Chapter 2 Map



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Chapter 2 Map

  • Friday, Sep 26 57 to middle of 62
  • Monday, Sep 29 62 to 64
  • Tuesday, Sep 30 65 to 69
  • Wednesday, Oct 1 69 to 72
  • Thursday, Oct 2 72 to 76
  • Friday, Oct 3 76 to 80
  • Monday, Oct 6 80 to 85
  • Tuesday, Oct 7 85 to 89
  • Wednesday, Oct 8 89 to end and chapter review
  • Thursday, Oct 9 no school
  • Friday, Oct 10 no school
  • Monday, Oct 13 no school
  • Tuesday, Oct 14 Chapter 2 Quiz – study guide and cards due
  • Wednesday, Oct 15 in class essay redo 1993 #1

Chapter 2 Neuroscience and Behavior

  • 150 years ago science discovers the brain/body connection
  • Early 1800’s - Franz Gall - Phrenology - reads the bumps on the skull to reveal mental abilities and character traits
  • ?????? Have we heard this debate before???

Phrenology

Phrenology - Simpson Style

Phrenology 2012 Style

Neural Communication (p. 58)

  • You couldn’t distinguish between small samples of brain tissue from a human and a monkey
  • Therefore, we can study neural systems from a monkey brain and learn about a human brain.

Neurons (p. 58)

  • Neurons (aka nerve cells) are the building blocks of our nervous systems
  • There are different types of neurons - ex - sensory neurons and motor neurons

Parts of the Neuron (p. 59)

  • Dendrite - receives messages
  • Axon - passes information to other neurons
  • Myelin sheath - fatty tissue insulates axons and speeds up transmission of neural impulses which are electrical signals (aka Action Potential)
  • Cell body or Soma - the cell’s life support centre

Myelin Sheath

  • Fatty tissue that insulates the axon and helps speed their impulses.
  • Multiple sclerosis is a disease in which the myelin sheath degenerates resulting in a slowing of all communication to muscles and the eventual loss of muscle control
  • See TB page 6 re Guillain Barre syndrome

Action Potential (p. 59)

  • Neurons fire an impulse - called an Action Potential - when they receive signals from sense receptors stimulated by pressure, heat or light OR when they are stimulated by chemical messages from neighbouring neurons
  • The Action Potential is a brief electrical charge that travels down the axon

Ions (p. 58)

  • Neurons exchange electrically charged atoms called ions
  • Ions are negatively charged or positively charged
  • Ions are inside and outside of each neuron

Resting Potential (p. 58)

  • The fluid in a resting axon has an excess of negatively charged ions while the fluid outside the axon has more positively charged ions.
  • This + outside/- inside state is called the resting potential
  • But ………. When the neuron fires …..

When the Neuron Fires (p. 59)

  • The axon opens and the positively charged outside ions flood into the first chamber of the axon. This depolarizes that part of the axon, causing the axon’s next channel to open, and so on and so on.
  • After the neuron fires, the neuron enters a resting pause called the REFRACTORY PERIOD where the neuron pumps the positively charged ions back outside. Once the neuron returns to the +outside/-inside state, it can then fire again.
  • The neuron cannot fire during the refractory period.

Excitatory and Inhibitory Signals (p. 58)

  • Dendrites receive signals
  • Signals are either excitatory(turn the neuron on) or inhibitory (turn the neuron off)
  • A neuron has a THRESHOLD which is a minimum intensity that it needs to turn ON.
  • If the excitatory - inhibitory signals exceed the threshold, then the neuron will trigger an action potential.

Threshold (p. 60)

  • Threshold is all or nothing. If a neuron’s threshold is met, the entire action potential will occur at the speed that neuron will normally fire.
  • Think of it like flushing a toilet - if the excitatory signals (pushing down the lever) minus the inhibitory signals (not pushing the lever) meet the threshold you get a complete flush.

