Mountain Dew
54 mg
lower. Coffee can contain between
80 and 175 milligrams of caffeine
Mellow Yellow
53 mg
(per 7 ounces) depending on
how it is brewed; espresso has
Diet Coke
47 mg
100 milligrams in just 1.5 to
Coca-Cola Classic
35 mg
2.0 ounces. Tea can contain
40–60 milligrams of caffeine
Dr Pepper
41 mg
(per 7 ounces). Ice tea contains
Pepsi Cola
38 mg
70 milligrams of caffeine
in 12 ounces.
Diet Pepsi
36 mg
Coke Zero
35 mg
Barq’s Root Beer
23 mg
Mug Root Beer
0 mg
Sprite
0 mg
Sierra Mist
0 mg
Source: Center for Science in the Public Interest. Caffeine Content
Activity 3: routes of Administration
1. Give students the opportunity to view the segment Pathways to
the Brain online, if possible. If not possible, move to Step 2.
Content Standard A:
Go to the supplement’s Web site. Select Lesson 3— Drugs Communicate and defend
Change the Way Neurons Communicate and then Pathways
a scientific argument.
to the Brain.
2. Give each student a copy of Master 3.6, How Do Drugs Get Into the
Brain? Students may work in groups of three to analyze the graph and answer the questions.
Note to teachers: The graph shown on Master 3.6 is a generalized
repre sentation of the speed and intensity of response to drugs. Very
few, if any, drugs are commonly taken by all of the different routes.
81
Student Lesson 3
The Brain: Understanding Neurobiology Through the Study of Addiction
Sample Answers to Questions on Master 3.6
Question 1. Four people who abuse drugs each take a drug. One person
injects 100 mil ligrams of a drug into a vein, one person smokes 100 milligrams
of the drug, one person snorts 100 milligrams of the drug, and one person
swallows or ingests 100 milligrams of the drug. Who will experience the
great est effect of the drug? The individual with the greatest concentration
of drug in the brain will have the greatest effect.
The graph indicates that the individuals who inhale the drug or inject
the drug into a vein will experience the greatest effect from the drug.
These individuals will have a higher concentration of the drug in the
brain than the people who snort (absorption through the mucous
membranes) or ingest the drug. The concentration of drug in the brain
will be slightly lower for inhalation than injection because some of the
smoked drug is exhaled in the smoke.
Question 2. Who will experience the quickest effect from the drug?
The person who inhales the drug will experience the quickest effect
from the drug (assuming the person inhales the whole 100 mg). The
inhaled drug goes through the lungs and into the left side of the heart
and then enters the arterial circulation to the brain, while injected
drugs enter the venous circulation that returns the blood to the right
side of the heart. The drug that enters the venous system takes longer
to exert its effect because the blood must go to the lungs and then
to the left side of the heart before it is pumped to the brain and
the rest of the body.
Question 3. Who will experience the least behavioral effect from the drug?
The person who ingests, or swallows, the drug will experience
the least effect.
Question 4. Who will experience the slowest effect from the drug?
The person who ingests, or swallows, the drug will also have the
slowest effect.
Question 5. Tobacco smokers can use nicotine patches to help them
quit smoking. The nicotine patches help the smoker slowly lower the
amount of nicotine that enters the body. How does the nicotine in the
patch enter the body?
Nicotine enters the body by absorption through the skin
into capillaries.
82
Question 6. Explain why the different ways of taking drugs cause
different behavioral responses.
Taking drugs by inhalation causes a very rapid increase in the level
of drug in the brain. Inhaled drugs are absorbed into the arterial
bloodstream in the lungs and then pumped to all parts of the body
including the brain. Taking drugs by intravenous (IV) injection also
causes a rapid increase in the drug level in the brain. It is slightly
slower than inhalation because the drug goes first to the right side of
the heart, is then pumped to the lungs where the blood is oxygenated,
then goes back to the left side of the heart, and finally to the brain and
body. Absorption through the skin or mucous membranes would be
even slower because the drug has a longer path to travel before being
circulated throughout the body. Drug response would be the slowest
after ingestion because the drug goes into the digestive tract and then
must pass through the walls of the stomach and intestine to enter the
blood capillaries.
3. Display a transparency of Master 3.7, What Should the Doctor
Do? Dis cuss the reasons why one action may be more appropriate
than others.
