We are on our way to ARVO, 2013 in Seattle, Washington to participate in the largest gathering of vision scientists and clinicians in the world. It’s the annual meeting of researchers presenting and discussing all things vision and ophthalmology and a large group from the Moran Eye Center will be going.
Over the next few days, you will see some of our research abstracts appear here as the presentations are completed at ARVO. We hope that it will give some insight into the work that goes on here at the Moran Eye Center and our passion for understanding vision and what goes wrong in blinding diseases.
If you are going to be at ARVO and want to meet up, leave us a comment here or send a Tweet to @BWJones or @Webvision1. We might even be able to work you into the Moran social on Monday the 2nd…
Look forward to seeing you there.
Authors Stylianos Michalakis, Karin Schäferhoff, Isabella Spiwoks-Becker, Nawal Zabouri, Susanne Koch, Fred Koch, Michael Bonin, Martin Biel, and Silke Haverkamp have a new paper out that looks at the earliest gene microarray analysis results associated with neurite outgrowth in the degenerate retina. The title is a overly broad, but the results focusing on gene expression changes in the A3B1 mouse retina (a CNGA3/CNGB1 double-knockout) are intriguing, particularly their proposal that Tp53, Smad and Stat3 signaling contribute to synaptic plasticity at least. Continued…
Categories: Interesting, Retinal Disease.
Shannon Boye, assistant professor, University of Florida Department of Ophthalmology will be delivering a seminar, Gene Therapy for Photoreceptor-Mediated Retinal Disease: Leber Congenital Amaurosis-1 (LCA1) on May 16th, 2013 at 12:00 Noon in the John A. Moran Eye Center Auditorium on the 1st floor.
There has been quite a bit of discussion of connectomes in the last while with President Obama’s new BRAIN initiative. It is important to consider some of the requirements of obtaining a true synapse level wiring map in the brain as many are articulating from this initiative. While there are new technologies that will be required to undertake this initiative for mapping the entire brain, the NIH NEI has been funding an ongoing project to study retinal circuitry which guides the community in how to approach a true synapse level map of the nervous system.
An example of this work in Current Opinion in Neurobiology titled Building Retinal Connectomes is a review that illustrates the importance of having a complete network graph of connectivities in the retina and by extension other neural systems. Complete network graphs are what will be required to understand how retinal systems (and any neural system) is constructed. Even though the retinal community understands how retinas are wired in broad strokes, the precise, fine details are critical and elucidating them requires a new level of complete annotation derived from advances in light and ultrastructural imaging, data management, navigation and validation.
Authors are Robert E. Marc, Bryan W. Jones, J. Scott Lauritzen, Carl B. Watt and James R. Anderson.
Categories: Interesting, Moran Eye Center, Moran Eye Center Research, Retinal Circuitry.
The VIG is designed as a resource for students and post-docs to present their work/research to their contemporaries and all interested parties who wish to attend and participate.
The April VIG at the John A. Moran Eye Center will be held on April 18th from 12:00pm to 1:00pm in the John A. Moran Eye Center auditorium on the 1st floor.
Categories: Moran Eye Center, Moran Eye Center Research, Vision Interest Group (VIG).
Monica Vetter, Professor of Neurobiology and Anatomy at the University of Utah will be delivering a seminar, Neurogenesis And Neurodegeneration In The Retina on April 23rd, 2013 at 12:00 Noon in the John A. Moran Eye Center Auditorium.
A continuum of events throughout life are essential to acquire and maintain normal vision. This includes generating the normal complement of neurons in the retina during development, and maintaining these neurons in the adult. Disorders of eye development can lead to congenital blindness, while degeneration of retinal neurons can cause progressive blindness at later ages.
In the developing retina our goal is to define the sequence of gene expression that governs neural differentiation, and understand how signaling pathways and epigenetic regulation modulates gene expression or function. Complex signaling events coordinate progenitor proliferation and differentiation, and can govern the expression of histone modifiers that are required for differentiation.
To investigate the process of neurodegeneration, we are probing the mechanisms underlying glaucoma, a neurodegenerative disease of the retina. We find that microglia, which are resident cells of the innate immune system, serve as early harbingers of neuronal decline. We are defining the signals leading to their recruitment and activation with disease progression, with the goal of targeting these and slowing degeneration.