How Neurons Communicate (p. 60)

  • 1850 - Sir Charles Sherrington noticed that neural impulses were taking a long time to travel a neural pathway and he inferred there must be brief interruptions in the transmission
  • Sherrington named the gap between the neurons the synapse

The Synapse (p 61)

  • 1. AP (electricity) travels from one neuron to another across the synapse
  • 2. When the AP reaches the axon, it stimulates the release of neurotransmitter molecules (chemicals)which cross the synapse.
  • 3. The neurotransmitters bind onto receptors on the dendrites of the next neuron. These neurotransmitters then excite or inhibit a new action potential in this neuron.
  • 4. Excess neurotransmitters are reabsorbed by the sending neuron - this is called REUPTAKE.

Neurotransmitters (p. 63)

  • There are many types of neurotransmitters
  • Think of neurotransmitters as brain chemicals
  • Certain brain neural pathways may use only 1 or 2 types of neurotransmitters
  • Neurotransmitters have particular effects on our emotions and behavior

Examples of Neurotransmitters (p. 62)

  • neurotransmitter
  • function
  • malfunction
  • Acetylcholine
  • ACh
  • Learning/memory/
  • muscle contraction
  • Too little - Curare poison blocks receptors causing paralysis
  • Too little - Botox paralyses muscles
  • Too much - Black widow spider floods ACh causing seizures
  • Too little - Alzheimers
  • dopamine
  • Movement/learning/attention/emotion
  • Too much - schizophrenia
  • Too little - Parkinson’s
  • Seratonin
  • Mood/hunger/sleep/arousal
  • Too little - depression
  • norepinephrine
  • Alertness/arousal
  • Too little - depression
  • GABA
  • Inhibitory
  • Glutamate
  • Excitatory/memory
  • To much - migraines and seizures

Endorphines (p 63)

  • Neurotransmitter similar to the drug morphine
  • Released in response to pain and vigorous exercise
  • Discovered after Pert and Snyder (1973) put a radioactive tracer on morphine and found it traveled to brain areas linked with mood and pain. They concluded that if we have these areas in the brain, we must have neurotransmitters that work in these brain areas.
  • We do!!!! They are called endorphines.
  • See page 8 TG

Drugs & Neurotransmitters (p63)

  • If we flood the brain with drugs like heroine and morphine (opiates) the brain may stop producing its own natural opiate endorphine
  • If the drugs stop we may be left with no natural opiates - our agonizing pain will persist until our body learns to produce endorphines again or until we get more artificial opiates.

Agonists & Antagonists (p 63)

  • Various drugs affect the synapse by either exciting or inhibiting neuron firing
  • Agonists excite neuron firing. They mimic a neurotransmitter or block reuptake. Ex. Morphine mimics endorphine.
  • Antagonists inhibit a neurotransmitter’s release OR are similar enough to the neurotransmitter to occupy the receptor site but not to simulate the site. Ex. Curare blocks Ach receptors causing paralysis.

Agonists and Antagonists (p.64)

  • A - neurotransmitter fits receptor site - key
  • B - agonist (excite) is close enough to the real neurotransmitter - key
  • C- antagonist (inhibit) is close enough to the real neurotransmitter to occupy receptor but not close enough to be a key
  • Activity - p. 10 TG
  • 1. Chain of shoulder squeezes timed
  • 2. Chain of ankle squeezes timed
  • Nervous System
  • Peripheral Nervous System
  • Central Nervous System
  • Somatic
  • (voluntary movement)
  • Autonomic
  • (self regulated organs/glands)
  • Sympathetic
  • (arousing)
  • Parasympathetic
  • (calming)

Nervous System (p. 65)

  • The central nervous system consists of our brain and spinal cord
  • Think of it as a lollipop

Peripheral Nervous System (p65)

  • Links the central nervous system to our sense receptors, muscles and glands
  • Contains sensory and motor axons bundled into nerves

3 Types of Neurons (p. 65)

  • 1. Sensory Neurons (millions) - send information from tissue and sense organs to brain and spinal cord
  • 2. Interneurons (billions and billions) - central nervous system’s neurons that communicate with other CNS neurons
  • 3. Motor Neurons (millions) - take instructions from the CNS back out to body tissues

Peripheral Nervous System (p 66) 2 parts to this system

  • Autonomic
  • Controls the glands and muscles of our internal organs.
  • Usually works on its own
  • Heartbeat, digestion, glandular activity
  • Dual system of Sympathetic and Parasympathetic

