responses have been shown to propagate beyond the V1 initial activation site in mouse, similar to higher mammals. Visually-evoked responses are, however, affected by neuronal circuits prior to V1 (retina, LGN), making the separate analysis of V1 difficult. Intracortical stimulation eliminates these initial processing steps. We used in vivo RH1691 voltage-sensitive dye (VSD) imaging and intracortical microstimulation in adult C57BL/6 mice to elucidate the spatiotemporal properties of population-level signal spreading in V1 cortical circuits. The evoked response was qualitatively similar to that measured in single-cell electrophysiological experiments in rodents: a fast transient fluorescence peak followed by a fast and a slow decrease or hyperpolarization, similar to EPSP and fast and slow IPSPs in single cells. The early cortical response expanded at speeds commensurate with long horizontal projections (at 5% of the peak maximum, 0.08–0.15 m/s) however, the bulk of the VSD signal propagated slowly (at half-peak maximum, 0.05–0.08 m/s) suggesting an important role of regenerative multisynaptic transmission through short horizontal connections in V1 spatial integrative functions. We also found a tendency for a widespread and fast cortical response suppression in V1, which was eliminated by GABAA-antagonists gabazine and bicuculline methiodide. Our results help understand the neuronal circuitry involved in lateral spreading in V1. PMID:26230520

Dark Light, Rod Saturation, and the Absolute and Incremental Sensitivity of Mouse Cone Vision

PubMed Central

Naarendorp, Frank; Esdaille, Tricia M.; Banden, Serenity M.; Andrews-Labenski, John; Gross, Owen P.; Pugh, Edward N.

2012-01-01

Visual thresholds of mice for the detection of small, brief targets were measured with a novel behavioral methodology in the dark and in the presence of adapting lights spanning ∼8 log10 units of intensity. To help dissect the contributions of rod and cone pathways, both wild-type mice and mice lacking rod (Gnat1−/−) or cone (Gnat2cpfl3) function were studied. Overall, the visual sensitivity of mice was found to be remarkably similar to that of the human peripheral retina. Rod absolute threshold corresponded to 12-15 isomerized pigment molecules (R*) in image fields of 800 to 3000 rods. Rod “dark light” (intrinsic retinal noise in darkness) corresponded to that estimated previously from single-cell recordings, 0.012R*s−1rod−1, indicating that spontaneous thermalisomerizations are responsible. Psychophysical rod saturation was measured for the first time in a nonhman species and found to be very similar to that of the human rod monochromat. Cone threshold corresponded to ∼5 R* cone−1 in an image field of 280 cones. Cone dark light was equivalent to ∼5000 R*s−1 cone−1, consistent with primate single-cell data but 100-fold higher than predicted by recent measurements of the rate of thermal isomerization of mouse cone opsins, indicating that nonopsin sources of noise determine cone threshold. The new, fully automated behavioral method is based on the ability of mice to learn to interrupt spontaneous wheel running on the presentation of a visual cue and provides an efficient and highly reliable means of examining visual function in naturally behaving normal and mutant mice. PMID:20844144

Review of DoD Malaria Research Programs,

DTIC Science & Technology

1992-05-01

the irraliated sporozoite vaccine. Work in the mouse model system and then extrapolate to human malarias. Study naturally acquired immune ...recombinant vaccines. Work simultaneously in the mouse model system and with human malarias. 3. Identify targets and mechanisms of protective immunity not...multivalent vaccines that attack these same targets. 3. Working again in the mouse model, non- human primate model, andI human systems we

High-frequency annular array with coaxial illumination for dual-modality ultrasonic and photoacoustic imaging

NASA Astrophysics Data System (ADS)

Filoux, Erwan; Sampathkumar, Ashwin; Chitnis, Parag V.; Aristizábal, Orlando; Ketterling, Jeffrey A.

2013-05-01

This paper presents a combined ultrasound and photoacoustic (PA) imaging (PAI) system used to obtain high-quality, co-registered images of mouse-embryo anatomy and vasculature. High-frequency ultrasound (HFU, >20 MHz) is utilized to obtain high-resolution anatomical images of small animals while PAI provides high-contrast images of the vascular network. The imaging system is based on a 40 MHz, 5-element, 6 mm aperture annular-array transducer with a 800 μm diameter hole through its central element. The transducer was integrated in a cage-plate assembly allowing for a collimated laser beam to pass through the hole so that the optical and acoustic beams were collinear. The assembly was mounted on a two-axis, motorized stage to enable the simultaneous acquisition of co-registered HFU and PA volumetric data. Data were collected from all five elements in receive and a synthetic-focusing algorithm was applied in post-processing to beamform the data and increase the spatial resolution and depth-of-field (DOF) of the HFU and PA images. Phantom measurements showed that the system could achieve high-resolution images (down to 90 μm for HFU and 150 μm for PAI) and a large DOF of >8 mm. Volume renderings of a mouse embryo showed that the scanner allowed for visualizing morphologically precise anatomy of the entire embryo along with corresponding co-registered vasculature. Major head vessels, such as the superior sagittal sinus or rostral vein, were clearly identified as well as limb bud vasculature.

Longitudinal Effects of Ketamine on Dendritic Architecture In Vivo in the Mouse Medial Frontal Cortex123

PubMed Central

Phoumthipphavong, Victoria; Barthas, Florent; Hassett, Samantha

2016-01-01

Abstract A single subanesthetic dose of ketamine, an NMDA receptor antagonist, leads to fast-acting antidepressant effects. In rodent models, systemic ketamine is associated with higher dendritic spine density in the prefrontal cortex, reflecting structural remodeling that may underlie the behavioral changes. However, turnover of dendritic spines is a dynamic process in vivo, and the longitudinal effects of ketamine on structural plasticity remain unclear. The purpose of the current study is to use subcellular resolution optical imaging to determine the time course of dendritic alterations in vivo following systemic ketamine administration in mice. We used two-photon microscopy to visualize repeatedly the same set of dendritic branches in the mouse medial frontal cortex (MFC) before and after a single injection of ketamine or saline. Compared to controls, ketamine-injected mice had higher dendritic spine density in MFC for up to 2 weeks. This prolonged increase in spine density was driven by an elevated spine formation rate, and not by changes in the spine elimination rate. A fraction of the new spines following ketamine injection was persistent, which is indicative of functional synapses. In a few cases, we also observed retraction of distal apical tuft branches on the day immediately after ketamine administration. These results indicate that following systemic ketamine administration, certain dendritic inputs in MFC are removed immediately, while others are added gradually. These dynamic structural modifications are consistent with a model of ketamine action in which the net effect is a rebalancing of synaptic inputs received by frontal cortical neurons. PMID:27066532

Effects of heavy ions on visual function and electrophysiology of rodents: the ALTEA-MICE project

NASA Technical Reports Server (NTRS)

Sannita, W. G.; Acquaviva, M.; Ball, S. L.; Belli, F.; Bisti, S.; Bidoli, V.; Carozzo, S.; Casolino, M.; Cucinotta, F.; De Pascale, M. P.;

The Use of Spinning-Disk Confocal Microscopy for the Intravital Analysis of Platelet Dynamics in Response to Systemic and Local Inflammation

PubMed Central

Jenne, Craig N.; Wong, Connie H. Y.; Petri, Björn; Kubes, Paul

2011-01-01

Platelets are central players in inflammation and are an important component of the innate immune response. The ability to visualize platelets within the live host is essential to understanding their role in these processes. Past approaches have involved adoptive transfer of labelled platelets, non-specific dyes, or the use of fluorescent antibodies to tag platelets in vivo. Often, these techniques result in either the activation of the platelet, or blockade of specific platelet receptors. In this report, we describe two new methods for intravital visualization of platelet biology, intravenous administration of labelled anti-CD49b, which labels all platelets, and CD41-YFP transgenic mice, in which a percentage of platelets express YFP. Both approaches label endogenous platelets and allow for their visualization using spinning-disk confocal fluorescent microscopy. Following LPS-induced inflammation, we were able to measure a significant increase in both the number and size of platelet aggregates observed within the vasculature of a number of different tissues. Real-time observation of these platelet aggregates reveals them to be large, dynamic structures that are continually expanding and sloughing-off into circulation. Using these techniques, we describe for the first time, platelet recruitment to, and behaviour within numerous tissues of the mouse, both under control conditions and following LPS induced inflammation. PMID:21949865

Changes in Otx2 and parvalbumin immunoreactivity in the superior colliculus in the platelet-derived growth factor receptor-β knockout mice.

PubMed

Zhao, Juanjuan; Urakawa, Susumu; Matsumoto, Jumpei; Li, Ruixi; Ishii, Yoko; Sasahara, Masakiyo; Peng, Yuwen; Ono, Taketoshi; Nishijo, Hisao

2013-01-01

The superior colliculus (SC), a relay nucleus in the subcortical visual pathways, is implicated in socioemotional behaviors. Homeoprotein Otx2 and β subunit of receptors of platelet-derived growth factor (PDGFR- β ) have been suggested to play an important role in development of the visual system and development and maturation of GABAergic neurons. Although PDGFR- β -knockout (KO) mice displayed socio-emotional deficits associated with parvalbumin (PV-)immunoreactive (IR) neurons, their anatomical bases in the SC were unknown. In the present study, Otx2 and PV-immunolabeling in the adult mouse SC were investigated in the PDGFR- β KO mice. Although there were no differences in distribution patterns of Otx2 and PV-IR cells between the wild type and PDGFR- β KO mice, the mean numbers of both of the Otx2- and PV-IR cells were significantly reduced in the PDGFR- β KO mice. Furthermore, average diameters of Otx2- and PV-IR cells were significantly reduced in the PDGFR- β KO mice. These findings suggest that PDGFR- β plays a critical role in the functional development of the SC through its effects on Otx2- and PV-IR cells, provided specific roles of Otx2 protein and PV-IR cells in the development of SC neurons and visual information processing, respectively.

Quantification and visualization of injury and regeneration to the ciliated epithelium using quantitative flow imaging and speckle variance optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Gamm, Ute A.; Huang, Brendan K.; Mis, Emily K.; Khokha, Mustafa K.; Choma, Michael A.

2017-04-01

Mucociliary flow is an important defense mechanism in the lung to remove inhaled pathogens and pollutants. A disruption of ciliary flow can lead to respiratory infections. Even though patients in the intensive care unit (ICU) either have or are very susceptible to respiratory infections, mucociliary flow is not well understood in the ICU setting. We recently demonstrated that hyperoxia, a consequence of administering supplemental oxygen to a patient in respiratory failure, can lead to a significant reduction of cilia-driven fluid flow in mouse trachea. There are other factors that are relevant to ICU medicine that can damage the ciliated tracheal epithelium, including inhalation injury and endotracheal tube placement. In this study we use two animal models, Xenopus embryo and ex vivo mouse trachea, to analyze flow defects in the injured ciliated epithelium. Injury is generated either mechanically with a scalpel or chemically by calcium chloride (CaCl2) shock, which efficiently but reversibly deciliates the embryo skin. In this study we used optical coherence tomography (OCT) and particle tracking velocimetry (PTV) to quantify cilia driven fluid flow over the surface of the Xenopus embryo. We additionally visualized damage to the ciliated epithelium by capturing 3D speckle variance images that highlight beating cilia. Mechanical injury disrupted cilia-driven fluid flow over the injured site, which led to a reduction in cilia-driven fluid flow over the whole surface of the embryo (n=7). The calcium chloride shock protocol proved to be highly effective in deciliating embryos (n=6). 3D speckle variance images visualized a loss of cilia and cilia-driven flow was halted immediately after application. We also applied CaCl2-shock to cultured ex vivo mouse trachea (n=8) and found, similarly to effects in Xenopus embryo, an extensive loss of cilia with resulting cessation of flow. We investigated the regeneration of the ciliated epithelium after an 8 day incubation period, and found that cilia had regrown and flow was completely restored. In conclusion, OCT is a valuable tool to visualize injury of the ciliated epithelium and to quantify reduction of generated flow. This method allows for systematic investigation of focal and diffuse injury of the ciliated epithelium and the assessment of mechanisms to compensate for loss of flow.

Synaptic Basis for Differential Orientation Selectivity between Complex and Simple Cells in Mouse Visual Cortex

PubMed Central

Li, Ya-tang; Liu, Bao-hua; Chou, Xiao-lin; Zhang, Li I.

2015-01-01

In the primary visual cortex (V1), orientation-selective neurons can be categorized into simple and complex cells primarily based on their receptive field (RF) structures. In mouse V1, although previous studies have examined the excitatory/inhibitory interplay underlying orientation selectivity (OS) of simple cells, the synaptic bases for that of complex cells have remained obscure. Here, by combining in vivo loose-patch and whole-cell recordings, we found that complex cells, identified by their overlapping on/off subfields, had significantly weaker OS than simple cells at both spiking and subthreshold membrane potential response levels. Voltage-clamp recordings further revealed that although excitatory inputs to complex and simple cells exhibited a similar degree of OS, inhibition in complex cells was more narrowly tuned than excitation, whereas in simple cells inhibition was more broadly tuned than excitation. The differential inhibitory tuning can primarily account for the difference in OS between complex and simple cells. Interestingly, the differential synaptic tuning correlated well with the spatial organization of synaptic input: the inhibitory visual RF in complex cells was more elongated in shape than its excitatory counterpart and also was more elongated than that in simple cells. Together, our results demonstrate that OS of complex and simple cells is differentially shaped by cortical inhibition based on its orientation tuning profile relative to excitation, which is contributed at least partially by the spatial organization of RFs of presynaptic inhibitory neurons. SIGNIFICANCE STATEMENT Simple and complex cells, two classes of principal neurons in the primary visual cortex (V1), are generally thought to be equally selective for orientation. In mouse V1, we report that complex cells, identified by their overlapping on/off subfields, has significantly weaker orientation selectivity (OS) than simple cells. This can be primarily attributed to the differential tuning selectivity of inhibitory synaptic input: inhibition in complex cells is more narrowly tuned than excitation, whereas in simple cells inhibition is more broadly tuned than excitation. In addition, there is a good correlation between inhibitory tuning selectivity and the spatial organization of inhibitory inputs. These complex and simple cells with differential degree of OS may provide functionally distinct signals to different downstream targets. PMID:26245969

Synaptic Basis for Differential Orientation Selectivity between Complex and Simple Cells in Mouse Visual Cortex.

PubMed

Li, Ya-tang; Liu, Bao-hua; Chou, Xiao-lin; Zhang, Li I; Tao, Huizhong W

2015-08-05

In the primary visual cortex (V1), orientation-selective neurons can be categorized into simple and complex cells primarily based on their receptive field (RF) structures. In mouse V1, although previous studies have examined the excitatory/inhibitory interplay underlying orientation selectivity (OS) of simple cells, the synaptic bases for that of complex cells have remained obscure. Here, by combining in vivo loose-patch and whole-cell recordings, we found that complex cells, identified by their overlapping on/off subfields, had significantly weaker OS than simple cells at both spiking and subthreshold membrane potential response levels. Voltage-clamp recordings further revealed that although excitatory inputs to complex and simple cells exhibited a similar degree of OS, inhibition in complex cells was more narrowly tuned than excitation, whereas in simple cells inhibition was more broadly tuned than excitation. The differential inhibitory tuning can primarily account for the difference in OS between complex and simple cells. Interestingly, the differential synaptic tuning correlated well with the spatial organization of synaptic input: the inhibitory visual RF in complex cells was more elongated in shape than its excitatory counterpart and also was more elongated than that in simple cells. Together, our results demonstrate that OS of complex and simple cells is differentially shaped by cortical inhibition based on its orientation tuning profile relative to excitation, which is contributed at least partially by the spatial organization of RFs of presynaptic inhibitory neurons. Simple and complex cells, two classes of principal neurons in the primary visual cortex (V1), are generally thought to be equally selective for orientation. In mouse V1, we report that complex cells, identified by their overlapping on/off subfields, has significantly weaker orientation selectivity (OS) than simple cells. This can be primarily attributed to the differential tuning selectivity of inhibitory synaptic input: inhibition in complex cells is more narrowly tuned than excitation, whereas in simple cells inhibition is more broadly tuned than excitation. In addition, there is a good correlation between inhibitory tuning selectivity and the spatial organization of inhibitory inputs. These complex and simple cells with differential degree of OS may provide functionally distinct signals to different downstream targets. Copyright © 2015 the authors 0270-6474/15/3511081-13$15.00/0.

Induction, immunochemical identity and immunofluorescence localization of an 80 000-molecular-weight peroxisome-proliferation-associated polypeptide (polypeptide PPA-80) and peroxisomal enoyl-CoA hydratase of mouse liver and renal cortex.

