Download or read book Organization of Spatiotemporal Frequency Tuning in the Mouse Visual System written by Helen Wang and published by . This book was released on 2022 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mouse visual cortex is a hierarchical and distributed system that consists of primary visual cortex and several higher visual cortical areas. Historically, the low acuity of the mouse visual system garnered little interest in the neuroscience community, so many key principles about visual and cortical circuits were first discovered in primate and cat vision. As transgenic mice and genetically targeted viral tools and novel recording methods developed, a renewed interest and appreciation in the mouse visual system has emerged. A detailed understanding of the mouse visual system on its own, as well as in comparison with other species, is critical for understanding how different visual areas and their cell types work to process visual input. In chapter one, two methods for recording single cell activity are used to measure the spatiotemporal frequency and direction tuning properties of deep layer cortical neurons in primary visual cortex and two higher visual areas. While previous studies have characterized the functional tuning properties of superficial (layer 2 and layer 3) neurons in mice, the tuning properties of deep layer (layer 5 and 6) and different projection classes of layer 5 neurons have been less well characterized. We use extracellular electrophysiology and two-photon calcium imaging and find that while deeper layer neurons are specialized for different spatial and temporal frequencies, there is also a greater overlap in tuning preferences than previously reported in superficial layers. We also find much stronger direction tuning in extratelencephalically projecting layer 5 neurons compared to intratelencephalically projecting layer 5 neurons in multiple visual areas. In chapter two, we examine if two different transgenic mouse lines label layer 4 neurons that may represent different spatial and temporal frequency channels in mice to determine if the organization of spatial and temporal frequency channels is conserved from primates. We find that the neurons labelled in layer 4 by these two mouse lines are both morphologically and functionally different. Together, this dissertation seeks to use modern neuroscience tools to elucidate a more detailed understanding of the functional organization of visual tuning in the mouse visual system.
Download or read book Characterizing the Spatial and Temporal Frequency Tuning Properties in Mouse Visual Cortex with Calcium Imaging written by Natalia Mesa and published by . This book was released on 2021 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the neocortex, neurons with similar functional properties are clustered together. While incompletely understood, this feature of cortical organization is conserved across a variety of species and sensory systems. In the visual cortex, neurons with similar receptive field properties lie close by in cortical space. The mouse has become an increasingly popular model organism to study vision. While mice lack the visual acuity of primates, there are unparalleled genetic tools available in mice that allow us to dissect the functional properties and connectivity of specific cell types. Mice use vision perform complex behavioral tasks, like hunt, and, like primates, their visual areas are organized hierarchically. While it is likely that mouse visual areas specialized to aid mice in performing visual tasks, there is also evidence that visual computation is different in mice and primates. In particular, visual tuning properties are mapped differently in primates and mice and this likely has relevant functional consequences. A hallmark of primate vision is the specialization of visual areas. The primate visual system is organized hierarchically such that receptive fields of neurons in higher visual areas become increasingly complex and specific. It is unknown to what extent a similar organization exists in mice. The functional role of mouse higher visual areas, and their homology to primate visual areas, is an active area of investigation. Understanding the differences and similarities between mice and primates is crucial to establishing the mouse as a relevant model organism for primate vision. Five previous studies have revealed that mouse higher visual areas have distinct spatial and temporal frequency tuning properties than primary visual area, V1. However, their findings have varied widely. Similarly, previous studies have also revealed that functional properties, mainly spatial frequency tuning and coherent motion tuning, change across the visual field, but this is under-characterized. The primary aim of my thesis was to study how receptive field properties are mapped across the mouse visual cortex and how tuning properties change across the visual field. The next is to understand how experimental conditions and experimental design choices can lead to different tuning measurements between studies. In my first project, I used a combination of widefield and 2-photon (2P) calcium imaging to investigate how spatial frequency (SF) and temporal frequency (TF) tuning properties are mapped in the mouse visual cortex. I found evidence of functional specialization at different receptive field altitude locations in V1 and higher visual areas. Neurons in anterior V1 (lower visual field of view) have lower average TF and SF tuning than posterior V1 (upper visual field of view). I measured whether tuning gradients, gradual changes in tuning properties across a visual area or areas, in V1 and higher visual areas were consistent across cortical layers and in thalamic (dLGN) axons. In most visual areas, gradients had the same slope with respect to