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 SENSORY SYSTEMS www.itk.ppke.hu Neurobiológia alapjai (Érző pályarendszerek) ZSOLT LIPOSITS Basics of Neurobiology: Sensory systems 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 3 www.itk.ppke.hu FEATURES OF THE GENERAL SENSORY SYSTEM TOUCH, PAIN, TEMPERATURE AND CONSCIOUS PROPRIOCEPTIVESTIMULI PROVIDE USEFUL INFORMATION ABOUT OBJECTS IN THE ENVIRONMENT AND THE ACTUAL STATE OF BODY PARTS FROM MOST PARTS OF THE BODY, TWO GENERAL SENSORY SYSTEMS CARRY THE INFORMATION FROM RECEPTORS TO HIGHER PROCESSING CENTERS, THE SPINO-THALAMIC SYSTEM AND THE MEDIAL LEMNISCUSSYSTEM. FROM THE HEAD REGION, THE TRIGEMINAL AND DORSAL TRIGEMINAL TRACTS FORWARD THESENSORY INFORMATION TO THE THALAMUS THE SYSTEMS ARE CROSSED AND MULTISYNAPTICIN NATURE THEY ARE LINKED TO THE SENSORY NUCLEI OF THE THALAMUS, ESPECIALLY THE VENTRAL POSTERO-MEDIAL AND VENTRAL POSTERO-LATERAL NUCLEI THE MAJOR PROCESSING SITE OF GENERAL SENSORY INFORMATION IS IN THE PRIMARY SOMATOSENSORYCORTEX LOCATED IN THE POSTCENTRALGYRUSOF THE PARIETAL LOBE (BRODMANNAREAS 3, 2, 1) Basics of Neurobiology: Tracts of spinal cord 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 4 www.itk.ppke.hu ORIGIN AND INITIAL COURSE OF THE MEDIAL LEMNISCUS SYSTEM FASCICULUS GRACILIS FASCICULUS CUNEAUTS FIRST ODER SENSORY NEURONS IN SPINAL GANGLIA FASCICULUS GRACILIS. THICK MYELINATED FIBERS FROM S, L, T6-12 SEGMENTS. ORIGIN: SPINAL GANGLIA. TERMINATION: NUCLEUS GRACILIS IN MEDULLA. FUNCTION: SENSORY. LIGHT TOUCH, VIBRATION, 2-POINT DISCRIMINATION, POSITION SENSE FASCICULUS CUNEATUS. THICK MYELINATED FIBERS FROM T1-6 AND ALL C SEGMENTS. ORIGIN: SPINAL GANGLIA. TERMINATION: NUCLEUS CUNEATUS . FUNCTION: SENSORY. LIGHT TOUCH, VIBRATION, 2-POINT DISCRIMINATION, POSITION SENSE Basics of Neurobiology: Sensory systems 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 5 www.itk.ppke.hu THE MEDIAL LEMNISCUS SYSTEM AT THE LEVEL OF ITS DECUSSATION FIBRAE ARCUATAE DECUSSATIO LEMNISCORUM N. GRACILIS N. CUNEATUS MEDIAL LEMNISCUS SECOND ORDER NEURONS THE AXONS OF FIRST ORDER NEURONS TERMINATE ON SECOND ORDER NEURONS RE- SIDING IN N. GRACILIS AND N. CUNEATUS. THE ASCENDING, CROSSED TRACT ORIGI- NATING FROM THEM IS THE MEDIAL LEMNISCUS, PROJECTING TO THE THALAMUS Basics of Neurobiology: Sensory systems 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 6 www.itk.ppke.hu PROJECTIONS OF THE MEDIAL LEMNISCUS SYSTEM TO THE THALAMUS AND THE SOMATOSENSORY CORTEX THE ASCENDING MEDIAL LEMNISCUS TERMINATES IN THE VENTRAL POSTERO-LATERAL NUCLEUS OF THE THALAMUS. CELLS OF THIS NUCLEUS SERVE AS THIRD ORDER NEURONS AND PROJECT TO THE PRIMARY SOMATOSENSORY CORTEX IN THE PARIETAL LOBE FROM THE HEAD REGION, LIGHT TOUCH, VIBRATION, 2-POINT DISCRIMINATION SENSES ARE PROCESSED BY THE PRIN-CIPLE SENSORY NUCLEUS OF THE TRIGE-MINAL NERVE LOCATED IN THE PONS. THE PROJECTION FROM THIS NUCLEUS TERMINATES IN THE VENTRAL POSTERO-MEDIAL NUCLEUS OF THE THALAMUS Gray759.png SECOND ORDER NEURONS THIRD ORDER NEURONS FIRST ORDER NEURONS Basics of Neurobiology: Sensory systems 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 7 www.itk.ppke.hu ORIGIN AND INITIAL COURSE