PubMed

Lalwani, N D; Reddy, M K; Mangkornkanok-Mark, M; Reddy, J K

1981-07-15

The hypolipidaemic drugs methyl clofenapate, BR-931, Wy-14643 and procetofen induced a marked proliferation of peroxisomes in the parenchymal cells of liver and the proximal-convoluted-tubular epithelium of mouse kidney. The proliferation of peroxisomes was associated with 6-12-fold increase in the peroxisomal palmitoyl-CoA oxidizing capacity of the mouse liver. Enhanced activity of the peroxisomal palmitoyl-CoA oxidation system was also found in the renal-cortical homogenates of hypolipidaemic-drug-treated mice. The activity of enoyl-CoA hydratase in the mouse liver increased 30-50-fold and in the kidney cortex 3-5-fold with hypolipidaemic-drug-induced peroxisome proliferation in these tissues, and over 95% of this induced activity was found to be heat-labile peroxisomal enzyme in both organs. Sodium dodecyl sulphate/polyacrylamide-gel-electrophoretic analysis of large-particle and microsomal fractions obtained from the liver and kidney cortex of mice treated with hypolipidaemic peroxisome proliferators demonstrated a substantial increase in the quantity of an 80000-mol.wt. peroxisome-proliferation-associated polypeptide (polypeptide PPA-80). The heat-labile peroxisomal enoyl-CoA hydratase was purified from the livers of mice treated with the hypolipidaemic drug methyl clofenapate; the antibodies raised against this electrophoretically homogeneous protein yielded a single immunoprecipitin band with purified mouse liver enoyl-CoA hydratase and with liver and kidney cortical extracts of normal and hypolipidaemic-drug-treated mice. These anti-(mouse liver enoyl-CoA hydratase) antibodies also cross-reacted with purified rat liver enoyl-CoA hydratase and with the polypeptide PPA-80 obtained from rat and mouse liver. Immunofluorescence studies with anti-(polypeptide PPA-80) and anti-(peroxisomal enoyl-CoA hydratase) provided visual evidence for the localization and induction of polypeptide PPA-80 and peroxisomal enoyl-CoA hydratase in the liver and kidney respectively of normal and hypolipidaemic-drug-treated mice. In the kidney, the distribution of these two proteins is identical and limited exclusively to the cytoplasm of proximal-convoluted-tubular epithelium. The immunofluorescence studies clearly complement the biochemical and ultrastructural observations of peroxisome induction in the liver and kidney cortex of mice fed on hypolipidaemic drugs. In addition, preliminary ultrastructural studies with the protein-A-gold-complex technique demonstrate that the heat-labile hepatic enoyl-CoA hydratase is localized in the peroxisome matrix.

Fluorescence molecular imaging system with a novel mouse surface extraction method and a rotary scanning scheme

NASA Astrophysics Data System (ADS)

Zhao, Yue; Zhu, Dianwen; Baikejiang, Reheman; Li, Changqing

2015-03-01

We have developed a new fluorescence molecular tomography (FMT) imaging system, in which we utilized a phase shifting method to extract the mouse surface geometry optically and a rotary laser scanning approach to excite fluorescence molecules and acquire fluorescent measurements on the whole mouse body. Nine fringe patterns with a phase shifting of 2π/9 are projected onto the mouse surface by a projector. The fringe patterns are captured using a webcam to calculate a phase map that is converted to the geometry of the mouse surface with our algorithms. We used a DigiWarp approach to warp a finite element mesh of a standard digital mouse to the measured mouse surface thus the tedious and time-consuming procedure from a point cloud to mesh is avoided. Experimental results indicated that the proposed method is accurate with errors less than 0.5 mm. In the FMT imaging system, the mouse is placed inside a conical mirror and scanned with a line pattern laser that is mounted on a rotation stage. After being reflected by the conical mirror, the emitted fluorescence photons travel through central hole of the rotation stage and the band pass filters in a motorized filter wheel, and are collected by a CCD camera. Phantom experimental results of the proposed new FMT imaging system can reconstruct the target accurately.

In situ intracellular calcium oscillations in osteocytes in intact mouse long bones under dynamic mechanical loading

PubMed Central

Jing, Da; Baik, Andrew D.; Lu, X. Lucas; Zhou, Bin; Lai, Xiaohan; Wang, Liyun; Luo, Erping; Guo, X. Edward

2014-01-01

Osteocytes have been hypothesized to be the major mechanosensors in bone. How in situ osteocytes respond to mechanical stimuli is still unclear because of technical difficulties. In vitro studies have shown that osteocytes exhibited unique calcium (Ca2+) oscillations to fluid shear. However, whether this mechanotransduction phenomenon holds for in situ osteocytes embedded within a mineralized bone matrix under dynamic loading remains unknown. Using a novel synchronized loading/imaging technique, we successfully visualized in real time and quantified Ca2+ responses in osteocytes and bone surface cells in situ under controlled dynamic loading on intact mouse tibia. The resultant fluid-induced shear stress on the osteocyte in the lacunocanalicular system (LCS) was also quantified. Osteocytes, but not surface cells, displayed repetitive Ca2+ spikes in response to dynamic loading, with spike frequency and magnitude dependent on load magnitude, tissue strain, and shear stress in the LCS. The Ca2+ oscillations were significantly reduced by endoplasmic reticulum (ER) depletion and P2 purinergic receptor (P2R)/phospholipase C (PLC) inhibition. This study provides direct evidence that osteocytes respond to in situ mechanical loading by Ca2+ oscillations, which are dependent on the P2R/PLC/inositol trisphosphate/ER pathway. This study develops a novel approach in skeletal mechanobiology and also advances our fundamental knowledge of bone mechanotransduction.—Jing, D., Baik, A. D., Lu, X. L., Zhou, B., Lai, X., Wang, L., Luo, E., Guo, X. E. In situ intracellular calcium oscillations in osteocytes in intact mouse long bones under dynamic mechanical loading. PMID:24347610

Polymorphic Expression of a Human Superficial Bladder Tumor Antigen Defined by Mouse Monoclonal Antibodies

NASA Astrophysics Data System (ADS)

Fradet, Yves; Islam, Nazrul; Boucher, Lucie; Parent-Vaugeois, Carmen; Tardif, Marc

1987-10-01

Three mouse monoclonal antibodies (mAbs), which define a highly restricted antigen, were obtained by simultaneous immunizations with superficial papillary bladder tumor cells and mouse polyclonal serum against normal urothelium. The antigen was detected by the avidin/biotin/peroxidase method in 30/44 superficial bladder tumors (68%) but in only 4/27 infiltrating urothelial cancers (with much less intensity). No normal adult or fetal tissues tested expressed the antigen, including normal urothelium from 40 individuals, 13 of whom had a bladder tumor positive for the antigen. Only 1 of 45 nonbladder tumors showed some reactivity with one of the three mAbs. Serological tests on a large panel of human cancer cell lines and normal cultured cells were negative. The antigen is highly stable and well preserved on paraffin-embedded tissues. Electrophoretic transfer blot experiments with fresh tumor extracts showed that all three mAbs react with a determinant on a component of 300,000 Mr (pI 9.5) and 62,000 Mr (pI 6.5). The antigen shows polymorphic expression at the cellular level on tissue sections and also at a molecular level on immunoblots where the two bands are differentially detected on extracts of a series of tumors but are not visualized on normal urothelium extracts. The characteristics of this antigenic system suggest that it may provide some insights about the biology of bladder cancer. Specific detection of the antigen on 70% of superficial bladder tumors with normal cytology may be useful for their diagnosis and follow-up.

Visualising Androgen Receptor Activity in Male and Female Mice

PubMed Central

Dart, D. Alwyn; Waxman, Jonathan; Aboagye, Eric O.; Bevan, Charlotte L.

2013-01-01

Androgens, required for normal development and fertility of males and females, have vital roles in the reproductive tract, brain, cardiovascular system, smooth muscle and bone. Androgens function via the androgen receptor (AR), a ligand-dependent transcription factor. To assay and localise AR activity in vivo we generated the transgenic “ARE-Luc” mouse, expressing a luciferase reporter gene under the control of activated endogenous AR. In vivo imaging of androgen-mediated luciferase activity revealed several strongly expressing tissues in the male mouse as expected and also in certain female tissues. In males the testes, prostate, seminal vesicles and bone marrow all showed high AR activity. In females, strong activity was seen in the ovaries, uterus, omentum tissue and mammary glands. In both sexes AR expression and activity was also found in salivary glands, the eye (and associated glands), adipose tissue, spleen and, notably, regions of the brain. Luciferase protein expression was found in the same cell layers as androgen receptor expression. Additionally, mouse AR expression and activity correlated well with AR expression in human tissues. The anti-androgen bicalutamide reduced luciferase signal in all tissues. Our model demonstrates that androgens can act in these tissues directly via AR, rather than exclusively via androgen aromatisation to estrogens and activation of the estrogen receptor. Additionally, it visually demonstrates the fundamental importance of AR signalling outside the normal role in the reproductive organs. This model represents an important tool for physiological and developmental analysis of androgen signalling, and for characterization of known and novel androgenic or antiandrogenic compounds. PMID:23940781

Cryo-imaging in a toxicological study on mouse fetuses

NASA Astrophysics Data System (ADS)

Roy, Debashish; Gargesha, Madhusudhana; Sloter, Eddie; Watanabe, Michiko; Wilson, David

2010-03-01

We applied the Case cryo-imaging system to detect signals of developmental toxicity in transgenic mouse fetuses resulting from maternal exposure to a developmental environmental toxicant (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD). We utilized a fluorescent transgenic mouse model that expresses Green Fluorescent Protein (GFP) exclusively in smooth muscles under the control of the smooth muscle gamma actin (SMGA) promoter (SMGA/EGFP mice kindly provided by J. Lessard, U. Cincinnati). Analysis of cryo-image data volumes, comprising of very high-resolution anatomical brightfield and molecular fluorescence block face images, revealed qualitative and quantitative morphological differences in control versus exposed fetuses. Fetuses randomly chosen from pregnant females euthanized on gestation day (GD) 18 were either manually examined or cryo-imaged. For cryo-imaging, fetuses were embedded, frozen and cryo-sectioned at 20 μm thickness and brightfield color and fluorescent block-face images were acquired with an in-plane resolution of ~15 μm. Automated 3D volume visualization schemes segmented out the black embedding medium and blended fluorescence and brightfield data to produce 3D reconstructions of all fetuses. Comparison of Treatment groups TCDD GD13, TCDD GD14 and control through automated analysis tools highlighted differences not observable by prosectors performing traditional fresh dissection. For example, severe hydronephrosis, suggestive of irreversible kidney damage, was detected by cryoimaging in fetuses exposed to TCDD. Automated quantification of total fluorescence in smooth muscles revealed suppressed fluorescence in TCDD-exposed fetuses. This application demonstrated that cryo-imaging can be utilized as a routine high-throughput screening tool to assess the effects of potential toxins on the developmental biology of small animals.

Interaction of fluorescently labeled pyrrole-imidazole polyamide probes with fixed and living murine and human cells.

PubMed

Nozeret, Karine; Loll, François; Cardoso, Gildas Mouta; Escudé, Christophe; Boutorine, Alexandre S

2018-06-01

Pericentromeric heterochromatin plays important roles in controlling gene expression and cellular differentiation. Fluorescent pyrrole-imidazole polyamides targeting murine pericentromeric DNA (major satellites) can be used for the visualization of pericentromeric heterochromatin foci in live mouse cells. New derivatives targeting human repeated DNA sequences (α-satellites) were synthesized and their interaction with target DNA was characterized. The possibility to use major satellite and α -satellite binding polyamides as tools for staining pericentromeric heterochromatin was further investigated in fixed and living mouse and human cells. The staining that was previously observed using the mouse model was further characterized and optimized, but remained limited regarding the fluorophores that can be used. The promising results regarding the staining in the mouse model could not be extended to the human model. Experiments performed in human cells showed chromosomal DNA staining without selectivity. Factors limiting the use of fluorescent polyamides, in particular probe aggregation in the cytoplasm, were investigated. Results are discussed with regards to structure and affinity of probes, density of target sites and chromatin accessibility in both models. Copyright © 2018 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

The scotopic electroretinogram of the sugar glider related to histological features of its retina.

PubMed

Akula, James D; Esdaille, Tricia M; Caffé, A Romeo; Naarendorp, Franklin

2011-11-01

The flash electroretinogram (ERG) was used to characterize the scotopic retinal function in a marsupial. Key parameter values of the a- and b-waves of adult male sugar gliders, Petaurus breviceps breviceps, elicited with ganzfeld flashes were determined under dark- and light-adapted conditions. Using standard histological methods, the thicknesses of the major layers of the retina were assessed to provide insight into the nature of the ERG responses. The ERG and histological results were compared to corresponding data for placental C57Bl/6 mice to establish whether the functional retinal specialization that underlies scotopic visual function in a marsupial parallels that of a placental mouse. The sensitivity of the a-wave assessed with the Lamb and Pugh (Invest Ophthalmol Vis Sci 47:5138-5152, 2006) "model" and that of the b-wave assessed with standard methods were lower in the sugar glider compared to the mouse. The thickness of the sugar glider retina was two-third of that of the mouse. The high-intensity flash ERG of the sugar glider substantially differed in shape from that of the mouse reflecting perhaps structural and functional differences between the two species at the level of the inner retina.

EAGLEView: A surface and grid generation program and its data management

NASA Technical Reports Server (NTRS)

Remotigue, M. G.; Hart, E. T.; Stokes, M. L.

1992-01-01

An old and proven grid generation code, the EAGLE grid generation package, is given an added dimension of a graphical interface and a real time data base manager. The Numerical Aerodynamic Simulation (NAS) Panel Library is used for the graphical user interface. Through the panels, EAGLEView constructs the EAGLE script command and sends it to EAGLE to be processed. After the object is created, the script is saved in a mini-buffer which can be edited and/or saved and reinterpreted. The graphical objects are set-up in a linked-list and can be selected or queried by pointing and clicking the mouse. The added graphical enhancement to the EAGLE system emphasizes the unique capability to construct field points around complex geometry and visualize the construction every step of the way.

Evaluating the Usability of Pinchigator, a system for Navigating Virtual Worlds using Pinch Gloves

NASA Technical Reports Server (NTRS)

Hamilton, George S.; Brookman, Stephen; Dumas, Joseph D. II; Tilghman, Neal

2003-01-01

Appropriate design of two dimensional user interfaces (2D U/I) utilizing the well known WIMP (Window, Icon, Menu, Pointing device) environment for computer software is well studied and guidance can be found in several standards. Three-dimensional U/I design is not nearly so mature as 2D U/I, and standards bodies have not reached consensus on what makes a usable interface. This is especially true when the tools for interacting with the virtual environment may include stereo viewing, real time trackers and pinch gloves instead of just a mouse & keyboard. Over the last several years the authors have created a 3D U/I system dubbed Pinchigator for navigating virtual worlds based on the dVise dV/Mockup visualization software, Fakespace Pinch Gloves and Pohlemus trackers. The current work is to test the usability of the system on several virtual worlds, suggest improvements to increase Pinchigator s usability, and then to generalize about what was learned and how those lessons might be applied to improve other 3D U/I systems.

Activity-Dependent Dysfunction in Visual and Olfactory Sensory Systems in Mouse Models of Down Syndrome

PubMed Central

Saqran, Lubna; Herrick, Scott P.; Frosch, Matthew P.; Hyman, Bradley T.

2017-01-01

Activity-dependent synaptic plasticity plays a critical role in the refinement of circuitry during postnatal development and may be disrupted in conditions that cause intellectual disability, such as Down syndrome (DS). To test this hypothesis, visual cortical plasticity was assessed in Ts65Dn mice that harbor a chromosomal duplication syntenic to human chromosome 21q. We find that Ts65Dn mice demonstrate a defect in ocular dominance plasticity (ODP) following monocular deprivation. This phenotype is similar to that of transgenic mice that express amyloid precursor protein (APP), which is duplicated in DS and in Ts65DN mice; however, normalizing APP gene copy number in Ts65Dn mice fails to rescue plasticity. Ts1Rhr mice harbor a duplication of the telomeric third of the Ts65Dn-duplicated sequence and demonstrate the same ODP defect, suggesting a gene or genes sufficient to drive the phenotype are located in that smaller duplication. In addition, we find that Ts65Dn mice demonstrate an abnormality in olfactory system connectivity, a defect in the refinement of connections to second-order neurons in the olfactory bulb. Ts1Rhr mice do not demonstrate a defect in glomerular refinement, suggesting that distinct genes or sets of genes underlie visual and olfactory system phenotypes. Importantly, these data suggest that developmental plasticity and connectivity are impaired in sensory systems in DS model mice, that such defects may contribute to functional impairment in DS, and that these phenotypes, present in male and female mice, provide novel means for examining the genetic and molecular bases for neurodevelopmental impairment in model mice in vivo. SIGNIFICANCE STATEMENT Our understanding of the basis for intellectual impairment in Down syndrome is hindered by the large number of genes duplicated in Trisomy 21 and a lack of understanding of the effect of disease pathology on the function of neural circuits in vivo. This work describes early postnatal developmental abnormalities in visual and olfactory sensory systems in Down syndrome model mice, which provide insight into defects in the function of neural circuits in vivo and provide an approach for exploring the genetic and molecular basis for impairment in the disease. In addition, these findings raise the possibility that basic dysfunction in primary sensory circuitry may illustrate mechanisms important for global learning and cognitive impairment in Down syndrome patients. PMID:28899917

Optoacoustic imaging in five dimensions

NASA Astrophysics Data System (ADS)

Deán-Ben, X. L.; Gottschalk, Sven; Fehm, Thomas F.; Razansky, Daniel

2015-03-01

We report on an optoacoustic imaging system capable of acquiring volumetric multispectral optoacoustic data in real time. The system is based on simultaneous acquisition of optoacoustic signals from 256 different tomographic projections by means of a spherical matrix array. Thereby, volumetric reconstructions can be done at high frame rate, only limited by the pulse repetition rate of the laser. The developed tomographic approach presents important advantages over previously reported systems that use scanning for attaining volumetric optoacoustic data. First, dynamic processes, such as the biodistribution of optical biomarkers, can be monitored in the entire volume of interest. Second, out-of-plane and motion artifacts that could degrade the image quality when imaging living specimens can be avoided. Finally, real-time 3D performance can obviously save time required for experimental and clinical observations. The feasibility of optoacoustic imaging in five dimensions, i.e. real time acquisition of volumetric datasets at multiple wavelengths, is reported. In this way, volumetric images of spectrally resolved chromophores are rendered in real time, thus offering an unparallel imaging performance among the current bio-imaging modalities. This performance is subsequently showcased by video-rate visualization of in vivo hemodynamic changes in mouse brain and handheld visualization of blood oxygenation in deep human vessels. The newly discovered capacities open new prospects for translating the optoacoustic technology into highly performing imaging modality for biomedical research and clinical practice with multiple applications envisioned, from cardiovascular and cancer diagnostics to neuroimaging and ophthalmology.

