Transcript Neurotransmission - AP Psychology Community

Neurotransmission
Using one or more examples, explain effects of
neurotransmission on human behavior.
Studies
• Martinez & Kesner
• Fisher
Terms
• Neuron
• Action Potential (and neural
anatomy)
• Neurotransmitters
• ACH
• Dopamine
• Drugs (agonist, antagonists
and reuptake inhibitors)
• Using one or more examples, explain effects
of neurotransmission on human behavior.
What is a Neuron?
• A nerve cell.
• It is estimated we have
about 100 billion of
them in our brain.
They essentially have one
purpose only….
• To communicate to
each other
But neurons NEVER touch….
• They are shomer nagia
(and will never ever
marry)
• There is always a space
in between them called
the synapse.
• The neurons essentially
throw chemicals back
and forth across the
synapse.
• Communication is a
chemical process, where
one neuron sends out
chemicals called
neurotransmitters.
• The next neuron will pick
it up with their dendrites
and may or may not keep
the message going.
• Neurotransmitters are stored
in vesicles and are sent to the
edge of the button and
released into the synapse.
• If it fits, it can bind with the
dendrites on the next neuron.
If enough neurotransmitter
binds, it will “fire” and send
neurotransmitter across next
synapse.
• Any unused neurotransmitter
will be sucked back into the
neuron. This process is called
reuptake. Then the
neurotransmitter can be used
again.
Types of Neurotransmitters
Acetylcholine (ACH)
• Involved in movement
and memory.
• Too much causes
convulsions (black
widow venom).
• Too little can cause
paralysis (curare) .
Martinez & Kesner (1991)
• Aim: Determine role of ACH on
memory
• Procedure: 3 groups of rats trained
to go through maze – received
food
• 1st – blocked ACH
• 2nd – blocked “clean-up” of ACH
• 3rd – no injections
• Results:
Less ACH  more errors
More ACH  fewer errors
• Conclusion: ACH played a key role
in creating a memory of the maze
Evaluation of the Study
• Strengths: Research
design & application 
experimental method
& control group helped
researchers see
cause/effect
relationship b/w ACH &
memory
• Limitations: Research
may not apply to
humans
Dopamine
• Involved in motor
movement, alertness
and memory.
• Too little can cause
Parkinson’s disease
• L-dopa is the drug for
Parkinsons…what do
you think it does?
Dopamine
• Too much dopamine
has been linked to
schizophrenia.
• Anti-psychotic
medication such as
chlorpromazine is used
for schizophrenia…what
do you think it does?
Cocaine and Dopamine
• A stimulant that brings
about intense feelings
of pleasure and
sometimes faster
cognitive ability.
• How do you think it
works?
Fisher (2004)
• Being “in love” is similar to
being “addicted”.
• Took 40 young people in
love.
• 20 with love returned, 20
with love rejected.
• Showed them pictures of
sweetheart, then just and
acquaintance off and on for
30 seconds each for 12
minutes.
• Gave them fMRI while
showing pictures.
Fisher (2004)
Results
• Increased blood flow
where areas of the brain
flood dopamine for those
where love reciprocated.
• Similar brain activity as if
you were on cocaine.
• Decreased in those
rejected.
• Love seems to not be an
emotion but a drive to
seek pleasure.
Serotonin
• Involved in mood
control.
• Prozac given to people
who are
depressed…what do
you think it does?
Drugs
• a substance which may
have medicinal,
intoxicating,
performance enhancing
or other effects when
taken or put into a
human body.
• In reality…they just
manipulate
neurotransmitters.
• Three ways
Agonists
• Some drugs mimic a
neurotransmitter thus
encourage its
production.
• Examples are opiates
(morphine, Oxycodone)
Antagonist
• Some drugs block the
production of
neurotransmitter.
• Dopamine receptor
antagonists are used for
some diseases such
as Schizophrenia, Bipolar
disorder, nausea and vo
miting. It can also control
the symptoms of hyper
sexuality and increased
orgasmic activity.
Reuptake Inhibitor
• Some drugs prevent the
reuptake of
neurotransmitters by
the axon terminal.
• SSRI - Selective
Serotonin Reuptake
Inhibitors (Celexa, Paxil,
Prozac or Zoloft)
• Cocaine
Stoned Mice
Drugs
• Our brain is
protected by a layer
of capillaries called
the blood-brain
barrier.
• The drugs that are
small enough to pass
through are called
psychoactive drugs.
Drugs
If a drug is used
often, a tolerance is
created for the
drug.
Thus you need more of
the drug to feel the
same effect.
If you stop using a
drug you can develop
withdrawal
symptoms.
Stimulants
• Speed up body
processes.
• More powerful ones
(like cocaine) give
people feelings of
invincibility.
Depressants
• Slows down body
processes.
• Alcohol
• Anxiolytics
(barbiturates and
tranquilizers)
Alcohol
• More than 86 billion
dollars are spent
annually on alcoholic
beverages.
• Alcohol is involved in
60% of ALL crimes.
• Alcohol is involved in
over 70% of sexually
related crimes.
• Is it worth the cost?
Hallucinogens
• Psychedelics
• Causes changes in
perceptions of
reality
• LSD, peyote,
psilocybin
mushrooms and
marijuana.
• Reverse tolerance or
synergistic effect
Opiates
• Has depressive and
hallucinogenic qualities.
• Agonist for endorphins
and dopamine.
• Derived from poppy
plant.
• Morphine, heroin,
methadone and codeine.
• All these drugs cross
the placental
barrier….teratogens.