Lecture 1 - Basic and Clinical Neuroscience PDF

From basic to clinical neuroscience: 18.10.2023 The brain – an introduction Anatomy and functional aspects of the human brain D. Lulé:  Brief history of neuroscience...

From basic to clinical neuroscience: 18.10.2023 The brain – an introduction Anatomy and functional aspects of the human brain D. Lulé:  Brief history of neuroscience Brain from mouse to man structure function Link between structure and function Survey  Brainstorming What do you know abou the brain? Function? Structure? Survey  History of the brain… Ancient Egypt : heart as seat of intelligence Ancient Greek (4th BC; Aristotle): heart is seat of intelligence brain was cooling mechanism for the blood Roman Empire (Galen): (fluid mechanical view) cerebellum dense  controls muscles cerebrum soft  controls senses Brief history Age of Enlightenment (Descartes): higher mental functions processed by the “soul„ (mind-body, dualist) 1900s: debated whether areas of the brain correspond to specific functions or if the brain functions as a whole ("aggregate field theory„ by e.g. Flourens vs. „phrenology“ by Gall).  „Phrenology“ (Gall, 1812) Comparison Time Friendship Brief history Paternal love www.state.sc.us  …physiological basics of the brain Structure: 1773: Luigi Galvani showed that electrically stimulating a nerve of a dissected frog caused movement of the attached muscle electrical theory 1906: Ramón y Cajal and Camillo Golgi: nobelprize for „work on nervous system“ individual neurons 1914: Otto Loewi (vagus substance, ACH), Henry Hallett Dale (1929-36) chemical neurotransmission Function: non-invasive studies in humans Brief history 20. Century: Broca and Wernicke observe consequences of brain lesions 1929: German physician Hans Berger: first electrical potentials from a living brain electroencephalography, EEG 1980´s: Photon Emission Tomographie, PET (radio labelling), 1990´s: functional magnetic resonance imaging, fMRI (blood flow change)  Facts concerning the brain 1200-1400 g mean 1245 g (female) mean 1375 g (male) neurons + glial cells (1 : 10-50) 1011 neurons (as many galaxies in universe) 1014 – 1015 synapses Glial cells: Oligodendroglia, Astroglia, Microglia Structure 78% H2O, 10% lipids, 8% proteins Brain from mouse to man Evolution of the brain www.brain.riken.jp/english/g_braaw/g2.html www.solarnavigator.net/biology/biology_images...  rat Evolution of the brain cat Cats and higher species Temporal pole Gyri and Sulci monkey Development of Gyri und Sulci accompanied evolution of intelligence Structure Gyri and Sulci develop following 7th month: unique pattern human Parietal lobe frontal lobe occipital lobe Sylvian fissure temporal lobe  Brain development humans Neural tube devides into 3 parts (up to day 28): forebrain (Proenzephalon) midbrain (Mesencephalon) endbrain (Rhombencephalon) Neural tube bends two times Structure  Directions within the brain Flexura Flexura Forebrain mesencephalica cervicalis Midbrain Endbrain Cervical Spine 3 cerebral vesicles Structure  Main structures Continuing day 29: 5 parts Proencephalon  Telen (end-)-, Diencephalon (inter-) Mesencephalon  (mid-) Mesencephalon Rhombencephalon  Meten (after-)-, Myelencephalon (marrowbrain) Telen,- Dien-, Mesen-, Meten-, Myelencephalon Telencephalon (endbrain): Cerebrum, Hippocampus, Bulbus olfactorius Diencephalon (interbrain): Thalamus, Hypothalamus, pituitary gland, Retina, … Mesencephalon (midbrain): Tectum, Tegmentum Metencephalon (afterbrain): Cerebellum, Pons Myelencaphalon (marrowbrain): Medulla oblongata Structure Eyes develop out of Diencephalon  Main structures Telencephalon (endbrain): Cerebrum, Hippocampus, Bulbus olfactorius Diencephalon (interbrain): Thalamus, Hypothalamus, pituitary gland, Retina, … Mesencephalon (midbrain): Structure Tectum, Tegmentum Metencephalon (afterbrain): Cerebellum, Pons Myelencaphalon (marrowbrain): Medulla oblongata Structure Can you name it?  … MRI of a brain Thalamus Structure http://en.wikipedia.org/wiki/Human_brain Orientation slicing  Landmarks Fissura longitudinalis Cerebri Structure Gyri and Sulci develop following 7th month: unique pattern www.ims.uni-stuttgart.de/phonetik/joerg/sgtutorial/architektur Structure More landmarks  Lobules Parietal lobe Frontal lobe Occipital lobe Structure Cerebellum Temporal lobe Anatomy Cerebrum Anatomy Sulci Anatomy Main structures Anatomy Anatomy Structure Sagittal view  Brainstorming: What do you see? Structure  Basal ganglia Nucleus caudatus Nucleus lentiformis Putamen Pallidum or Globus pallidus Structure Caudatum and Putamen form the Striatum Structure Basal ganglia Task: voluntary motor function, as well as other executive functions e.g. spontaneity, affect, taking initiative, will-power, drive, planning, anticipation, motoric selection Structure Four ventricles  Linings Soft linigs Brain Structure Structure 12 cranial nerves  Neurons of the cortex Afferent (input) Efferent (output) Interneurons (connections between neurons) Pyramidial cells Non-pyramidial cells (basket cells, chandelier cells) most afferent neurons mostly interneurons, axons don´t all efferent neurons leave cortex most use glutamate Structure most use GABA main dendrite to cortical surface (pyramide) dendrites have spines with synapses to other neurons dendrites have no spines  Fibre tracts Association fibres (Axones within cortex, bunch of fibres are called Fasciculi). Fasciculus arcuatus Connection between sensory (Wernicke) and motor (Broca) language area Commissural fibres (Connection between hemispheres) Projection fibres (Connection between cortex and subcortex) Corpus callosum Commissural fibres Structure brainstem Projection fibres Association fibres Spinal chord  Excitatory and inhibitory neurons in the brain brainstem cerebellum cortex ACH FR (formatio reticularis) striate cortex acetylcholine septal cortex basal forebrain Dopamin substantia nigra hypothalamus olfactory bulb FR Serotonine FR (e.g. Raphé) Glutamate, Aspartate olive nomplex thalamus cereb. cortex neocortex Structure pons nuclei (granular cells) hippocampus olfactory bulb nucleus subthalamicus GABA thalamus cereb. cortex striate cortex hypothalamus (except granular hippocampus cells) basal forebrain  Layers of the cortex Allocortex (Ammonshorn, Dentatus and Parahippocampus): 3 (molecular, pyramidal-, fusifrom layer) cortex Neo (or Iso-) Cortex: 6 Structure (molecular-, external granular, internal pyramidal, internal granular, internal pyramidal, fusiform layer) Cerebellum: 3 (molecular-, Purkinje-, granula layer) cerebellum  Layers of the cortex Allocortex: 3 (cornu ammonis, dentate Neo (or Iso-) cortex: 6 and parahippocampal gyrus) I. Molecular layer Cerebellar cortex: 3 non-pyram., parallel fibres II. External granular layer small pyram. III. External pyramidal layer big pyram., axons form cortico-cortical fibres IV. Internal granular layer modified pyram., non-pyram., afferents from thalamus Structure V. Internal pyramidal layer biggest pyram., efferents to basal ganglia, spinal cord VI. Fusiform layer small pyram., non-pyram. axons to other cortical and subcortical areas http://www.cerebromente.org.br/n01/arquitet/camadas_i.htm  Layers of the cortex Photomicrograph of a Golgi stained section of the cerebral cortex. In the photo, diverse pyramidal neurones of Structure Layer V can be seen www.unav.es/neurologia/Lanciego  Brainstorming Structures of the brain? Most common cells in brain? Most common excitatory neurotransmitter in brain/CNS? Structure Layers of the cortex? www.unav.es/neurologia/Lanciego  Examination of brain function in the clinics and in research From basic to clinical neuroscience D. Lulé:  Survey Functional networks in the brain Applied imaging techniques in Neuroscience Studies on cortical plasticity in neurodegeneration Survey Summary  „Phrenology“ (Gall, 1812) Comparison Structure & Function Time Friendship Paternal love www.state.sc.us Structure & Function …and size does not matter 7 year old Surgery with 3 years to stop epileptic seizures Normal cognitive functions (2 languages, normal motor functions etc.) Brain‘s capacity for plasticity is substantially reduced throughout lifetime (you can‘t remove a cerebral hemisphere in an adult without major loss of function or eventually death) Structure & Function Cytoarchitecture Division of brain based on cytoarchitechture by Brodmann in 1907 (52 fields)  Combining structure and function Cytoarchitechture and functional Structure & Function networks by Brodmann (1907) Function Structure & Function Lobules (view from above) Structure & Function Lobules (lateral view)  Function: main sections Motor cortex Somatosensory cortex Sensory associative cortex Visual Structure & Function associative cortex Broca’s