World Wind 3D Earth Viewing

NASA Technical Reports Server (NTRS)

Hogan, Patrick; Maxwell, Christopher; Kim, Randolph; Gaskins, Tom

2007-01-01

World Wind allows users to zoom from satellite altitude down to any place on Earth, leveraging high-resolution LandSat imagery and SRTM (Shuttle Radar Topography Mission) elevation data to experience Earth in visually rich 3D. In addition to Earth, World Wind can also visualize other planets, and there are already comprehensive data sets for Mars and the Earth's moon, which are as easily accessible as those of Earth. There have been more than 20 million downloads to date, and the software is being used heavily by the Department of Defense due to the code s ability to be extended and the evolution of the code courtesy of NASA and the user community. Primary features include the dynamic access to public domain imagery and its ease of use. All one needs to control World Wind is a two-button mouse. Additional guides and features can be accessed through a simplified menu. A JAVA version will be available soon. Navigation is automated with single clicks of a mouse, or by typing in any location to automatically zoom in to see it. The World Wind install package contains the necessary requirements such as the .NET runtime and managed DirectX library. World Wind can display combinations of data from a variety of sources, including Blue Marble, LandSat 7, SRTM, NASA Scientific Visualization Studio, GLOBE, and much more. A thorough list of features, the user manual, a key chart, and screen shots are available at http://worldwind.arc.nasa.gov.

Preclinical fluorescent mouse models of pancreatic cancer

NASA Astrophysics Data System (ADS)

Bouvet, Michael; Hoffman, Robert M.

2007-02-01

Here we describe our cumulative experience with the development and preclinical application of several highly fluorescent, clinically-relevant, metastatic orthotopic mouse models of pancreatic cancer. These models utilize the human pancreatic cancer cell lines which have been genetically engineered to selectively express high levels of the bioluminescent green fluorescent (GFP) or red fluorescent protein (RFP). Fluorescent tumors are established subcutaneously in nude mice, and tumor fragments are then surgically transplanted onto the pancreas. Locoregional tumor growth and distant metastasis of these orthotopic implants occurs spontaneously and rapidly throughout the abdomen in a manner consistent with clinical human disease. Highly specific, high-resolution, real-time visualization of tumor growth and metastasis may be achieved in vivo without the need for contrast agents, invasive techniques, or expensive imaging equipment. We have shown a high correlation between florescent optical imaging and magnetic resonance imaging in these models. Alternatively, transplantation of RFP-expressing tumor fragments onto the pancreas of GFP-expressing transgenic mice may be used to facilitate visualization of tumor-host interaction between the pancreatic tumor fragments and host-derived stroma and vasculature. Such in vivo models have enabled us to serially visualize and acquire images of the progression of pancreatic cancer in the live animal, and to demonstrate the real-time antitumor and antimetastatic effects of several novel therapeutic strategies on pancreatic malignancy. These fluorescent models are therefore powerful and reliable tools with which to investigate human pancreatic cancer and therapeutic strategies directed against it.

Vitamin A in Stargardt disease-an evidence-based update.

PubMed

Federspiel, Cecilie Aalund; Bertelsen, Mette; Kessel, Line

2018-06-25

High intake of vitamin A is suspected to be a risk factor for the progression of Stargardt disease (STGD1) and many health authorities recommend Stargardt patients not to use oral vitamin A supplements outside that provided naturally in the food. The present study provides the first systematic review of the current level of evidence regarding the role of supplementary vitamin A in STGD1. We conducted a systematic scientific literature search in the Pubmed database on studies reporting on the effect of oral vitamin A or serum retinol on visual function. In animal studies neither high nor low serum retinol in an Abca4 knockout mouse model of Stargardt showed any effect on electroretinography (ERG). In humans, significantly better visual function was reported in a cross-sectional study of patients with a low dietary intake of vitamin A, whereas a prospective study did not find any correlation between vitamin A supplementation and visual acuity. A newly introduced vitamin A substitute (C20-D(3)-vitamin A) has shown promising effects on ERG in a Stargardt mouse model. There are few studies on the effect of vitamin A in STGD1. The scarcity and inconclusiveness of evidence available impel further research efforts to reach a more confident conclusion. Currently, recommendations to avoid vitamin A dietary supplementation rely mainly on a theoretical background. Animal studies on vitamin A substitute as a possible therapeutic approach in preventing or slowing vision loss in STGD1 seems promising but further clinical trials are needed to verify the results.

Modulation of GSK-3 provides cellular and functional neuroprotection in the rd10 mouse model of retinitis pigmentosa.

PubMed

Sánchez-Cruz, Alonso; Villarejo-Zori, Beatriz; Marchena, Miguel; Zaldivar-Díez, Josefa; Palomo, Valle; Gil, Carmen; Lizasoain, Ignacio; de la Villa, Pedro; Martínez, Ana; de la Rosa, Enrique J; Hernández-Sánchez, Catalina

2018-04-16

Retinitis pigmentosa (RP) is a group of hereditary retinal neurodegenerative conditions characterized by primary dysfunction and death of photoreceptor cells, resulting in visual loss and, eventually, blindness. To date, no effective therapies have been transferred to clinic. Given the diverse genetic etiology of RP, targeting common cellular and molecular retinal alterations has emerged as a potential therapeutic strategy. Using the Pde6b rd10/rd10 mouse model of RP, we investigated the effects of daily intraperitoneal administration of VP3.15, a small-molecule heterocyclic GSK-3 inhibitor. Gene expression was analyzed by quantitative PCR and protein expression and phosphorylation by Western blot. Photoreceptor preservation was evaluated by histological analysis and visual function was assessed by electroretinography. In rd10 retinas, increased expression of pro-inflammatory markers and reactive gliosis coincided with the early stages of retinal degeneration. Compared with wild-type controls, GSK-3β expression (mRNA and protein) remained unchanged during the retinal degeneration period. However, levels of GSK-3β Ser9 and its regulator Akt Ser473 were increased in rd10 versus wild-type retinas. In vivo administration of VP3.15 reduced photoreceptor cell loss and preserved visual function. This neuroprotective effect was accompanied by a decrease in the expression of neuroinflammatory markers. These results provide proof of concept of the therapeutic potential of VP3.15 for the treatment of retinal neurodegenerative conditions in general, and RP in particular.

Development of a small prototype for a proof-of-concept of OpenPET imaging

NASA Astrophysics Data System (ADS)

Yamaya, Taiga; Yoshida, Eiji; Inaniwa, Taku; Sato, Shinji; Nakajima, Yasunori; Wakizaka, Hidekatsu; Kokuryo, Daisuke; Tsuji, Atsushi; Mitsuhashi, Takayuki; Kawai, Hideyuki; Tashima, Hideaki; Nishikido, Fumihiko; Inadama, Naoko; Murayama, Hideo; Haneishi, Hideaki; Suga, Mikio; Kinouchi, Shoko

2011-02-01

The OpenPET geometry is our new idea to visualize a physically opened space between two detector rings. In this paper, we developed the first small prototype to show a proof-of-concept of OpenPET imaging. Two detector rings of 110 mm diameter and 42 mm axial length were placed with a gap of 42 mm. The basic imaging performance was confirmed through phantom studies; the open imaging was realized at the cost of slight loss of axial resolution and 24% loss of sensitivity. For a proof-of-concept of PET image-guided radiation therapy, we carried out the in-beam tests with 11C radioactive beam irradiation in the heavy ion medical accelerator in Chiba to visualize in situ distribution of primary particles stopped in a phantom. We showed that PET images corresponding to dose distribution were obtained. For an initial proof-of-concept of real-time multimodal imaging, we measured a tumor-inoculated mouse with 18F-FDG, and an optical image of the mouse body surface was taken during the PET measurement by inserting a digital camera in the ring gap. We confirmed that the tumor in the gap was clearly visualized. The result also showed the extension effect of an axial field-of-view (FOV); a large axial FOV of 126 mm was obtained with the detectors that originally covered only an 84 mm axial FOV. In conclusion, our initial imaging studies showed promising performance of the OpenPET.

A neuronal circuit for colour vision based on rod-cone opponency.

PubMed

Joesch, Maximilian; Meister, Markus

2016-04-14

In bright light, cone-photoreceptors are active and colour vision derives from a comparison of signals in cones with different visual pigments. This comparison begins in the retina, where certain retinal ganglion cells have 'colour-opponent' visual responses-excited by light of one colour and suppressed by another colour. In dim light, rod-photoreceptors are active, but colour vision is impossible because they all use the same visual pigment. Instead, the rod signals are thought to splice into retinal circuits at various points, in synergy with the cone signals. Here we report a new circuit for colour vision that challenges these expectations. A genetically identified type of mouse retinal ganglion cell called JAMB (J-RGC), was found to have colour-opponent responses, OFF to ultraviolet (UV) light and ON to green light. Although the mouse retina contains a green-sensitive cone, the ON response instead originates in rods. Rods and cones both contribute to the response over several decades of light intensity. Remarkably, the rod signal in this circuit is antagonistic to that from cones. For rodents, this UV-green channel may play a role in social communication, as suggested by spectral measurements from the environment. In the human retina, all of the components for this circuit exist as well, and its function can explain certain experiences of colour in dim lights, such as a 'blue shift' in twilight. The discovery of this genetically defined pathway will enable new targeted studies of colour processing in the brain.

Rank Order Coding: a Retinal Information Decoding Strategy Revealed by Large-Scale Multielectrode Array Retinal Recordings.

PubMed

Portelli, Geoffrey; Barrett, John M; Hilgen, Gerrit; Masquelier, Timothée; Maccione, Alessandro; Di Marco, Stefano; Berdondini, Luca; Kornprobst, Pierre; Sernagor, Evelyne

2016-01-01

How a population of retinal ganglion cells (RGCs) encodes the visual scene remains an open question. Going beyond individual RGC coding strategies, results in salamander suggest that the relative latencies of a RGC pair encode spatial information. Thus, a population code based on this concerted spiking could be a powerful mechanism to transmit visual information rapidly and efficiently. Here, we tested this hypothesis in mouse by recording simultaneous light-evoked responses from hundreds of RGCs, at pan-retinal level, using a new generation of large-scale, high-density multielectrode array consisting of 4096 electrodes. Interestingly, we did not find any RGCs exhibiting a clear latency tuning to the stimuli, suggesting that in mouse, individual RGC pairs may not provide sufficient information. We show that a significant amount of information is encoded synergistically in the concerted spiking of large RGC populations. Thus, the RGC population response described with relative activities, or ranks, provides more relevant information than classical independent spike count- or latency- based codes. In particular, we report for the first time that when considering the relative activities across the whole population, the wave of first stimulus-evoked spikes is an accurate indicator of stimulus content. We show that this coding strategy coexists with classical neural codes, and that it is more efficient and faster. Overall, these novel observations suggest that already at the level of the retina, concerted spiking provides a reliable and fast strategy to rapidly transmit new visual scenes.

Genomic localization of the Z/EG transgene in the mouse genome.

PubMed

Colombo, Sophie; Kumasaka, Mayuko; Lobe, Corrinne; Larue, Lionel

2010-02-01

The Z/EG transgenic mouse line, produced by Novak et al., displays tissue-specific EGFP expression after Cre-mediated recombination. The autofluorescence of EGFP allows the visualization of cells of interest displaying Cre recombination. The initial construct was designed such that cells without Cre recombination express the beta-galactosidase marker, facilitating counterselection. We used inverse PCR to identify the site of integration of the Z/EG transgene, to improve the efficiency of homozygous Z/EG mouse production. Recombined cells produced large amounts of EGFP protein, resulting in higher levels of fluorescence and therefore greater contrast with nonrecombined cells. We mapped the transgene to the G1 region of chromosome 5. This random insertion was found to have occurred 230-bp upstream from the start codon of the Rasa4 gene. The insertion of the Z/EG transgene in the C57BL/6 genetic background had no effect on Rasa4 expression. Homozygous Z/EG mice therefore had no obvious phenotype. (c) 2009 Wiley-Liss, Inc.

The embryonic mouse hindbrain as a qualitative and quantitative model for studying the molecular and cellular mechanisms of angiogenesis.

PubMed

Fantin, Alessandro; Vieira, Joaquim M; Plein, Alice; Maden, Charlotte H; Ruhrberg, Christiana

2013-02-01

The mouse embryo hindbrain is a robust and adaptable model for studying sprouting angiogenesis. It permits the spatiotemporal analysis of organ vascularization in normal mice and in mouse strains with genetic mutations that result in late embryonic or perinatal lethality. Unlike postnatal models such as retinal angiogenesis or Matrigel implants, there is no requirement for the breeding of conditional knockout mice. The unique architecture of the hindbrain vasculature allows whole-mount immunolabeling of blood vessels and high-resolution imaging, as well as easy quantification of angiogenic sprouting, network density and vessel caliber. The hindbrain model also permits the visualization of ligand binding to blood vessels in situ and the analysis of blood vessel growth within a natural multicellular microenvironment in which endothelial cells (ECs) interact with non-ECs to refine the 3D organ architecture. The entire procedure, from embryo isolation to imaging and through to results analysis, takes approximately 4 d.

Borders and Comparative Cytoarchitecture of the Perirhinal and Postrhinal Cortices in an F1 Hybrid Mouse

PubMed Central

Beaudin, Stephane A.; Singh, Teghpal; Agster, Kara L.

2013-01-01

We examined the cytoarchitectonic and chemoarchitectonic organization of the cortical regions associated with the posterior rhinal fissure in the mouse brain, within the framework of what is known about these regions in the rat. Primary observations were in a first-generation hybrid mouse line, B6129PF/J1. The F1 hybrid was chosen because of the many advantages afforded in the study of the molecular and cellular bases of learning and memory. Comparisons with the parent strains, the C57BL6/J and 129P3/J are also reported. Mouse brain tissue was processed for visualization of Nissl material, myelin, acetyl cholinesterase, parvalbumin, and heavy metals. Tissue stained for heavy metals by the Timm’s method was particularly useful in the assignment of borders and in the comparative analyses because the patterns of staining were similar across species and strains. As in the rat, the areas examined were parcellated into 2 regions, the perirhinal and the postrhinal cortices. The perirhinal cortex was divided into areas 35 and 36, and the postrhinal cortex was divided into dorsal (PORd) and ventral (PORv) subregions. In addition to identifying the borders of the perirhinal cortex, we were able to identify a region in the mouse brain that shares signature features with the rat postrhinal cortex. PMID:22368084

Testing of Visual Field with Virtual Reality Goggles in Manual and Visual Grasp Modes

PubMed Central

Wroblewski, Dariusz; Francis, Brian A.; Sadun, Alfredo; Vakili, Ghazal; Chopra, Vikas

2014-01-01

Automated perimetry is used for the assessment of visual function in a variety of ophthalmic and neurologic diseases. We report development and clinical testing of a compact, head-mounted, and eye-tracking perimeter (VirtualEye) that provides a more comfortable test environment than the standard instrumentation. VirtualEye performs the equivalent of a full threshold 24-2 visual field in two modes: (1) manual, with patient response registered with a mouse click, and (2) visual grasp, where the eye tracker senses change in gaze direction as evidence of target acquisition. 59 patients successfully completed the test in manual mode and 40 in visual grasp mode, with 59 undergoing the standard Humphrey field analyzer (HFA) testing. Large visual field defects were reliably detected by VirtualEye. Point-by-point comparison between the results obtained with the different modalities indicates: (1) minimal systematic differences between measurements taken in visual grasp and manual modes, (2) the average standard deviation of the difference distributions of about 5 dB, and (3) a systematic shift (of 4–6 dB) to lower sensitivities for VirtualEye device, observed mostly in high dB range. The usability survey suggested patients' acceptance of the head-mounted device. The study appears to validate the concepts of a head-mounted perimeter and the visual grasp mode. PMID:25050326

Observations on gas exchange and element recycle within a gas-closed algal-mouse system

NASA Technical Reports Server (NTRS)

Smernoff, D. T.; Wharton, R. A., Jr.; Averner, M. M.

1986-01-01

Life support systems based on bioregeneration rely on the control and manipulation of organisms. Algae are potentially useful for a variety of Closed Ecological Life Support System (CELSS) functions including the revitalization of atmospheres, production of food and for nitrogen fixation. The results of experiments conducted with a gas-closed algal-mouse system designed to investigate gas exchange phenomena under varying algal environmental conditions, and the ability of algae to utilize oxidized mouse solid waste are reported. Inherent instabilities exist between the uptake and release of carbon dioxide (CO2) and oxygen (O2) by the mouse and algae in a gas-closed system. Variations in light intensity and cell density alter the photosynthetic rate of the algae and enable short-term steady-state concentrations of atmospheric CO2 and O2. Different nitrogen sources (urea and nitrate) result in different algal assimilatory quotients (AQ). Combinations of photosynthetic rate and AQ ratio manipulations were examined for their potential in stabilizing atmospheric gas concentrations in the gas-closed algal-mouse system.

