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 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 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 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 Fitting the Mind to the World written by Colin W. G. Clifford and published by Oxford University Press. This book was released on 2005-05-05 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book brings together a collection of studies from international researchers who demonstrate the brain's remarkable capacity to adapt its representation of the visual world in response to changes in its environment."--BOOK JACKET.

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 Neural Mechanisms of Color Vision written by Bevil Richard Conway and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dr. Conway mapped the spatial and temporal structure of the cone inputs to single neurons in the primary visual cortex of the alert macaque. Color cells had receptive fields that were often Double-Opponent, an organization of spatial and chromatic opponency sufficient to form the basis for color constancy and spatial color contrast. Almost all color cells gave a bigger response to color when preceded by an opposite color, suggesting that these cells also encode temporal color contrast. In sum, color perception is likely subserved by a subset of specialized neurons in the primary visual cortex. These cells are distinct from those that likely underlie form and motion perception. Color cells establish three color axes sufficient to describe all colors; moreover these cells are capable of computing spatial and temporal color contrast - and probably contribute to color constancy computations - because the receptive fields of these cells show spatial and temporal chromatic opponency.

Download or read book Spatiotemporal Properties of the Visual System and the Effect of Attention written by Patricia Anne Costello and published by . This book was released on 2003 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Adaptation on Single Neuron and Population Coding in Mouse Primary Visual Cortex written by Rachel Elizabeth Houlton and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of the Visual System written by Retina Research Foundation (U.S.). Symposium and published by MIT Press. This book was released on 1991 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of the Visual System presents a selection of current studies that clearly illustrate principles of visual system development. These range from retinal development in fish and frogs to the effects of abnormal visual experience on the primary visual cortex of the cat. The book is unique in addressing four specific and fundamental aspects of development: cell lineage and cell fate, specificity and targeting of axons, specification of visual cortex, and correlates of the critical period. Encompassing technical advances in cellular and molecular biology and in video imaging and microscopy, contributions in each of these areas provide new information at the cellular and molecular levels to complement the now classic descriptions of visual development previously available at the level of neural systems.ContributorsKaren L. Allendoerfer, David M. Altshuler, Antonella Antonini, Seymour Benzer, Edward M. Callaway, Constance L. Cepko, Hollis T. Cline, Max S. Cynader, N. W. Daw, Scott E. Fraser, K. Fox, Eckhard Friauf, Anirvan Ghosh, R. W. Guillery, William A. Harris, Christine E. Holt, Lawrence C. Katz, Susan McConnell, Pamela A. Raymond, Thomas A. Reh, Carla J. Shatz, Michael P. Stryker, Claudia A. 0. Stuermer, Mriganka Sur, David L. Turner, T. N. Wiesel

Download or read book Influence of Adaptation on Single Neuron and Population Coding in Mouse Primary Visual Cortex written by R. E. Houlton and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Cure of Imperfect Sight by Treatment Without Glasses written by W. Bates and published by Mary I. Oliver, Clark Night. This book was released on 2011-07-03 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Black & White Version.) Dr. Bates Original book. Natural Eyesight Improvement. Better Eyesight Magazine; July, 1919 to December, 1919 and Eyecharts attached in this Paperback book.Ophthalmologist William H. Bates discovered and perfected Natural Eyesight Improvement, The Bates Method'. He discovered the natural principles, true, normal function of the eyes (visual system) and applied natural methods, relaxation to return the eyes, eye muscles to normal function with healthy eyes, clear vision. He cured; unclear close and distant vision, astigmatism, crossed, wandering eyes, cataracts, glaucoma & other eye conditions. Natural Eyesight (Vision) Improvement was practiced years before Dr. Bates discovered it. It is the normal, natural function of the eyes. Hidden from the public by eye surgeons, Optometrists, optical businesses for over 100 years because this method works, is easy, anyone can learn, teach it, including children. It produces healthy eyes, clear vision and frees the patient from the need to purchase eyeglasses, drugs, unnecessary eye surgery. This book includes 12 Free PDF E-Books; Natural Eyesight Improvement Training; Do It Yourself-Natural Eyesight Improvement-Original and Modern Bates Method. 100+ Color Pictures. Less reading; Easy to learn steps-Read the short directions on the pictures to quickly learn, apply a treatment, activity for Fast Vision Improvement. (All of Dr. Bates, Clark Night's Kindle, Paperback books are in this E-Book.)+ Better Eyesight Magazine by Ophthalmologist William H. Bates - (Unedited, Full Set -132 Magazine Issues - 11 Years-July, 1919 to June, 1930.) Illustrated with 500 Pictures and additional, up to date Modern Natural Eyesight Improvement Training.+ Original Better Eyesight Magazine by Ophthalmologist William H. Bates - Photo copy of all his Original Antique Magazine Pages in the 1900's Print. (Unedited, Full Set 132 Magazine Issues-11 Years-July, 1919 to June, 1930.) A History Book. Learn Natural Eyesight Improvement Treatments directly from the Original Eye Doctor that discovered and practiced this effective, safe, natural method! Magazines &Method Hidden from the public by eye surgeons, Optometrists, optical businesses for over 100 years because this method works and frees the patient from the need to purchase eyeglasses, drugs, unnecessary eye surgery. Yes, it can and has reversed cataracts and other eye conditions!+ The Cure of Imperfect Sight by Treatment Without Glasses by Dr. Bates (Photo Copy of the Original Antique Book Pages) with Pictures. Dr. Bates First, Original Book. (Text version with Modern Treatments included.) 2nd Printing Title: Perfect Sight Without Glasses.+ Medical Articles by Dr. Bates - with Pictures.+ Stories From The Clinic by Emily C. A. Lierman/Bates. (Dr. Bates Clinic Assistant, Wife.)+ Use Your Own Eyes by Dr. William B. MacCracken M.D. (Trained with Dr. Bates.)+ Normal Sight Without Glasses by Dr. William B. MacCracken M.D.+ Strengthening The Eyes by Bernarr MacFadden & Dr. Bates - with Pictures and Modern Training. (Trained with Dr. Bates. One of the First Physical Fitness Teachers.)+ EFT Training Booklet - with Acupressure, Energy balance, strengthening, Positive Emotions.Easy step by step directions with Pictures.+ Seeing, Reading Fine Print Clear, Clear Close Vision (Presbyopia Treatments) with Videos.+ Eight Correct, Relaxed Vision Habits- A Quick Course in Natural Eyesight Improvement.+ Astigmatism Removal Treatments+ Eyecharts - 15 Large, Small and Fine Print Big C, E Charts for Close and Distant Vision, White and Black Letter Charts, Tumbling E Chart, Astigmatism Test and Removal Charts, Behavioral Optometry Charts. Eyechart Video Lessons.+ Audio & Video Lessons in Every Chapter - Learn a Treatment, Activity Quick and Easy.+ Videos Page; Links to 35+ Natural Eyesight Improvement Training Videos.See 'William H. Bates, Author's Page', for Video of internal book pages, full description of the Paperback & 12 free E-books.

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 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 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 Layer 4 in Primary Visual Cortex written by Jun Zhuang and published by . This book was released on 2013 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Adaptation to Contrast and Speed written by Markus Antero Hietanen and published by . This book was released on 2008 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: