Download or read book Determine the Neuronal Circuits of M1 Intrinsically Photosensitive Retinal Ganglion Cells ipRGCs at the Single cell Level and Their Downstream Functions written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Spontaneous and Light sensing Neural Circuits of the Developing Retina written by David Antonio Arroyo and published by . This book was released on 2016 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of neural circuits is perhaps one of the most fascinating phenomena of nature. Neural circuits combine an intrinsic program, that manifest itself in the form of spontaneous activity and molecular markers, with input from the environment to mature into a perfect arrangement of circuits that define how we interact with the world. The immature mammalian retina is a perfect example of the intricacies of neural circuit development. The developing retina exhibits a robust pattern of spontaneous activity, known as retinal waves. Retinal waves are necessary for proper development of the neural connections in early parts of the visual pathway. Recent research on this topic establishes that specific spatiotemporal properties of waves instruct specific aspects of visual map formation. In addition, retinal waves have recently found roles in cell differentiation, cell migration, and synapse formation. Thus, understanding the underlying mechanisms of the spatiotemporal properties of waves and exploring new ways in which waves could influence developing neural circuits will contribute to our understanding the role of spontaneous activity in developmental processes of the nervous system. In mice during postnatal days 1-9, retinal waves are generated by cholinergic starburst amacrine cells (SACs), which are excitatory retinal interneurons at this stage. Starburst amacrine cells exhibit slow afterhyperpolarizations that are thought to set a refractory period and thus the periodicity and frequency of waves. Using an array of electrophysiological methods such as patch-clamp and multi-electrode array recordings, and calcium imaging, we showed that the 2- pore potassium channel TREK1 underlies SACs slow afterhyperpolarization and thus wave frequency. First, we found that the SACs afterhyperpolarization is physiologically and pharmacologically consistent with a slow potassium current generated by a 2-pore potassium channel. Second, gene expression analysis of SACs revealed the expression of TREK1. Lastly, either silencing the putative TREK1-activated signaling pathways or knocking out TREK1 increases the frequency of retinal waves. Our work provides an example of how molecular mechanisms generate specific spatiotemporal properties of waves, which are important for the development of the visual system. In addition to instructing the wiring of retinal inputs to the visual centers of the brain, retinal waves influence developmental aspects within the retina. Prior to the onset of vision, which happens after cessation of waves, the retina relies on intrinsically photosensitive retinal ganglion cells (ipRGCs) for light detection. We explored the influence of spontaneous retinal waves on the ipRGC-dependent light response of the developing retina. We combined patch- clamp recordings, calcium imaging, multi-electrode array recordings, and tracer coupling, among other methods to determine interactions between cholinergic waves and ipRGC circuits. First, we found that ipRGCs form gap junction connections with other retinal neurons, including other ipRGCs. Second, blocking cholinergic waves induces ipRGCs to form more gap junction connections. Third, blocking waves dramatically increases the number of light-responsive cells. Fourth, waves evoke dopamine release in the developing retina. Lastly, blocking dopamine signaling increases the number of light-responsive cells, similar to blocking waves. We concluded that retinal waves evoke dopamine release that act on ipRGC to down regulate their gap junction coupling. Thus, retinal waves modulate ipRGC gap junction coupling via dopaminergic signaling to regulate the overall light response of the developing retina. To further explore the properties of the light responses of developing ipRGCs, we characterized their light-evoked calcium transients. There are 5 different types of ipRGCs identified in adult mice, and 3 physiological types in developing mice. Pooling data from a large population of ipRGCs we analyzed amplitude, latency, and response decay of ipRGC light responses. We found that although amplitude and latency exhibited a large variation across cells, they could not be used to classify cells into different subtypes of ipRGCs. In contrast, response decay showed multimodal distributions and thus potential as a classifier for developing ipRGC types. This work contributes to our understanding of light-sensing in the developing retina.