Fluorescent scanning laser ophthalmoscopy for cellular resolution in vivo mouse retinal imaging: benefits and drawbacks of implementing adaptive optics (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhang, Pengfei; Goswami, Mayank; Pugh, Edward N.; Zawadzki, Robert J.

2016-03-01

Scanning Laser Ophthalmoscopy (SLO) is a very important imaging tool in ophthalmology research. By combing with Adaptive Optics (AO) technique, AO-SLO can correct for ocular aberrations resulting in cellular level resolution, allowing longitudinal studies of single cells morphology in the living eyes. The numerical aperture (NA) sets the optical resolution that can be achieve in the "classical" imaging systems. Mouse eye has more than twice NA of the human eye, thus offering theoretically higher resolution. However, in most SLO based imaging systems the imaging beam size at mouse pupil sets the NA of that instrument, while most of the AO-SLO systems use almost the full NA of the mouse eye. In this report, we first simulated the theoretical resolution that can be achieved in vivo for different imaging beam sizes (different NA), assumingtwo cases: no aberrations and aberrations based on published mouse ocular wavefront data. Then we imaged mouse retinas with our custom build SLO system using different beam sizes to compare these results with theory. Further experiments include comparison of the SLO and AO-SLO systems for imaging different type of fluorescently labeled cells (microglia, ganglion, photoreceptors, etc.). By comparing those results and taking into account systems complexity and ease of use, the benefits and drawbacks of two imaging systems will be discussed.

Mouse V1 population correlates of visual detection rely on heterogeneity within neuronal response patterns

PubMed Central

Montijn, Jorrit S; Goltstein, Pieter M; Pennartz, Cyriel MA

2015-01-01

Previous studies have demonstrated the importance of the primary sensory cortex for the detection, discrimination, and awareness of visual stimuli, but it is unknown how neuronal populations in this area process detected and undetected stimuli differently. Critical differences may reside in the mean strength of responses to visual stimuli, as reflected in bulk signals detectable in functional magnetic resonance imaging, electro-encephalogram, or magnetoencephalography studies, or may be more subtly composed of differentiated activity of individual sensory neurons. Quantifying single-cell Ca2+ responses to visual stimuli recorded with in vivo two-photon imaging, we found that visual detection correlates more strongly with population response heterogeneity rather than overall response strength. Moreover, neuronal populations showed consistencies in activation patterns across temporally spaced trials in association with hit responses, but not during nondetections. Contrary to models relying on temporally stable networks or bulk signaling, these results suggest that detection depends on transient differentiation in neuronal activity within cortical populations. DOI: http://dx.doi.org/10.7554/eLife.10163.001 PMID:26646184

Cross-modality Sharpening of Visual Cortical Processing through Layer 1-Mediated Inhibition and Disinhibition

PubMed Central

Ibrahim, Leena A.; Mesik, Lukas; Ji, Xu-ying; Fang, Qi; Li, Hai-fu; Li, Ya-tang; Zingg, Brian; Zhang, Li I.; Tao, Huizhong Whit

2016-01-01

Summary Cross-modality interaction in sensory perception is advantageous for animals’ survival. How cortical sensory processing is cross-modally modulated and what are the underlying neural circuits remain poorly understood. In mouse primary visual cortex (V1), we discovered that orientation selectivity of layer (L)2/3 but not L4 excitatory neurons was sharpened in the presence of sound or optogenetic activation of projections from primary auditory cortex (A1) to V1. The effect was manifested by decreased average visual responses yet increased responses at the preferred orientation. It was more pronounced at lower visual contrast, and was diminished by suppressing L1 activity. L1 neurons were strongly innervated by A1-V1 axons and excited by sound, while visual responses of L2/3 vasoactive intestinal peptide (VIP) neurons were suppressed by sound, both preferentially at the cell's preferred orientation. These results suggest that the cross-modality modulation is achieved primarily through L1 neuron and L2/3 VIP-cell mediated inhibitory and disinhibitory circuits. PMID:26898778

A simple method for in vivo labelling of infiltrating leukocytes in the mouse retina using indocyanine green dye.

PubMed

Sim, Dawn A; Chu, Colin J; Selvam, Senthil; Powner, Michael B; Liyanage, Sidath; Copland, David A; Keane, Pearse A; Tufail, Adnan; Egan, Catherine A; Bainbridge, James W B; Lee, Richard W; Dick, Andrew D; Fruttiger, Marcus

2015-11-01

We have developed a method to label and image myeloid cells infiltrating the mouse retina and choroid in vivo, using a single depot injection of indocyanine green dye (ICG). This was demonstrated using the following ocular models of inflammation and angiogenesis: endotoxin-induced uveitis, experimental autoimmune uveoretinitis and laser-induced choroidal neovascularization model. A near-infrared scanning ophthalmoscope was used for in vivo imaging of the eye, and flow cytometry was used on blood and spleen to assess the number and phenotype of labelled cells. ICG was administered 72 h before the induction of inflammation to ensure clearance from the systemic circulation. We found that in vivo intravenous administration failed to label any leukocytes, whereas depot injection, either intraperitoneal or subcutaneous, was successful in labelling leukocytes infiltrating into the retina. Progression of inflammation in the retina could be traced over a period of 14 days following a single depot injection of ICG. Additionally, bright-field microscopy, spectrophotometry and flow cytometric analysis suggest that the predominant population of cells stained by ICG are circulating myeloid cells. The translation of this approach into clinical practice would enable visualization of immune cells in situ. This will not only provide a greater understanding of pathogenesis, monitoring and assessment of therapy in many human ocular diseases but might also open the ability to image immunity live for neurodegenerative disorders, cardiovascular disease and systemic immune-mediated disorders. © 2015. Published by The Company of Biologists Ltd.

Microbiological contamination in digital radiography: evaluation at the radiology clinic of an educational institution.

PubMed

Malta, Cristiana P; Damasceno, Naiana Nl; Ribeiro, Rosangela A; Silva, Carolina Sf; Devito, Karina L

2016-12-01

The aim of this study was to evaluate the contamination rate of intra and extraoral digital X ray equipment in a dental radiology clinic at a public educational institution. Samples were collected on three different days, at two times in the day: in the morning, before attending patients, and at the end of the day, after appointment hours and before cleaning and disinfection procedures. Samples were collected from the periapical X-ray machine (tube head, positioning device, control panel and activator button), the panoramic X- ray machine (temporal support, bite block, control panel and activator button), the intraoral digital system (sensor), and the digital system computers (keyboard and mouse). The samples were seeded in different culture media, incubated, and colony forming units (CFU/mL) counted. Biochemical tests were performed for suspected colonies of Staphylococcus, Streptococcus and Gramnegative bacilli (GNB). Fungi were visually differentiated into filamentous fungi and yeasts. The results indicated the growth of fungi and Staphylococcus fromall sampling locations. GNB growth was observed from all sites sampled from the intraoral X-ray equipment. On the panoramic unit, GNB growth was observed in samples from activator button, keyboard and mouse. In general, a higher number of CFU/mL was present before use. It can be concluded that more stringent protocols are needed to control infection and prevent X-ray exams from acting as vehicle for cross contamination. Sociedad Argentina de Investigación Odontológica.

Refractive index measurement of the mouse crystalline lens using optical coherence tomography

PubMed Central

Chakraborty, Ranjay; Lacy, Kip D.; Tan, Christopher C.; Park, Han na; Pardue, Machelle T.

2014-01-01

In recent years, there has been a growing interest for using mouse models in refractive development and myopia research. The crystalline lens is a critical optical component of the mouse eye that occupies greater than 50% of the ocular space, and significant increases in thickness with age. However, changes in refractive index of the mouse crystalline lens are less known. In this study, we examined the changes in thickness and refractive index of the mouse crystalline lens for two different strains, wild-type (WT) and a nyx mutant (nob) over the course of normal visual development or after form deprivation. Refractive index and lens thickness measurements were made on ex vivo lens using spectral domain optical coherence tomography (SD-OCT). Comparison of refractive index measurements on 5 standard ball lenses using the SD-OCT and their known refractive indices (manufacturer provided) indicated good precision (intra-class correlation coefficient, 0.998 and Bland-Altman coefficient of repeatability, 0.116) of the SD-OCT to calculate mouse lens refractive index ex vivo. During normal visual development, lens thickness increased significantly with age for three different cohorts of mice, aged 4 (average thickness from both eyes; WT: 1.78 ± 0.03, nob: 1.79 ± 0.08 mm), 10 (WT: 2.02 ± 0.05, nob: 2.01 ± 0.04 mm) and 16 weeks (WT: 2.12 ± 0.06, nob: 2.09 ± 0.06 mm, p<0.001). Lens thickness was not significantly different between the two strains at any age (p=0.557). For mice with normal vision, refractive index for isolated crystalline lenses in nob mice was significantly greater than WT mice (mean for all ages; WT: 1.42 ± 0.01, nob: 1.44 ± 0.001, p<0.001). After 4 weeks of form deprivation to the right eye using a skull-mounted goggling apparatus, a thinning of the crystalline lens was observed in both right and left eyes of goggled animals compared to their naïve controls (average from both the right and the left eye) for both strains (p=0.052). In form deprived mice, lens refractive index was significantly different between the goggled animals and non-goggled naïve controls in nob mice, but not in WT mice (p=0.009). Both eyes of goggled nob mice had significantly greater lens refractive index (goggled, 1.49 ± 0.01; opposite, 1.47 ± 0.03) compared to their naïve controls (1.45 ± 0.02, p<0.05). The results presented here suggest that there are genetic differences in the crystalline lens refractive index of the mouse eye, and that the lens refractive index in mice significantly increase with form deprivation. Research applications requiring precise optical measurements of the mouse eye should take these lens refractive indices into account when interpreting SD-OCT data. PMID:24939747

The application of surgical navigation system using optical molecular imaging technology in orthotopic breast cancer and metastasis studies

NASA Astrophysics Data System (ADS)

Chi, Chongwei; Zhang, Qian; Kou, Deqiang; Ye, Jinzuo; Mao, Yamin; Qiu, Jingdan; Wang, Jiandong; Yang, Xin; Du, Yang; Tian, Jie

2014-02-01

Currently, it has been an international focus on intraoperative precise positioning and accurate resection of tumor and metastases. The methods such as X-rays, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) have played an important role in preoperative accurate diagnosis. However, most of them are inapplicable for intraoperative surgery. We have proposed a surgical navigation system based on optical molecular imaging technology for intraoperative detection of tumors and metastasis. This system collects images from two CCD cameras for real-time fluorescent and color imaging. For image processing, the template matching algorithm is used for multispectral image fusion. For the application of tumor detection, the mouse breast cancer cell line 4T1-luc, which shows highly metastasis, was used for tumor model establishment and a model of matrix metalloproteinase (MMP) expressing breast cancer. The tumor-bearing nude mice were given tail vein injection of MMP 750FAST (PerkinElmer, Inc. USA) probe and imaged with both bioluminescence and fluorescence to assess in vivo binding of the probe to the tumor and metastases sites. Hematoxylin and eosin (H&E) staining was performed to confirm the presence of tumor and metastasis. As a result, one tumor can be observed visually in vivo. However liver metastasis has been detected under surgical navigation system and all were confirmed by histology. This approach helps surgeons to find orthotopic tumors and metastasis during intraoperative resection and visualize tumor borders for precise positioning. Further investigation is needed for future application in clinics.

Experience-Dependent Synaptic Plasticity in V1 Occurs without Microglial CX3CR1

PubMed Central

Stevens, Beth

2017-01-01

Brief monocular deprivation (MD) shifts ocular dominance and reduces the density of thalamic synapses in layer 4 of the mouse primary visual cortex (V1). We found that microglial lysosome content is also increased as a result of MD. Previous studies have shown that the microglial fractalkine receptor CX3CR1 is involved in synaptic development and hippocampal plasticity. We therefore tested the hypothesis that neuron-to-microglial communication via CX3CR1 is an essential component of visual cortical development and plasticity in male mice. Our data show that CX3CR1 is not required for normal development of V1 responses to visual stimulation, multiple forms of experience-dependent plasticity, or the synapse loss that accompanies MD in layer 4. By ruling out an essential role for fractalkine signaling, our study narrows the search for understanding how microglia respond to active synapse modification in the visual cortex. SIGNIFICANCE STATEMENT Microglia in the visual cortex respond to monocular deprivation with increased lysosome content, but signaling through the fractalkine receptor CX3CR1 is not an essential component in the mechanisms of visual cortical development or experience-dependent synaptic plasticity. PMID:28951447

Visual Arrestin 1 Acts as a Modulator for N-Ethylmaleimide Sensitive Factor in the Photoreceptor Synapse

PubMed Central

Huang, Shun-Ping; Brown, Bruce M.; Craft, Cheryl M.

2010-01-01

In the G-protein coupled receptor (GPCR) phototransduction cascade, visual Arrestin1 (Arr1) binds to and deactivates phosphorylated light-activated opsins, a process that is critical for effective recovery and normal vision. In this report, we discovered a novel synaptic interaction between Arr1 and N-ethylmaleimide sensitive factor (NSF) that is enhanced in a dark environment when mouse photoreceptors are depolarized and the rate of exocytosis is elevated. In the photoreceptor synapse, NSF functions to sustain a higher rate of exocytosis, in addition to the compensatory endocytosis to retrieve and to recycle vesicle membrane and synaptic proteins. Not only does Arr1 bind to the junction of NSF N-terminal and its first ATPase domains in an ATP-dependent manner in vitro, but Arr1 also enhances both NSF ATPase and NSF disassembly activities. In vivo experiments in mouse retinas with the Arr1 gene knocked out, the expression levels of NSF and other synapse-enriched components, including vesicular glutamate transporter 1 (vGLUT1), excitatory amino acid transporter 5 (EAAT5), and vesicle associated membrane protein 2 (VAMP2), are markedly reduced, which lead to a substantial decrease in the exocytosis rate with FM1-43. Thus, we propose that the Arr1 and NSF interaction is important for modulating normal synaptic function in mouse photoreceptors. This study demonstrates a vital alternative function for Arr1 in the photoreceptor synapse and provides key insights into the potential molecular mechanisms of inherited retinal diseases, such as Oguchi disease and Arr1-associated retinitis pigmentosa. PMID:20631167

Restoration of visual function by expression of a light-gated mammalian ion channel in retinal ganglion cells or ON-bipolar cells

PubMed Central

Gaub, Benjamin M.; Berry, Michael H.; Holt, Amy E.; Reiner, Andreas; Kienzler, Michael A.; Dolgova, Natalia; Nikonov, Sergei; Aguirre, Gustavo D.; Beltran, William A.; Flannery, John G.; Isacoff, Ehud Y.

2014-01-01

Most inherited forms of blindness are caused by mutations that lead to photoreceptor cell death but spare second- and third-order retinal neurons. Expression of the light-gated excitatory mammalian ion channel light-gated ionotropic glutamate receptor (LiGluR) in retinal ganglion cells (RGCs) of the retina degeneration (rd1) mouse model of blindness was previously shown to restore some visual functions when stimulated by UV light. Here, we report restored retinal function in visible light in rodent and canine models of blindness through the use of a second-generation photoswitch for LiGluR, maleimide-azobenzene-glutamate 0 with peak efficiency at 460 nm (MAG0460). In the blind rd1 mouse, multielectrode array recordings of retinal explants revealed robust and uniform light-evoked firing when LiGluR-MAG0460 was targeted to RGCs and robust but diverse activity patterns in RGCs when LiGluR-MAG0460 was targeted to ON-bipolar cells (ON-BCs). LiGluR-MAG0460 in either RGCs or ON-BCs of the rd1 mouse reinstated innate light-avoidance behavior and enabled mice to distinguish between different temporal patterns of light in an associative learning task. In the rod-cone dystrophy dog model of blindness, LiGluR-MAG0460 in RGCs restored robust light responses to retinal explants and intravitreal delivery of LiGluR and MAG0460 was well tolerated in vivo. The results in both large and small animal models of photoreceptor degeneration provide a path to clinical translation. PMID:25489083

In Vivo Visualization of Endoplasmic Reticulum Stress in the Retina Using the ERAI Reporter Mouse.

PubMed

Alavi, Marcel V; Chiang, Wei-Chieh; Kroeger, Heike; Yasumura, Douglas; Matthes, Michael T; Iwawaki, Takao; LaVail, Matthew M; Gould, Douglas B; Lin, Jonathan H

2015-10-01

Endoplasmic reticulum (ER) stress activates inositol requiring enzyme 1 (IRE1), a key regulator of the unfolded protein response. The ER stress activated indicator (ERAI) transgenic mouse expresses a yellow fluorescent GFP variant (Venus) when IRE1 is activated by ER stress. We tested whether ERAI mice would allow for real-time longitudinal studies of ER stress in living mouse eyes. We chemically and genetically induced ER stress, and qualitatively and quantitatively studied the Venus signal by fluorescence ophthalmoscopy. We determined retinal cell types that contribute to the signal by immunohistology, and we performed molecular and biochemical assays using whole retinal lysates to assess activity of the IRE1 pathway. We found qualitative increase in vivo in fluorescence signal at sites of intravitreal tunicamycin injection in ERAI eyes, and quantitative increase in ERAI mice mated to RhoP23H mice expressing ER stress-inducing misfolded rhodopsin protein. As expected, we found that increased Venus signal arose primarily from photoreceptors in RhoP23H/+;ERAI mice. We found increased Xbp1S and XBP1s transcriptional target mRNA levels in RhoP23H/+;ERAI retinas compared to Rho+/+;ERAI retinas, and that Venus signal increased in ERAI retinas as a function of age. Fluorescence ophthalmoscopy of ERAI mice enables in vivo visualization of retinas undergoing ER stress. ER stress activated indicator mice enable identification of individual retinal cells undergoing ER stress by immunohistochemistry. ER stress activated indicator mice show higher Venus signal at older ages, likely arising from amplification of basal retinal ER stress levels by GFP's inherent stability.

