Neuro 101 All Lecture Notes Duke University PDF

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Neuro101 Biological Basis of Behavior. Taught by Prof. Christina Williams, Spring 2016. Includes notes from all lectures given in course....

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Neuro101 All Lecture Notes Duke University How do we go about studying brain and behavior relationships? 1. Manipulate brain, study behavior (somatic intervention) 2. Manipulate behavior, study brain (behavioral intervention) 3. Correlate brain and behavior, change in one correlates with change in other a. But correlation does not equal causation Research Perspectives 1. Description 2. Evolution 3. Development 4. Mechanism 5. Clinical/Application/Intervention Many methods fMRI, TMS, Electrophysiology, Lesions/stimulation, immunohistochemistry, measuring neurochemicals, receptors, proteins, RNA, examining genes or gene expression How do discoveries in Neuroscience get made? 1. Function of the corpus callosum 2. Localization of function in the cerebral cortex 3. Lateralization of brain function How did the different functions of the L & Right hemisphere get discovered? Roger Sperry- investigated the function of the corpus callosum Mike Gazzagnia- cut corpus callosum in epilepsy patients to study effects of CC cutting Sperry"The corpus callosum is made up of the axons of neurons" 1. Taught cat to press a blue bar when a square appeared while blindfolded one eye 2. Cut corpus callosum and optic nerve- right brain only gets information from right visual field, left brain only gets information from left visual field 2nd experiment: if the corpus callosum was cut, could the cat still do it? NO Intact corpus callosum= transmission of information from one hemisphere to the other "The two hemisphere of the cerebral cortex function independently" What did we learn? 1. Two minds that can work independently but share information via the corpus callosum 2. Functions in brains are lateralized- more representation in one hemisphere so some actions 3. Functions are localized (to some degree)- area specialized by function

Review: What neuroscience approach was used by Sperry in his initial examination of the corpus callosum study? Somatic intervention- manipulate the brain-> examine behavior Why do the two separate hemispheres have different functions? What is the evolutionary advantage?

Neuro101 All Lecture Notes Duke University Having different functions on different sides provides fro regional specialization, allowing for many modalities to work together near each other. Those that are far away are less likely to work together. Also, if there is damage to one side of the brain, we still have functionality As you become older, you become less lateralized. The Left hemisphere is not as efficient so it recruits some of right 5 Properties of Language Production vs. Comprehension -different brain regions for each, but overlap 1. Phonology- sounds of words 2. Semantics- meaning of words 3. Grammar- combinational rules (syntax) 4. Orthography- set of symbols and rules for written language 5. Language is creative and generative 1. Phonology1. Frequency, tone, amplitude, looking anatomically at how sounds are made 2. Is language what makes humans unique? Debate 3. Other animals make sounds that have meaning but mainly to convey signals/alarms a. Ex. vervet monkeys have distinct danger calls for eagles, snakes, and leopards To use language to convey complex meaning you need grammar o Hierarchical structure to grammar/syntax o Most animals fail to learn grammar a. Exception: to some extent, some apes can understand grammar  Kanzy the ape: displays this ability o Humans can't help but learn grammar Orthography Use off written symbols and their rules Bonobo chimps can learn and use written symbols What do language skills in chimps look like? o Understand the sounds of words o Understand the meaning of words o Use combinatory rules But CAN NOT Use words in novel combinations Do not talk about abstract ideas, the furture or past Brain control of langauge- lateralized to left hemisphere Language Development (Patricia Kuhl- Ted Talk)

Neuro101 All Lecture Notes Duke University o a. o o a.

Kid's language system is not the same as an immature system of the adult Kids are less lateralized Massive reorganization occurs with experience Kids condense to left hemisphere when reach about 20 months of age In general, females are less lateralized then males