altitude. Interestingly, I found TF gradients that did not change abruptly across areal borders. While TF tuning differed across cortical layers, the relationship between TF and altitude was consistent across laminar populations and in dLGN axons. Therefore, gradients in V1 and some higher visual areas likely result from input from dLGN axons. In my second project, I examined how different inclusion criteria can impact reported tuning properties. Neurophysiology studies require the use of inclusion criteria to identify neurons responsive to the experimental stimuli. Five recent studies used calcium imaging to measure the preferred tuning properties of layer 2/3 pyramidal neurons in mouse visual areas. These five studies used different experimental designs that employed different inclusion criteria and report different, sometimes conflicting results. Experimental design choices and inclusion criteria both affect the subpopulation of neurons that are selected for. Here, I examined how different inclusion criteria can impact reported tuning properties, modifying inclusion criteria to select different sub-populations from the same dataset of almost 17,000 layer 2/3 neurons from the Allen Brain Observatory. The choice of inclusion criteria greatly affected the mean tuning properties of the resulting sub-populations; indeed, the differences in mean tuning due to inclusion criteria were often of comparable magnitude to the differences between studies. In particular, the mean preferred TFs of visual areas changed markedly with inclusion criteria, such that the rank ordering of visual areas based on their TF preferences changed with the percentage of neurons included. These results demonstrate that the current understanding of the functional organization of the mouse visual cortex obtained from previous experiments critically depends on the inclusion criteria used.Collectively, my research has advanced our understanding of visual processing in the mouse.
Download or read book Spatiotemporal Tuning and Contrast Adaptation in Mouse Primary Visual Cortex written by Emily Elizabeth LeDue and published by . This book was released on 2012 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Mice have emerged as a popular model of cortical visual processing due to their genetic manipulability. Compared to traditional animal models of visual processing there is less research describing the visual system of mice. Before we can use the genetic techniques available in mice, we must examine the similarity between their visual processing, and that of common animal models used in vision research. One useful method to characterize the way information about form and motion is processed is to examine the interaction between selectivity for spatial and temporal frequency of sine-wave gratings in a given visual area. In experiment 1, we investigated spatiotemporal tuning in neurons of mouse primary visual cortex (V1). Tuning for stimulus speed can readily be extracted from the spatiotemporal profile of a neuron, and we were interested in whether recently described differences in the degree of speed tuning in mouse V1 and macaque V1 were due to methodology. We confirm that speed tuning is rare in mouse V1, demonstrating a difference between motion processing in the striate cortex of mice and macaques. In experiment 2, we examined the spatiotemporal dependence of contrast adaptation in mouse V1 neurons. Little is known about the underlying cellular mechanisms of contrast adaptation, so the mouse provides an attractive model in which to study this phenomenon. We characterized the spatial and temporal frequency dependence of contrast adaptation in mouse V1 neurons simultaneously using a dynamic contrast ramp. We found that for most mouse V1 neurons there was often a difference between the grating that elicited maximal firing, and the grating where adaptation was most pronounced, such that adaptation was usually stronger at higher spatial frequencies.
Download or read book A Spatiotemporal Frequency Perspective on the Columnar Organization of Population Activity in Visual Cortex written by Amit Basole and published by . This book was released on 2005 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Photoreceptor Throughput to Visual Cortex written by Issac Rhim and published by . This book was released on 2021 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work in this dissertation aims to (1) examine the presence of a functional map in the mouse visual cortex by measuring its variable cone M-opsin and S-opsin inputs, as predicted by the graded dorsoventral cone opsin expression in the retina (Rhim et al., 2017), (2) devise a method for measuring rod saturation and utilize it to characterize differential spatio-temporal tuning between rod-mediated and cone-mediated vision in V1 (Rhim et al., 2021), and (3) study the representation of color and form. We report that the dorsoventral cone opsin expression gradient in the retina is recapitulated in the mouse visual cortex, including primary visual cortex (V1) and higher visual areas (HVAs). This provides a first finding of a functional map in the mouse cortex, next to retinotopy map. Next, we exploit this feature in the mouse cortex to measure variable opsin inputs to the cortex to provide a model to estimate rod saturation. This is a much-needed foundation in mouse vision research, which will help future studies to differentially quantify inputs from the three photoreceptor opsins found in mice: rhodopsin, S-opsin, and M-opsin. We exemplify this by studying the spatio-temporal tuning of rod-mediated vs. cone-mediated vision in V1. Cone-mediated V1 responds to 2.5-fold higher temporal frequencies than rod-mediated V1, highlighting differences in rod vs. cone information throughput. Lastly, we study the mechanisms underlying spatio-chromatic processing in the cortex. We find that V1’s spatial frequency (SF) tuning is more low-pass to color contrast than brightness (i.e., luminance) contrast. Furthermore, our data can be accounted by a random wiring model with rhodopsin and cone S-opsin inputs to single-opponent V1 neurons. While classic models of single-opponency require selective wiring for ON and OFF subfields from each photoreceptor class, we find this to be inconsistent with our data. This provides a new insight to mechanism underlying color vision
