Download Biological Bases of Behavior

Neurons and Neuronal Communication:
The Structure of a Neuron
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There are billions of neurons
(nerve cells) throughout the body.
Neurons and Neuronal Communication:
The Structure of a Neuron
There are billions of neurons
(nerve cells) throughout the body.
Biological Bases
of Behavior
Neural Anatomy
Searching for the self by studying the body
Phrenology
Phrenology
(developed by Franz Gall in
the early 1800’s):
the study of bumps on the
skull and their relationship
to mental abilities and
character traits
 Phrenology yielded one big idea-that the brain might have
different areas that do different
things (localization of function).
Today’s search for the biology of the self: biological
psychology
 Biological psychology
includes neuroscience,
behavior genetics,
neuropsychology, and
evolutionary psychology.
 All of these
subspecialties explore
different aspects of:
how the nature of mind
and behavior is rooted in
our biological heritage.
 Our study of the biology
of the mind begins with
the “atoms” of the mind:
neurons.
Neurons and Neuronal Communication:
The Structure of a Neuron
There are billions of neurons
(nerve cells) throughout the body.
Action potential:
a neural impulse that travels down an
axon like a wave
Just as “the wave” can flow to the right in a stadium even
though the people only move up and down, a wave moves
down an axon although it is only made up of ion exchanges
moving in and out.
The Synapse
The synapse is a
junction between the
axon tip of the
sending neuron and
the dendrite or cell
body of the receiving
neuron.
The synapse is
also known as the
“synaptic
junction” or
“synaptic gap.”
Neurons and Neuronal Communication:
The Structure of a Neuron
There are billions of neurons
(nerve cells) throughout the body.
Types of Neurons
Sensory
neurons
carry
messages IN
from the
body’s tissues
and sensory
receptors to
the CNS for
processing.
Interneurons
(in the brain
and spinal
cord) process
information
between the
sensory input
and motor
output.
Motor
neurons
carry
instructions
OUT from
the CNS out
to the
body’s
tissues.
The “Nerves”
are not the same as neurons.
Nerves consist of
neural “cables”
containing many
axons.
Nerves are part of
the peripheral
nervous system and
connect muscles,
glands, and sense
organs to the
central nervous
system.
Day 2
Do Now
 Draw
and label the following parts of a
neuron. Provide a short definition what
each part does for the neuron.
 Dendrite
 Axon
 Myelin Sheath
 Terminal Branch
Neural Transmission
Action potential:
a neural impulse that travels down an
axon like a wave
Just as “the wave” can flow to the right in a stadium even
though the people only move up and down, a wave moves
down an axon although it is only made up of ion exchanges
moving in and out.
In Groups: MAD LIBS!!
The electricity, or __________ __________, is
detected in the __________. These carry the
message through the __________, which is
covered in a __________ __________, and ends
at the __________ __________. __________ are
released into the __________. The next
neuron’s __________ receive the remaining
chemicals. The synapse is cleared by the
__________ of the neural chemicals.
In Groups: MAD LIBS!!
The electricity, or neural impulse, is detected
in the dendrites. These carry the message
through the axon, which is covered in a
myelin sheath, and ends at the axon
terminals. Neurotransmitters are released into
the synapse. The next neuron’s dendrites
receive the remaining chemicals. The
synapse is cleared by the reuptake of the
neural chemicals.
In Groups: MAD LIBS!!
The electricity, or neural impulse, is detected
in the dendrites. These carry the message
through the axon, which is covered in a
myelin sheath, and ends at the axon
terminals. Neurotransmitters are released into
the synapse. The next neuron’s dendrites
receive the remaining chemicals. The
synapse is cleared by the reuptake of the
neural chemicals.
Neural Transmission
 Movement
of ions causes polarization, which
potentiates the impulse along the axon.
 The INSIDE of the neuron (axon) contains more
K+ than the OUTSIDE.

Keep in mind, this is NOT a case of one side
being positive and the other being negative.
 Bozeman
 TED-Ed
Ted-Ed Review
Refractory
The Synapse
The synapse is a
junction between the
axon tip of the
sending neuron and
the dendrite or cell
body of the receiving
neuron.
The synapse is
also known as the
“synaptic
junction” or
“synaptic gap.”
Neurotransmitters
Neurotransmitters are
chemicals used to
send a signal across
the synaptic gap.
