Chapter 2 Part 1 PDF

WHAT CELLS MAKE UP OUR NERVOUS SYSTEM? Chapter 2 – Part I  QUIZZES (20% OF FINAL GRADE) ▪ Quiz 1 opens today, closes 9/8. Covers today’s material only ▪ Highest 8 quiz scores will count towards your final grade ...

WHAT CELLS MAKE UP OUR NERVOUS SYSTEM? Chapter 2 – Part I  QUIZZES (20% OF FINAL GRADE) ▪ Quiz 1 opens today, closes 9/8. Covers today’s material only ▪ Highest 8 quiz scores will count towards your final grade  controls our internal organs 8 WHAT IS THE NERVOUS SYSTEM? PVS-CNS - Brain ▪ Complex & highly organized body system: Receives information from the world around us PNS ↓ Transmits the information through the spinal CNS cord/brain extreme amount of of organization the nervous system ↓ Processes the information in the brain generates motor command ↓ Directs our body’s reaction to the world back out to PNS & Controls our internal functions  HOW DOES THE NERVOUS SYSTEM CONTROL BEHAVIOR? takes external world in fo ↑ to brain. Neurons process signol Neuron 1 ▪ 2 types of cells – neurons & glia send it back out and Synapses → Neurons transmit information → Glia act as supporting cells ↳ Support neuron al metabolism protect help , ▪ Neurons communicate with each maintains activity Neuron 2 other through L synapses Specialized structure where mode projections are very close not but exectly touching ▪ Neurons are organized in a precise order to form a circuit - how information travel through multiple neurons  All behavior arises from neurons – even if they are few in number True of humans + animals not everything has neurons SIMPLE TO COMPLICATED NERVOUS SYSTEMS  ROUNDWORM (C. ELEGANS) Sensory ?302 Neurons ▪ 302 Neurons → Sensory neurons (receive input) ↳ sense water , small , ph → Motor neurons (move body) carry out information → Interneurons: neurons that Interneurons process information between very simplistic nervou system no the broin ; body neurons distributed throughout sensory & motor neurons Depends combine information on internal conditions process information & can sense temp smell , ph make decision and eX : predator near w h e r if thirsty may ignore pred. , C Ele from send info to motor neurons food is.... Le towards ▪ Arranged in simple circuits that can or away can more if well fed will avoid pred. effectively things smells reactions through produce simple behavior Can be taught ↳ Smells ex : can have pepperment meaning small = food nearby Motor Neurons ROUNDWORM (C. ELEGANS) most congregated ganglion(nucleus (Not suphisticated enoughfo toward head be abrein D a cellbodya neurons This movie was generated by Chris Grove. HTTPS://DOI.ORG/10.7554/ELIFE.17686.020  BRAIN NO SEA SLUG (APLYSIA CALIFORNICA) one of the first used for learning and memory ▪ ~ ?1818,000 , 000 Neurons → Sensory (receive same S input) elegant → Motor (move body) as c. → Interneurons Where it draws in water ▪ Gill and siphon withdrawal reflex processing ▪ Eric Kandel won the Nobel will retreat Gill Prize in 2000 based on information from interneuron  RAT (RATTUS NORVEGICUS) ↳ mammals ~50 ▪? 50million ~ million neurons · have a brain ▪ Nervous system now has many parts same S→ Central nervous system (brain & spinal cord) &→ Peripheral nervous system: as humon → Sympathetic nervous system fight / flight · → Parasympathetic nervous system a digest rest + → Enteric nervous system digestive system ▪ More neurons → more complex circuits → more complex functions & · nervous system organization very similar to humans  HUMAN (HOMO SAPIENS) Sensory Motor Neurons Neurons categorization und based on function , location ▪ ?~8080billion ~ billion neurons interneurons ↳ can have subcategories ▪ More neurons, more discrete brains regions, more complex circuits ▪ Capable of abilities no other species on earth  SIMILARITIES ▪ Neurons are the building blocks of the nervous system and the element of processing information decisions ↳ even wh few neurons can process and more ▪ Neurons are connected to each other via synapses to form circuits in all species including C elegans. ▪ Certain aspects of the nervous system are shared across all species (e.g. sensory neurons) and especially closely related species (e.g. brain and spinal cord in mammals) - only humans and rodents  CLASS QUESTION True or False? In all animals, circuits formed by neurons drive behavior Answer: True ? TRUE NOT TRUE of PLANTS , Viruses NEURONS  THE FIRST CELLULAR NEUROANATOMISTS - NOBEL PRIZE IN 1906 Camillo Golgi processesofneuroanother # ▪ Staining technique to visualize entire neuron ▪ Thought neurons were continuous like tubing Soma = cell body Neurites = axons & dendrites  THE FIRST CELLULAR NEUROANATOMISTS - NOBEL PRIZE IN 1906 Camillo Golgi Santiago Ramon y Cajal ▪ Staining technique to ▪ Used Golgi’s method visualize entire neuron ▪ Thought neurons ▪ Thought neurons came close to each were continuous like other, but did not tubing (NOT TRUE) touch (TRUE) & ▪ Neuron Doctrine: - each neuron is an independent unit - information must be transmitted across gaps between neurons We now know as synopse GOLGI STAINING REVEALS VARIETY OF NEURON SHAPES different neuron shopes Notoll look the some All nove cell bodies and neurites but in diff potterns  NEURONS ARE POLARIZED one flow can't even though go have they backwards elaborate polorized/ structures directiooil they nove to neurons the some basic structure No spine  