Transcript Neurotransmission

Neurotransmission
• 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) .
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?
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 vomiting.
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 are either….
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.
• Derived from poppy
plant.
• Morphine, heroin,
methadone and codeine.
• All these drugs cross
the placental
barrier….teratogens.