8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 1 Development of Complex Curricula for Molecular Bionics and Infobionics Programs within a consortial* framework** Consortium leader PETER PAZMANY CATHOLIC UNIVERSITY Consortium members SEMMELWEIS UNIVERSITY, DIALOG CAMPUS PUBLISHER The Project has been realised with the support of the European Union and has been co-financed by the European Social Fund *** **Molekuláris bionika és Infobionika Szakok tananyagának komplex fejlesztése konzorciumi keretben ***A projekt az Európai Unió támogatásával, az Európai Szociális Alap társfinanszírozásával valósul meg. PETER PAZMANY CATHOLIC UNIVERSITY SEMMELWEIS UNIVERSITY sote_logo.jpg dk_fejlec.gif INFOBLOKK 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 2 Peter Pazmany Catholic University Faculty of Information Technology BASICS OF NEUROBIOLOGY VISUAL SYSTEM www.itk.ppke.hu Neurobiológia alapjai (Látórendszer) ZSOLT LIPOSITS Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 3 www.itk.ppke.hu FEATURES OF THE VISUAL SYSTEM THE VISUAL SYSTEM IS PART OF THE CNS. IT CONSISTS OF THE RETINAAND ITS PROJECTIONS, THE LATERAL GENICULATE BODY, THE OPTIC RADIATION, THE PRIM-ARY AND SECONDARY CORTICAL PROCESSING CENTERS. IN ASSOCIATION WITH THE SYSTEM, THE OCULOMOTOR REFLEX AND ACCOMMODATION ARE FUNCTI-ONALLY IMPORTANT MECHANISMS THE MAIN TASK OF THE VISUAL SYSTEM IS THE CONSCIOUS PERCEPTION OF THE VISUAL SCENE. THE INFORMATION ABOUT THE LIGHT/DARK PERIODS OF THE DAY IS DIRECTED TO THE SUPRACHIASMATIC NUCLEUS OF THE HYPOTHALAMUS THAT ORCHESTRATES THE DIURNAL (CIRCADIAN) RHYTHM OF SEVERAL NEURONAL, ENDOCRINE AND METABOLIC FUNCTIONS ALTHOUGH THE VISUAL FIELD IS REPRESENTED IN ALL KEY UNITS OF THEVISUAL SYSTEM FROM THE RETINA TO THE CORTICAL VISUAL AREAS, THE PROPER BINOC-ULAR VISION (SHAPE, SIZE, SHARPNESS, DEPTH, COLOR OF OBJECTS) REQUIRES A DELICATE COOPERATION OF PROCESSING STRUCTURES PERFORMING AT DIFFE-RENT LEVELS IN THE HIERARCHY OF THE NEURONAL ORGANIZATION THE IMAGE AND SPECIAL ATTRIBUTES OF THE OBJECTS SEEN IN THE BINOCULAR VISUAL FIELD ARE GRADUALLY BUILD UP FROM SIMPLEX (RETINA) TO COMPLEX (VISUAL CORTEX) PROCESSING LEVELS Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 4 www.itk.ppke.hu SCHEME OF THE ORGANIZATION OF THE VISUAL SYSTEM RETINA LATERAL GENICULATE BODY PRIMARY VISUAL CORTEX SECONDARY VISUAL AREAS SUPRACHIASMATIC NUCLEUS LIMBIC STRUCTURES PRETECTAL REGION EDINGER-WESTPHAL NUCLEUS CIRCADIAN RHYTHMS ACCOMMODATION PUPILLARY LIGHT REFLEX BINOCULAR VISION Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 5 www.itk.ppke.hu THE REFRACTIVE STRUCTURES OF THE EYE BALL F eye2 THE LIGHT RAY TRAVERSES THROUGH THE FOLLOWING STRUCTURES EN ROUTE TO THE PHOTORECEPTORS: CORNEA ANTERIOR CHAMBER PUPIL POSTERIOR CHAMBER LENS VITREOUS BODY RETINA Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 6 www.itk.ppke.hu THE STRUCTURE OF THE RETINA 1. PIGMENT CELL LAYER 2. LAYER OF RODS AND CONES 3. OUTER LIMITING MEMBRANE 4. OUTER NUCLEAR LAYER 5. OUTER PLEXIFORM LAYER 6. INNER NUCLEAR