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    Unit 2: The Biological
    Basis of Behavior
    What is this chapter about?

       Neuroscience
           The study of the brain and the nervous system

       More specifically, Psychobiology
           The branch of psychology that deals with the biological basis of
            behavior and mental processes
    What might we find out???

       What part of our brain tells us we are tired?

       Can schizophrenia be controlled by taking a pill?

       Does our reaction to stress help us survive?

       Why does our heart beat fast for several minutes after we are
    Down to Basics: The Neuron
       “Messenger” Cell
           Receives and transmits information

       Vary in size and shape

       100 billion in brain alone

       Composed of nucleus, cytoplasm, and the cell membrane (its

       **Contains fibers that extend out to receive and transmit

             Neuron                                     Tree
    Hi, I’m a neuron!!!

   Dendrite (Greek for tree):
       Picks up messages from other neurons and transmits it to the cell body

       Axon (Greek for axle)
           Single, long fiber that carries outgoing messages from cell body down to
            other neurons
           Can be 1mm to 3 feet long
           Splits into terminal branches.
    “Nerve,” or “Tract”

       Group of axons bundled together like wires in an electrical
    Myelin Sheath

       White, fatty covering that is pinched at intervals
           White matter = group of myelinated axons
           Gray matter (brain) = group of unmyelinated axons

       Purpose:
            1.   Provide insulation so that signals from nearby neurons don’t
            2.   Increase speed of action potential

    What types of neurons are there?!

       Sensory Neurons:
           Collect messages from sense organs and carry them to spinal
            cord or brain!
           Aka afferent

    Types of Neurons (cont.)

       Interneurons
           Carry message from one neuron to another
           Aka association neurons

                                      Pain! That
                                                        Got it,

    Sensory Neuron
    Types of Neurons (cont.)

       Motor Neurons
           Carry messages from the spinal cord or brain to muscles and
           Aka Efferent neurons   Pain in the               Got it!!
                                   hand!! Pull it            Hand, move it!!

                                                           Motor Neuron
             Types of Neurons
    Glial Cells

       Glial Cells (Greek for glue):
           Hold the neurons in place
           Prove nourishment
           Remove waste
           Form myelin sheath
           Prevent harmful substances from moving from
            blood stream to brain
    Neural Impulse
   So how does these neurons
    REALLY communicate? (no, it’s
    not in call-out bubbles)

   Cell membrane acts as barrier
    between fluid inside and
    outside of cell.

   Impulse occurs as a result of the
    exchange of charged particles
    called ions over cell membrane

   Intraneural transmission -
    within on neuron

   This is an ELECTRICAL process
      Neural Impulse
   There are more negative ions inside
    the neuron- NEGATIVE CHARGE

   This is called “RESTING POTENTIAL”

   Picture a compressed spring ready to

   When an area on membrane is
    stimulated by incoming message***,
    channels open!!!

   NA+ wants in and CL- wants out
    (electromagnetic gradient) to reach

   K+ wants out (concentration gradient)-
    that area returns to NEGATIVE

                                             Domino Effect!!!!!!
      Neural Impulse

   Chain reaction sends message for
    entire axon to DEPOLARIZE
    (equilibrium from negative charge)

   Impulse SHOOTS down the axon at up
    to 400 ft/sec!!!!!! (275mph)

   Picture a fuse burning

   So where does this “message” come
    from, and how does it get passed
    Neural Impulse
       **Stimulated by an incoming message (remember?!)

       A message sent by ONE NEURON won’t cut it!!!
           This will only result in ‘graded potential’

       Graded potentials that are caused by either

       will result in crossing “threshold of excitation” (fire away!!)

    A message that won’t work….



                             NEURON WITH “GRADED
    A message that will work!!!!
                    FIRE!!! FIRE! FIRE!
                    FIRE! FIRE! FIRE!
                    FIRE! FIRE! FIRE!



                           NEURON WITH “ACTION
    Another message that will work!!!
              FIRE!!!         FIRE!!!