Reuptake:
Recycling Neurotransmitters [NTs]
Reuptake:
After the neurotransmitters
stimulate the receptors on
the receiving neuron, the
chemicals are taken back up
into the sending neuron to
be used again.
Neurotransmitters
Neurons and Neuronal Communication:
The Structure of a Neuron
There are billions of neurons
(nerve cells) throughout the body.
Keys that almost fit:
Agonist and Antagonist Molecules
An agonist molecule fills
the receptor site and
activates it, acting like the
neurotransmitter.
An antagonist molecule fills the
lock so that the
neurotransmitter cannot get in
and activate the receptor site.
Roles of Different Neurotransmitters
Some Neurotransmitters and Their Functions
Neurotransmitter Function
Problems Caused by Imbalances
Serotonin
Affects mood, hunger,
sleep, and arousal
Undersupply linked to depression;
some antidepressant drugs raise
serotonin levels
Dopamine
Influences movement,
learning, attention, and
emotion
Oversupply linked to schizophrenia;
undersupply linked to tremors and
decreased mobility in Parkinson’s
disease and ADHD
Acetylcholine
(ACh)
Enables muscle action,
learning, and memory
ACh-producing neurons deteriorate as
Alzheimer’s disease progresses
Norepinephrine
Helps control alertness
and arousal
Undersupply can depress mood and
cause ADHD-like attention problems
GABA (gammaaminobutyric acid
A major inhibitory
neurotransmitter
Undersupply linked to seizures,
tremors, and insomnia
Glutamate
A major excitatory
neurotransmitter;
involved in memory
Oversupply can overstimulate the brain,
producing migraines or seizures; this is
why some people avoid MSG
(monosodium glutamate) in food
Serotonin
pathways
Networks of neurons that
communicate with serotonin
help regulate mood.
Dopamine
pathways
Networks of neurons that
communicate with dopamine are
involved in focusing attention
and controlling movement.
Do Now
 What
kinds of neurons are in the brain?
 What kinds of neurons make up the spinal
cord?
 What kinds of neurons send messages to
muscles and organs?
 IRL: What is it called when you react
automatically to stimuli (like touching a fire)?
Types of Neurons
Sensory
neurons
carry
messages IN
from the
body’s tissues
and sensory
receptors to
the CNS for
processing.
Motor
neurons
carry
instructions
OUT from
the CNS out
to the
body’s
tissues.
Interneurons
(in the brain
and spinal
cord) process
information
between the
sensory input
and motor
output.
Agenda
• 1 min/person to share
– How do you study outside of class?
– What do you do to prepare?
• Time, place, materials, etc.
– Do you feel like it’s effective?
• Gallery Walk
• Review Trackers
Together, let’s…
 Get
out three colors.
 Make a legend for K+ and Na+
AND neurotransmitters.
 Draw
where K+ and Na+ appear at
different stages of neural transmission.
Neural Communication:
Seeing all the Steps Together
Neural Transmission
Neural Transmission
Neural Transmission
Neural Transmission
Neural Transmission
Neural Transmission
Neural Transmission
Neural Transmission
Neural Transmission Interrupted
Biological Bases
of Behavior
Nervous System
The Inner and Outer Parts of the
Nervous System
The central
nervous
system
[CNS]
consists of
the brain
and spinal
cord.
The CNS
makes
decisions
for the
body.
Describe the difference
between these two
nervous systems.
The
peripheral
nervous
system [PNS]
consists of
‘the rest’ of
the nervous
system.
The PNS
gathers and
sends
information
to and from
the rest of
the body.
More Parts of the Nervous System
The Peripheral Nervous System
Outline the Nervous System
Outline the Nervous System
NS
PNS
CNS
Autonomic
Sympathetic
Parasympathetic
Somatic
Sensory
Brain
Motor
Spine
The
Autonomic
Nervous
System:
The sympathetic
NS arouses
(fight-or-flight)
The
parasympathetic
NS calms
(rest and digest)
Describe an event you
had to run away from.
Which system triggered
that response?
Interneurons in the Spine
Your spine’s
interneurons trigger
your hand to pull
away from a fire
before you can say
OUCH!
This is an example
of a reflex action.
Write another example
of a reflex action.
Share examples with
your group.
Do Now
1. An axon transmits messages _____ the cell
body and a dendrite transmits messages
_____ the cell body.
2. Hormones are to the endocrine system as
____________ are to the nervous system.
3. Name the two major divisions of the nervous
system.