Autonomic System (p 66) 2 parts to this system

  • Sympathetic
  • Responds to alarms
  • Arouses us for defense
  • Raises heartbeat, lowers digestion, raises blood sugar
  • Parasympathetic
  • Responds after stress
  • Calms us back down
  • Lowers heartbeat, raises digestion, lowers blood sugar
  • Nervous System
  • Peripheral Nervous System
  • Central Nervous System
  • Somatic
  • (voluntary movement)
  • Autonomic
  • (self regulated organs/glands)
  • Sympathetic
  • (arousing)
  • Parasympathetic
  • (calming)

Central Nervous System (p67)

  • CNS is the brain and spinal cord
  • Spinal Cord - connects peripheral nervous system to the brain
  • Reflexes - can be as simple as a single sensory neuron and a single motor neuron communicating via an interneuron in the spine. Therefore, you jerk your hand away from a flame before the pain information reaches the brain

Severed Spinal Cord (p67)

  • If the spinal cord is severed, you loose all sensation (pleasure and pain) and voluntary movement in the body regions whose sensory and motor neurons connect with the spine below the injury point.
  • BUT, you may still have reflex - you would exhibit the knee-jerk without feeling the tap

Neural Networks (68)

  • Neurons cluster into work groups called neural networks.
  • As a neural network is used over and over the connections between the neurons get stronger and faster and more efficient.
  • So listen to your mother and practice your piano!!!!

Tools to Study the Brain (70)

  • Clinical Observation
  • Electroencephalogram (EEG)
  • CT Scan (xray)
  • PET Scan
  • MRI
  • Functional MRI

Tools to Study the Brain

  • Clinical Observation record the results of damage to specific brain areas (after the accident)
  • EEG record the electrical activity in brain
  • Microelectrodes can detect the electrical pulse in a single neuron

Tools to Study the Brain (71)

  • CT Scan xrays the brain
  • PET Scan displays brain activity by detecting where a radioactive form of glucose goes while the brain performs a task - see p. 71

Tools to Study the Brain

  • MRI - head is put in magnetic field producing a picture of brain’s sof tissue
  • Functional MRI - detects blood flow in brain during activity
  • See bottom p 71

Brain of a Psychopath

  • http://www.youtube.com/watch?v=yyCEDnKxxLc
  • Showing Digital Media clip of the psychopath brain (5 minutes)

Lower Level Brain Structures (72) The Brainstem

  • Begins where the spinal cord enters the skull and swells slightly forming the medulla.
  • Medulla - heartbeat and breathing
  • Reticular formation - arousal/filters and relays information
  • Thalamus - receives information from senses (except smell) and routes it to areas dealing with sight, hearing, taste and touch. Also routes information to cerebellum and medulla. Also slows electrical impulses during sleep and speeds them up during waking.
  • Pons – connects 2 hemispheres and the medulla with cerebral cortex. Heartbeat and breathing as well as sleep

Cerebellum (73)

  • Extends from the rear of the brain stem
  • Coordinates voluntary movement (ex walking) and balance without conscious effort
  • Also enables one type of nonverbal learning and memory

Cerebellum Video (6 min)

  • http://www.youtube.com/watch?v=TCisaP09yFU

Limbic System (74)

  • Donut shaped system at the border of the brainstem and cerebral hemispheres
  • Associated with emotions of fear and aggression and food and sex drives
  • Includes the amygdala, hippocampus, and hypothalamus

Limbic System (74) Amygdala

  • Influences fear and aggression
  • Kluver and Bucy turned an ill-tempered monkey into a mellow monkey by removing it
  • Stimulating different sites on the amygdala will produce aggression or fear
  • Don’t try this at home on a human!!!