                                  NEURON WITH “ACTION
    Keep in mind….
 It  doesn’t matter how strong the message is
    (how many neurons fire or how many times
    one neighboring neuron fires)…
      In other words… the pirate can’t fire his
       cannon “harder”
      Like a light switch…. ON or OFF.
    Interneural Communication
   Neurons don’t touch each other

   Impulse has traveled down the length of the axon

   Signal end up at terminal buttons, very end points of the axon

   Then what?

   Signal must get to other neurons,

    but how?

   Answer: the Synapse!!!!!
    The Synapse
 The   synapse
       Composed   of the terminal button of
        one neuron, the synaptic space, and the
        dendrites or cell body of the receiving

 Synaptic     space (synaptic cleft)
       Tiny  gap between neurons
       Messages must travel across the space to
        get from one neuron to the next
    Chemical Communication
       When neuron fires, impulse is sent to branches into the
        terminal button, or synaptic knob

       Synaptic vesicles release neurotransmitters

       Each neurotransmitter has a special receptor
            “Lock and key”

       After neurotransmitters are released, they are:
        1.   Scooped up by neighboring neuron OR
        2.   Reabsorbed and recycled by the sending neuron
        3.   Disposed of.
    Neurotransmitters: What do they say???

Acetylcholine                    (Ach)
       Arousal, attention, memory, motivation, and movement.
       Located where neurons connect to muscle cells
       Degeneration of neurons that produce Ach linked to Alzheimer’s
       Depletion of Dopamine increases Ach to Dopamine ratio in Parkinson’s

       Overproduction: spasms, tremors
       Underproduction: paralysis

   Botulism:
       Prevents release of ACh (no signal to muscles)- results in???

   Curare:
       Blocks ACh receptors… results in??
    Neurotransmitters: What do they say???
Dopamine                  (DA)
       Pleasure, emotion, reward-seeking behavior (food, sex, drugs),
        learning, involved in basal ganglia functioning (voluntary control)

       Overabundance: Receive message of excess pleasure
       Undersupply in BG: Parkinson’s disease (loss of fine motor

   Cocaine:
       Inhibits dopamine reuptake to prolong lifetime in synapse
       Antidepressants do a similar thing

   Amphetamines/Methamphetamines: (ecstasy, meth)
       Encourage release of dopamine from synaptic vesicles

   Nicotine:
       Increase dopamine in pleasure seeking areas of brain (basal ganglia)
    Neurotransmitters: What do they say???
     Regulationof sleep, dreaming, mood, eating, pain,
     aggressive behavior.

     Undersupply:
      In brain stem: lowered heart rate, trouble breathing
      Depression

      Antidepressant   Medications:
        MAOI: prevent breakdown of Serotonin
        SSRI: Selective Serotonin Reuptake Inhibitor
                                                    Endorphins make you
                                                    happy! Happy people

+                                                   don’t kill other people!

    Neurotransmitters: What do they say???
      Inhibition of pain (“turn down” neurons that transmit message
       of pain to brain)
      Released during strenuous exercise (“runner’s high,” weight
       lifting, no pain during game)

     Overabundance: Inhibition   of pain
     Undersupply: pains, aches

     Morphine, Opium
      Mimic endorphin and fit into their “lock”
      After a while, body stops producing natural endorphins =
    Neurotransmitters: What do they say???
GABA       (Gamma Aminobutyric Acid)
 Inhibitory   neurotransmitter (hyperpolarize neurons
    to prevent firing)
 Overabundance:     Sleep disorders
 Undersupply: Extreme    anxiety

 Alcohol, Anti-anxiety medications:
     “Encourage” reception of GABA
     Relaxing effect
    Psychopharmacology (cont.)
   Drugs and toxins either aid or inhibit neurotransmitters

   Caffeine
     increases release of excitatory neurotransmitters by
      blocking adenosine, which inhibits the release of these
     Two-three cups of coffee block adenosine receptors for
      several hours
                                   Here’s your
                                   adenosine blocker!
    What have you learned?

     What   are the three types of neurons?

     What part of the neuron receives a message? What
     part of the neuron sends the message?