Paul Broca Had patient that could not speak but could comprehend speech Broca's area- frontal lobe Carl Wernicke Patient can speak but can't comprehend speech Wernicke's area- temporal lobe The 6 Step Wernicke Geshwind Model o Word heard o Processed in primary auditory cortex o Sent to Wernicke's area for comprehension o Arcuate fasciculus transmits it to Broca's o Broca's turns meaning to responsive action o Primary motor cortex The Arcuate Fasciculus The bundle of axons transmitting information from Wernicke's area to Broca's When damaged in stroke, will have conduction aphasia- cannot repeat words or sentences unless they can be visulized Researcher finds longer, more complex fasciculus in humans that in other animals What is the brain- language system in the deaf? Exactly the same, motor control is directed to hands rather than mouth No Support for The Wernicke Gershwind model Damage to these areas causes only temporary language deficits; therefore more areas must be involved Demonstrate category specific semantic deficits Ex only missing certain types of info, such as naming tools Functional imaging studies have shown very specific and widespread activations for components of language Study by Damasio & Damasio People shown images of tools, animals, people Activation in 3 specific, separate regions Language must have organization in the brain What else have we learned? Brain regions activated in language activate in other regions & Language activates areas that are involved in the meaning of words Kids start off as language generalists, then become specialists with parentese

Neuro101 All Lecture Notes Duke University

Chimps do not have which of the following abilities? They cannot generate novel words But they can learn to use written symbols, understand the meaning of words, and understand elementary grammar If I had a stroke that damaged the arcuate fasciculus, what language deficit would I have and why? Would have conduction aphasia- cannot repeat back a word that is said to you. Arcuate fasciculus is pathway from Wernicke's to Broca's area. Comprehension is intact, but cannot be translated into sound because pathway is severed. However, if given enough time, any word that they can produce "a picture in their head" that would allow them in other brain regions to imagine; concrete images (might be able to say kick or book, but might not be able to say philosophy) Modern cognitive neuroscience methods, like fMRI, have revealed language loss that is not easily explained by the Wernicke- Geshwind model. What has been found? o There appear to be other regions involved in language; lesions in other areas produces aphasia o The brain systems involved in language are also involved in other cognitive functions o There are people who have a brain injury and do not lose specific comprehension, may lose ability to only name animals or tools o Model is too simplistic, much more complex processes at work Describe 2 ways that brain- language relations are different in infants than adults? Greater neuroplasticity, greater plasticity in other hemisphere to acquire full fledged language if damage is done in LH, also greater ability to learn second languages We are not lateralized at birth, only once we start to learn language do we become lateralized, see left lateralization at about 14 months Brain is tuned to sound of language learning, can learn all different sounds for all language, once focus one language stop hearing sounds used in foreign languages Language is Universal- every culture has a language, commonalities across languages, we evolved to acquired a language o Genes that code for language? FOXP2 a. Located on chromosome 7 b. Mutation in gene causes severe language and grammar difficulties c. Affected individuals have trouble with both production and comprehension, have dyslexic tendencies, difficulty processing sentences, and poor spelling and grammar o Seen in other animals for communication

Neuro101 All Lecture Notes Duke University a.

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Can take mutated human gene and place in mouse, found that mouse no longer can communicate using ultrasounds  Placed in songbirds, never acquire species song, even when grow up listening to parents song Found that human version FOXP2 gene made is easier for animals to learn complex associations a. Places healthy FOXP2`` gene in mouse, found that cognitive skills for association tasks did better b. "These finings suggest that FOXP2 may aid humans with a key component of learning language", used for associational learning

THE BRAIN TOUR PART 1 Highlights, important parts, development of neuroanatomy Brian Weighs 3 lbs Use 20% of body's oxygen Half of the genome is involved in CNS function Hass 100 billion neurons, 100 bill* 10 glial cells Brains come in all sizes and shapes but are all laid out according to the same basic plan What does the basic plan look like? The nervous system is a long tube Compact rounded skull for facilitating birth Central nervous system- brain and spinal cord- encased in bone PNS not encased

Neuro101 All Lecture Notes Duke University

Neuro101 All Lecture Notes Duke University

Lateral- towards the outside of the brain Medial- towards the inside of the brain Brain develops in 3 segments, then 2 divide in 2 o Forebrain a. telencephalon b. diencephalon o Midbrain o Hindbrain a. Cerebellum b. Medulla Within tube flows cerebral spinal fluid (CSF) o Shock absorber between skull and brain o Mediates blood and brain in change of nutrients/waste a. Ventricles in center of brain help with nutrient distribution, aids blood vessels in providing nutrients/taking away waste How does the brain get its shape during development? Tube that curls, front of brain is very large. When growing, reaches top of skull then begins to curve down and over, then back, then towards the side