Limbic System’s Hippocampus (74)

  • The hippocampus is where we process and form new memories
  • Memory trick - ends in CAMPUS - where we learn things that we remember

Limbic System’s Hypothalamus (75)

  • Controls our body maintenance functions such as hunger, thirst, body temperature and sexual behavior
  • Releases hormones that control the pituitary gland which in turn influences other glands to release their hormones
  • Is also our pleasure centre

Limbic System’s Hypothalamus - Reward Centre (75)

  • Olds and Milner (1954) discovered by mistake that putting an electrode in a rat’s hypothalamus caused it to keep returning to the place where it got the electrode. They discovered a Reward Centre. The rat would press a lever 1000’s of times and cross an electrified floor to do it.
  • Olds and Milner Clip 1 minute

Limbic System’s Hypothalamus (75)

  • Neurosurgeon has used electrodes to calm violent patients. The patients report mild pleasure.
  • Blum (1996) believe that addictive disorders like alcoholism may stem from a reward deficiency syndrome - a deficiency in the hypothalamus.

The Cerebral Cortex (77)

  • Wrinkled surface layer of the cerebral hemispheres
  • The body’s ultimate control and information processing centre
  • The more complex the cerebral cortex, the more advanced the animal

The Cerebral Cortex (77)

  • Think of it like wrinkled toilet paper
  • It is 1/8th of an inch thick and contains 20 billion nerve cells and 9 times as many GLIAL CELLS that support and nourish the nerve cells

Brain Hemispheres (77)

  • We have a right and left brain hemisphere each divided into 4 lobes
  • Frontal - speaking, muscle movement, planning, judgment
  • Parietal - top of head - includes sensory cortex
  • Occipital - rear - visual
  • Temporal lobes - above ears - auditory

Functions of the Cortex (78)

  • The simpler the function, the more localized it will be in a specific brain area
  • As functions get more complex, they involve more areas of the cortex

Motor Functions (78)

  • The motor cortex is the ribbon running across the top of your head from ear to ear
  • 1870 - Fitz and Hitzig stimulated parts of a dog’s motor cortex and caused various body parts to move
  • Stimulating the left brain motor cortex moves body parts on the right side of your body
  • Try activity on page 78
  • Which body areas have the most cortex space???

Sensory Cortex (79)

  • Receives information from skin senses and moving body parts
  • Ribbon behind motor cortex
  • If you stimulate the sensory cortex, the person will “feel” like someone touched them

Sensory Cortex (80)

  • The more sensitive the body area (ex. Lips) the more cortex area devoted to that area
  • Plasticity ---- if you loose a finger, the sensory cortex for that finger branches out to receive sensory imput from adjacent fingers which will become more sensitive

Auditory Cortex (80)

  • In your temporal lobes above your ears
  • Well practiced pianists have larger than normal auditory cortexes
  • MRIs of schizophrenia patients show auditory cortex activity during hallucinations

Occipital Lobe/Visual Cortex (80)

  • Back of the head
  • A bash to the head can cause you to see light (or go blind if you get hit hard enough)
  • Visual information hits the occipital lobe and then travels to areas that process words, emotions, etc

Association Area (80)

  • 3/4 of the cortex is uncommitted to sensory or muscular activity - this is called the association area
  • This area is more complex - sensory input is put together with memory for example
  • The more complex the animal, the bigger the association area
  • Association areas in our frontal lobe is where we judge, plan and process new memory

Frontal Lobe Association Area Phineas Gage (81)

  • In 1848 Phineas takes a rod through his left cheek and out the skull
  • After this Phineas can sit up, speak, remember but his personality is altered. He is “morally” damaged
  • Narrated Phineas Clip 3 minutes
  • Allan Alda Clip on Phineas

Phineas Gage

Association Areas in the Parietal Lobes (82)

  • Left side performs language, math functions. This area in Einstein’s brain was oversized
  • Area in right temporal lobe recognizes faces
  • But remember, complex functions involve many brain areas

Language Areas (82)

  • Many brain areas are involved in language
  • Aphasia - an impairment of language - many types of aphasia

Broca’s Area (82)

  • 1865- physician Paul Broca finds that damage to the left frontal lobe causes person to struggle to form words. But, the person can still sing and can still comprehend speech
  • http://www.youtube.com/watch?v=f2IiMEbMnPM&feature=related

Wernicke’s Area (82)

  • 1874 - Carl Wernicke discovered that damage to the left temporal lobe causes people to speak meaningless words. Their understanding of speech is also affected.
  • http://www.youtube.com/watch?v=dKTdMV6cOZw&feature=related