A novel mouse model of tuberous sclerosis complex (TSC): eye-specific Tsc1-ablation disrupts visual-pathway development

PubMed Central

Jones, Iwan; Hägglund, Anna-Carin; Törnqvist, Gunilla; Nord, Christoffer; Ahlgren, Ulf; Carlsson, Leif

2015-01-01

ABSTRACT Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome that is best characterised by neurodevelopmental deficits and the presence of benign tumours (called hamartomas) in affected organs. This multi-organ disorder results from inactivating point mutations in either the TSC1 or the TSC2 genes and consequent activation of the canonical mammalian target of rapamycin complex 1 signalling (mTORC1) pathway. Because lesions to the eye are central to TSC diagnosis, we report here the generation and characterisation of the first eye-specific TSC mouse model. We demonstrate that conditional ablation of Tsc1 in eye-committed progenitor cells leads to the accelerated differentiation and subsequent ectopic radial migration of retinal ganglion cells. This results in an increase in retinal ganglion cell apoptosis and consequent regionalised axonal loss within the optic nerve and topographical changes to the contra- and ipsilateral input within the dorsal lateral geniculate nucleus. Eyes from adult mice exhibit aberrant retinal architecture and display all the classic neuropathological hallmarks of TSC, including an increase in organ and cell size, ring heterotopias, hamartomas with retinal detachment, and lamination defects. Our results provide the first major insight into the molecular etiology of TSC within the developing eye and demonstrate a pivotal role for Tsc1 in regulating various aspects of visual-pathway development. Our novel mouse model therefore provides a valuable resource for future studies concerning the molecular mechanisms underlying TSC and also as a platform to evaluate new therapeutic approaches for the treatment of this multi-organ disorder. PMID:26449264

A novel mouse model of tuberous sclerosis complex (TSC): eye-specific Tsc1-ablation disrupts visual-pathway development.

PubMed

Jones, Iwan; Hägglund, Anna-Carin; Törnqvist, Gunilla; Nord, Christoffer; Ahlgren, Ulf; Carlsson, Leif

2015-12-01

Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome that is best characterised by neurodevelopmental deficits and the presence of benign tumours (called hamartomas) in affected organs. This multi-organ disorder results from inactivating point mutations in either the TSC1 or the TSC2 genes and consequent activation of the canonical mammalian target of rapamycin complex 1 signalling (mTORC1) pathway. Because lesions to the eye are central to TSC diagnosis, we report here the generation and characterisation of the first eye-specific TSC mouse model. We demonstrate that conditional ablation of Tsc1 in eye-committed progenitor cells leads to the accelerated differentiation and subsequent ectopic radial migration of retinal ganglion cells. This results in an increase in retinal ganglion cell apoptosis and consequent regionalised axonal loss within the optic nerve and topographical changes to the contra- and ipsilateral input within the dorsal lateral geniculate nucleus. Eyes from adult mice exhibit aberrant retinal architecture and display all the classic neuropathological hallmarks of TSC, including an increase in organ and cell size, ring heterotopias, hamartomas with retinal detachment, and lamination defects. Our results provide the first major insight into the molecular etiology of TSC within the developing eye and demonstrate a pivotal role for Tsc1 in regulating various aspects of visual-pathway development. Our novel mouse model therefore provides a valuable resource for future studies concerning the molecular mechanisms underlying TSC and also as a platform to evaluate new therapeutic approaches for the treatment of this multi-organ disorder. © 2015. Published by The Company of Biologists Ltd.

Use of micro computed-tomography and 3D printing for reverse engineering of mouse embryo nasal capsule

NASA Astrophysics Data System (ADS)

Tesařová, M.; Zikmund, T.; Kaucká, M.; Adameyko, I.; Jaroš, J.; Paloušek, D.; Škaroupka, D.; Kaiser, J.

2016-03-01

Imaging of increasingly complex cartilage in vertebrate embryos is one of the key tasks of developmental biology. This is especially important to study shape-organizing processes during initial skeletal formation and growth. Advanced imaging techniques that are reflecting biological needs give a powerful impulse to push the boundaries of biological visualization. Recently, techniques for contrasting tissues and organs have improved considerably, extending traditional 2D imaging approaches to 3D . X-ray micro computed tomography (μCT), which allows 3D imaging of biological objects including their internal structures with a resolution in the micrometer range, in combination with contrasting techniques seems to be the most suitable approach for non-destructive imaging of embryonic developing cartilage. Despite there are many software-based ways for visualization of 3D data sets, having a real solid model of the studied object might give novel opportunities to fully understand the shape-organizing processes in the developing body. In this feasibility study we demonstrated the full procedure of creating a real 3D object of mouse embryo nasal capsule, i.e. the staining, the μCT scanning combined by the advanced data processing and the 3D printing.

Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents

PubMed Central

Dobrivojević, Marina; Bohaček, Ivan; Erjavec, Igor; Gorup, Dunja; Gajović, Srećko

2013-01-01

Aim To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). Methods Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. Results Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. Conclusion MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema. PMID:23444240

Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents.

PubMed

Dobrivojević, Marina; Bohaček, Ivan; Erjavec, Igor; Gorup, Dunja; Gajović, Srećko

2013-02-01

To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema.

Imaging deep skeletal muscle structure using a high-sensitivity ultrathin side-viewing optical coherence tomography needle probe

PubMed Central

Yang, Xiaojie; Lorenser, Dirk; McLaughlin, Robert A.; Kirk, Rodney W.; Edmond, Matthew; Simpson, M. Cather; Grounds, Miranda D.; Sampson, David D.

2013-01-01

We have developed an extremely miniaturized optical coherence tomography (OCT) needle probe (outer diameter 310 µm) with high sensitivity (108 dB) to enable minimally invasive imaging of cellular structure deep within skeletal muscle. Three-dimensional volumetric images were acquired from ex vivo mouse tissue, examining both healthy and pathological dystrophic muscle. Individual myofibers were visualized as striations in the images. Degradation of cellular structure in necrotic regions was seen as a loss of these striations. Tendon and connective tissue were also visualized. The observed structures were validated against co-registered hematoxylin and eosin (H&E) histology sections. These images of internal cellular structure of skeletal muscle acquired with an OCT needle probe demonstrate the potential of this technique to visualize structure at the microscopic level deep in biological tissue in situ. PMID:24466482

Cognitive Styles, Demographic Attributes, Task Performance and Affective Experiences: An Empirical Investigation into Astrophysics Data System (ADS) Core Users

NASA Astrophysics Data System (ADS)

Tong, Rong

As a primary digital library portal for astrophysics researchers, SAO/NASA ADS (Astrophysics Data System) 2.0 interface features several visualization tools such as Author Network and Metrics. This research study involves 20 ADS long term users who participated in a usability and eye tracking research session. Participants first completed a cognitive test, and then performed five tasks in ADS 2.0 where they explored its multiple visualization tools. Results show that over half of the participants were Imagers and half of the participants were Analytic. Cognitive styles were found to have significant impacts on several efficiency-based measures. Analytic-oriented participants were observed to spent shorter time on web pages and apps, made fewer web page changes than less-Analytic-driving participants in performing common tasks, whereas AI (Analytic-Imagery) participants also completed their five tasks faster than non-AI participants. Meanwhile, self-identified Imagery participants were found to be more efficient in their task completion through multiple measures including total time on task, number of mouse clicks, and number of query revisions made. Imagery scores were negatively associated with frequency of confusion and the observed counts of being surprised. Compared to those who did not claimed to be a visual person, self-identified Imagery participants were observed to have significantly less frequency in frustration and hesitation during their task performance. Both demographic variables and past user experiences were found to correlate with task performance; query revision also correlated with multiple time-based measurements. Considered as an indicator of efficiency, query revisions were found to correlate negatively with the rate of complete with ease, and positively with several time-based efficiency measures, rate of complete with some difficulty, and the frequency of frustration. These results provide rich insights into the cognitive styles of ADS' core users, the impact of such styles and demographic attributes on their task performance their affective and cognitive experiences, and their interaction behaviors while using the visualization component of ADS 2.0, and would subsequently contribute to the design of bibliographic retrieval systems for scientists.

Shipboard Calibration Network Extension Utilizing COTS Products

DTIC Science & Technology

2014-09-01

to emulate the MCS system console. C. KEYBOARD VIDEO AND MOUSE (KVM) SWITCH A ServSwitch Wizard IP Plus KVM switch is used to allow remote access...9 C. KEYBOARD VIDEO AND MOUSE (KVM) SWITCH .......................... 10 D. ROUTER...mechanical, and electrical KVM Keyboard Video and Mouse LAN Local Area Network MCS Machinery Control Systems NIST National Institute of Standards and

Noninvasive multi–photon fluorescence microscopy resolves retinol and retinal–condensation products in mouse eyes

PubMed Central

Palczewska, Grazyna; Maeda, Tadao; Imanishi, Yoshikazu; Sun, Wenyu; Chen, Yu; Williams, David R.; Piston, David; Maeda, Akiko; Palczewski, Krzysztof

2010-01-01

Multi–photon excitation fluorescence microscopy (MPM) can image certain molecular processes in vivo. In the eye, fluorescent retinyl esters in sub–cellular structures called retinosomes mediate regeneration of the visual chromophore, 11–cis–retinal, by the visual cycle. But harmful fluorescent condensation products were also identified previously. We report that in wild type mice, excitation with λ ~730 nm identified retinosomes in the retinal pigment epithelium, whereas excitation with λ ~910 nm revealed at least one additional retinal fluorophore. The latter fluorescence was absent in eyes of genetically modified mice lacking a functional visual cycle, but accentuated in eyes of older WT mice and mice with defective clearance of all–trans–retinal, an intermediate in the visual cycle. MPM, a noninvasive imaging modality that facilitates concurrent monitoring of retinosomes along with potentially harmful products in aging eyes, has the potential to detect early molecular changes due to age–related macular degeneration and other defects in retinoid metabolism. PMID:21076393

Three Types of Cortical L5 Neurons that Differ in Brain-Wide Connectivity and Function

PubMed Central

Kim, Euiseok J.; Juavinett, Ashley L.; Kyubwa, Espoir M.; Jacobs, Matthew W.; Callaway, Edward M.

2015-01-01

SUMMARY Cortical layer 5 (L5) pyramidal neurons integrate inputs from many sources and distribute outputs to cortical and subcortical structures. Previous studies demonstrate two L5 pyramid types: cortico-cortical (CC) and cortico-subcortical (CS). We characterize connectivity and function of these cell types in mouse primary visual cortex and reveal a new subtype. Unlike previously described L5 CC and CS neurons, this new subtype does not project to striatum [cortico-cortical, non-striatal (CC-NS)] and has distinct morphology, physiology and visual responses. Monosynaptic rabies tracing reveals that CC neurons preferentially receive input from higher visual areas, while CS neurons receive more input from structures implicated in top-down modulation of brain states. CS neurons are also more direction-selective and prefer faster stimuli than CC neurons. These differences suggest distinct roles as specialized output channels, with CS neurons integrating information and generating responses more relevant to movement control and CC neurons being more important in visual perception. PMID:26671462

Three Types of Cortical Layer 5 Neurons That Differ in Brain-wide Connectivity and Function.

PubMed

Kim, Euiseok J; Juavinett, Ashley L; Kyubwa, Espoir M; Jacobs, Matthew W; Callaway, Edward M

2015-12-16

Cortical layer 5 (L5) pyramidal neurons integrate inputs from many sources and distribute outputs to cortical and subcortical structures. Previous studies demonstrate two L5 pyramid types: cortico-cortical (CC) and cortico-subcortical (CS). We characterize connectivity and function of these cell types in mouse primary visual cortex and reveal a new subtype. Unlike previously described L5 CC and CS neurons, this new subtype does not project to striatum [cortico-cortical, non-striatal (CC-NS)] and has distinct morphology, physiology, and visual responses. Monosynaptic rabies tracing reveals that CC neurons preferentially receive input from higher visual areas, while CS neurons receive more input from structures implicated in top-down modulation of brain states. CS neurons are also more direction-selective and prefer faster stimuli than CC neurons. These differences suggest distinct roles as specialized output channels, with CS neurons integrating information and generating responses more relevant to movement control and CC neurons being more important in visual perception. Copyright © 2015 Elsevier Inc. All rights reserved.

Preclinical Magnetic Resonance Imaging and Systems Biology in Cancer Research

PubMed Central

Albanese, Chris; Rodriguez, Olga C.; VanMeter, John; Fricke, Stanley T.; Rood, Brian R.; Lee, YiChien; Wang, Sean S.; Madhavan, Subha; Gusev, Yuriy; Petricoin, Emanuel F.; Wang, Yue

2014-01-01

Biologically accurate mouse models of human cancer have become important tools for the study of human disease. The anatomical location of various target organs, such as brain, pancreas, and prostate, makes determination of disease status difficult. Imaging modalities, such as magnetic resonance imaging, can greatly enhance diagnosis, and longitudinal imaging of tumor progression is an important source of experimental data. Even in models where the tumors arise in areas that permit visual determination of tumorigenesis, longitudinal anatomical and functional imaging can enhance the scope of studies by facilitating the assessment of biological alterations, (such as changes in angiogenesis, metabolism, cellular invasion) as well as tissue perfusion and diffusion. One of the challenges in preclinical imaging is the development of infrastructural platforms required for integrating in vivo imaging and therapeutic response data with ex vivo pathological and molecular data using a more systems-based multiscale modeling approach. Further challenges exist in integrating these data for computational modeling to better understand the pathobiology of cancer and to better affect its cure. We review the current applications of preclinical imaging and discuss the implications of applying functional imaging to visualize cancer progression and treatment. Finally, we provide new data from an ongoing preclinical drug study demonstrating how multiscale modeling can lead to a more comprehensive understanding of cancer biology and therapy. PMID:23219428

Comparative analysis and visualization of multiple collinear genomes

PubMed Central

2012-01-01

Background Genome browsers are a common tool used by biologists to visualize genomic features including genes, polymorphisms, and many others. However, existing genome browsers and visualization tools are not well-suited to perform meaningful comparative analysis among a large number of genomes. With the increasing quantity and availability of genomic data, there is an increased burden to provide useful visualization and analysis tools for comparison of multiple collinear genomes such as the large panels of model organisms which are the basis for much of the current genetic research. Results We have developed a novel web-based tool for visualizing and analyzing multiple collinear genomes. Our tool illustrates genome-sequence similarity through a mosaic of intervals representing local phylogeny, subspecific origin, and haplotype identity. Comparative analysis is facilitated through reordering and clustering of tracks, which can vary throughout the genome. In addition, we provide local phylogenetic trees as an alternate visualization to assess local variations. Conclusions Unlike previous genome browsers and viewers, ours allows for simultaneous and comparative analysis. Our browser provides intuitive selection and interactive navigation about features of interest. Dynamic visualizations adjust to scale and data content making analysis at variable resolutions and of multiple data sets more informative. We demonstrate our genome browser for an extensive set of genomic data sets composed of almost 200 distinct mouse laboratory strains. PMID:22536897

Characterization of the retina in the alpha7 nicotinic acetylcholine receptor knockout mouse

NASA Astrophysics Data System (ADS)

Smith, Marci L.

Acetylcholine receptors (AChRs) are involved in visual processing and are expressed by inner retinal neurons in all species studied to date (Keyser et al., 2000; Dmitrieva et al., 2007; Liu et al., 2009), but their distribution in the mouse retina remains unknown. Reductions in alpha7 nicotinic AChRs (nAChRs) are thought to contribute to memory and visual deficits observed in Alzheimer's and schizophrenia (Coyle et al., 1983; Nordberg et al., 1999; Leonard et al., 2006). However, the alpha7 nAChR knockout (KO) mouse has a mild phenotype (Paylor et al., 1998; Fernandes et al., 2006; Young et al., 2007; Origlia et al., 2012). The purpose of this study was to determine the expression of AChRs in wildtype (WT) mouse retina and to assess whether up-regulation of other AChRs in the alpha7 nAChR KO retina may explain the minimal deficits described in the KO mouse. Reverse-transcriptase PCR (RT-PCR) showed that mRNA transcripts for alpha2-7, alpha 9, alpha10, beta2-4 nAChR subunits and m1-m5 muscarinic AChR (mAChR) subtypes were present in WT murine retina. Western blot analysis confirmed the presence of alpha3-5, alpha9, and m1-m5 AChR proteins and immunohistochemical analysis demonstrated nAChR and mAChR proteins expressed by subsets of bipolar, amacrine and ganglion cells. This is the first reported expression of alpha9 and alpha10 nAChR transcripts and alpha9 nAChR proteins in the retina of any species. Quantitative RT-PCR (qPCR) showed changes in AChR transcript expression in the alpha7 nAChR KO mouse retina relative to WT. Within whole retina alpha2, alpha9, alpha10, beta4, m1 and m4 AChR transcripts were up-regulated, while alpha5 nAChR transcripts were down-regulated. However, cell populations showed subtle differences; m4 mAChR transcripts were up-regulated in the ganglion cell layer and outer portion of the inner nuclear layer (oINL),while beta4 nAChR transcript up-regulation was limited to the oINL. Surprisingly, alpha2, alpha9, beta4, m2 and m4 transcripts were down-regulated in the inner portion of the INL. These results indicate that compensation is mediated by differential regulation of more than one receptor type and changes in mRNA expression vary between cell populations.