Exit Ticket
• Describe the purpose of each of the studies
below:
– Harry Harlow
– Stanley Milgram
– Martin Seligman
– Sherif et. al.
– J. B. Watson
– Philip Zimbardo
Free Response Question
• Psychologists adhere to the
•
following guidelines when doing
research:
– Rights and well-being of participants
> study’s value to science.
– Participants must be allowed to give
informed consent.
– Deception must be justified.
– Participants may withdraw.
– Participants must be told about risks.
– Investigators must debrief
participants.
– Data must remain confidential.
Make and support a claim
about which of the
following psychologists
conducted the most
unethical study.
– Harry Harlow
– Stanley Milgram
– Martin Seligman
– Sherif et. al.
– J. B. Watson
– Philip Zimbardo
The Brain
Plasticity: The Brain is Flexible
If the brain is damaged,
especially in the general
association areas of the
cortex:
 the brain does not
repair damaged
neurons, BUT it can
restore some functions
 it can form new
connections, reassign
existing networks, and
insert new neurons,
some grown from stem
cells
This 6-year-old had a
hemispherectomy to end lifethreatening seizures; her
remaining hemisphere
compensated for the damage.
Our Two
Hemispheres
Lateralization (“going to one side”)
The two hemispheres serve some different functions.
How do we know about these differences?
 Brain damage studies revealed many functions of
the left hemisphere.
 Brain scans and split brain studies show more about
the functions of the two hemispheres, and how they
coordinate with each other.
The intact but lateralized brain
Right-Left Hemisphere Differences
Left Hemisphere
Right Hemisphere
Feelings and intuition
Thoughts and logicDesign a T-Chart.
Big picture such as “forest”
Details such as “trees”
Decide now what
information is actually
Language: words andimportant.Language: tone, inflection,
context
definitions
Inferences and associations
Linear and literal
Perception
Calculation
Wholes, including the self
Pieces and details
Survey
• Scale of 1-5: Today’s lecture was clear.
– 5 very clear; 1 not very clear
• What would have made this lecture more
effective?
• Write a summary of what you learned.
• Give an example of how you can study this
material.
Separating the Hemispheres:
Factors to Keep in Mind
 Each hemisphere controls the opposite side of
the body AND is aware of the visual field on
that opposite side.
 Without the corpus callosum, the halves of
the body and the halves of the visual field do
not work together.
 Only the left half of the brain has enough
verbal ability to express its thoughts out loud.
Areas of the brain and their functions
Brainstem
Older Brain
Structures
Newer Brain
Structures
• Coordinates the
body
Cerebellum
Limbic System
• manages emotions,
and connects
thought to body
Cerebral Cortex
• integrates
information
The Brainstem:
Pons and Medulla
The Base of the
Brainstem:
The Medulla
 The medulla controls the most basic functions
such as heartbeat and breathing.
 Someone with total brain damage above the
medulla could still breathe independently, but
someone with damage in this area could not.
The Brainstem:
The Pons
The pons helps
coordinate automatic
and unconscious
movements.
The Thalamus (“Inner Chamber”)
 The thalamus is the “sensory
switchboard” or “router.”
 All sensory messages, except
smell, are routed through the
thalamus on the way to the
cortex (higher, outer brain).
 The thalamus also sends
messages from the cortex to
the medulla and cerebellum.
Reticular (“Netlike”) Formation
 The reticular formation is a
nerve network in the brainstem.
 It enables alertness, (arousal)
from coma to wide awake.
 It also filters incoming sensory
information.
Cerebellum (“little brain”)
The cerebellum
helps coordinate
voluntary
movement such as
playing a sport.
The cerebellum has many other
functions, including enabling
nonverbal learning and memory.
The Limbic (“Border”) System
The limbic system coordinates:
 emotions such as fear and
aggression.
 basic drives such as hunger
and sex.
 the formation of episodic
memories.
The hippocampus
(“seahorse”)
 processes conscious,
episodic memories.
 works with the amygdala
to form emotionally
charged memories.
The Amygdala (“almond”)
 consists of two lima beansized neural clusters.
 helps process emotions,
especially fear and
aggression.
The Amygdala
 Electrical
stimulation of a
cat’s amygdala
provokes aggressive
reactions.
 If you move the
electrode very
slightly and cage
the cat with a
mouse, the cat will
cower in terror.