Download or read book Feedback Figures it Out written by and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Visual perception is a creative process. An elaborate hierarchy of interconnected areas processes visual information, while incorporating predictions about the visual scene. How the brain creates the perceptually stable images, is a central question in the field of Neuroscience. This thesis was aimed at addressing fundamental questions on the organizational and computational principles of the visual cortex. We utilized a range of genetic tools, physiological recording techniques, computational procedures, and psychophysics methods to measure and manipulate neuronal activity in behaving mice. A long-standing argument questioning the transferability of research insights from the mouse to human vision has been that the mouse retina lacks a fovea. We demonstrated that the representation of space in mouse visual cortex resembles that in humans in a previously unforeseen manner. We measured cortex-wide population receptive-fields (pRFs) and discovered a region directly in front of, and slightly above the mouse with considerably smaller pRFs, called the ‘focea’. The decrease in pRF size in the focea was not caused by smaller receptive fields (RF) of individual neurons. Instead, a more orderly representation of space and an over-representation of binocular regions cause reduced pRF sizes in the focea. Using behavioral paradigms, we showed that mice have improved visual resolution in the focea and that mice make compensatory eye movements to stabilize this region. These experiments advance our knowledge about organizational principles of the mouse visual system and have important implications for the translatability of research on mouse vision. After examining organizational principles of the visual system, we explored functional properties of the visual cortex, investigating the neural circuits underlying perceptual organization.
Download or read book Evolution of Nervous Systems written by Georg F. Striedter and published by Academic Press. This book was released on 2016-11-23 with total page 2064 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evolution of Nervous Systems, Second Edition, Four Volume Set is a unique, major reference which offers the gold standard for those interested both in evolution and nervous systems. All biology only makes sense when seen in the light of evolution, and this is especially true for the nervous system. All animals have nervous systems that mediate their behaviors, many of them species specific, yet these nervous systems all evolved from the simple nervous system of a common ancestor. To understand these nervous systems, we need to know how they vary and how this variation emerged in evolution. In the first edition of this important reference work, over 100 distinguished neuroscientists assembled the current state-of-the-art knowledge on how nervous systems have evolved throughout the animal kingdom. This second edition remains rich in detail and broad in scope, outlining the changes in brain and nervous system organization that occurred from the first invertebrates and vertebrates, to present day fishes, reptiles, birds, mammals, and especially primates, including humans. The book also includes wholly new content, fully updating the chapters in the previous edition and offering brand new content on current developments in the field. Each of the volumes has been carefully restructured to offer expanded coverage of non-mammalian taxa, mammals, primates, and the human nervous system. The basic principles of brain evolution are discussed, as are mechanisms of change. The reader can select from chapters on highly specific topics or those that provide an overview of current thinking and approaches, making this an indispensable work for students and researchers alike. Presents a broad range of topics, ranging from genetic control of development in invertebrates, to human cognition, offering a one-stop resource for the evolution of nervous systems throughout the animal kingdom Incorporates the expertise of over 100 outstanding investigators who provide their conclusions in the context of the latest experimental results Presents areas of disagreement and consensus views that provide a holistic view of the subjects under discussion
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 The Inferior Colliculus written by Jeffery A. Winer and published by Springer Science & Business Media. This book was released on 2005-12-05 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Connecting the auditory brain stem to sensory, motor, and limbic systems, the inferior colliculus is a critical midbrain station for auditory processing. Winer and Schreiner's The Inferior Colliculus, a critical, comprehensive reference, presents the current knowledge of the inferior colliculus from a variety of perspectives, including anatomical, physiological, developmental, neurochemical, biophysical, neuroethological and clinical vantage points. Written by leading researchers in the field, the book is an ideal introduction to the inferior colliculus and central auditory processing for clinicians, otolaryngologists, graduate and postgraduate research workers in the auditory and other sensory-motor systems.