LAYER 7. INNER PLEXIFORM LAYER 8. GANGLION CELL LAYER 9. OPTIC NERVE FIBER LAYER 10. OUTER LIMITING MEMBRANE Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 7 www.itk.ppke.hu PHOTORECEPTOR CELLS OF THE RETINA ILLUSTRATION OF RODS AND CONES, THE PHOTORECEPTORS OF THE RETINA R O D R O D C O N E OUTER SEGMENT INNER SEGMENT FIBER NETWORKING OF PHOTORECEPTOR, BIPOLAR, HORIZON-TAL, GANGLION AND AMACRINE CELLS IN THE RETINA. NOTE THE CONVERGENCE DIRECTION OF LIGHT DIRECTION OF IMPULSE DEPICTION OF THE FOVEA CENTRALIS. NOTE THE EXCLUSIVE PRESENCE OF CONES THE TRICOLOR MECHANISM OF COLOR DETECTION. SPECTRUM SENSITIVE CONES Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 8 www.itk.ppke.hu SIGNAL TRANSDUCTION IN THE RETINA THE LIGHT RAY PASSES THROUGH THE INNER LAYERS OF THE RETINA ANDREA-CHES THE OUTER SEGMENTS OF PHOTORECEPTOR CELLS, THE RODS AND CONES SHINING LIGHT ON PHOTORECEPTORS LEADS TO HYPERPOLARIZATION OF THE RECEPTOR CELLS IN DARK, THE RECEPTOR CELLS ARE DEPOLARIZEDRESULTINGINSODIUM AND CALCIUM INFLUX THROUGH CYCLIC GUANOSINE MONOPHOSPHATE (cGMP)-GATED CHANNELS. THIS INWARD CURRENT AT THE OUTER SEGMENT IS OPPOSED BYAN OUTWARD CURRENT OF POTASSIUM. THE NET BALANCE OF CATIONS RESULTSIN A MEMBRANE POTENTIAL OF -40 mV THE ABSORPTION OF LIGHT REDUCES THE cGMP CONTENT IN THE PHOTORECEPTOR LEADING TO THE CLOSURE OF OUTER SEGMENT CATION CHANNELS. ACCORDINGLY, THE EFFLUX OF POTASSIUM IONS BECOMES DOMINANT, THE POSITIVE CHARGE DECREASES AND HYPERPOLARIZATION DEVELOPS visn2 Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 9 www.itk.ppke.hu Center Surround Center cone On-center Bipolar cell depolarized Off-center Bipolar cell hyperpolarized - + + + Surround On-center ganglion Off-center ganglion Glutamate Glutamate ON AND OFF CENTERS OF THE RETINA Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 10 www.itk.ppke.hu MAIN COMPONENTS AND PROJECTIONS OF THE VISUAL SYSTEM A. APPEARANCE OF OPTIC STRUCTURES ON THE VENTRAL BRAIN SURFACE. B. THE RETINOGENICULATE AND GENICULOSTRIATE PROJECTIONS. HISTOLOGY OF THE CGL (C) AND V1 (D) OPTIC NERVE OPTIC TRACT OPTIC CHIASM LATERAL GENICULATE BODY (CGL) PRIMARY VISUAL CORTEX V1 OPTIC RADIATION PARVICELLULAR LAYERS MAGNOCELLULAR LAYERS A D C B VISUAL FIELDS RETINAL FIELDS Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 11 www.itk.ppke.hu THE GENICULO-STRIATE PROJECTION. OCULAR DOMINANCE COLUMNS IMAGING AT RETINAL (A), LATERAL GENICULATE BODY (B)AND PRIMARY VISUAL CORTEX (C)LEVELS RIGHT LEFT LATERAL GENICULATE BODY MONOCULAR PRIMARY VISUAL CORTEX (STRIATE CORTEX) BINOCULAR OCULAR DOMINANCE COLUMNS IN THE VISUAL CORTEX A B C Basics of Neurobiology: Visual system 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 12 www.itk.ppke.hu RIGHT LEFT TEMPORAL NASAL TEMPORAL MEDIAL LATERAL LEFT LATERAL GENICULATE BODY VISUAL CORTEX 1. BLINDNESS OF LEFT EYE 3. BITEMPORAL HETERONYM HEMIANOPSIA 4. HOMONYM HEMIANOPSIA REPRESENTATION OF THE RETINA IN LATERAL GENICULATE NUCLEUS AND VISUAL CORTEX LOSS OF VISUAL FIELD DUE TO DAMAGE OF THE VISUAL STRUCTURES