Download or read book Local Circuitry and Function of Deep Layer Neurons in Monkey Primary Visual Cortex written by Farran Briggs and published by . This book was released on 2003 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Micro Meso and Macro Connectomics of the Brain written by Henry Kennedy and published by Springer. This book was released on 2016-03-10 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has brought together leading investigators who work in the new arena of brain connectomics. This includes ‘macro-connectome’ efforts to comprehensively chart long-distance pathways and functional networks; ‘micro-connectome’ efforts to identify every neuron, axon, dendrite, synapse, and glial process within restricted brain regions; and ‘meso-connectome’ efforts to systematically map both local and long-distance connections using anatomical tracers. This book highlights cutting-edge methods that can accelerate progress in elucidating static ‘hard-wired’ circuits of the brain as well as dynamic interactions that are vital for brain function. The power of connectomic approaches in characterizing abnormal circuits in the many brain disorders that afflict humankind is considered. Experts in computational neuroscience and network theory provide perspectives needed for synthesizing across different scales in space and time. Altogether, this book provides an integrated view of the challenges and opportunities in deciphering brain circuits in health and disease.
Download or read book Cerebral Cortex written by Alan Peters and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 10 is a direct continuation and extension of Volume 3 in this series, Visual Cortex. Given the impressive proliferation of papers on visual cortex over the intervening eight years, Volume 10 has specifically targeted visual cortex in primates and, even so, it has not been possible to survey all of the major or relevant developments in this area. Some research areas are experiencing rapid change and can best be treated more comprehensively in a subsequent volume; for example, elaboration of color vision; patterns and subdivisions of functional columns. One major goal of this volume has been to provide an overview of the intrinsic structural and functional aspects of area 17 itself. Considerable pro gress has been made since 1985 in unraveling the modular and laminar organi zation of area 17; and this aspect is directly addressed in the chapters by Peters, Lund et al., Wong-Riley, and Casagrande and Kaas. A recurring leitmotif here is the evidence for precise and exquisite order in the interlaminar and tangential connectivity of elements. At the same time, however, as detailed by Lund et al. and Casagrande and Kaas, the very richness of the connectivity implies a multi plicity of processing routes. This reinforces evidence that parallel pathways may not be strictly segregated. Further connectional complexity is contributed by the various sets of inhibitory neurons, as reviewed by Lund et al. and Jones et al.
Download or read book Neuronal Operations in the Visual Cortex written by G.A. Orban and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: The invitation by the editors of the series "studies of brain function" to contribute a monograph on the visual cortex gives me the opportunity to present in a concentrated manner much of the work I have done on the visual cortical areas of cat and monkey. However, the field of visual cortical physi ology is so active and so diverse that the presentation of only my own work would have given a very incomplete view of visual cortical functioning. Therefore this monograph also reviews most of the studies carried out on the subject in the last two decades. Where possible I have tried not only to describe the cortical machinery but also its possible functional purpose regarding vision. In doing this I have expressed my personal views rather than just reviewing the experimental facts. Much of the work presented in this monograph has been supported by the National Research Council of Belgium and the Research Council of the Catholic University of Leuven. I express my gratitude to them. I have en joyed collaborating in these studies with P. O. Bishop, H. Kato, H. Kennedy, K. P. Hoffmann, H. Maes, J. Duysens, E. Vandenbussche, and H. van der Glas. I am much indebted to all those who have commented on earlier versions of this monograph: J. Allman, H. Barlow, J. BuBier, M. Callens, J. Duysens, O. J. Griisser, P. Heggelund, H. Kennedy, L. C. Orban and L. Palmer.