DENDRITES AND SPINES INPUT ZONE receive informations to get info from & ↑ ▪ Dendrites = branches neurons many numerous branches Dendrites every dendrite ▪ Spines = mushroom-shaped has many spines Gunere protrusions from dendrites synopses form ▪ A neuron has many dendrites/ spines most input directly Spines are specialized can come on to spine but input and create greeter connections dendrite also through ▪ Input zone - where information/ signals are received ▪ Dendrites/spines from one neuron receive chemical signals from other neurons Spines  SOMA ▪ Soma = cell body Soma ▪ Integration zone of all the signals various dendrites from ▪ Mitochondria – produce energy ▪ Cell nucleus – contains genetic instructions ▪ Ribosomes – translate genetic instructions into proteins  AXON HILLOCK at end of Soma ▪ Also called axon initial segment ↑ decision location send info whether to to next neuron or not ▪ Final location where integration occurs and the decision to generate an electrical communication signal is Axon hillock made if decision is to send signol - electrical will be sent ▪ Most neurons have one axon hillock ↳ only can make quick can be one decision of a yes , No , yes, no time but can't say at some time Y/N  AXON electrical a close as signal/Action possible potential gets to next neuron conducted down axon ▪ Conduction zone ▪ Most neurons have one axon Axon ▪ Role #1: Conduct electrical signal on the cell membrane away from cell body to next neuron  AXON protein transport ▪ Role #2: Transport 9 material between electrical signal one action potential only travele anterograde soma and axon direction only direction terminal back forth + eX : proteins ; was te if protein misforms ▪ Anterograde S terminal away from = to axon cell body if axon termine the body damaged communicateis to needs body there rode · retrog tocell -ex of domage Transport ▪ Retrograde = from axon From end of terminal toward axon body cell AXON Axon  Synapses AXON TERMINAL release info to cross gop in synopse to dendritic Spines of the second neuron Neuron 1 ▪ Output zone ▪ Axon terminals from one neuron axomind releases chemical signals onto many other neurons Neuron 2 signal electrica to causes pockets chemical releasein to gop Axon ↓ terminals electricol signal converted to chemied signal at oxon terminal  (2) dendridic Spine SYNAPSE connects to axon terminal (1) as chemical signol Pre-synaptic axon terminal axon termine con also be Synaptic colled pre-synoptic cleft: where chemical terminal dendritiv spine = post-synoplic signal terminal When chemical signal released reaches dendritic spine flow across gop into it converte book Post-synaptic signal electrical by of dendritic binding proteins spine dendritic spine INFORMATION FLOWS THROUGH A NEURON new electrice signol generated ▪ Electrical signal in neuron at hillock ▪ Chemical signal between neurons ↳ does not enter the cell releases onto a lot of information neurons  Each neuron may receive and make thousands to tens of thousands of synapses to proportional of neurons species amount neuron constantlyot work  CLASS QUESTION · Where is the neuron's output zone? Answer: F?F terminal the axon GLIA (GLIAL CELLS)  GLIAL CELLS SUPPORT AND ENHANCE NEURAL ACTIVITY Oligodendrocyte/ Astrocyte Schwann cell Neuron ▪ Types of glial cells → Astrocytes → Oligodendrocytes/ Schwann cells → Microglial cells Microglial Cell ASTROCYTES - STAR SHAPED CELLS  ASTROCYTES tripartite - ▪ Monitor & support the buffering Pre-synaptic Post-synaptic metabolic and biochemical the neuron axon dendritic terminal spine needs of neurons Pre-synaptic axon terminal ▪ Regulate synaptic signaling as part of the “tripartite pre/post synapse” / Astro wrap around synopse monitor Astrocyte chemical Post-synaptic signols dendritic spine Astrocyte  ASTROCYTES pothogen preventeentering from ▪ Help form the blood brain barrier by sitting between blood capillaries and neurons only things that een cross such as nutrients , oxygen con cross ▪ React to brain injury (repair and scarring) form will scor to blood loss prevent in brein  OLIGODENDROCYTES AND SCHWANN CELLS & secrete substance w rops that a xo n out from coming electried current insulation & prevents ~ allows current to lost from point A - B - ▪ Insulate axons by wrapping myelin Neuron axon around them – white matter Myelin ▪ Oligodendrocytes are in the central same S nervous system (brain and spinal cord) & major function ▪ Schwann cells are in the peripheral nervous system Oligodendrocyte/ Schwann cell OLIGODENDROCYTES Nodes of Ranvier = gaps in myelin sheath · doesn't evenly coot exon  will physically MICROGLIA site of injury ; ↓ ↳ constantly monitoring release chemicals to attract other (loca area microglia ▪ Brain immune cell de of threat look for any sign migrote Car brain trigger microglia throughout immune ▪ Monitor local environment for response threat or injury ▪ Migrate to injury site to remove I debris/dead cells cord · brain + Spinal immune have separate then rest of system body  CLASS QUESTION Which of the following myelinate neurons in the Central Nervous System? A. Schwann cells if said PNS B. Microglia C. Oligodendrocytes D. Astrocytes Answer: C?  SUMMARY ▪ Neurons o Polarized o Dendrites, soma, axon, axon hillock, axon terminals o Synapses ▪ Glia o Astrocytes o Myelinating cells (Oligodendrocytes and Schwann cells) o Microglia