On the basis of what you have learned about how drugs act in the body,
If students understand
how should morphine be given to the patient? Should the morphine be
that taking drugs into the
given as a pill, a shot, or an inhalant? Consider each alternative and
body by different routes
explain why the different methods should or should not be chosen.
causes different responses,
The question concerning how morphine should be administered
they should be able to
to a patient to relieve pain is designed to assess whether students
explain that the different
understand how different ways of getting drugs into the body changes
ways of administering
their effects. The doctor’s goal is to relieve the patient’s pain quickly so
drugs can have
that the fracture can be set.
advantages and disadvantages. Use this
On the basis of the graph that students analyzed on Master 3.6, the
doctor should elect to give morphine as an inhalant or an injection.
sce nario to evaluate
In each case, the drug reaches the brain quickly. Inhaled drugs can
students’ understanding.
reach the brain even faster than injected drugs. Perhaps the main
disadvantage of giving the morphine as an inhaled drug is the amount
of drug that actually enters the blood stream is more variable. If the drug
is injected, all of the drug is delivered into the bloodstream. The doctor
knows how much morphine enters the bloodstream. Giving a pill to
the patient would be less effective than the other means for pain relief
because it would take longer for the drug to act and its concentration in
the blood stream would be lower.
83
Student Lesson 3
The Brain: Understanding Neurobiology Through the Study of Addiction
Lesson 3 Organizer: WEB VErSION
What the Teacher Does
Procedure
reference
Activity 1: Drugs Alter Neurotransmission
Review neurotransmission with students. If helpful, have students
Page 73
watch the animation from Lesson 2 again.
Step 1
Draw a chart on the board with the column headings: “Change
Page 73
in neurotransmission” and “Effect on neurotransmitter release
Step 2
or availability.”
Ask students if they can think of ways that neurotransmission could
Pages 73–74
be altered. Fill in the chart. Ask questions such as
Step 3
• What would happen if the amount of certain components in the
process increased or decreased?
• How would that change affect the responding neuron?
Add a third column to the chart with the heading “Drug that acts
Page 74
this way.” Write the name of the drug next to the appropriate
Step 4
change.
Display a transparency of Master 3.1. Point out that cocaine blocks
Pages 74–75
the dopamine transporters. Ask,
Step 5
• “How does this blocking action affect dopamine levels in the
synaptic cleft?”
• “What is the effect on the postsynaptic neuron?”
Show the online animation of how cocaine acts. Select
Page 75
Lesson 3— Drugs Change the Way Neurons Communicate.
Step 6
Display the top half of a transparency of Master 3.2. Explain how
Page 75
methamphetamine acts by blocking dopamine transporters and by
Step 7
passing through the neuron cell membrane to trigger vesicle release.
Ask how these actions affect the postsynaptic neuron.
Show the bottom half of Master 3.2. Explain that nicotine binds
Page 75
to nicotine receptors on the presynaptic neuron and causes
Step 8
the neuron to release more neurotransmitter with each action
potential. Ask how this activity affects the postsynaptic neuron.
84
What the Teacher Does
Procedure
reference
Display a transparency of Master 3.3. Explain that in the presence Page 76
of alcohol, GABA activity is enhanced, resulting in greater Cl– influx
Steps 9–10
into the presynaptic neuron and, consequently, greater inhibition of
the neuron. Use the fol owing questions to help students understand
how alcohol affects neurotransmission.
• How does alcohol affect the activity of the neurons?
• If the presynaptic neuron releases GABA as its neurotransmitter,
does the amount of GABA released increase or decrease when
alcohol is present in the body?
• How does this affect the release of dopamine from the
postsynaptic neuron?
Complete a summary by completing a line for alcohol on the chart
Have students compare the actions of alcohol and cocaine on
Page 77
neurotransmission. Use the fol owing questions to guide the discussion.
Step 11
• How does the way alcohol alters dopamine neurotransmission
differ from the way cocaine changes dopamine neurotransmission?
• Are there any similarities in how alcohol and cocaine change
neurotransmission?
Activity 2: How Does Caffeine Affect You?
Several days before this activity, assign students to the caffeinated
Page 78
or caffeine-free group. Remind students to bring the appropriate
Step 1
can of soft drink and a signed permission form (Master 3.4).
Have students spend several minutes sitting quietly so their heart
Page 78
rates are at a resting level. Probe students’ knowledge about caffeine.
Step 2
Teach students how to find their pulse, count their heartbeat, and
Page 78
calculate their resting heart rate.
Step 3
Distribute one copy of Master 3.5 to each student. Ask students to
Page 78
count their heartbeats for 15 seconds while you time them. Have
Step 4
students calculate their resting heart rate and enter the number in
the data table on the master.
Ask students to work in pairs. Distribute cans of soft drink. Allow
Page 79
students time to work through the instructions on the master.
Step 5
85
Student Lesson 3
The Brain: Understanding Neurobiology Through the Study of Addiction
What the Teacher Does
Procedure
reference
Discuss the results of the investigation with the class. Use the
Pages 79–80
following questions to guide the discussion.