     Describe the process by which a neuron fires
     (starting with “resting potential”)

     Whatis the role of neurotransmitters? How can
     drugs affect them?
Nervous System Organization

 Centralnervous
 system (CNS)
          of the brain
  Consists
  and spinal cord

 Peripheral    nervous
  Connects  the CNS to the
  rest of the body
     Somatic nervous system
     Autonomic nervous system
Central Nervous System


     Brain           Spinal Cord
    Parts of the Brain - Refresher!
    PrimitiveCentral Core
    Limbic System
    Highly evolved Cerebral Hemisphere
        As you move from the inside towards the outside of the brain,
         higher level mental processes are performed.
The Brain – The Central Core

 Medulla
  Controls breathing,
  heart rate, and blood

 Pons
           the sleep-
  Maintains
  wake cycle

 Cerebellum
  Coordinates   body’s
The Brain – The Central Core

 Thalamus
    Relays information from
     sensory receptors to the
     brain – except smell

 Hypothalamus
    Influences motivated
    Regulates hunger, thirst,
     body temperature, and
     sexual drive.
    Directly involved in
     emotional behavior
    The Brain – The Central Core

       Reticular formation
           Network of neurons found throughout the brain
           Serves to alert and arouse higher brain in response to incoming
           Can be subdued (sleep, anesthetics)
           Damage to this area can induce a coma.
The Brain – The Limbic System

 Ringof structures located
 between the central core and
 the cerebral hemispheres

 Importantto learning and
 emotional behavior
    Hippocampus essential in
     formation of new memories
      Damage = no new memories

    Amygdala, together with the
     hippocampus, is important for
     regulating emotions
      Damage = docile behavior,
       overstimulation = fear/ panic
Do Now:
   Phil has always been a calm and reliable individual. His
    friends count on him for advice because of his “level-
    headed” nature. Recently, however, Phil has been acting
    differently and has become much more aggressive. In his
    last football game, Phil started a fight with the referee and
    had to be taken to the hospital. Once at the hospital, Phil’s
    mom began to explain his abrupt shift to aggressive and
    irritable behavior to the doctor. The doctor immediately
    ordered an fMRI.

   What brain structure would the doctor take a close look at
    for abnormalities?? (Think aggression!)

Cerebral Cortex

   Cortex = Bark

   Two Hemispheres

   Each hemisphere has four
       Occipital
       Temporal
       Parietal                       BARK
       Frontal

   Each hemisphere is better at
    specific tasks than the other
    (math/language vs. creative
       “Hemispheric Specialization”
Break up into your groups!!!!

        Fill in the section of the chart that pertains
         to your brain structure.

        Prepare a poster to present to the class.

        You may take a book from the back of the
         room to supplement your research.

        Markers, scissors, glue, and poster paper
         are available at the front of the room.
    Lobes of the Brain- What do they
       Temporal Lobe

       Parietal Lobe

       Occipital Lobe

       Frontal Lobe

       Corpus Callosum
The Cerebral Cortex- Occipital Lobe
 Occipital     lobe
    Receives and processes visual
    Damage
      Blindness

        Visual field defects

        Hallucinations
        Illusions (images appearing
         larger of smaller) and color
         identification problems.
        Dream loss
ccipital Lobe

The Cerebral Cortex- Temporal Lobe
 Temporal         lobe
       Complex visual tasks such as face
       Receives and processes auditory
       Some language processing

   Damage:
       Auditory perception (What is that
        sound? Where is it coming from?)
       Selective attention (Filtering various
       Language comprehension (She’s
        driving me nuts!!)
       Long term memory (Ten-second Tom)
Temporal Lobe

        Temporal- Talk

          Are you my mom?!!
The Cerebral Cortex- Parietal Lobe

 Parietal       lobe
       Receives sensory
        information from body
        (sensory cortex)
       Involved in spatial abilities
       Coordinates body position

   Damage
       Ignore part of the body (lose
       Failure to reach for an object
        with visual guidance (or catch a
       Can’t identify objects
   Parietal – Perception- sPace

Cerebral Cortex- Frontal Lobe
 Frontal        lobe
       Control center – coordinates
       Controls voluntary
        movement (motor cortex),
        attention, setting goals, and
        expression of appropriate
        emotions (Whether or not it
        wants to listen to Amy G.