Download or read book Ultrastructure of Melanopsin Expressing Retinal Ganglion Cell Circuitry in the Retina and Brain Regions that Mediate Light Driven Behavior written by Yu Hsin Liu and published by . This book was released on 2017 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Melanopsin-expressing retinal ganglion cells (mRGC) are intrinsically photosensitive and combine their melanopsin-based photoresponses with rod and cone signals to convey light information to a subset of retinal brain targets. mRGC axons to non-image forming (NIF) visual centers are essential for the proper functioning of processes like circadian photoentrainment and pupillary light reflex. Surprisingly, mRGCs also send axons to image-forming regions of the brain. It is unknown how mRGCs mediate such diverse functions. Classically, a cell's morphology and location in a biological system is a direct reflection of its synaptic connections and, by definition, their function. mRGCs can be divided into five subtypes (M1-M5) based on morphology and dendritic stratification in the inner plexiform layer. In the classical sense, since M1s send axons to only a subset of mRGC-target regions and are the only subtype that monostratify in the OFF-sublamina, M1s likely serve a distinct function from other subtypes. However, M1s, like all mRGCs, exhibit an ON-response. This reveals a hole in what we understand about intraretinal connectivity and attenuates the weight that should be afforded to stratification in determining function. While the other mRGC subtypes have distinct morphology and branching patterns, it is unknown whether they serve specific functions. Thus, in order to explore the structure-function relationship of mRGC subtypes, we must consider connectivity. Unfortunately, the variable expression of melanopsin protein between subtypes and across the architecture of a single mRGC and the lack of unique markers for up- and downstream interactors has precluded rigorous study of mRGC connectivity in the retina and central targets. We use a correlated light and electron microscopy label and serial blockface scanning electron microscopy to explore the architecture and synaptic partners of mRGCs in an attempt to better understand the connectivity of mRGC subtypes. We show significant differences in the ultrastructure of mRGC axonal terminals in mRGC-recipient brain regions, stratification-specific differences in mRGC dendrites, and catalog the intraretinal connections specific to mRGC subtypes.

Download or read book Seeing Without Rods Or Cones Contributions of Intrinsically photosensitive Retinal Ganglion Cells to the Image forming Visual System written by Stewart Madon and published by . This book was released on 2013 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: "It was long thought that rods and cones were the only components of the mammalian retina capable of conveying light information to the brain. Recently, a novel class of transduction-capable retinal ganglion cells containing the photopigment melanopsin were discovered in the mammalian retina identified as an “intrinsically photosensitive retinal ganglion cell” or ipRGC. Most of the functionality associated with ipRGCs has been linked to nonperceptual, non-cortical visual operations such as circadian (day-night) phase modulation and pupillary constriction. More recently, however, two subpopulations of ipRGCs have been identified called M1 and M2 cells, with the latter showing “blue-yellow” chromatic opponency that possibly links to brightness or colour pattern vision – properties associated with the retinogeniculostriate, or image-forming visual system. The present study expands on the current understanding of these putative image-forming non-traditional photoreceptor systems. To this end, I developed two stimulus paradigms that target short-wavelength-sensitive cones (S-cones) to tease out the unique contributions of ipRGCs that have neural associations with S-cone visual functioning. In the first paradigm, I measured detection thresholds using short-wavelength selective stimuli that are temporally presented with either an onset or offset “sawtooth” profile to ascertain ipRGC input to the S-OFF, “brightness” pathways. The results revealed differences in the asymmetry between S-ON and S-OFF pathways dependent upon adapting field conditions that were expected to influence ipRGCs over other photoreceptors. In the second experiment, I used a modification of an S-cone contrast sensitivity task employing homochromatic “blue” sine-grating gabors of varying spatial frequencies to directly test ipRGC involvement in spatial pattern vision. The results from the second experiment showed a slight advantage to the perception of low spatial frequency gabors superimposed on chromatic adapting fields that were expected to influence ipRGCs more than the others. Preliminary evidence supporting a spatial tuning property of ipRGCs was also found. Overall, these findings suggest that ipRGCs have measurable influences on conscious, image-forming perceptions, and shed further light on the microcircuitry of the retinogeniculate pathway."-- from abstract.