This beautiful article in The Atlantic by Alexis Madrigal talks about the eyes of cetaceans or whales and has some beautiful imagery from photographer Bryant Austin. More importantly, the article asks: “So, what does the world look like to a whale?” which is a fundamental question in comparative anatomy.
The really unusual thing about this article is that vision science gets very little coverage in the popular press and this particular article discusses some of the science of vision including retinal science, after interviews with Leo Peichl who studies comparative anatomy of the mammalian retina at Max Planck. I’ve long admired Leo’s work and am pleased to see it covered in The Atlantic along with work by Sonke Johnsen, Michael Land and Dan-Eric Nilsson, particularly by one of my favorite writers, Alexis Madrigal.
Image of Ella the whale’s eye from Bryant Austin.
Just seeing an eye… and only the eye is enough to establish the first components of neural facial recognition. In this interesting paper by Elias B. Issa and James J. DiCarlo, the authors found using a combination of functional magnetic resonance imaging (fMRI) that the first stage in the primate visual/face processing circuitry is tuned to regions in images containing eyes. Even a single eye is enough to trigger recognition pathways.
fMRI and electrophysiological recording work in facial processing has established that the facial processing network possesses six areas that are extensively interconnected and the anatomical analysis suggests a nested, hierarchical layout where signals progressing through the system become more established. This of course begs for a true connectomics analysis which will be difficult at the large scale, but tractable at the mesoscale. It turns out that this is an interesting computational problem as identification of isolated components of images that connate larger meaning is difficult. Discovering how neural systems unravel this will have substantial importance to diverse applications.
This is a fluorescently tagged primary visual cortex neuron from a light microscope capture of a brain slice preparation. These data were focus stacked revealing a tremendous amount of detail including the spines. Focus stacking is common method in confocal microscopy, but many folks do not realize that you can also do it with traditional light microscopy of just about anything using ImageJ or Adobe Photoshop. See here for an example and discussion of focus stacking.
Categories: Art of Vision.
This image shows a slit lamp retro-illumination photograph through dilated pupil revealing silicone oil in anterior chamber following retinal re-attachment surgery. Silicone oil is a commonly used approach for retinal tamponade during surgery in the vitreous or for retinal reattachment surgery. While the silicone does assist with successful reattachment, often it causes optical complications resulting in followup surgeries to remove the silicone oil typically 2-8 months later. Gas bubbles with SF6 or C3F8 are also used, with the advantage that there is no myopic shift post operation and no followup surgery is required.
This image was taken by Paula Morris of the Moran Eye Center using a Zeiss photo slitlamp and a Nikon D-1S camera at and 24x magnification. Notably, this image won Honorable mention in the Photo Slit Lamp Biomigraography Division in 2007.
Categories: Art of Vision, Moran Eye Center.
Vitreoretinal lymphoma is a form of central nervous system (CNS) lymphoma that often is misdiagnosed as uveitis, but is the most common form of intraocular lymphoma. A proper diagnosis of vitreoretinal lymphoma requires the histological identification of lymphoma typed cells within the vitreous of the globe or retina which can be a trick due to reactive lymphocytes as well as necrotic regions in the retina. Contemporary approaches also require immunohistochemistry to reveal the monoclonality.
This rare form of lymphoma commonly has a poor prognosis and is often associated with a CNS lymphoma in aged populations. That said, historically treatment, like other retinal cancers was commonly enucleation. These days, chemotherapy combined with radiation therapy is more commonly used, though without good outcomes in many cases due to the difficulty delivering drugs into the eye from systemic administration. New approaches are being explored through the direct injection of drugs into the globe and those efforts are ongoing.
Fundus photos were made by James Gilman of the Moran Eye Center.
Categories: Grand Rounds.
Trilobites were one of the most successful marine arthropods that lived from the Early Cambrian throughout the Devonian, finally going extinct in the Permian ages, a run of over 270 million years. They are well represented in the fossil record and even the earliest forms had complex compound eyes much like modern arthropods. These eyes had elongated lenses composed of calcite that modeling has revealed to provide excellent optical properties with good depth of field and little to no spherical aberration. These lenses brought light to photoreceptor cells at the base of the lens, but we’ve never before had an understanding of what that structure or anatomy looked like.