   Damage
       Personality ( Phineas Gage:
        A Case Study in Frontal Lobe Association
        Area Damage)

       Immorality (stroke patients
        and debt/infidelity)
       Difficulty making decisions

   Is the “pilot” of the brain             Fairness – Frontal

   Cockpit is in the FRONT of the          Fidelity – Frontal
                                        It makes us who we are!!!!
             Sensory and Motor Cortex
                                          What we would look like if the size of our
                                          features matched the allocated space in
                                          these areas

          Sensory Cortex                      Motor Cortex

   Located at the front of the      Located at the rear of the
    parietal lobes                    frontal lobe

   Registers body touch             Allows us to move
Corpus Callosum
     Fibers  that connect the
        two hemispheres
       Allows close communication
        between left and right

   The story of “Vicki”

   Each hemisphere appears to
    specialize in certain functions
    (Hemispheric Specialization)

   Damage – No communication
    between lobes
       Right brain can’t tell left what it
    Parts of the Brain - Refresher!
    PrimitiveCentral Core – Function?
    Limbic System – Function?
    Highly evolved Cerebral
     Hemisphere- Function?
   As you move from the inside towards the outside of the brain,
    higher level mental processes are performed.
Language Centers- Left Hemisphere

   Broca’s Area                        Wernicke’s Area

   Language Production                 Language Comprehension

   Damage = Aphasia (inability to      Damage = Trouble
    utter words)                         understanding the meaning of
                                         words and sentences
   “Ta”
                                        Charles Landry

                                             Language in most people
    Split-Brain Research

       Much information about functions of each hemisphere has
        come from studying split-brain patients
    Association Areas

           These areas integrate all of this information!!!!
    Neural Plasticity
   The brain is able to change structurally as a result of

   An enhanced environment increases neuron size and synaptic
    connections more learning takes place
       EX: Guitar players’ brains are larger where left hand dexterity is
       EX: Reading to a child will enable their connections to grow,
        enabling them to learn more.

   Neuroplasticity in rats and humans!!! (videos)

   Neurogenesis- the production of new brain cells.

    Tools for Studying the
    Nervous System
+ Microelectrode/Macroelectrode
    Microelectrode
        Very small electrodes inserted into individual neurons
        Used to study activity of a single neuron (action potentials,
         effects of drugs and toxins on neurons)

    Macroelectrode
        Used to get a picture of overall activity in the brain
        An example is an EEG, which uses electrodes placed on a
         person’s scalp to measure brain activity
        Strength/rhythm of neural activity (study sleep)
    Structural Imaging
       Computerized Axial Tomography (CT-scan)
           Uses X-rays at different angles to create a 3-D image of the brain

       Magnetic Resonance Imaging (MRI)
           Uses a magnetic field and radio waves to produce images of inner
            brain structures
           Shows tissue degeneration
    Functional Imaging

       EEG imaging
           electrical activity on the scalp from millions of neurons is used to
            produce a continuous picture of activity in the brain
           Identifies abnormal activity (seizures?)

       Magentoencephalography (MEG) and Magnetic source
        imaging (MSI)
           Can localize activity more precisely than EEG
           Tells you where brain activity takes place
    Functional Imaging
   Positron Emission Tomography (PET) and Single Photon
    Emission Computed Tomography (SPECT)
       Use radioactive glucose to determine location of greatest brain
       Active part of brain will break down glucose

   Functional Magnetic Resonance Imaging (fMRI)
       Shows function and structure by measuring movement of blood
        molecules within the brain
    The Spinal Cord
+ The Spinal Cord
    Complex cable of nerves that connects brain to rest of the

    Carries motor impulses from the brain to internal organs and

    Carries sensory information from extremities and internal
     organs to the brain

    Damage: When severed, parts of the brain are disconnected
     from the body.