Download or read book Webvision written by Helga Kolb and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Diversity in the Neuronal Machine written by Ivan Soltesz and published by Oxford University Press. This book was released on 2006 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aims to provide insights into the striking degree of cellular diversity found in the interneuronal microcircuits in the brain's neocortex and hippocampus. This book elaborates on different ideas about interneuronal diversity that rest upon theoretical and experimental results and is useful for neuroscientists.

Download or read book The New Visual Neurosciences written by John S. Werner and published by MIT Press. This book was released on 2013-10-25 with total page 1693 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of contemporary research in the vision sciences, reflecting the rapid advances of recent years. Visual science is the model system for neuroscience, its findings relevant to all other areas. This essential reference to contemporary visual neuroscience covers the extraordinary range of the field today, from molecules and cell assemblies to systems and therapies. It provides a state-of-the art companion to the earlier book The Visual Neurosciences (MIT Press, 2003). This volume covers the dramatic advances made in the last decade, offering new topics, new authors, and new chapters. The New Visual Neurosciences assembles groundbreaking research, written by international authorities. Many of the 112 chapters treat seminal topics not included in the earlier book. These new topics include retinal feature detection; cortical connectomics; new approaches to mid-level vision and spatiotemporal perception; the latest understanding of how multimodal integration contributes to visual perception; new theoretical work on the role of neural oscillations in information processing; and new molecular and genetic techniques for understanding visual system development. An entirely new section covers invertebrate vision, reflecting the importance of this research in understanding fundamental principles of visual processing. Another new section treats translational visual neuroscience, covering recent progress in novel treatment modalities for optic nerve disorders, macular degeneration, and retinal cell replacement. The New Visual Neurosciences is an indispensable reference for students, teachers, researchers, clinicians, and anyone interested in contemporary neuroscience. Associate Editors Marie Burns, Joy Geng, Mark Goldman, James Handa, Andrew Ishida, George R. Mangun, Kimberley McAllister, Bruno Olshausen, Gregg Recanzone, Mandyam Srinivasan, W.Martin Usrey, Michael Webster, David Whitney Sections Retinal Mechanisms and Processes Organization of Visual Pathways Subcortical Processing Processing in Primary Visual Cortex Brightness and Color Pattern, Surface, and Shape Objects and Scenes Time, Motion, and Depth Eye Movements Cortical Mechanisms of Attention, Cognition, and Multimodal Integration Invertebrate Vision Theoretical Perspectives Molecular and Developmental Processes Translational Visual Neuroscience

Download or read book The Retina written by John E. Dowling and published by Harvard University Press. This book was released on 2012-01-15 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: John Dowling’s The Retina, published in 1987, quickly became the most widely recognized introduction to the structure and function of retinal cells. In this Revised Edition, Dowling draws on twenty-five years of new research to produce an interdisciplinary synthesis focused on how retinal function contributes to our understanding of brain mechanisms. The retina is a part of the brain pushed out into the eye during development. It retains many characteristics of other brain regions and hence has yielded significant insights on brain mechanisms. Visual processing begins there as a result of neuronal interactions in two synaptic layers that initiate an analysis of space, color, and movement. In humans, visual signals from 126 million photoreceptors funnel down to one million ganglion cells that convey at least a dozen representations of a visual scene to higher brain regions. The Revised Edition calls attention to general principles applicable to all vertebrate retinas, while showing how the visual needs of different animals are reflected in their retinal variations. It includes completely new chapters on color vision and retinal degenerations and genetics, as well as sections on retinal development and visual pigment biochemistry, and presents the latest knowledge and theories on how the retina is organized anatomically, physiologically, and pharmacologically. The clarity of writing and illustration that made The Retina a book of choice for a quarter century among graduate students, postdoctoral fellows, vision researchers, and teachers of upper-level courses on vision is retained in Dowling’s new easy-to-read Revised Edition.