Neuro101 All Lecture Notes Duke University One can track how in the brain grow by how the ventricular system curves (was inner part of neural tube) Hydrocephalus- when there is a blockage in the ventricular system, causes swelling of the ventricles that takes up space where neurons would be Developmental History of Brain and Spinal Cord Zygote Gastrulation Ectoderm Central nervous system Peripheral nervous system Epidermis (skin) Mesoderm Skeletal system Muscles Vascular region Endoderm Gut, lungs, liver Cell Lineage Early stem cells become early progenitor cells that then become… 1. Neurons 2. Oligodendrocytes and astrocytes Neuronal stem cells are born near the central canal (ventricles) and they migrate away before differentiating All cells are born in neural tube (in germinal matrix) then migrate How do these cells know where to go? Chemical signals, pathways 6 Stages of Neuronal Development 1. Neurogenesis- birth 2. Migration- getting to the right place 3. Differentiation- develop and acquire identity a. Chemical identity, shape identity, neuron or glial cell, chemicals manufactured/receptors possessed 1. Synaptogenesis- connecting with others 1. Cell death- dying of loneliness a. Need to synapse to live 2. Synapse Rearrangement- making fewer but stronger connections

How does the developing ectoderm become a tube? Called Induction 1. Starts as flat tissue of ectoderm 2. Center of tissue in-folds and a valley is created 3. Walls of valley fold over and join at the top 4. A central, "underground" river-lake is created, surrounded by tissue

Neuro101 All Lecture Notes Duke University The tissue cells of the brain and spinal cord

Neuro101 All Lecture Notes Duke University

Sometimes the ends never seal up- opening at base of spinal code, nerves to the legs may not develop; if brain never closes up, child is born with no brain, replaced with CSF

Neuro101 All Lecture Notes Duke University

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Why does the neocortex have wrinkles? Brain would take up a lot of space if smooth, wrinkled to reduce surface area to it fits in skull Much smoother in animals

1/26 Past Lecture Questions True or False The corpus callosum is medial to the cerebral hemispheres True The CNS and bone both develop from endoderm False, CNS and skin develop together from the ectoderm During development stem cells all over the brain divide and migrate to their appropriate locations before differentiating False, do not develop all over the brain, only develop in the germinal matrix

Neuro101 All Lecture Notes Duke University The surface of the cerebral hemispheres are convoluted True Why then can you see convolutions in a mid-sagittal section? That is still considered surface of the cerebral cortex, it is a big long tube that is folded over, interior of brain is still considered surface of cerebral cortex. Will only see nonconvolution inside at corpus callosum because that is the only area that is connected What is the name of the fluid filled canal that runs through the brain and spinal cord? How did it develop? Why is it there? Central canal. During development, brain folding over (involution) creates a tube, fills with CSF that forms ventricles and central canal. There to provide additionally nutrients to brain and spinal cord and remove waste. What are the main 3 divisions of the brain? Which two further divide? Forebrain, midbrain, hindbrain Forebrain- telencephalon and diencephalon Hindbrain- metencephalon, myelencephalon

What's inside? Grey- White Matter 1. Surface of brain looks grey, interior looks white 2. Multiple sclerosis- demyelination disease- immune system attacks myelin 3. Slows down speed at which neurons can communicate, leads to difficulty movement Multiple commissures for information crossing Massa intermedia Anterior commissure Posterior Commissure Hippocampal commisure What's in the forebrain? Telencephalon

Diencephalon

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a. Thalamus b. Hypothalamus

b. c. d. e. f.

Neocortex (newest part of brain) Hippocampus Basal Ganglion Lateral Ventricles Olfactory tract/bulb Amygdala

Neocortex2. Grey matter outside, white matter inside, 4-6 mm deep 3. Smooth in mammals, it has deep grooves (sulci) and wrinkles (gyri) in primates in many other mammals 4. In humans, 76% of the brain's volume, 20% of neurons

Neuro101 All Lecture Notes Duke University 5. 6 layers segregated by cell type, neuronal input, or cell density 6. Divided into several lobes and different regions of the neocortex have different functions Neocortex has 4 major lobes Temporal- hearing Frontal- motor Parietal- somatosensory Occipital- seeing First place where information if processed-primary visual cortex in the occipital lobe So named by the first place to process information in cortex, does not mean only place to process 7. Frontal names motor because of primary motor cortex a. PMC- send information directly to spinal cord and out to your muscles, direct control of body's muscles mapped onto the cortex, homunculus 