area Primary Auditory cortex Primary Visual cortex Wernicke’s area  The motor system Primary motor cortex (M1) Supplementary Posterior parietal cortex motor cortex (SMA) Structure & Function Premotor cortex (PMA)  The Motor System Motor homunculus Primary motor cortex (M1) Hip Trunk Arm Hand Structure & Function Foot Face Tongue Larynx  The motor system Representation of the body in the brain Structure & Function motor sensory Vision and the cortex The visual system  The visual system Dorsal pathway: Where? How? motion, representation of Vision and the cortex object locations, and control of the eyes and arms Ventral pathway: What? Form recognition and object representation www.utdallas.edu/~tres/integ/sen4/sense_4.html (macaque brain)  The visual system …and this is how the Vision and the cortex visual network looks like… Pessoa L. On the relationship between emotion and cognition. Nature Reviews Neuroscience 9, 148-158 (2008)  Emotional System Phineas Gage 19th Century First evidence for connection between brain (lesion) and (reduced) emotional processing capacity Structure & Function Death mask Lesion in frontal area is PC based reconstruction of visible iron rod in Phineas head Structure & Function Limbic system www.lifesci.sussex.ac.uk/.../emotion2.htm  Emotions and the limbic system Cortical areas Hippocampus (Ammonshorn, Emotions and the cortex Gyrus dentatus, Subiculum) Gyrus cinguli, Gyrus parahippocampalis Subcortical areas Amygdala Limbic frontal regions (Area septi, Ncl. interstitialis der Stria terminalis, Ncl. accumbens) Limbic Areale im Diencephalon (Thalamus, Hypothalamus, Ncl. habenularis) Limbic Midbrain (Ncl. interpeduncularis, Area tegmenti ventralis, Ncl. tegmenti dorsalis)  Emotions and the ventromedial prefrontal cortex => understanding of humour Emotions and the cortex The neighbor of Mr Smiths asks him: „ Do you need your landmower today?“, and Mr Smith replies „Yes“. Which of the following sentences makes the story a joke? The neighbor responds: a) „Hups“, when he tripped over the rake b) „Good, so you don‘t need your golf clubs and I can have them“ c) „oh great, can I borrow your landmower when you are done?„ d) „The birds are picking the seeds of my lawn“ 56  Emotions Basal ganglia and insula Facial expression „disgust“ Evaluation of aversive stimuli Emotions and the cortex Lesions in basal ganglia => problems in recognizing disgust in faces 57 Emotions and the cortex Emotions and mirror neurons Gallese und Rizzolatti Mirror neurons helps in interpretation and comprehension of (emotional) actions of others  Measuring Emotions Cortical activity modulation Emotional strategy (anger) (approach/withdrawal) Verbal response Methods autonomous nervous system (ANS)  Measuring Emotions 1. Tests (neuropsychology, behavior, SAMs) 2. Neurophysiology 3. Brain imaging techniques Methods  1. Tests (Neuropsychology, SAMs) Valence Arousal Methods pleasant unpleasant exciting Not exciting Self assessment manikin = SAM  2. Neurophysiology Measuring voltage between electrodes on skin surface Showing picture  physical reaction (heart Methods rate, skin conductance etc.) e.g. in polygraph: changes in voice, skin conductance, heart rate  3. Applied imaging techniques (function) 1920‘s : EEG (Hans Berger, 1929) 1960‘s : MEG (David Cohen, 1968) 1970‘s : PET, SPECT (Phelps, 1975; Ter-Pogossian, 1975) 1990‘s : MRI based fMRI (Siege Ogawa, 1992; Kenneth Kwong, 1992) Methods and DTI (Denis LeBihan, 1985; Peter J Basser, 1994) EEG = Electroencephalography MEG = Magnetoencephalography PET = Positron Emission Tomography SPECT = Single Photon Emission Computed Tomography MRI = Magnetic Resonance Imaging DTI = Diffusion Tensor Imaging  EEG 10-20 system Methods  Functional MRI (fMRI) Measuring blood flow in brain Methods Magnet resonance imaging (MRI): magnetic field (no radiation)  fMRI: measuring BOLD Neuronal activity  O²  oxygenised blood  signal change in magnetic field can be measured as blood oxygenation level dependency (BOLD) Nervecell Action Methods potential Methods Imaging Techniques  Summary Long rocky road of neuroscience Main structural parts/functional networks of the brain Association of structure and function Functional cortical networks share some structures (e.g. cingulate cortex, hippocampus) Evidence for plasticity in the brain Different means to measure cognitive function in vivo