Download or read book Mammalian Transient Receptor Potential TRP Cation Channels written by Bernd Nilius and published by Springer. This book was released on 2014-06-24 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: ​In this fast moving field the main goal of this volume is to provide up-to-date information on the molecular and functional properties and pharmacology of mammalian TRP channels. Leading experts in the field describe properties of a single TRP protein/channel or portray more general principles of TRP function and important pathological situations linked to mutations of TRP genes or their altered expression. Thereby this volume on Transient Receptor Potential (TRP) Channels provides valuable information for readers with different expectations and backgrounds, for those who are approaching this field of research as well as for those wanting to make a trip to TRPs.

Download or read book Biological Timekeeping Clocks Rhythms and Behaviour written by Vinod Kumar and published by Springer. This book was released on 2017-02-15 with total page 663 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a concise, comprehensive and up-to-date account of fundamental concepts and potential applications of biological timekeeping mechanisms in animals and humans. It also discusses significant aspects of the organization and importance of timekeeping mechanisms in both groups. Divided into seven sections, it addresses important aspects including fundamental concepts; animal and human clocks; clock interactions; clocks and metabolism and immune functions; pineal, melatonin and timekeeping; and clocks, photoperiodism and seasonal behaviours. The book also focuses on biological clock applications in a 24x7 human society, particularly in connection with life-style associated disorders like obesity and diabetes. It is a valuable resource for advanced undergraduates, researchers and professionals engaged in the study of the science of biological timekeeping.

Download or read book Synapse Development and Maturation written by Pasko Rakic and published by Academic Press. This book was released on 2020-05-29 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synapse Development and Maturation, the latest release in the Comprehensive Developmental Neuroscience series, presents the latest information on the genetic, molecular and cellular mechanisms of neural development. The book provides a much-needed update that underscores the latest research in this rapidly evolving field, with new section editors discussing the technological advances that are enabling the pursuit of new research on brain development. This volume focuses on the synaptogenesis and developmental sequences in the maturation of intrinsic and synapse-driven patterns. - Features leading experts in various subfields as section editors and article authors - Presents articles that have been peer reviewed to ensure accuracy, thoroughness and scholarship - Includes coverage of mechanisms which regulate synapse formation and maintenance during development - Covers neural activity, from cell-intrinsic maturation, to early correlated patterns of activity

Download or read book The Visual System of Fish written by Ron Douglas and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 531 pages. Available in PDF, EPUB and Kindle. Book excerpt: A question often asked of those of us who work in the seemingly esoteric field of fish vision is, why? To some of us the answer seems obvious - how many other visual scientists get to dive in a tropical lagoon in the name of science and then are able to eat their subjects for dinner? However, there are better, or at least scientifically more acceptable, reasons for working on the visual system of fish. First, in terms of numbers, fish are by far the most important of all vertebrate classes, probably accounting for over half (c. 22 000 species) of all recognized vertebrate species (Nelson, 1984). Furthermore, many of these are of commercial importance. Secondly, if one of the research aims is to understand the human visual system, animals such as fish can tell us a great deal, since in many ways their visual systems, and specifically their eyes, are similar to our own. This is fortunate, since there are several techniques, such as intracellular retinal recording, which are vital to our understanding of the visual process, that cannot be performed routinely on primates. The cold blooded fish, on the other hand, is an ideal subject for such studies and much of what we know about, for example, the fundamentals of information processing in the retina is based on work carried out on fish (e. g. Svaetichin, 1953).