Parietal Lobe contains primary somatosensory cortex- your feeling of touch from various body parts are mapped onto this region Temporal Lobe contains primary auditory region Each lobe of the neocortex contains a primary regions of processing- eg. The occipital lobe is the first neocortical region to receive visual information, yet these areas have many other functions

Fusiform face region Right ventral temporal lobe (visual and spatial processing) Lateralized phenomenon, but that does not mean there is no activation on the other side Takes a long time to develop- not done until about ten or eleven years Propagnosia or face blindness- lesions to this region in adult Looking at fusiform activations in healthy vs. autism, find that less activation in people with autism Researchers conclude: (1) that facial brain recognition regions are built in, autism doesn't have proper development or possibly (2) children with autism have issues with social interactions and spend less tie looking at people, haven't been exposed to faces as much as a healthy control and therefore region did not develop properly What else does the frontal cortex do? Case study: Phineas Gage was a railroad construction foreman who was blasting rock near Cavendish, Vermont in 1848 when a thirteen pound iron rod was shot through his brain Following, became a very different person, became erratic, unorganized, started drinking Prefrontal Cortex- Executive function- making judgements, assessing social situations, monitoring behavior

Neuro101 All Lecture Notes Duke University Hippocampus Curled structure, due to curling of brain (inside telencephalon), named after the Greek word for seahorse The neocortex and many interior telencephalon structures are curled Functions: laying down of declarative memory, relational/spatial information processing Alzheimer's- hippocampus neurodegenerative disease Basal Ganglion (also called Striatum)  Caudate, putamen, and Globus pallidus  Curled structures  Movement selection/planning, movements that are habit (such as throwing a ball, not thinking about individual movements)  Moves the movements from individual muscles groups to a sequence that one has learned  Also contains reward and desire centers: Nucleus accumbus, ventral pallidum, ventral tegmental area Amygdala- emotion Olfactory bulb- smell Lateral Ventricles  

Shock Absorber Mediates blood and brain in exchange of nutrients/waste Makes CSF

What's in the diencephalon? Thalamus  relays messages between lower brainstem and cerebral cortex, also called a way station, filled with connections Hypothalamus Feeding, fleeing, fighting, reproductive behavior, matenence functions, governs endocrine system, reward, circadian rhythms Pituitary- master gland Pineal Gland- controls circadian rhythms, releases hormones Descartes "I think therefore I am", thought seat of soul here What's in the mesencephalon?  Superior and Inferior Colliculi- midbrain structure which process sound and visual input in terms of orienting but without conscious understanding of what is being seen or heard  Primitive parts  Phenomenon of blindsight  Processes not by type of input, but in terms of general shape, called "orienting response"  automatic orienting response- not talking about what it is but where it is a. Ex. walking in dark across campus, look at where you think sound is even though there is nothing to see, just orienting body to it

Neuro101 All Lecture Notes Duke University What's in the metencephalon? Pons- Arousal, assists in controlling automatic functions, relays sensory information, critical for sleep Cerebellum- coordination of movement, sensory-motor integration, timing, orienting motor input to sensory input What's in the myelencephalon? Medulla- controls respiration, blood pressure, heart rate, relays information to and from spinal cord

Warm Up What structure is caudal to the medulla? Spinal cord What brain region contains the thalamus? Diencephalon What is the main function of the cerebellum? Sensory motor integration, modulator of motor function Study sheep brain neuroanatomy for exams Spinal cord has it axons on the outside and cell bodies on the inside (opposite of brain) white outside, grey inside Diencephalon- thalamus and hypothalamus Today's Topics Peripheral nervous System Development and Evolution of Brains Neural Communication 1 Transmission odd information down axons Peripheral nervous System- all of the nerves that are outside the CNS  Cranial Nerves-attached to brain a. Some motor (efferent), some sensory (afferent), some both (two way highway, info can travel both ways as motor and sensory) b. Directly attach to brain directly, bypassing the spinal cord directly 2. Spinal Nerves- attached to spinal cord a. All are both motor and sensory (all two way highways) b. Attach directly to the spinal cord Nerve means many neurons bundled together outside CNS Cranial Nerves

Neuro101 All Lect...