Download or read book Local Functional Input to Neurons in Deep Layers of Rat Visual Cortex written by Amir Zarrinpar and published by . This book was released on 2006 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unraveling the precise connectivity of underlying neural circuits will lead to a better understanding of how the cortex accomplishes even the most effortless task. It has been a fundamental goal of neurophysiology to identify individual cell types based on morphological and/or intrinsic physiological properties and to discover their respective role in the circuitry within which they are embedded. To understand visual cortical circuitry even better, this dissertation focuses on the deep layers (layers 5 and 6) of the rat visual system. These cells, which comprise more than half of the cortical depth in the rat, are in a unique position in the visual system circuitry. Compared to the superficial layers, the deep layers have a greater diversity of cell morphologies and probably play a more varied role in visual information processing. We studied dendritic morphologies and local excitatory input to individual layer 6 and layer 5 neurons in rat visual cortex by combining intracellular labeling and recording with laser-scanning photostimulation. We found significant differences in the sources of local excitatory input to different cell types. In layer 6 we found six distinct cell subtypes which we characterized based on morphology and sublaminar organization. Most notably, there were differences in local input to neurons that were likely to project only to the lateral geniculate nucleus versus those that were likely also to project to the lateral posterior nucleus. In layer 5 we distinguished three non-overlapping cell subtypes based on both their morphological and intrinsic physiological properties. Although all cell types received significant input from all layers. One subset of cells, presumed to be cortico-cortical projecting neurons, received stronger input from layer 4 and weaker input from layer 5 when compared to the others. We did not find any differences in input patterns between two subtypes that had similar morphology but different firing patterns. Using an analysis of synchronous activity, however, we showed that although the two cell types receive the same laminar input patterns, they receive input from different cell populations within those layers.
Download or read book Handbook of Brain Microcircuits written by Gordon M. Shepherd and published by Oxford University Press. This book was released on 2018 with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to focus on principles, each chapter in this work is brief, organized around 1-3 wiring diagrams of the key circuits, with several pages of text that distil the functional significance of each microcircuit
Download or read book Specificity and Diversity of Local Connections in Macaque Primary Visual Cortex written by Atomu Sawatari and published by . This book was released on 1999 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Circuitry Underlying Response Properties of Neurons in the Primary Visual Cortex Spatiotemporal Receptive Field of Synaptic Inputs written by Chenmei Jennie Chen and published by . This book was released on 2009 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Functional Anatomy of Visual Processing in the Cerebral Cortex of the Macaque written by Koen Nelissen and published by Leuven University Press. This book was released on 2006 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we examined the monkey cortical regions involved in processing of color, visual motion information, and the recognition of actions done by others. The aim was to gain better insight in the functional organization of the monkey visual cortex using in-house developed functional imaging techniques. Two different functional imaging techniques were used in these studies, the double-label deoxyglucose technique (DG) and functional magnetic resonance imaging (fMRI) in the awake monkey (Chapter 2). Both techniques allow to obtain an overview of stimulus-related neural activity throughout the whole brain, integrated over a limited amount of time. The results of the color experiments (Chapter 3) clearly showed that color related information is processed within a group of areas belonging to the ventral stream, which is involved in the perception of objects. Color-related metabolic activity was observed in visual areas V1, V2, V3, V4 and inferotemporal cortex (area TEO and TE). These findings set to rest the longstanding controversial claims that color would be processed almost selectively in one extrastriate visual area (V4) (Zeki SM, Brain Res 1973 53: 422-427). These results also show the usefulness of whole brain functional mapping techniques, as a complimentary approach to single cell measurements. In Chapter 4, we investigated which regions in the superior temporal sulcus (STS) of the monkey are involved in the analysis of motion. While the caudal part of the STS has been studied extensively, including area MT/V5 and MST, little is known about motion sensitivity in more anterior-ventral