Download or read book The Visual Neurosciences written by John Simon Werner and published by MIT Press. This book was released on 2004 with total page 975 pages. Available in PDF, EPUB and Kindle. Book excerpt: An essential reference book for visual science.
Download or read book The Claustrum written by John R. Smythies and published by Academic Press. This book was released on 2013-11-11 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present day is witnessing an explosion of our understanding of how the brain works at all levels, in which complexity is piled on complexity, and mechanisms of astonishing elegance are being continually discovered. This process is most developed in the major areas of the brain, such as the cortex, thalamus, and striatum. The Claustrum instead focuses on a small, remote, and, until recently, relatively unknown area of the brain. In recent years, researchers have come to believe that the claustrum is concerned with consciousness, a bold hypothesis supported by the claustrum's two-way connections with nearly every other region of the brain and its seeming involvement with multisensory integrations—the hallmark of consciousness. The claustrum, previously in a humble position at the back of the stage, might in fact be the conductor of the brain's orchestra. The Claustrum brings together leading experts on the claustrum from the varied disciplines of neuroscience, providing a state-of-the-art presentation of what is currently known about the claustrum, promising lines of current research (including epigenetics), and projections of new lines of investigation on the horizon. - Develops a unifying hypothesis about the claustrum's role in consciousness, as well as the integration of sensory information and other higher brain functions - Discusses the involvement of the claustrum with autism, schizophrenia, epilepsy, Alzheimer's disease, and Parkinson's disease - Coverage of all aspects of the claustrum, from its evolution and development to promising new lines of research, including epigenetics, provides a platform and point of reference for future investigative efforts
Download or read book The Primate Visual System written by Jon H. Kaas and published by CRC Press. This book was released on 2003-07-28 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last 20 years of research have been marked by exceptional progress in understanding the organization and functions of the primate visual system. This understanding has been based on the wide application of traditional and newly emerging methods for identifying the functionally significant subdivisions of the system, their interconnections, the
Download or read book The Senses A Comprehensive Reference written by and published by Academic Press. This book was released on 2020-09-30 with total page 5215 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Senses: A Comprehensive Reference, Second Edition, Seven Volume Set is a comprehensive reference work covering the range of topics that constitute current knowledge of the neural mechanisms underlying the different senses. This important work provides the most up-to-date, cutting-edge, comprehensive reference combining volumes on all major sensory modalities in one set. Offering 264 chapters from a distinguished team of international experts, The Senses lays out current knowledge on the anatomy, physiology, and molecular biology of sensory organs, in a collection of comprehensive chapters spanning 4 volumes. Topics covered include the perception, psychophysics, and higher order processing of sensory information, as well as disorders and new diagnostic and treatment methods. Written for a wide audience, this reference work provides students, scholars, medical doctors, as well as anyone interested in neuroscience, a comprehensive overview of the knowledge accumulated on the function of sense organs, sensory systems, and how the brain processes sensory input. As with the first edition, contributions from leading scholars from around the world will ensure The Senses offers a truly international portrait of sensory physiology. The set is the definitive reference on sensory neuroscience and provides the ultimate entry point into the review and original literature in Sensory Neuroscience enabling students and scientists to delve into the subject and deepen their knowledge. All-inclusive coverage of topics: updated edition offers readers the only current reference available covering neurobiology, physiology, anatomy, and molecular biology of sense organs and the processing of sensory information in the brain Authoritative content: world-leading contributors provide readers with a reputable, dynamic and authoritative account of the topics under discussion Comprehensive-style content: in-depth, complex coverage of topics offers students at upper undergraduate level and above full insight into topics under discussion
Download or read book The Parietal Lobe written by and published by Academic Press. This book was released on 2018-03-05 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Parietal Lobe, Volume 151, the latest release from the Handbook of Clinical Neurology series, provides a foundation on the neuroanatomy, neurophysiology and clinical neurology/neuropsychology of the parietal lobe that is not only applicable to both basic researchers and clinicians, but also to students and specialists who are interested in learning more about disorders brought on by damage or dysfunction. Topics encompass the evolution, anatomy, connections, and neurophysiology, the major neurological and neuropsychological deficits and syndromes caused by damage, the potential for improvement via transcranial stimulation, and the role of the parietal in the cerebral networks for perception and action. - Provides a broad overview of the neuroanatomy, neurophysiology and clinical neurology of this region of the cortex - Offers additional insights regarding the role of the parietal in the cerebral networks for perception and action - Addresses the most frequent complications associated with damage, including somatosensory, perceptual, language, and memory, deficits, pain, optic ataxia, spatial neglect, apraxia, and more - Edited work with chapters authored by global leaders in the field - Presents the broadest, most expert coverage available
Download or read book The Auditory Cortex written by Jeffery A. Winer and published by Springer Science & Business Media. This book was released on 2010-12-02 with total page 711 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been substantial progress in understanding the contributions of the auditory forebrain to hearing, sound localization, communication, emotive behavior, and cognition. The Auditory Cortex covers the latest knowledge about the auditory forebrain, including the auditory cortex as well as the medial geniculate body in the thalamus. This book will cover all important aspects of the auditory forebrain organization and function, integrating the auditory thalamus and cortex into a smooth, coherent whole. Volume One covers basic auditory neuroscience. It complements The Auditory Cortex, Volume 2: Integrative Neuroscience, which takes a more applied/clinical perspective.