OF THE SPINOTHALAMIC TRACT SPINOTHALAMIC TRACT. ORIGIN: CONTRALATERAL GREY MATTER, LAMINAE I, IV AND V. TERMINATION: THALAMUS. FUNCTION: SENSORY. NOXIOUS PAIN AND THERMAL STIMULI, CRUDE TOUCH FIRST ORDER NEURON IN SPINAL GANGLIA SECOND ORDER NEURON IN SPINAL GREY MATTER SPINOTHALAMIC TRACT (EDINGER TRACT) Basics of Neurobiology: Sensory systems 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 8 www.itk.ppke.hu COURSE OF THE SPINOTHALAMIC AND TRIGEMINAL TRACTS FIRST ORDER NEURON SECOND ORDER NEURON THIRD ORDER NEURON FIRST ORDER NEURON SECOND ORDER NEURON THIRD ORDER NEURON S P I N O T H A L A M I C T R I G E M I N A L Basics of Neurobiology: Sensory systems 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 9 www.itk.ppke.hu SOMATOTOPIC ORGANIZATION IN THE PRIMARY SENSORY CORTEX F Homunculus_photo_2 Figure 1. A B C A. REPRESENTATION OF DIFFERENT BODY PARTS IN THE SOMATOSENSORY CORTEX. THE FACE AND HANDS ARE OVERREPRESENTED. B. THE SENSORY HOMUNCULUS. C. ILLUSTRATION OF THE WHISKER BARREL FIELDS OF THE RODENT BRAIN Basics of Neurobiology: Sensory systems 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 10 www.itk.ppke.hu COMPARISON OF THE TWO SENSORY SYSTEMS THE MEDIAL LEMNISCUS SYSTEM sensory_system1 sensory_system2 THE SPINOTHALAMIC SYSTEM Basics of Neurobiology: Sensory systems 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 11 www.itk.ppke.hu SOMATIC SENSATIONS TRANSMITTED BY THE TWO SENSORY SYSTEMS MEDIAL LEMNISCUS SPINOTHALAMIC TOUCH SENSATIONSWITH HIGH DEGREE OF LOCALIZATION OF THE STIMULUS PAIN TOUCH SENSATIONS REQUIRING TRANSMISSION OF FINE GRADIENTS OF INTENSITY CRUDE TOUCH AND PRESSURE SENSATIONS SENSATIONS THAT SIGNAL MOVEMENT AGAINST THE SKIN THERMAL SENSATIONS (COLD, WARM) PHASIC SENSATION (VIBRATION) SEXUAL SENSATIONS POSITION SENSATIONS TICKLE SENSATION PRESSURE SENSATIONS, FINE DEGREES OF JUDGMENT OF PRESSURE INTENSITY ITCH SENSATION Basics of Neurobiology: Sensory systems 8/8/2011. TÁMOP –4.1.2-08/2/A/KMR-2009-0006 12 www.itk.ppke.hu PAIN SENSATION THE PAIN PATHWAY OF DESCARTES TISSUE DAMAGE EVOKES ACUTE OR CHRONIC PAIN WHICH IS AN UNPLEASANT SENSORY AND EMOTIONAL EXPERIENCE. IT NEGATIVELYINFLUENCES THE QUALITY OF LIFE. PAIN KILLING IS A PRIMARY OBLIGATION OF MEDICALPRACTICE. PAINFUL EVENTS ARE CATEGORIZED ACCORDING TO DURATION, SEVERITY, ANATOMICAL LOCATION, BODY SYSTEM INVOLVED, CAUSE, TEMPORAL FEATURES AND THE NEUROCHEMICAL MECHANISMS INVOLVED IN 1962, MELZACK AND WALL INTRODUCED THE PAIN GATE THEORY. ACCORDING TO THAT THE PROJECTING NEURONS CARRYING TISSUE DAMAGE/PAIN-RELATED INFORMATION TO HIGHER PROCESSING SENSORY CENTERS ARE CONTROLLED LOCALLY IN THEGREY MATTER BY INCOMING INFORMATION OF NON-NOXIOUS STIMULI, THESE ARRIVE FROM THE SEGMEN-TAL LEVEL VIA THICK, MYELINATED FIBERS OF MECHANORECEPTORS AND ALSO TRACTS DESCENDING FROM THE BRAIN STEM. OPENING OF THE PAIN GATE AND PAIN THRESHOLD LEVEL SEEM TO DEPEND ON THE ACTUAL BALANCE OF INFORMATION SUPPLIED BY THESE, MULTIPLE SYSTEMS PROJECTING NEURON INTERNEURONS SPINOTHALAMICPATHWAY INFORMATION FROM NOCICEPTORS VIA C FIBERS INFORMATION FORM MECHANORECEPTORS VIA A FIBERS DESCENDING PATHWAYS FROM BRAIN STEM + - - - + +/- GATING