STS regions. Using fMRI, we were able to localize and delineate six different motion sensitive regions in the STS. One of these regions, that we termed 1st (lower superior temporal), had not been described so far. We were able to further characterize the six motion sensitive regions, using a wide variety of motion-sensitivity tests. The results of the latter tests suggested that motion related information might be processed along a second pathway within the STS, in addition to the MT-MST path (which is involved in the perception of heading). This second pathway, which includes the more rostral motion sensitive STS regions (FST, 1st and STPm) is possibly involved in the visual processing of biological movements (movements of animate objects) and actions. Finally, we investigated how and where in the monkey brain visual information about actions done is processed (Chapter 5 and 6). We found (Chapter 5) that, in agreement with earlier single unit results, the observation of grasping movements activates several regions in the premotor cortex of the monkey. Remarkable is that these premotor regions predominantly have a motor function, coding different types of higher order motor acts (for instance grasping of an object). These results are in agreement with earlier suggestions that we are able to understand actions done by others, because observation of a particular motor act activates our own motor representation of the same act. Furthermore, these studies suggested that within the frontal cortex of the monkey, there is a distinction between context-dependent (a person grasping) and more abstract (a hand grasping) action representations. In Chapter 6 we studied two other regions which are involved in the processing of visual information of actions done by others, the superior temporal sulcus (STS) and the parietal cortex. In the parietal cortex, we found a similar distinction between context-dependent and more abstract action representations as observed in prefrontal cortex. These results suggest that the parietal cortex is not only involved in the visual control of action planning, but also in the visual processing of actions performed by others. Based upon anatomical connections between the STS, parietal and frontal regions and motion-, form- and action-related functional properties of the former regions, we tentatively suggest how information about actions done by others might be sent from the STS to the frontal cortex along three different pathways. The latter working hypothesis will be tested in the future by additional fMRI control experiments and by combining fMRI, inactivation and microstimulation experiments while monkeys perform grasping tasks and/or view actions performed by others.
Download or read book What can simple brains teach us about how vision works written by Davide Zoccolan and published by Frontiers Media SA. This book was released on 2015-11-18 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vision is the process of extracting behaviorally-relevant information from patterns of light that fall on retina as the eyes sample the outside world. Traditionally, nonhuman primates (macaque monkeys, in particular) have been viewed by many as the animal model-of-choice for investigating the neuronal substrates of visual processing, not only because their visual systems closely mirror our own, but also because it is often assumed that “simpler” brains lack advanced visual processing machinery. However, this narrow view of visual neuroscience ignores the fact that vision is widely distributed throughout the animal kingdom, enabling a wide repertoire of complex behaviors in species from insects to birds, fish, and mammals. Recent years have seen a resurgence of interest in alternative animal models for vision research, especially rodents. This resurgence is partly due to the availability of increasingly powerful experimental approaches (e.g., optogenetics and two-photon imaging) that are challenging to apply to their full potential in primates. Meanwhile, even more phylogenetically distant species such as birds, fish, and insects have long been workhorse animal models for gaining insight into the core computations underlying visual processing. In many cases, these animal models are valuable precisely because their visual systems are simpler than the primate visual system. Simpler systems are often easier to understand, and studying a diversity of neuronal systems that achieve similar functions can focus attention on those computational principles that are universal and essential. This Research Topic provides a survey of the state of the art in the use of animal models of visual functions that are alternative to macaques. It includes original research, methods articles, reviews, and opinions that exploit a variety of animal models (including rodents, birds, fishes and insects, as well as small New World monkey, the marmoset) to investigate visual function. The experimental approaches covered by these studies range from psychophysics and electrophysiology to histology and genetics, testifying to the richness and depth of visual neuroscience in non-macaque species.