Download or read book Neuronal Input Pathways to the Brain s Biological Clock and their Functional Significance written by Jens Hannibal and published by Springer Science & Business Media. This book was released on 2006-06-07 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rhythmic changes in physiology and behaviour within a 24 h period occur in living organisms on earth to meet the challenges associated with the daily changes in the external environment. The circadian pacemaker responsible for the temporal internal organisation and the generation of endogenous rhythms of approximately 24 h is located in the hypothalamic suprachiasmatic nucleus (SCN) in mammals. The endogenous period generated by the pacemaker is close to, but generally not equal to 24 h and the biological clock therefore needs to be daily adjusted (entrained) by external cues. The daily alteration of light and darkness due to the rotation of our planet on its own axis in relation to the sun is the most prominent "zeitgeber" which adjusts the phase of the circadian rhythms to the astronomical day length, a process known as photoentrainment. In mammals, light is perceived only through photoreceptors located in the retina. Light information is mediated to the SCN via the retinohypothalamic tract (RHT) by activation of the classical photoreceptor system of rods and cones and a more recently identified system of intrinsic photosensitive retinal ganglion cells (ipRGCs) using melanopsin as a photopigment.

Download or read book Electrophysiology Measurements for Studying Neural Interfaces written by Mohammad M. Aria and published by Academic Press. This book was released on 2020-05-15 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrophysiology Measurements for Studying Neural Interfaces helps readers to choose a proper cell line and set-up for studying different bio-electronic interfaces before delving into the electrophysiology techniques available. Therefore, this book details the materials and devices needed for different types of neural stimulation such as photoelectrical and photothermal stimulations. Also, modern techniques like optical electrophysiology and calcium imaging in this book provides readers with more available approaches to monitor neural activities in addition to whole-cell patch-clamp technology. - Details steps of an electrophysiology project from start to finish for graduate students employing the technique in their research - Includes sample electrophysiological studies with multiple cell lines (PC12, N2a, NG108, SHSY, and embryonic stem cell lines) to facilitate research - Features data analysis of electrophysiology results from various relevant experiments and cell culture tips

Download or read book Principles of Neurobiology written by Liqun Luo and published by Garland Science. This book was released on 2020-09-05 with total page 761 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles of Neurobiology, Second Edition presents the major concepts of neuroscience with an emphasis on how we know what we know. The text is organized around a series of key experiments to illustrate how scientific progress is made and helps upper-level undergraduate and graduate students discover the relevant primary literature. Written by a single author in a clear and consistent writing style, each topic builds in complexity from electrophysiology to molecular genetics to systems level in a highly integrative approach. Students can fully engage with the content via thematically linked chapters and will be able to read the book in its entirety in a semester-long course. Principles of Neurobiology is accompanied by a rich package of online student and instructor resources including animations, figures in PowerPoint, and a Question Bank for adopting instructors.

Download or read book Research and Highlights written by Argonne National Laboratory and published by . This book was released on 1991 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The First Steps in Seeing written by Robert W. Rodieck and published by Sinauer Associates Incorporated. This book was released on 1998-01-01 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: The First Steps in Seeing is about the eyes, and how they capture an image and convert it to the neural messages that ultimately result in visual experience. A full appreciation of how the eyes work is rooted in diverse areas of science-optics; biochemistry and photochemistry; molecular biology, cell biology, neurobiology, and evolutionary biology; psychology and psychophysics. The findings related to vision from any one of these fields are not difficult to understand in themselves, but, in order to be clear and precise, each discipline has developed its own set of words and conceptual relations-in effect, its own language-and for those wanting a broad introduction to vision these separate languages can present more of an impediment to understanding than an aid. However, what lies beneath these words usually has a beautiful simplicity, and it is the aim of The First Steps in Seeing to describe how we see in a manner that is understandable to all. In this book, the use of technical terms is restricted, and several hundred full-color illustrations ensure that the terms that are used are associated with a picture, icon, or graph that visually expresses their meaning. Experimental findings have been recast in terms of the natural world whenever possible, and broad themes bring together lines of thought that are often treated separately. Fourteen main chapters form a "thread" that tells the main scientific story and can be read without specialized knowedge or reliance on other sources. This thread is linked to fourteen discussions which explore certain crucial topics in greater depth. Notes link the material presented in the thread and in the special topics discussions to important review articles and seminal research papers. The First Steps in Seeing is an innovative, authoritative work that belongs in the library of anyone with an interest in visual perception.