Interactive 3D Mars Visualization

NASA Technical Reports Server (NTRS)

Powell, Mark W.

2012-01-01

The Interactive 3D Mars Visualization system provides high-performance, immersive visualization of satellite and surface vehicle imagery of Mars. The software can be used in mission operations to provide the most accurate position information for the Mars rovers to date. When integrated into the mission data pipeline, this system allows mission planners to view the location of the rover on Mars to 0.01-meter accuracy with respect to satellite imagery, with dynamic updates to incorporate the latest position information. Given this information so early in the planning process, rover drivers are able to plan more accurate drive activities for the rover than ever before, increasing the execution of science activities significantly. Scientifically, this 3D mapping information puts all of the science analyses to date into geologic context on a daily basis instead of weeks or months, as was the norm prior to this contribution. This allows the science planners to judge the efficacy of their previously executed science observations much more efficiently, and achieve greater science return as a result. The Interactive 3D Mars surface view is a Mars terrain browsing software interface that encompasses the entire region of exploration for a Mars surface exploration mission. The view is interactive, allowing the user to pan in any direction by clicking and dragging, or to zoom in or out by scrolling the mouse or touchpad. This set currently includes tools for selecting a point of interest, and a ruler tool for displaying the distance between and positions of two points of interest. The mapping information can be harvested and shared through ubiquitous online mapping tools like Google Mars, NASA WorldWind, and Worldwide Telescope.

A non-retinoid antagonist of Retinol-Binding Protein 4 rescues phenotype in a model of Stargardt disease without inhibiting the visual cycle.

PubMed

Racz, Boglarka; Varadi, Andras; Kong, Jian; Allikmets, Rando; Pearson, Paul G; Johnson, Graham; Cioffi, Christopher L; Petrukhin, Konstantin

2018-06-05

A primary pathological defect in the heritable eye disorder Stargardt disease is excessive accumulation of cytotoxic lipofuscin bisretinoids in the retina. Age-dependent accumulation of lipofuscin in the retinal pigment epithelium (RPE) matches the age-dependent increase in the incidence of the atrophic (dry) form of age-related macular degeneration (AMD) and therefore may be one of several pathogenic factors contributing to AMD progression. Lipofuscin bisretinoid synthesis in the retina depends on the influx of serum retinol from the circulation into the RPE. Formation of the tertiary retinol-binding protein 4 (RBP4)-transthyretin-retinol complex in the serum is required for this influx. Herein, we report the pharmacological effects of the non-retinoid RBP4 antagonist, BPN-14136. BPN-14136 dosing in the Abca4-/- mouse model of increased lipofuscinogenesis significantly reduced serum RBP4 levels and inhibited bisretinoid synthesis, and this inhibition correlated with a partial reduction in visual cycle retinoids such as retinaldehydes serving as bisretinoid precursors. BPN-14136 administration at doses inducing maximal serum RBP4 reduction did not produce changes in the rate of the visual cycle, consistent with minimal changes in dark adaptation. Abca4-/- mice exhibited dysregulation of the complement system in the retina, and BPN-14136 administration normalized the retinal levels of proinflammatory complement cascade components such as complement factors D and H, C-reactive protein, and C3. We conclude that BPN-14136 has several beneficial characteristics, combining inhibition of bisretinoid synthesis and reduction in retinaldehydes with normalization of the retinal complement system. BPN-14136, or a similar compound, may be a promising drug candidate to manage Stargardt disease and dry AMD. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Visualizing Epithelial Expression in Vertical and Horizontal Planes With Dual Axes Confocal Endomicroscope Using Compact Distal Scanner.

PubMed

Li, Gaoming; Li, Haijun; Duan, Xiyu; Zhou, Quan; Zhou, Juan; Oldham, Kenn R; Wang, Thomas D

2017-07-01

The epithelium is a thin layer of tissue that lines hollow organs, such as colon. Visualizing in vertical cross sections with sub-cellular resolution is essential to understanding early disease mechanisms that progress naturally in the plane perpendicular to the tissue surface. The dual axes confocal architecture collects optical sections in tissue by directing light at an angle incident to the surface using separate illumination and collection beams to reduce effects of scattering, enhance dynamic range, and increase imaging depth. This configuration allows for images to be collected in the vertical as well as horizontal planes. We designed a fast, compact monolithic scanner based on the principle of parametric resonance. The mirrors were fabricated using microelectromechanical systems (MEMS) technology and were coated with aluminum to maximize near-infrared reflectivity. We achieved large axial displacements [Formula: see text] and wide lateral deflections >20°. The MEMS chip has a 3.2×2.9 mm 2 form factor that allows for efficient packaging in the distal end of an endomicroscope. Imaging can be performed in either the vertical or horizontal planes with [Formula: see text] depth or 1 ×1 mm 2 area, respectively, at 5 frames/s. We systemically administered a Cy5.5-labeled peptide that is specific for EGFR, and collected near-infrared fluorescence images ex vivo from pre-malignant mouse colonic epithelium to reveal the spatial distribution of this molecular target. Here, we demonstrate a novel scanning mechanism in a dual axes confocal endomicroscope that collects optical sections of near-infrared fluorescence in either vertical or horizontal planes to visualize molecular expression in the epithelium.

A Low-Cost, Reliable, High-Throughput System for Rodent Behavioral Phenotyping in a Home Cage Environment

PubMed Central

Parkison, Steven A.; Carlson, Jay D.; Chaudoin, Tammy R.; Hoke, Traci A.; Schenk, A. Katrin; Goulding, Evan H.; Pérez, Lance C.; Bonasera, Stephen J.

2016-01-01

Inexpensive, high-throughput, low maintenance systems for precise temporal and spatial measurement of mouse home cage behavior (including movement, feeding, and drinking) are required to evaluate products from large scale pharmaceutical design and genetic lesion programs. These measurements are also required to interpret results from more focused behavioral assays. We describe the design and validation of a highly-scalable, reliable mouse home cage behavioral monitoring system modeled on a previously described, one-of-a-kind system [1]. Mouse position was determined by solving static equilibrium equations describing the force and torques acting on the system strain gauges; feeding events were detected by a photobeam across the food hopper, and drinking events were detected by a capacitive lick sensor. Validation studies show excellent agreement between mouse position and drinking events measured by the system compared with video-based observation – a gold standard in neuroscience. PMID:23366406

Multimodal nonlinear optical imaging of cartilage development in mouse model

NASA Astrophysics Data System (ADS)

He, Sicong; Xue, Wenqian; Sun, Qiqi; Li, Xuesong; Huang, Jiandong; Qu, Jianan Y.

2017-02-01

Kinesin-1 is a kind of motor protein responsible for intracellular transportation and has been studied in a variety of tissues. However, its roles in cartilage development are not clear. In this study, a kinesin-1 heavy chain (Kif5b) knockout mouse model is used to study the functions of kinesin-1 in the cartilage development. We developed a multimodal nonlinear optical (NLO) microscope system integrating stimulated Raman scattering (SRS), second harmonic generation (SHG) and two-photon excited fluorescence (TPEF) to investigate the morphological and biomedical characteristics of fresh tibial cartilage from normal and mutant mice at different developmental stages. The combined forward and backward SHG imaging resolved the fine structure of collagen fibrils in the extracellular matrix of cartilage. Meanwhile, the chondrocyte morphology in different zones of cartilage was visualized by label-free SRS and TPEF images. The results show that the fibrillar collagen in the superficial zone of cartilage in postnatal day 10 and 15 (P10 and P15) knockout mice was significantly less than that of control mice. Moreover, we observed distorted morphology and disorganization of columnar arrangement of chondrocytes in the growth plate cartilage of mutant mice. This study reveals the significant roles of kinesin-1 in collagen formation and chondrocyte morphogenesis.

Urokinase injection-triggered clearance enhancement of a 4-arm PEG-conjugated 64Cu-bombesin analog tetramer: A novel approach for the improvement of PET imaging contrast.

PubMed

Matsumura, Kazushi; Zouda, Maki; Wada, Yasuhiro; Yamashita, Fumiyoshi; Hashida, Mitsuru; Watanabe, Yasuyoshi; Mukai, Hidefumi

2018-05-07

Radiolabeled antibodies, polyethylene glycol-conjugated (PEGylated) peptides, liposomes, and other materials were investigated as positron-emission tomography (PET) probes. These substances accumulate in tumors but often remain too long in circulation. We investigated the combination of intravenous urokinase injection and its substrate linker as a triggered radioisotope clearance enhancement system to improve imaging contrast. To this end, we synthesized a four-arm PEGylated 64 Cu-bombesin analog tetramer with a urokinase substrate linker. In mouse blood, it was almost perfectly cleaved and degraded into smaller radioactive fragments in vitro with urokinase (≥20,000 IU/mL). In mouse blood circulation, ∼50-65% of the probe was rapidly degraded after the urokinase injection and the radioactive fragments were eliminated mainly from the kidney. In contrast, tumor radioactivity levels did not change, and therefore, the tumors were clearly visualized. The tumor/blood ratio, an indicator of imaging contrast, increased 2.5 times, while elimination of the radioisotope from the blood was enhanced. This approach has the potential to improve imaging contrast using various PET probes. It could also shorten the time required to obtain sufficient contrast and decrease patient radiation exposure. Copyright © 2018 Elsevier B.V. All rights reserved.

Predators Are Attracted to the Olfactory Signals of Prey

PubMed Central

Hughes, Nelika K.; Price, Catherine J.; Banks, Peter B.

2010-01-01

Background Predator attraction to prey social signals can force prey to trade-off the social imperatives to communicate against the profound effect of predation on their future fitness. These tradeoffs underlie theories on the design and evolution of conspecific signalling systems and have received much attention in visual and acoustic signalling modes. Yet while most territorial mammals communicate using olfactory signals and olfactory hunting is widespread in predators, evidence for the attraction of predators to prey olfactory signals under field conditions is lacking. Methodology/Principal Findings To redress this fundamental issue, we examined the attraction of free-roaming predators to discrete patches of scents collected from groups of two and six adult, male house mice, Mus domesticus, which primarily communicate through olfaction. Olfactorily-hunting predators were rapidly attracted to mouse scent signals, visiting mouse scented locations sooner, and in greater number, than control locations. There were no effects of signal concentration on predator attraction to their prey's signals. Conclusions/Significance This implies that communication will be costly if conspecific receivers and eavesdropping predators are simultaneously attracted to a signal. Significantly, our results also suggest that receivers may be at greater risk of predation when communicating than signallers, as receivers must visit risky patches of scent to perform their half of the communication equation, while signallers need not. PMID:20927352

Optical coherence microscopy as a novel, non-invasive method for the 4D live imaging of early mammalian embryos.

PubMed

Karnowski, Karol; Ajduk, Anna; Wieloch, Bartosz; Tamborski, Szymon; Krawiec, Krzysztof; Wojtkowski, Maciej; Szkulmowski, Maciej

2017-06-23

Imaging of living cells based on traditional fluorescence and confocal laser scanning microscopy has delivered an enormous amount of information critical for understanding biological processes in single cells. However, the requirement for a high numerical aperture and fluorescent markers still limits researchers' ability to visualize the cellular architecture without causing short- and long-term photodamage. Optical coherence microscopy (OCM) is a promising alternative that circumvents the technical limitations of fluorescence imaging techniques and provides unique access to fundamental aspects of early embryonic development, without the requirement for sample pre-processing or labeling. In the present paper, we utilized the internal motion of cytoplasm, as well as custom scanning and signal processing protocols, to effectively reduce the speckle noise typical for standard OCM and enable high-resolution intracellular time-lapse imaging. To test our imaging system we used mouse and pig oocytes and embryos and visualized them through fertilization and the first embryonic division, as well as at selected stages of oogenesis and preimplantation development. Because all morphological and morphokinetic properties recorded by OCM are believed to be biomarkers of oocyte/embryo quality, OCM may represent a new chapter in imaging-based preimplantation embryo diagnostics.

Mouse Curve Biometrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulz, Douglas A.

2007-10-08

A biometric system suitable for validating user identity using only mouse movements and no specialized equipment is presented. Mouse curves (mouse movements with little or no pause between them) are individually classied and used to develop classication histograms, which are representative of an individual's typical mouse use. These classication histograms can then be compared to validate identity. This classication approach is suitable for providing continuous identity validation during an entire user session.

Skeletal, cardiac, and respiratory muscle function and histopathology in the P448Lneo- mouse model of FKRP-deficient muscular dystrophy.

PubMed

Yu, Qing; Morales, Melissa; Li, Ning; Fritz, Alexander G; Ruobing, Ren; Blaeser, Anthony; Francois, Ershia; Lu, Qi-Long; Nagaraju, Kanneboyina; Spurney, Christopher F

2018-04-06

Fukutin-related protein (FKRP) mutations are the most common cause of dystroglycanopathies known to cause both limb girdle and congenital muscular dystrophy. The P448Lneo- mouse model has a knock-in mutation in the FKRP gene and develops skeletal, respiratory, and cardiac muscle disease. We studied the natural history of the P448Lneo- mouse model over 9 months and the effects of twice weekly treadmill running. Forelimb and hindlimb grip strength (Columbus Instruments) and overall activity (Omnitech Electronics) assessed skeletal muscle function. Echocardiography was performed using VisualSonics Vevo 770 (FujiFilm VisualSonics). Plethysmography was performed using whole body system (ADInstruments). Histological evaluations included quantification of inflammation, fibrosis, central nucleation, and fiber size variation. P448Lneo- mice had significantly increased normalized tissue weights compared to controls at 9 months of age for the heart, gastrocnemius, soleus, tibialis anterior, quadriceps, and triceps. There were no significant differences seen in forelimb or hindlimb grip strength or activity monitoring in P448Lneo- mice with or without exercise compared to controls. Skeletal muscles demonstrated increased inflammation, fibrosis, central nucleation, and variation in fiber size compared to controls (p < 0.05) and worsened with exercise. Plethysmography showed significant differences in respiratory rates and decreased tidal and minute volumes in P448Lneo- mice (p < 0.01). There was increased fibrosis in the diaphragm compared to controls (p < 0.01). Echocardiography demonstrated decreased systolic function in 9-month-old mutant mice (p < 0.01). There was increased myocardial wall thickness and mass (p < 0.001) with increased fibrosis in 9-month-old P448Lneo- mice compared to controls (p < 0.05). mRNA expression for natriuretic peptide type A (Nppa) was significantly increased in P448Lneo- mice compared to controls at 6 months (p < 0.05) and for natriuretic peptide type B (Nppb) at 6 and 9 months of age (p < 0.05). FKRP-deficient P448Lneo- mice demonstrate significant deficits in cardiac and respiratory functions compared to control mice, and this is associated with increased inflammation and fibrosis. This study provides new functional outcome measures for preclinical trials of FKRP-related muscular dystrophies.

4D atlas of the mouse embryo for precise morphological staging.

PubMed

Wong, Michael D; van Eede, Matthijs C; Spring, Shoshana; Jevtic, Stefan; Boughner, Julia C; Lerch, Jason P; Henkelman, R Mark

2015-10-15

After more than a century of research, the mouse remains the gold-standard model system, for it recapitulates human development and disease and is quickly and highly tractable to genetic manipulations. Fundamental to the power and success of using a mouse model is the ability to stage embryonic mouse development accurately. Past staging systems were limited by the technologies of the day, such that only surface features, visible with a light microscope, could be recognized and used to define stages. With the advent of high-throughput 3D imaging tools that capture embryo morphology in microscopic detail, we now present the first 4D atlas staging system for mouse embryonic development using optical projection tomography and image registration methods. By tracking 3D trajectories of every anatomical point in the mouse embryo from E11.5 to E14.0, we established the first 4D atlas compiled from ex vivo 3D mouse embryo reference images. The resulting 4D atlas comprises 51 interpolated 3D images in this gestational range, resulting in a temporal resolution of 72 min. From this 4D atlas, any mouse embryo image can be subsequently compared and staged at the global, voxel and/or structural level. Assigning an embryonic stage to each point in anatomy allows for unprecedented quantitative analysis of developmental asynchrony among different anatomical structures in the same mouse embryo. This comprehensive developmental data set offers developmental biologists a new, powerful staging system that can identify and compare differences in developmental timing in wild-type embryos and shows promise for localizing deviations in mutant development. © 2015. Published by The Company of Biologists Ltd.

Differences in Pathogenesis for Salmonella enterica serovar Typhimurium in the Mouse Versus the Swine Model Identify Bacterial Gene Products Required for Systemic but not Gastrointestinal Disease

USDA-ARS?s Scientific Manuscript database

Over the last several decades, the mouse model of Typhoid fever has been an extremely productive model to investigate Salmonella enterica serovar Typhimurium pathogenesis. The mouse is the paradigm for investigating systemic disease due to infection by Salmonella; however, the swine model of gastro...