Download or read book Neural Mechanisms of Signal Convergence in the Primate Primary Visual Pathway written by Kacie Dougherty and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Cat Primary Visual Cortex written by Bertram Payne and published by Academic Press. This book was released on 2001-11-17 with total page 733 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by experts on the forefront of investigations of brain function, vision, and perception, the material presented is of an unparalleled scientific quality, and shows that analyses of enormous breadth and sophistication are required to probe the structure and function of brain regions. The articles are highly persuasive in showing what can be achieved by carrying out careful and imaginative experiments. The Cat Primary Visual Cortex should emerge as essential reading for all those interested in cerebral cortical processing of visual signals or researching or working in any field of vision. - Comprehensive account of cat primary visual cortex - Generous use of illustrations including color - Covers research from structure to connections to functions - Chapters by leaders in the field - Topics presneted on multiple, compatible levels
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 Role of Layer 6 in the Local Circuit of Cat Primary Visual Cortex written by Franziska D. Sägesser and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Visual Population Codes written by Nikolaus Kriegeskorte and published by MIT Press. This book was released on 2012 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: How visual content is represented in neuronal population codes and how to analyze such codes with multivariate techniques. Vision is a massively parallel computational process, in which the retinal image is transformed over a sequence of stages so as to emphasize behaviorally relevant information (such as object category and identity) and deemphasize other information (such as viewpoint and lighting). The processes behind vision operate by concurrent computation and message passing among neurons within a visual area and between different areas. The theoretical concept of "population code" encapsulates the idea that visual content is represented at each stage by the pattern of activity across the local population of neurons. Understanding visual population codes ultimately requires multichannel measurement and multivariate analysis of activity patterns. Over the past decade, the multivariate approach has gained significant momentum in vision research. Functional imaging and cell recording measure brain activity in fundamentally different ways, but they now use similar theoretical concepts and mathematical tools in their modeling and analyses. With a focus on the ventral processing stream thought to underlie object recognition, this book presents recent advances in our understanding of visual population codes, novel multivariate pattern-information analysis techniques, and the beginnings of a unified perspective for cell recording and functional imaging. It serves as an introduction, overview, and reference for scientists and students across disciplines who are interested in human and primate vision and, more generally, in understanding how the brain represents and processes information.
Download or read book Interlaminar Connectivity in Mouse Primary Visual Cortex written by Marley Rossa and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A distinguishing feature of the mammalian cerebral cortex is its laminar architecture, each layer containing a unique composition of neuronal types with distinct morphologies, molecular markers, and electrophysiological properties. These neurons form precise, specific synaptic connections with one another to form complex microcircuits that underlie sensory information processing. By compartmentalizing computation into layers, the cortex can efficiently channel and transform information to represent and interact with the external world. Therefore, deciphering the precise input and output connectivity structure of different neuronal types in the context of their respective layers is necessary to fully appreciate their unique functional roles in the representation and manipulation of sensory information. This dissertation builds on the traditional idea of a canonical interlaminar circuit by characterizing fundamental intracortical connections between excitatory and inhibitory cell types. Chapter 1 explores the relative functional input distributions from 5 layer-specific excitatory subpopulations to 4 cell types in mouse primary visual cortex (V1). By optogenetically activating these excitatory subpopulations and recording from targeted excitatory and inhibitory subtypes across cortical layers 2/3-6, I elucidate a complex interlaminar network that provides a novel framework for visual information processing. In Chapter 2, I approach the interlaminar connectivity of mouse V1 from a transcriptomic perspective using our newly developed method Single Transcriptome Assisted Rabies Tracing (START). By combining rabies tracing using glycoprotein (G)-deleted rabies virus (RVdG) with snRNAseq, we identify, and transcriptomic ally characterize cells projecting to the same layer-specific subpopulations as in Chapter 1. We find that START generates results consistent with established circuit models validating the utility of START as a circuit tracing tool. More importantly, with the increased cell type granularity achieved with transcriptomic characterization of inputs, we were able to uncover specific subtypes of somatostatin and parvalbumin interneurons that provide input to excitatory cells across layers. Taken together, findings from Chapters 1 and 2 demonstrate layer and cell type specificity in cortical circuit structure, indicating that a cell's laminar position and synaptic connectivity are deeply intertwined with its functional role. Understanding cell type diversity in the context of circuit architecture forms the foundation of a novel framework for cortical information processing.