                       Motor             Sensory
                       Info              Info
    The Spinal Cord

       The spinal cord controls some protective reflex movements
        without any input from the brain
The Peripheral Nervous System

            Nervous System

        Somatic        Autonomic
    Nervous System   Nervous System

              Sympathetic    Parasympathetic
                Division         Division
    The Somatic Nervous System

       Consists of neurons that
        communicate between the
        body and the brain

       Afferent neurons
           Neurons that carry messages
            from sense organs to spinal cord

       Efferent neurons
           Neurons that carry messages
            from the spinal cord or brain to
            muscles and glands
The Autonomic Nervous System

                  Sympathetic   division
                   Most active when you
                    are angry, afraid, or
                   Fight-or-flight response
                   Increases heart rate and
                   Stops digestion
The Autonomic Nervous System

 Parasympathetic
  Calms  body
  Produces effects
   opposite to those of the
   sympathetic division
  Reduces heart rate and
  Restores digestion
    The Endocrine System
    The Endocrine System

       Helps coordinate and integrate complex psychological

       Endocrine glands secrete hormones into the bloodstream
           Has similar effects to neurotransmitters, but this is a slower and
            longer lasting process

       Hormones serve to organize the nervous system and body

       Hormones also activate behavior, such as sexual behavior
The Endocrine System

 Thyroid    gland
  Secreteshormones
  (primarily thyroxin) that
  control metabolism

 Parathyroid   glands
  Control levels of
  calcium and phosphate
  which in turn controls
  levels of excitability
The Endocrine System

 Pineal   gland
  Secretes
  which regulates the
  sleep-wake cycle

 Pancreas
  Regulates   blood-sugar
  Secretes insulin and
The Endocrine System
 Pituitary   gland
  Referred  to as the
   “master gland” because
   it regulates many other

 Gonads
  Ovaries and testes
   secrete estrogens and

 Adrenal     glands
  Secretes  hormones in
   reaction to stress
  epinephrine

    Genes, Evolution, and

       Heredity - transmission of trait from one generation to next

       Chromosomes
           Pairs of thread like bodies that contain genes

       Deoxyribonucleic acid (DNA)
           Organic molecule arranged in a double-helix
           Contains the “code of life”
    Behavior Genetics

       Study of behavior from a genetic perspective

       Genes establish a range of potential outcomes
           Can change based on environmental influences
           Weight, educational success

       Animal behavior genetic studies include:
           Strain studies
           Selection studies
    Human Behavior Genetics

       Family studies
           Assume that close family members share more of a trait than non-
           Used to assess the heritability of psychological disorders or traits

       Twin studies
           Used to determine how heritable a trait or disorder may be
           Identical twins would have highest heritability
    Human Behavior Genetics
       Adoption studies
           Used to assess the influence of environment

       Molecular genetics
           Direct study of the genetic code
           Human Genome Project- Map all of the genes
    Social Implications
       Study of biological origins of behavior could lead to
        genocide and eugenics aimed at eliminating certain types of

       Could also be used to create new categories of people, such
        as people bred to be good soldiers or manual laborers

       Discussion

       Breeding? Genocide? Amniocentesis?
    Evolutionary Psychology
       Natural selection
           “Survival of the fittest”

       Evolutionary psychology looks at the adaptive or survival value
        of behaviors

       Discussion

       Why do men consider sex to be more recreational? Why do they
        prefer young, attractive women?

       What is the explanation for women who are gold-diggers?

       Do the evolutionary explanations “justify” certain behavior?
    The End
    Do Now, Day 3:

    Do Now: Day 2
   Describe the order of communication between neurons
          I step on a tack

          You catch a fly ball.
          You notice a bright light out of the corner of your
     Describe “neural impulse” using the words:

      1.   Resting potential, dendrite, axon, terminal
      2.   Resting potential, incoming stimulus,
           depolarization, chain reaction
      3.   Resting potential, incoming stimulus, sodium,
           chloride, potassium, electromagnetic gradient,
           concentration gradient, action potential, terminal
           branches, synapse, neurotransmitter.
    Explain this picture.

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