The problem of course with the fossil record is that very little internal structure remains in fossilized specimens. However, a very cool new study that examines trilobite eyes through X-ray tomography by Brigitte Schoenemann and Euan N. K. Clarkson reveals how these cells looked, down, perhaps to the cellular level. Followup work with μct-scanning and synchrotron radiation analysis reveals that the sensory structures (like rod or cone outer segments) are arranged in flower petal like structures around a central, diamond shaped photoreceptor cell body with pigment granules packed in-between. Its kind of like a modern limulus eye (image here).
It will be interesting to see if they can image other species of trilobite to get an evolutionary look at how eyes and perhaps primitive retinas developed over 500 million years ago.
Image Credit: Bryan William Jones, Ph.D.
Vision in fishes and crustaceans is a fascinating and understudied area. In past decades, there were far more studies on the visual systems of sea-dwelling creatures, but with the push towards applied or translational research, the number of reports in these species have dropped off, much to our detriment as one never knows where the applications of basic research will pay off.
At the same time, the whole study of bioluminescence and vision is an interesting examination of how organisms use bioluminescence for mating, warning or aposematism, crypsis or counter-illumination and predation. It is explicitly a visual phenomenon and as such, has informed a variety of investigations into biomedical, commercial and military applications. Continued…
Jason Shepherd, Assistant Professor in Neurobiology and Anatomy at the University of Utah will be delivering a seminar titled “Cellular Mechanisms of Experience Dependent Plasticity in Mouse Visual Cortex” on March 19th at 12:00 in the John A. Moran Eye Center Auditorium.
Abstract: A myriad of mechanisms have been suggested to account for the full richness of cortical plasticity. We found that visual cortex lacking the activity-dependent gene Arc is imprevious to the effects of deprivation or experience. Using intrinsic signal imaging and chronic visually evoked potential recordings, we found that Arc KO mice did not exhibit depression of deprived-eye responses or a shift in ocular dominance after brief monocular deprivation. Moreover, Arc KO mice lacked stimulus-selective response potentiation, as in in vivo form of plasticity that resembles long-term potentiation (LTP). Although Arc KO mice exhibited normal visual acuity, baseline ocular dominance was abnormal and resembled that observed after dark-rearing. These data suggest that Arc is required for the experience-dependent processes that normall establish and modify synaptic connections in visual cortex.
Fish have some of the most amazing retinas in the animal kingdom. Like other fish species that live in environments with little to no light, the elephantnose fish (Gnathonemus petersii) use electrical fields to navigate through dark and murky waters. However, unlike some of those species, the elephantnose fish has not lost its eyes through evolution and uses vision for some functions.
This paper published in Science back in May, 2012 by authors Moritz Kreysing, Roland Pusch, Dorothee Haverkate, Meik Landsberger, Jacob Engelmann, Janina Ruiter, Carlos Mora-Ferrer, Elke Ulbricht, Jens Grosche, Kristian Franze, Stefan Streif, Sarah Schumacher, Felix Makarov, Johannes Kacza, Jochen Guck, Hartwig Wolburg, James K. Bowmaker, Gerhard von der Emde, Stefan Schuster, Hans-Joachim Wagner, Andreas Reichenbach, and Mike Francke shows that the elephantnose fish has absolutely unique and interesting structures that optimize light capture ability and make them insensitive to spatial noise. Also in the mesopic range they match the rod and cone opsin sensitivity curves allowing the use of both rods and cones throughout large ranges of light intensities, but importantly, arrange the cone photoreceptors in functional assemblies that act as photonic reflectors, creating lightwells in a sense that optimize photon capture. The rod photoreceptors meanwhile are positioned *behind* the photonic lightwells or reflectors. The result is that the photonic lightwells or reflectors become wavelength sensitive light intensifiers that functionally match the dynamic range of both rods and cones while boosting sensitivity in the red wavelengths that are the first wavelengths filtered out by water. The thinking is that this allows the elephantnose fish to easily see large predators in murky or turbid environments.