Probing myocardium biomechanics using quantitative optical coherence elastography

NASA Astrophysics Data System (ADS)

Wang, Shang; Lopez, Andrew L.; Morikawa, Yuka; Tao, Ge; Li, Jiasong; Larina, Irina V.; Martin, James F.; Larin, Kirill V.

2015-03-01

We present a quantitative optical coherence elastographic method for noncontact assessment of the myocardium elasticity. The method is based on shear wave imaging optical coherence tomography (SWI-OCT), where a focused air-puff system is used to induce localized tissue deformation through a low-pressure short-duration air stream and a phase-sensitive OCT system is utilized to monitor the propagation of the induced tissue displacement with nanoscale sensitivity. The 1-D scanning of M-mode OCT imaging and the application of optical phase retrieval and mapping techniques enable the reconstruction and visualization of 2-D depth-resolved shear wave propagation in tissue with ultra-high frame rate. The feasibility of this method in quantitative elasticity measurement is demonstrated on tissue-mimicking phantoms with the estimated Young's modulus compared with uniaxial compression tests. We also performed pilot experiments on ex vivo mouse cardiac muscle tissues with normal and genetically altered cardiomyocytes. Our results indicate this noncontact quantitative optical coherence elastographic method can be a useful tool for the cardiac muscle research and studies.

Mutagenicity testing with transgenic mice. Part II: Comparison with the mouse spot test

PubMed Central

Wahnschaffe, Ulrich; Bitsch, Annette; Kielhorn, Janet; Mangelsdorf, Inge

2005-01-01

The mouse spot test, an in vivo mutation assay, has been used to assess a number of chemicals. It is at present the only in vivo mammalian test system capable of detecting somatic gene mutations according to OECD guidelines (OECD guideline 484). It is however rather insensitive, animal consuming and expensive type of test. More recently several assays using transgenic animals have been developed. From data in the literature, the present study compares the results of in vivo testing of over twenty chemicals using the mouse spot test and compares them with results from the two transgenic mouse models with the best data base available, the lacI model (commercially available as the Big Blue® mouse), and the lacZ model (commercially available as the Muta™ Mouse). There was agreement in the results from the majority of substances. No differences were found in the predictability of the transgenic animal assays and the mouse spot test for carcinogenicity. However, from the limited data available, it seems that the transgenic mouse assay has several advantages over the mouse spot test and may be a suitable test system replacing the mouse spot test for detection of gene but not chromosome mutations in vivo. PMID:15676065

Method, accuracy and limitation of computer interaction in the operating room by a navigated surgical instrument.

PubMed

Hurka, Florian; Wenger, Thomas; Heininger, Sebastian; Lueth, Tim C

2011-01-01

This article describes a new interaction device for surgical navigation systems--the so-called navigation mouse system. The idea is to use a tracked instrument of a surgical navigation system like a pointer to control the software. The new interaction system extends existing navigation systems with a microcontroller-unit. The microcontroller-unit uses the existing communication line to extract the needed 3D-information of an instrument to calculate positions analogous to the PC mouse cursor and click events. These positions and events are used to manipulate the navigation system. In an experimental setup the reachable accuracy with the new mouse system is shown.

The Role of the Oculomotor System in Updating Visual-Spatial Working Memory across Saccades

PubMed Central

Boon, Paul J.; Belopolsky, Artem V.; Theeuwes, Jan

2016-01-01

Visual-spatial working memory (VSWM) helps us to maintain and manipulate visual information in the absence of sensory input. It has been proposed that VSWM is an emergent property of the oculomotor system. In the present study we investigated the role of the oculomotor system in updating of spatial working memory representations across saccades. Participants had to maintain a location in memory while making a saccade to a different location. During the saccade the target was displaced, which went unnoticed by the participants. After executing the saccade, participants had to indicate the memorized location. If memory updating fully relies on cancellation driven by extraretinal oculomotor signals, the displacement should have no effect on the perceived location of the memorized stimulus. However, if postsaccadic retinal information about the location of the saccade target is used, the perceived location will be shifted according to the target displacement. As it has been suggested that maintenance of accurate spatial representations across saccades is especially important for action control, we used different ways of reporting the location held in memory; a match-to-sample task, a mouse click or by making another saccade. The results showed a small systematic target displacement bias in all response modalities. Parametric manipulation of the distance between the to-be-memorized stimulus and saccade target revealed that target displacement bias increased over time and changed its spatial profile from being initially centered on locations around the saccade target to becoming spatially global. Taken together results suggest that we neither rely exclusively on extraretinal nor on retinal information in updating working memory representations across saccades. The relative contribution of retinal signals is not fixed but depends on both the time available to integrate these signals as well as the distance between the saccade target and the remembered location. PMID:27631767

Multiscale Imaging of the Mouse Cortex Using Two-Photon Microscopy and Wide-Field Illumination

NASA Astrophysics Data System (ADS)

Bumstead, Jonathan R.

The mouse brain can be studied over vast spatial scales ranging from microscopic imaging of single neurons to macroscopic measurements of hemodynamics acquired over the majority of the mouse cortex. However, most neuroimaging modalities are limited by a fundamental trade-off between the spatial resolution and the field-of-view (FOV) over which the brain can be imaged, making it difficult to fully understand the functional and structural architecture of the healthy mouse brain and its disruption in disease. My dissertation has focused on developing multiscale optical systems capable of imaging the mouse brain at both microscopic and mesoscopic spatial scales, specifically addressing the difference in spatial scales imaged with two-photon microscopy (TPM) and optical intrinsic signal imaging (OISI). Central to this work has been the formulation of a principled design strategy for extending the FOV of the two-photon microscope. Using this design approach, we constructed a TPM system with subcellular resolution and a FOV area 100 times greater than a conventional two-photon microscope. To image the ellipsoidal shape of the mouse cortex, we also developed the microscope to image arbitrary surfaces within a single frame using an electrically tunable lens. Finally, to address the speed limitations of the TPM systems developed during my dissertation, I also conducted research in large-scale neural phenomena occurring in the mouse brain imaged with high-speed OISI. The work conducted during my dissertation addresses some of the fundamental principles in designing and applying optical systems for multiscale imaging of the mouse brain.

Mouse fetal whole intestine culture system for ex vivo manipulation of signaling pathways and three-dimensional live imaging of villus development.

PubMed

Walton, Katherine D; Kolterud, Asa

2014-09-04

Most morphogenetic processes in the fetal intestine have been inferred from thin sections of fixed tissues, providing snapshots of changes over developmental stages. Three-dimensional information from thin serial sections can be challenging to interpret because of the difficulty of reconstructing serial sections perfectly and maintaining proper orientation of the tissue over serial sections. Recent findings by Grosse et al., 2011 highlight the importance of three- dimensional information in understanding morphogenesis of the developing villi of the intestine(1). Three-dimensional reconstruction of singly labeled intestinal cells demonstrated that the majority of the intestinal epithelial cells contact both the apical and basal surfaces. Furthermore, three-dimensional reconstruction of the actin cytoskeleton at the apical surface of the epithelium demonstrated that the intestinal lumen is continuous and that secondary lumens are an artifact of sectioning. Those two points, along with the demonstration of interkinetic nuclear migration in the intestinal epithelium, defined the developing intestinal epithelium as a pseudostratified epithelium and not stratified as previously thought(1). The ability to observe the epithelium three-dimensionally was seminal to demonstrating this point and redefining epithelial morphogenesis in the fetal intestine. With the evolution of multi-photon imaging technology and three-dimensional reconstruction software, the ability to visualize intact, developing organs is rapidly improving. Two-photon excitation allows less damaging penetration deeper into tissues with high resolution. Two-photon imaging and 3D reconstruction of the whole fetal mouse intestines in Walton et al., 2012 helped to define the pattern of villus outgrowth(2). Here we describe a whole organ culture system that allows ex vivo development of villi and extensions of that culture system to allow the intestines to be three-dimensionally imaged during their development.

PyGaze: an open-source, cross-platform toolbox for minimal-effort programming of eyetracking experiments.

PubMed

Dalmaijer, Edwin S; Mathôt, Sebastiaan; Van der Stigchel, Stefan

2014-12-01

The PyGaze toolbox is an open-source software package for Python, a high-level programming language. It is designed for creating eyetracking experiments in Python syntax with the least possible effort, and it offers programming ease and script readability without constraining functionality and flexibility. PyGaze can be used for visual and auditory stimulus presentation; for response collection via keyboard, mouse, joystick, and other external hardware; and for the online detection of eye movements using a custom algorithm. A wide range of eyetrackers of different brands (EyeLink, SMI, and Tobii systems) are supported. The novelty of PyGaze lies in providing an easy-to-use layer on top of the many different software libraries that are required for implementing eyetracking experiments. Essentially, PyGaze is a software bridge for eyetracking research.

Ultrahigh resolution optical coherence elastography using a Bessel beam for extended depth of field

NASA Astrophysics Data System (ADS)

Curatolo, Andrea; Villiger, Martin; Lorenser, Dirk; Wijesinghe, Philip; Fritz, Alexander; Kennedy, Brendan F.; Sampson, David D.

2016-03-01

Visualizing stiffness within the local tissue environment at the cellular and sub-cellular level promises to provide insight into the genesis and progression of disease. In this paper, we propose ultrahigh-resolution optical coherence elastography, and demonstrate three-dimensional imaging of local axial strain of tissues undergoing compressive loading. The technique employs a dual-arm extended focus optical coherence microscope to measure tissue displacement under compression. The system uses a broad bandwidth supercontinuum source for ultrahigh axial resolution, Bessel beam illumination and Gaussian beam detection, maintaining sub-2 μm transverse resolution over nearly 100 μm depth of field, and spectral-domain detection allowing high displacement sensitivity. The system produces strain elastograms with a record resolution (x,y,z) of 2×2×15 μm. We benchmark the advances in terms of resolution and strain sensitivity by imaging a suitable inclusion phantom. We also demonstrate this performance on freshly excised mouse aorta and reveal the mechanical heterogeneity of vascular smooth muscle cells and elastin sheets, otherwise unresolved in a typical, lower resolution optical coherence elastography system.

Binocular Goggle Augmented Imaging and Navigation System provides real-time fluorescence image guidance for tumor resection and sentinel lymph node mapping

NASA Astrophysics Data System (ADS)

B. Mondal, Suman; Gao, Shengkui; Zhu, Nan; Sudlow, Gail P.; Liang, Kexian; Som, Avik; Akers, Walter J.; Fields, Ryan C.; Margenthaler, Julie; Liang, Rongguang; Gruev, Viktor; Achilefu, Samuel

2015-07-01

The inability to identify microscopic tumors and assess surgical margins in real-time during oncologic surgery leads to incomplete tumor removal, increases the chances of tumor recurrence, and necessitates costly repeat surgery. To overcome these challenges, we have developed a wearable goggle augmented imaging and navigation system (GAINS) that can provide accurate intraoperative visualization of tumors and sentinel lymph nodes in real-time without disrupting normal surgical workflow. GAINS projects both near-infrared fluorescence from tumors and the natural color images of tissue onto a head-mounted display without latency. Aided by tumor-targeted contrast agents, the system detected tumors in subcutaneous and metastatic mouse models with high accuracy (sensitivity = 100%, specificity = 98% ± 5% standard deviation). Human pilot studies in breast cancer and melanoma patients using a near-infrared dye show that the GAINS detected sentinel lymph nodes with 100% sensitivity. Clinical use of the GAINS to guide tumor resection and sentinel lymph node mapping promises to improve surgical outcomes, reduce rates of repeat surgery, and improve the accuracy of cancer staging.

Stimulus relevance modulates contrast adaptation in visual cortex

PubMed Central

Keller, Andreas J; Houlton, Rachael; Kampa, Björn M; Lesica, Nicholas A; Mrsic-Flogel, Thomas D; Keller, Georg B; Helmchen, Fritjof

2017-01-01

A general principle of sensory processing is that neurons adapt to sustained stimuli by reducing their response over time. Most of our knowledge on adaptation in single cells is based on experiments in anesthetized animals. How responses adapt in awake animals, when stimuli may be behaviorally relevant or not, remains unclear. Here we show that contrast adaptation in mouse primary visual cortex depends on the behavioral relevance of the stimulus. Cells that adapted to contrast under anesthesia maintained or even increased their activity in awake naïve mice. When engaged in a visually guided task, contrast adaptation re-occurred for stimuli that were irrelevant for solving the task. However, contrast adaptation was reversed when stimuli acquired behavioral relevance. Regulation of cortical adaptation by task demand may allow dynamic control of sensory-evoked signal flow in the neocortex. DOI: http://dx.doi.org/10.7554/eLife.21589.001 PMID:28130922

Enhanced Antigen Retrieval of Amyloid β Immunohistochemistry

PubMed Central

Kai, Hideaki; Ogino, Koichi; Hatsuta, Hiroyuki; Murayama, Shigeo; Kitamoto, Tetsuyuki

2012-01-01

Senile plaques, extracellular deposits of amyloid β peptide (Aβ), are one of the pathological hallmarks of Alzheimer disease (AD). As the standard immunohistochemical detection method for Aβ deposits, anti-Aβ immunohistochemistry combined with antigen retrieval (AR) by formic acid (FA) has been generally used. Here, we present a more efficient AR for Aβ antigen. On brain sections of AD and its mouse model, a double combination of either autoclave heating in EDTA buffer or digestion with proteinase K plus FA treatment reinforced Aβ immunoreactivity. A further triple combination of digestion with proteinase K (P), autoclave heating in EDTA buffer (A), and FA treatment (F), when employed in this order, gave a more enhanced immunoreactivity. Our PAF method prominently visualized various forms of Aβ deposits in AD that have not been clearly detected previously and revealed numerous minute-sized plaques both in AD and the mouse model. Quantification of Aβ loads showed that the AR effect by the PAF method was 1.86-fold (in the aged human brain) and 4.64-fold (in the mouse brain) higher than that by the FA method. Thus, the PAF method could have the potential to be the most sensitive tool so far to study Aβ pathology in AD and its mouse model. PMID:22821668

Nimesulide, a COX-2 inhibitor, does not reduce lesion size or number in a nude mouse model of endometriosis.

PubMed

Hull, M L; Prentice, A; Wang, D Y; Butt, R P; Phillips, S C; Smith, S K; Charnock-Jones, D S

2005-02-01

Women with endometriosis have elevated levels of cyclooxygenase-2 (COX-2) in peritoneal macrophages and endometriotic tissue. Inhibition of COX-2 has been shown to reduce inflammation, angiogenesis and cellular proliferation. It may also downregulate aromatase activity in ectopic endometrial lesions. Ectopic endometrial establishment and growth are therefore likely to be suppressed in the presence of COX-2 inhibitors. We hypothesized that COX-2 inhibition would reduce the size and number of ectopic human endometrial lesions in a nude mouse model of endometriosis. The selective COX-2 inhibitor, nimesulide, was administered to estrogen-supplemented nude mice implanted with human endometrial tissue. Ten days after implantation, the number and size of ectopic endometrial lesions were evaluated and compared with lesions from a control group. Immunohistochemical assessment of vascular development and macrophage and myofibroblast infiltration in control and treated lesions was performed. There was no difference in the number or size of ectopic endometrial lesions in control and nimesulide-treated nude mice. Nimesulide did not induce a visually identifiable difference in blood vessel development or macrophage or myofibroblast infiltration in nude mouse explants. The hypothesized biological properties of COX-2 inhibition did not influence lesion number or size in the nude mouse model of endometriosis.

Cryptic Translocation Identification in Human and Mouse using Several Telomeric Multiplex FISH (TM-FISH) Strategies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henegariu, O; Artan, S; Greally, J M

2003-08-19

Experimental data published in recent years showed that up to 10% of all cases with mild to severe idiopathic mental retardation may result from small rearrangements of the subtelomeric regions of human chromosomes. To detect such cryptic translocations, we developed a ''telomeric'' multiplex FISH assay, using a set of previously published and commercially available subtelomeric probes. This set of probes includes 41 cosmid/PAC/P1 clones located from less than 100kb to about 1 Mb from the end of the chromosomes. Similarly, a published mouse probe set, comprised of BACs hybridizing to the closest known marker toward the centromere and telomere ofmore » each mouse chromosome, was used to develop a mouse-specific ''telomeric'' M-FISH. Three different combinatorial labeling strategies were used to simultaneously detect all human sub-telomeric regions on one slide. The simplest approach uses only three fluors, and can be performed in laboratories lacking sophisticated imaging equipment or personnel highly trained in cytogenetics. A standard fluorescence microscope equipped with only three filters is sufficient. Fluor-dUTPs and labeled probes can be custom-made, thus dramatically reducing costs. Images can be prepared using generic imaging software (Adobe Photoshop), and analysis performed by simple visual inspection.« less

AN IMPROVEMENT TO THE MOUSE COMPUTERIZED UNCERTAINTY ANALYSIS SYSTEM

EPA Science Inventory

The original MOUSE (Modular Oriented Uncertainty System) system was designed to deal with the problem of uncertainties in Environmental engineering calculations, such as a set of engineering cast or risk analysis equations. It was especially intended for use by individuals with l...

Learning and Recognition of a Non-conscious Sequence of Events in Human Primary Visual Cortex.

