Light Projection on Retina

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Sensory Systems Modality Stimulus Receptor Class Receptors Nervous Vision Light Photoreceptors Rods, cones System Audition Sound Mechanoreceptor Hair cells (cochlea) Vestibular Gravity, Mechanoreceptors Hair cells (vestibular labyrinth) acceleration Somatic Dorsal root ganglion neurons Perception Touch Pressure Mechanoreceptor Cutaneous mechanoreceptors Memory Proprioception Displacement Mechanoreceptor Muscle and joint receptors Temperature Thermal Thermoreceptor Cold and warm receptors Sensory inputs: Planning Motor responses: Pain Chemical, thermal, Chemoreceptor, Chemical, thermal, and light, sound, …… limb movement, or mechanical themoreceptor, or mechanical nociceptors skin pressure, facial expression, mechanoreceptor odor … speech … Itch Chemical Chemoreceptor Chemical nociceptor Taste Chemical Chemoreceptor Taste buds Smell Chemical Chemoreceptor Olfactory sensory neurons Transduction Light Projection on Retina Transduction 1 Cone Response Visual pathway Decussation Hierarchical and Parallel Processing Receptive Field 2 Geometry of Projection Geometry of Projection Retinal image size is inversely proportional to distance Ponzo’s Illusion Left eye Right eye 3 Muller-Lyer Illusion “Circular World” of the Zulus (South Africa) David Marr’s Concept of a Computational Theory for Understanding an Information Processing Task in the Brain We cannot understand how a bird flies by only studying its wings, but need, in addition, an aerodynamic theory of lift generation by the flow patterns around the wings. We cannot understand how a computer works by only studying the transistors on the circuit boards and their connections, but need, in addition, concepts of operating system, data structure, and application programs. 4 David Marr’s Concept of a Computational Theory for Understanding an Information Processing Task in the Brain Therefore, even if some day we had complete knowledge of every molecule in the brain, and could record the electrical activities of every cell at any time, we would still not understand how the brain processes information. We need, in addition, a computational theory which specifies how the electrical signals carried by a large number of neurons could act in concert to solve a certain perceptual problem. 5.

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On the Existence of Mechanoreceptors Within the Neurovascular Unit of the Rodent and Rabbit Brain
bioRxiv preprint doi: https://doi.org/10.1101/480921; this version posted November 28, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. On the existence of mechanoreceptors within the neurovascular unit of the rodent and rabbit brain Jorge Larriva-Sahd, Martha León-Olea (*), Víctor Vargas-Barroso (**), Alfredo Varela-Echavarría and Luis Concha Departments of Developmental Biology and Physiology, Instituto de Neurobiología. Campus Juriquilla. Universidad Nacional Autónoma de México. Boulevard Universitario 3001, Juriquilla, Querétaro, CP 76230, México. (*) Department of Functional Neuromorphology, Instituto Mexicano de Psiquiatría “Ramón de la Fuente Muñiz” Av México Xochimilco 101, Delegación Tlalpan CP14370, México DF, México. (**) Present address: Institute of Science and Technology Austria (IST), Am Campus 1, 3400, Klosterneuburg, Austria.Correspondence: Correspondence: Jorge Larriva-Sahd e-mail: [email protected] Telephone: 5256-234030 Orcid ID: 0000-0002-7254-0773 bioRxiv preprint doi: https://doi.org/10.1101/480921; this version posted November 28, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. Abstract. We describe a set of perivascular interneurons (PINs) originating a series of fibro-vesicular complexes (FVCs) throughout the gray matter of the adult rabbit and rat brain. PINs-FVCs are ubiquitous throughout the brain vasculature as defined in Golgi-impregnated specimens.
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455 The roles and functions of cutaneous mechanoreceptors Kenneth O Johnson Combined psychophysical and neurophysiological research has nerve ending that is sensitive to deformation in the resulted in a relatively complete picture of the neural mechanisms nanometer range. The layers function as a series of of tactile perception. The results support the idea that each of the mechanical filters to protect the extremely sensitive recep- four mechanoreceptive afferent systems innervating the hand tor from the very large, low-frequency stresses and strains serves a distinctly different perceptual function, and that tactile of ordinary manual labor. The Ruffini corpuscle, which is perception can be understood as the sum of these functions. located in the connective tissue of the dermis, is a rela- Furthermore, the receptors in each of those systems seem to be tively large spindle shaped structure tied into the local specialized for their assigned perceptual function. collagen matrix. It is, in this way, similar to the Golgi ten- don organ in muscle. Its association with connective tissue Addresses makes it selectively sensitive to skin stretch. Each of these Zanvyl Krieger Mind/Brain Institute, 338 Krieger Hall, receptor types and its role in perception is discussed below. The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2689, USA; e-mail: [email protected] During three decades of neurophysiological and combined Current Opinion in Neurobiology 2001, 11:455–461 psychophysical and neurophysiological studies, evidence has accumulated that links each of these afferent types to 0959-4388/01/$ — see front matter © 2001 Elsevier Science Ltd. All rights reserved. a distinctly different perceptual function and, furthermore, that shows that the receptors innervated by these afferents Abbreviations are specialized for their assigned functions.
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