The Hypothalamus:
 lies below (“hypo”) the thalamus.
 regulates body temperature and
ensures adequate food and water
intake (homeostasis), and is
involved in sex drive.
 directs the endocrine system via
messages to the pituitary gland.
Thalamus
The Hypothalamus as a Reward Center Riddle: Why did the rat
cross the grid?
Why did the rat want to
get to the other side?
Pushing the pedal that
stimulated the electrode
placed in the
hypothalamus was much
more rewarding than food
pellets.
Brain Structures
Practice
Split visual field
Each hemisphere does
not perceive what each
EYE sees. Instead, it
perceives the half of the
view in front of you that
goes with the half of the
body that is controlled
by that hemisphere.
Split Brain Research
Grab two colors.
Split Brain Research
Split Brain Research
Practice
Definition
Word Bank
Full of interneurons that store automatic
processes.
Medulla
Relays information to other parts of the brain.
Pons
Stores memories.
Amygdala
Maintains balance and regulates walking
processes.
Spinal Cord
Regulates heart beat and breathing.
Hippocampus
Controls automatic body movements, like
blinking.
Thalamus
Regulates negative emotions.
Cerebellum
Practice
Definition
Word Bank
Full of interneurons that store automatic
processes.
Spinal Cord
Relays information to other parts of the brain.
Thalamus
Stores memories.
Hippocampus
Maintains balance and regulates walking
processes.
Cerebellum
Regulates heart beat and breathing.
Medulla
Controls automatic body movements, like
blinking.
Pons
Regulates negative emotions.
Amygdala
Endocrine System
The Endocrine System
The endocrine system
refers to a set of glands that
produce chemical
messengers called
hormones.
The Body’s “Slow but Sure”
Endocrine Message System
 The endocrine
system sends
molecules as
messages, just like
the nervous system,
but it sends them
through the
bloodstream instead
of across synapses.
 These molecules,
called hormones,
are produced in
various glands
around the body.
 The messages go to
the brain and other
tissues.
Adrenal Glands
produce hormones such as
adrenaline/epinephrine,
noradrenaline/norepinephrine, and
cortisol.
Adrenal Glands
Pancreas
1. The sympathetic
“fight or flight”
nervous system
responds to stress
by sending a
message to
adrenal glands to
release the
hormones listed
above.
2. Effect: increased
heart rate, blood
pressure, and
blood sugar. These
provide ENERGY
for the fight or
flight!
The Pituitary Gland
 The pituitary gland is the
“master gland” of the
endocrine system.
 It is controlled through
the nervous system by the
nearby brain area--the
hypothalamus.
 The pituitary gland
produces hormones that
regulate other glands
such as the thyroid.
 It also produces growth
hormone (especially
during sleep) and
oxytocin, the “bonding”
hormone.
Pituitary gland
Scanning Technology
Intentional brain damage:
Lesions (surgical
destruction of brain
tissue)
 performed on animals
 has yielded some insights,
especially about less
complex brain structures
 no longer necessary, as
we now can chemically or
magnetically deactivate
brain areas to get similar
information
98
Split-Brain Patients
 “Split” = surgery in
which the connection
between the brain
hemispheres is cut in
order to end severe
full-brain seizures
 Study of split-brain
patients has yielded
insights discussed at
the end of the chapter
Monitoring activity in the brain
Tools to read electrical, metabolic, and
magnetic activity in the brain:
EEG:
electroencephalogram
PET: positron emission
tomography
MRI: magnetic
resonance imaging
fMRI: functional MRI
EEG:
electroencephalogram
An EEG (electroencephalogram)
is a recording of the electrical
waves sweeping across the
brain’s surface.
An EEG is useful in studying
seizures and sleep.
101
PET: positron emission
tomography
The PET scan allows us to see what
part of the brain is active by
tracing where a radioactive form
of glucose goes while the brain
performs a given task.
MRI: magnetic
resonance imaging
MRI (magnetic resonance
imaging) makes images from
signals produced by brain tissue
after magnets align the spin of
atoms.
The arrows below show
ventricular enlargement in a
schizophrenic patient (right).
fMRI: functional MRI
Functional MRI reveals
brain activity and
function rather than
structures.
Functional MRI
compares successive
MRI images taken a
split second apart, and
shows changes in the
level of oxygen in
bloodflow in the brain.
103
Do Now
 Meet
 Pull
with your partners.
out your materials and BRAIN HAT.
 Study
diagrams and notes.
Brain Model
Cue the Brain Song