PubMed

Rosenthal, Clive R; Andrews, Samantha K; Antoniades, Chrystalina A; Kennard, Christopher; Soto, David

2016-03-21

Human primary visual cortex (V1) has long been associated with learning simple low-level visual discriminations [1] and is classically considered outside of neural systems that support high-level cognitive behavior in contexts that differ from the original conditions of learning, such as recognition memory [2, 3]. Here, we used a novel fMRI-based dichoptic masking protocol-designed to induce activity in V1, without modulation from visual awareness-to test whether human V1 is implicated in human observers rapidly learning and then later (15-20 min) recognizing a non-conscious and complex (second-order) visuospatial sequence. Learning was associated with a change in V1 activity, as part of a temporo-occipital and basal ganglia network, which is at variance with the cortico-cerebellar network identified in prior studies of "implicit" sequence learning that involved motor responses and visible stimuli (e.g., [4]). Recognition memory was associated with V1 activity, as part of a temporo-occipital network involving the hippocampus, under conditions that were not imputable to mechanisms associated with conscious retrieval. Notably, the V1 responses during learning and recognition separately predicted non-conscious recognition memory, and functional coupling between V1 and the hippocampus was enhanced for old retrieval cues. The results provide a basis for novel hypotheses about the signals that can drive recognition memory, because these data (1) identify human V1 with a memory network that can code complex associative serial visuospatial information and support later non-conscious recognition memory-guided behavior (cf. [5]) and (2) align with mouse models of experience-dependent V1 plasticity in learning and memory [6]. Copyright © 2016 Elsevier Ltd. All rights reserved.

A modulatory role of the Rax homeobox gene in mature pineal gland function: Investigating the photoneuroendocrine circadian system of a Rax conditional knockout mouse.

PubMed

Rohde, Kristian; Bering, Tenna; Furukawa, Takahisa; Rath, Martin Fredensborg

2017-10-01

The retinal and anterior neural fold homeobox gene (Rax) controls development of the eye and the forebrain. Postnatal expression of Rax in the brain is restricted to the pineal gland, a forebrain structure devoted to melatonin synthesis. The role of Rax in pineal function is unknown. In order to investigate the role of Rax in pineal function while circumventing forebrain abnormalities of the global Rax knockout, we generated an eye and pineal-specific Rax conditional knockout mouse. Deletion of Rax in the pineal gland did not affect morphology of the gland, suggesting that Rax is not essential for pineal gland development. In contrast, deletion of Rax in the eye generated an anophthalmic phenotype. In addition to the loss of central visual pathways, the suprachiasmatic nucleus of the hypothalamus housing the circadian clock was absent, indicating that the retinohypothalamic tract is required for the nucleus to develop. Telemetric analyses confirmed the lack of a functional circadian clock. Arylalkylamine N-acetyltransferase (Aanat) transcripts, encoding the melatonin rhythm-generating enzyme, were undetectable in the pineal gland of the Rax conditional knockout under normal conditions, whereas the paired box 6 homeobox gene, known to regulate pineal development, was up-regulated. By injecting isoproterenol, which mimics a nocturnal situation in the pineal gland, we were able to induce pineal expression of Aanat in the Rax conditional knockout mouse, but Aanat transcript levels were significantly lower than those of Rax-proficient mice. Our data suggest that Rax controls pineal gene expression and via Aanat may modulate melatonin synthesis. © 2017 International Society for Neurochemistry.

Adaptive eye-gaze tracking using neural-network-based user profiles to assist people with motor disability.

PubMed

Sesin, Anaelis; Adjouadi, Malek; Cabrerizo, Mercedes; Ayala, Melvin; Barreto, Armando

2008-01-01

This study developed an adaptive real-time human-computer interface (HCI) that serves as an assistive technology tool for people with severe motor disability. The proposed HCI design uses eye gaze as the primary computer input device. Controlling the mouse cursor with raw eye coordinates results in sporadic motion of the pointer because of the saccadic nature of the eye. Even though eye movements are subtle and completely imperceptible under normal circumstances, they considerably affect the accuracy of an eye-gaze-based HCI. The proposed HCI system is novel because it adapts to each specific user's different and potentially changing jitter characteristics through the configuration and training of an artificial neural network (ANN) that is structured to minimize the mouse jitter. This task is based on feeding the ANN a user's initially recorded eye-gaze behavior through a short training session. The ANN finds the relationship between the gaze coordinates and the mouse cursor position based on the multilayer perceptron model. An embedded graphical interface is used during the training session to generate user profiles that make up these unique ANN configurations. The results with 12 subjects in test 1, which involved following a moving target, showed an average jitter reduction of 35%; the results with 9 subjects in test 2, which involved following the contour of a square object, showed an average jitter reduction of 53%. For both results, the outcomes led to trajectories that were significantly smoother and apt at reaching fixed or moving targets with relative ease and within a 5% error margin or deviation from desired trajectories. The positive effects of such jitter reduction are presented graphically for visual appreciation.

A novel mouse model of anterior segment dysgenesis (ASD): conditional deletion of Tsc1 disrupts ciliary body and iris development

PubMed Central

Hägglund, Anna-Carin; Jones, Iwan

2017-01-01

ABSTRACT Development of the cornea, lens, ciliary body and iris within the anterior segment of the eye involves coordinated interaction between cells originating from the ciliary margin of the optic cup, the overlying periocular mesenchyme and the lens epithelium. Anterior segment dysgenesis (ASD) encompasses a spectrum of developmental syndromes that affect these anterior segment tissues. ASD conditions arise as a result of dominantly inherited genetic mutations and result in both ocular-specific and systemic forms of dysgenesis that are best exemplified by aniridia and Axenfeld–Rieger syndrome, respectively. Extensive clinical overlap in disease presentation amongst ASD syndromes creates challenges for correct diagnosis and classification. The use of animal models has therefore proved to be a robust approach for unravelling this complex genotypic and phenotypic heterogeneity. However, despite these successes, it is clear that additional genes that underlie several ASD syndromes remain unidentified. Here, we report the characterisation of a novel mouse model of ASD. Conditional deletion of Tsc1 during eye development leads to a premature upregulation of mTORC1 activity within the ciliary margin, periocular mesenchyme and lens epithelium. This aberrant mTORC1 signalling within the ciliary margin in particular leads to a reduction in the number of cells that express Pax6, Bmp4 and Msx1. Sustained mTORC1 signalling also induces a decrease in ciliary margin progenitor cell proliferation and a consequent failure of ciliary body and iris development in postnatal animals. Our study therefore identifies Tsc1 as a novel candidate ASD gene. Furthermore, the Tsc1-ablated mouse model also provides a valuable resource for future studies concerning the molecular mechanisms underlying ASD and acts as a platform for evaluating therapeutic approaches for the treatment of visual disorders. PMID:28250050

Instillation and Fixation Methods Useful in Mouse Lung Cancer Research.

PubMed

Limjunyawong, Nathachit; Mock, Jason; Mitzner, Wayne

2015-08-31

The ability to instill live agents, cells, or chemicals directly into the lung without injuring or killing the mice is an important tool in lung cancer research. Although there are a number of methods that have been published showing how to intubate mice for pulmonary function measurements, none are without potential problems for rapid tracheal instillation in large cohorts of mice. In the present paper, a simple and quick method is described that enables an investigator to carry out such instillations in an efficient manner. The method does not require any special tools or lighting and can be learned with very little practice. It involves anesthetizing a mouse, making a small incision in the neck to visualize the trachea, and then inserting an intravenous catheter directly. The small incision is quickly closed with tissue adhesive, and the mice are allowed to recover. A skilled student or technician can do instillations at an average rate of 2 min/mouse. Once the cancer is established, there is frequently a need for quantitative histologic analysis of the lungs. Traditionally pathologists usually do not bother to standardize lung inflation during fixation, and analyses are often based on a scoring system that can be quite subjective. While this may sometime be sufficiently adequate for gross estimates of the size of a lung tumor, any proper stereological quantification of lung structure or cells requires a reproducible fixation procedure and subsequent lung volume measurement. Here we describe simple reliable procedures for both fixing the lungs under pressure and then accurately measuring the fixed lung volume. The only requirement is a laboratory balance that is accurate over a range of 1 mg-300 g. The procedures presented here thus could greatly improve the ability to create, treat, and analyze lung cancers in mice.

Confocal imaging of whole vertebrate embryos reveals novel insights into molecular and cellular mechanisms of organ development

NASA Astrophysics Data System (ADS)

Hadel, Diana M.; Keller, Bradley B.; Sandell, Lisa L.

2014-03-01

Confocal microscopy has been an invaluable tool for studying cellular or sub-cellular biological processes. The study of vertebrate embryology is based largely on examination of whole embryos and organs. The application of confocal microscopy to immunostained whole mount embryos, combined with three dimensional (3D) image reconstruction technologies, opens new avenues for synthesizing molecular, cellular and anatomical analysis of vertebrate development. Optical cropping of the region of interest enables visualization of structures that are morphologically complex or obscured, and solid surface rendering of fluorescent signal facilitates understanding of 3D structures. We have applied these technologies to whole mount immunostained mouse embryos to visualize developmental morphogenesis of the mammalian inner ear and heart. Using molecular markers of neuron development and transgenic reporters of neural crest cell lineage we have examined development of inner ear neurons that originate from the otic vesicle, along with the supporting glial cells that derive from the neural crest. The image analysis reveals a previously unrecognized coordinated spatial organization between migratory neural crest cells and neurons of the cochleovestibular nerve. The images also enable visualization of early cochlear spiral nerve morphogenesis relative to the developing cochlea, demonstrating a heretofore unknown association of neural crest cells with extending peripheral neurite projections. We performed similar analysis of embryonic hearts in mouse and chick, documenting the distribution of adhesion molecules during septation of the outflow tract and remodeling of aortic arches. Surface rendering of lumen space defines the morphology in a manner similar to resin injection casting and micro-CT.

Omega-3 polyunsaturated fatty acids preserve retinal function in type 2 diabetic mice.

PubMed

Sapieha, P; Chen, J; Stahl, A; Seaward, M R; Favazza, T L; Juan, A M; Hatton, C J; Joyal, J-S; Krah, N M; Dennison, R J; Tang, J; Kern, T S; Akula, J D; Smith, L E H

2012-07-23

Diabetic retinopathy (DR) is associated with hyperglycemia-driven microvascular pathology and neuronal compromise in the retina. However, DR is also linked to dyslipidemia. As omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are protective in proliferative retinopathy, we investigated the capacity of ω-3PUFAs to preserve retinal function in a mouse model of type 2 diabetes mellitus (T2DM). Male leptin-receptor-deficient (db/db) mice were maintained for 22 weeks (4 weeks-26 weeks of life) on calorically and compositionally matched diets, except for 2% enrichment in either ω-3 or ω-6PUFAs. Visual function was assessed at 9, 14 and 26 weeks by electroretinography. Retinal capillary and neuronal integrity, as well as glucose challenge responses, were assessed on each diet. The ω-3PUFA diet significantly preserved retinal function in the mouse model of T2DM to levels similar to those observed in nondiabetic control mice on normal chow. Conversely, retinal function gradually deteriorated in db/db mice on a ω-6PUFA-rich diet. There was also an enhanced ability of ω-3PUFA-fed mice to respond to glucose challenge. The protection of visual function appeared to be independent of cytoprotective or anti-inflammatory effects of ω-3PUFAs. This study identifies beneficial effects of dietary ω-3PUFAs on visual function in T2DM. The data are consistent with dyslipidemia negatively impacting retinal function. As ω-3PUFA lipid dietary interventions are readily available, safe and inexpensive, increasing ω-3PUFA intake in diabetic patients may slow the progression of vision loss in T2DM.

In vivo three-dimensional optical coherence tomography and multiphoton microscopy in a mouse model of ovarian neoplasia

NASA Astrophysics Data System (ADS)

Watson, Jennifer M.; Marion, Samuel L.; Rice, Photini Faith; Bentley, David L.; Besselsen, David; Utzinger, Urs; Hoyer, Patricia B.; Barton, Jennifer K.

2013-03-01

Our goal is to use optical coherence tomography (OCT) and multiphoton microscopy (MPM) to detect early tumor development in a mouse model of ovarian neoplasia. We hope to use information regarding early tumor development to create a diagnostic test for high-risk patients. In this study we collect in vivo images using OCT, second harmonic generation and two-photon excited fluorescence from non-vinylcyclohexene diepoxide (VCD)-dosed and VCD-dosed mice. VCD causes follicular apoptosis (simulating menopause) and leads to tumor development. Using OCT and MPM we visualized the ovarian microstructure and were able to see differences between non-VCD-dosed and VCD-dosed animals. This leads us to believe that OCT and MPM may be useful for detecting changes due to early tumor development.

Evaluation of microvascular anastomosis using real-time ultrahigh resolution Fourier domain Doppler optical coherence tomography

PubMed Central

Huang, Yong; Tong, Dedi; Zhu, Shan; Wu, Lehao; Mao, Qi; Ibrahim, Zuhaib; Lee, WP Andrew; Brandacher, Gerald; Kang, Jin U.

2014-01-01

Background Evolution and improvements in microsurgical techniques and tools have paved the way for super-microsurgical anastomoses with vessel diameters often approaching below 0.8 mm in the clinical realm and even smaller (0.2–0.3 mm) in murine models. Several imaging and monitoring devices have been introduced for post-operative monitoring but intra-operative guidance, assessment and predictability have remained limited to binocular optical microscope and surgeon’s experience. We present a high-resolution real time 3D imaging modality for intra-operative evaluation of luminal narrowing, thrombus formation and flow alterations. Methods An imaging modality that provides immediate, in-depth high resolution 3D structure view and flow information of the anastomosed site called phase resolved Doppler optical coherence tomography (PRDOCT) was developed. 22 mouse femoral artery anastomoses and 17 mouse venous anastomoses were performed and evaluated with PRDOCT. Flow status, vessel inner lumen 3D structure, and early thrombus detection were analyzed based on PRDOCT imaging results. Initial PRDOCT based predictions were correlated with actual long term surgical outcomes. Eventually four cases of mouse orthotopic limb transplantation were carried out and PRDOCT predicted long term patency were confirmed by actual results. Results PRDOCT was able to provide high-resolution 3D visualization of the vessel flow status and vessel inner lumen. The assessments based on PRDOCT visualization shows a 92% sensitivity and 90% specificity for arterial anastomoses and 90% sensitivity and 86% specificity for venous anastomoses. Conclusions PRDOCT is an effective evaluation tool for microvascular anastomosis. It can predict the long term vessel patency with high sensitivity and specificity. PMID:25811583

Improvement of two-photon microscopic imaging in deep regions of living mouse brains by utilizing a light source based on an electrically controllable gain-switched laser diode

NASA Astrophysics Data System (ADS)

Sawada, Kazuaki; Kawakami, Ryosuke; Fang, Yi-Cheng; Hung, Jui-Hung; Kozawa, Yuichi; Otomo, Kohei; Sato, Shunichi; Yokoyama, Hiroyuki; Nemoto, Tomomi

2018-02-01

In vivo two-photon microscopy is an advantageous technique for observing living mouse brains at high spatial resolutions. We previously used a 1064 nm high-power light source based on an electrically controllable gain-switched laser diode (maximum power: 4 W, repetition rate: 10 MHz, pulse width: 7.5 picoseconds) and successfully visualized EYFP expressing neurons at deeper regions in H-line mouse brains under living conditions. However, severe damages were frequently observed when the laser power after the objective lens was over 600 mW, suggesting that a higher average power might not be suitable for visualizing neural structures and functions at deep regions. To increase fluorescent signals as a strategy to avoid such invasions, here, we evaluated the effects of the excitation laser parameters such as the repetition rate (5 - 10 MHz), or the peak power, at the moderate average powers (10 - 500 mW), by taking the advantage that this electrically controllable light source could be used to change the repetition rate independently from the average power or the pulse width. The fluorescent signals of EYFP at layer V of the cerebral cortex were increased by approximately twofold when the repetition rate was decreased from 10 MHz to 5 MHz at the same average power. We also confirmed similar effects in the EYFP solution (335 μM) and fixed brain slices. These results suggest that in vivo two-photon microscopic imaging might be improved by increasing the peak power at the same average power while avoiding the severe damages in living brains.

Histological and reference system for the analysis of mouse intervertebral disc.

PubMed

Tam, Vivian; Chan, Wilson C W; Leung, Victor Y L; Cheah, Kathryn S E; Cheung, Kenneth M C; Sakai, Daisuke; McCann, Matthew R; Bedore, Jake; Séguin, Cheryle A; Chan, Danny

2018-01-01

A new scoring system based on histo-morphology of mouse intervertebral disc (IVD) was established to assess changes in different mouse models of IVD degeneration and repair. IVDs from mouse strains of different ages, transgenic mice, or models of artificially induced IVD degeneration were assessed. Morphological features consistently observed in normal, and early/later stages of degeneration were categorized into a scoring system focused on nucleus pulposus (NP) and annulus fibrosus (AF) changes. "Normal NP" exhibited a highly cellularized cell mass that decreased with natural ageing and in disc degeneration. "Normal AF" consisted of distinct concentric lamellar structures, which was disrupted in severe degeneration. NP/AF clefts indicated more severe changes. Consistent scores were obtained between experienced and new users. Altogether, our scoring system effectively differentiated IVD changes in various strains of wild-type and genetically modified mice and in induced models of IVD degeneration, and is applicable from the post-natal stage to the aged mouse. This scoring tool and reference resource addresses a pressing need in the field for studying IVD changes and cross-study comparisons in mice, and facilitates a means to normalize mouse IVD assessment between different laboratories. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:233-243, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.