Download or read book Inhibitory Synaptic Plasticity written by Melanie A. Woodin and published by Springer Science & Business Media. This book was released on 2010-11-02 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume will explore the most recent findings on cellular mechanisms of inhibitory plasticity and its functional role in shaping neuronal circuits, their rewiring in response to experience, drug addiction and in neuropathology. Inhibitory Synaptic Plasticity will be of particular interest to neuroscientists and neurophysiologists.
Download or read book Visual Dysfunction in Schizophrenia A View into the Mechanisms of Madness written by Randolph Blake and published by Frontiers Media SA. This book was released on 2015-05-11 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on visual perception in schizophrenia has a long history. However, it is only recently that it has been included in mainstream efforts to understand the cognitive neuroscience of the disorder and to assist with biomarker and treatment development (e.g., the NIMH CNTRICS and RDoC initiatives). Advances in our understanding of visual disturbances in schizophrenia can tell us about both specific computational and neurobiological abnormalities, and about the widespread computational and neurobiological abnormalities in the illness, of which visual disturbances constitute well-studied, replicable, low-level examples. Importantly, far from being a passive sensory registration process, visual perception is active, inferential, and hypothesis-generating, and therefore can provide excellent examples of breakdowns in general brain functions in schizophrenia. Despite progress made in understanding visual processing disturbances in schizophrenia, many challenges exist and many unexplored areas are in need of examination. For example, the directional relationships between perceptual and cognitive disturbances (e.g., in attention, memory, executive function, predictive coding) remain unclear in many cases, as do links with symptoms, including visual hallucinations. The effect of specific visual disturbances on multisensory integration in schizophrenia has also not been explored. In addition, few studies of vision in schizophrenia have used naturalistic stimuli, including real-world objects, and almost no studies have examined processing during interaction with objects or visual exploration, which can provide important data on functioning of the perception for action pathway. Relatedly, studies of visual processing in schizophrenia have also not been conducted within contexts that include emotional stimulation and the presence of reinforcers – characteristics of many real-world situations - and the consequences of this are likely to be an incomplete view of how and when perception is abnormal in the condition. An additional important area involves treatment of visual disturbances in schizophrenia. Two major questions regarding this are: 1) can visual processing be improved in cases where it is impaired (and by what types of interventions affecting which cognitive and neurobiological mechanisms)? and 2) what are the clinical and functional benefits of improving specific visual functions in people with schizophrenia? Other important and understudied questions concern: 1) the extent to which indices of visual functioning can serve as biomarkers such as predictors of relapse, treatment response, and/or recovery; 2) the potential role of visual functioning in diagnosing and predicting illness; 3) the extent to which some visual perception disturbances are diagnostically specific to schizophrenia; and 4) the extent to which visual disturbances are truly manifestations of disease, as opposed to aspects of normal variation that, in combination with disease, serves to modify the clinical presentation. This Frontiers Research Topic explores some of these, and other issues facing this exciting interface between vision science and schizophrenia research. We include papers that span the entire range of different Frontiers paper types, including those that are data driven (using psychophysics, electroencephalography, neuroimaging, computational and animal models, and other methods), reviews, hypotheses, theories, opinion, methods, areas of impact, and historical perspectives.
