Transcript Week Three Slides

Central Nervous System
Stimulants
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Constricted Blood Vessels
Increased Pulse
Increased Blood Pressure
Increased Energy, alertness, and strength
Euphoria
Decreased appetite
Drug Effects on
Neurotransmission: Nicotine
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Acts on cell body in VTA to
increase number of action
potentials
Also binds to receptors on axon
terminals in nucleus accumbens to
release more dopamine with each
action potential
Nicotine’s Impact on
Nerve Cells
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Nicotine binds to
presynaptic
neuron receptors
Causing neuron to
excite-firing more
action potentials
More dopamine is
released
Drug
Effects
on the Cell
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Drugs of abuse all directly or indirectly increase
dopamine binding to post synaptic receptor with
acute behavioral effects
Chronically, this increases cAMP levels and leads to
a cascade of changed cell activity
Drug Effects on
Neurotransmission: Caffeine
 Mild Stimulant
 Prevents another chemical
(adenosine) from binding to
its receptor (antagonist)
–Adenosine is a natural sleep
inducer
Drug Effects on
Neurotransmission: Cocaine
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Blocks the dopamine
transporter
Rapid rise of
dopamine in
synapse
– Binds post synaptic
receptors
– Initial Euphoria
Cocaine’s Impact on
Nerve Cells
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Cocaine blocks
dopamine
transporter
Inhibits reuptake
of dopamine
Prolonging the
stimulation
Other Chronic Drug Effects
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Cell Death
– Neurons don’t
grow back
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Alcohol,
ecstasy, meth
Effect memory,
mood, learning
Your Brain on Drugs
1-2 Min
3-4
6-7
7-8
9-10
10-20
5-6
8-9
20-30
Your Brain After Drugs
Persistent Effects of Drug Use
Amygdala
not lit up
Amygdala
activated
Front of Brain
Back of Brain
Nature Video
Cocaine Video
Cues for Cocaine and
Normal Pleasures Activate
Brain Sites Childress, 1999
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Cues for Cocaine
– Cocaine abusers may experience a
powerful urge to use when they
encounter environmental cues associated
with use
– Limbic regions of the brain are activated
when watching cocaine- related videos
Childress, 1999
Persistent Effects of Drug
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As a result of intracellular changes, the
previously cocaine addicted brain has
persistently altered functioning (craving)
Environmental Cues