Angular Gyrus (82)

  • A third brain area involved in reading aloud
  • This area receives the visual information from the visual cortex and recodes it into an auditory form which Wernicke’s area then uses to derive meaning.
  • If this area is damaged you can speak but not read

Norman Geschwind’s Explanation of How We use Language (83)

Hoof Hearted

Catch It

Brain Reorganization (84)

  • Plasticity - the brain can change and reorganize itself following damage
  • Ex - scientists severed the neural pathways for sensory information coming from the arm to the brain. The area of the sensory cortex shifted its function and began to respond when the monkey was touched on the face

Brain Reorganization (84)

  • Kempermann and Gage (1999) discover that adult mice and humans can generate new brain cells
  • Stem cells can develop into any type of brain cell have been discovered in the fetal brain
  • Phantom limbs
  • Hemispherectomies - people retain their memory, personality, humour

Divided Brain (85)

  • Left side - generally is the dominant side - in most people it controls reading, writing, speaking, math
  • Left side of brain controls right side of body
  • Right side - more emotion, music, art, spatial relations

Splitting the Brain (85)

  • 1961 - neurosurgeons Vogel and Bogen sever the Corpus Collosum in epileptic patients. The seizures stop and their personalities and intellect were hardly affected.
  • Sperry, Myers and Gazzaniga had previously divided cat and monkey brains

Corpus Callosum (86)

  • Band of neural fibers that connects the two hemispheres of the brain.
  • It does serve a purpose
  • Enter - the split brain patients!!!!!

Vision with a Normal Brain (86)

  • Information from the left visual field goes to the right hemisphere (and vice versa). Then the corpus callosum shares the information from side to side.
  • Split brains don’t share the information

Split Brain Experiment Gazzaniga (86) http://www.youtube.com/watch?v=aCv4K5aStdU

  • Left Visual Field
  • HE
  • This goes from left visual field to right brain. The right side brain controls the left hand so the left hand points to “HE”
  • Right Visual Field
  • ART
  • This goes from right visual field to left brain which controls speech. Patient says “ART”.

Brain Organization and Handedness (89)

  • 90% are right handed and 95% of these process speech in their left hemispheres
  • 10% are left handed - 50% process speech in their left hemispheres - 25% process it in the right - 25% process it in both!
  • 9 in 10 fetuses suck their right thumbs
  • Babies will show a R or L preference within 2 days of birth - they turn their heads R or L

Handedness

  • Geschwind and Behan (1984) - Left handers have more reading disabilities, allergies, migranes
  • Left handers are more common among musicians, mathematicians, baseball players, architects
  • Coren (1993) - found that left handed people are 15% of 10 year olds, 5% of 50 year olds and less than 1% of 80 years olds. WHY - Coren thinks it may be that lefties die younger!!!!!

Brain Parts Review!!!

Endocrine System (94)

  • Body’s “slow” chemical communication system
  • Hormones - chemical messengers produced in one tissue that affect another
  • Hormones influence our growth, reproduction, metabolism, mood

Adrenal Gland (94)

  • When stressed, autonomic nervous system orders our adrenal gland to release the hormones epinephrine and norepinephrine (AKA adrenaline and noradrenaline) which increase heart rate, blood pressure and blood sugar.
  • Part of the fight or flight reaction

Pituitary Gland (95)

  • Most influential gland
  • Controlled by the hypothalamus
  • Releases hormones that affect growth and cause other glands to release their hormones (ex. Sex hormones – estrogen/progesterone F, testosterone)

Nervous System and Endocrine System (95)

  • These 2 systems affect each other.
  • Brain --- pituitary --- other glands --- hormones --- brain

Other Glands (96)

  • Thyroid - metabolism
  • Pineal - melatonin
  • Parathyroid - regulates calcium in the blood
  • Adrenal - fight/flight
  • Pancreas - blood sugar
  • Ovary - estrogen
  • Testis - Testosterone

Ideas Program

  • The Science of Morality

God is in the Neurons Video 22 minutes

  • http://www.youtube.com/watch?v=oPEdDcs_8ZQ&ob=av3e


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