Step 6
• Did your heart rate go up, down, or stay the same after you
drank a caffeinated soft drink?
• If you drank a caffeine-free soft drink, how did your heart
rate change?
• What happened if you drank water?
• Why was it important that some students drink the same
amount of a caffeine-free soft drink? Why did some students
drink water?
• How long did the effect of caffeine last?
• Did all the members of the class have exactly the same results
when they drank a caffeinated soft drink?
• Why do people respond differently to caffeine?
• What could your results from the caffeine investigation tell you
about how individuals respond to drugs of abuse?
If you have several classes, you may wish to pool data to have a
Page 80
larger sample size for analysis.
Step 7
Discuss how the dose of caffeine may affect the response.
Page 80
Encourage students to design an experiment to investigate this.
Step 8
Activity 3: Routes of Administration
Give students the opportunity to view the appropriate online
Page 81
segment. To access the segment, click on Lesson 3— Drugs Change
Step 1
the Way the Neurons Communicate from the activities menu. Then
select Pathways to the Brain.
Give each student one copy of Master 3.6. Have students work in
Pages 81–83
groups of three for this step.
Step 2
Display a transparency of Master 3.7. Discuss as a class why one
Page 83
action may be more appropriate than others.
Step 3
= Involves using the Internet.
= Involves copying a master.
= Involves making a transparency.
86
Lesson 3 Organizer: PrINT VErSION
What the Teacher Does
Procedure
reference
Activity 1: Drugs Alter Neurotransmission
Review neurotransmission with students.
Page 73
Step 1
Draw a chart on the board with the column headings: “Change in
Page 73
neurotransmission” and “Effect on neurotransmitter release or
Step 2
availability.”
Ask students if they can think of ways that neurotransmission could
Pages 73–74
be altered. Fill in the chart. Ask questions such as
Step 3
• What would happen if the amount of certain components in the
process increased or decreased?
• How would that change affect the responding neuron?
Add a third column to the chart with the heading “Drug that acts
Page 74
this way.” Write the name of the drug next to the appropriate change.
Step 4
Display a transparency of Master 3.1. Point out that cocaine blocks
Pages 74–75
the dopamine transporters. Ask,
Step 5
• “How does this blocking action affect dopamine levels in the
(skip
synaptic cleft?”
Step 6)
• “What is the effect on the postsynaptic neuron?”
Display the top half of a transparency of Master 3.2. Explain how
Page 75
methamphetamine acts by blocking dopamine transporters and
Step 7
by passing through the neuron cell membrane to trigger vesicle
release. Ask how these actions affect the postsynaptic neuron.
Show the bottom half of Master 3.2. Explain that nicotine binds
Page 75
to nicotine receptors on the presynaptic neuron and causes
Step 8
the neuron to release more neurotransmitter with each action
potential. Ask how this activity affects the postsynaptic neuron.
87
Student Lesson 3
The Brain: Understanding Neurobiology Through the Study of Addiction
What the Teacher Does
Procedure
reference
Display a transparency of Master 3.3. Explain that in the presence
Page 76
of alcohol, GABA activity is enhanced, resulting in greater Cl– influx
Steps 9–10
into the presynaptic neuron and, consequently, greater inhibition
of the neuron. Use the following questions to help students
understand how alcohol affects neurotransmission.
• How does alcohol affect the activity of the neurons?
• If the presynaptic neuron releases GABA as its neurotransmitter,
does the amount of GABA released increase or decrease when
alcohol is present in the body?
• How does this affect the release of dopamine from the
postsynaptic neuron?
Complete a summary by completing a line for alcohol on the chart
Have students compare the actions of alcohol and cocaine on
Page 77
neurotransmission. Use the following questions to guide the
Step 11
discussion.
• How does the way alcohol alters dopamine neurotransmission
differ from the way cocaine changes dopamine neurotransmission?
• Are there any similarities in how alcohol and cocaine change
neurotransmission?
Activity 2: How Does Caffeine Affect You?
Several days before this activity, assign students to the caffeinated
Page 78
or caffeine-free group. Remind students to bring the appropriate
Step 1
can of soft drink and a signed permission form (Master 3.4).
Have students spend several minutes sitting quietly so their heart
Page 78
rates are at a resting level. Probe students’ knowledge about caffeine.
Step 2
Teach students how to find their pulse, count their heartbeat, and
Page 78
calculate their resting heart rate.
Step 3
Distribute one copy of Master 3.5 to each student. Ask students to
Page 78
count their heartbeats for 15 seconds while you time them. Have
Step 4
students calculate their resting heart rate and enter the number in
the data table on the master.
Ask students to work in pairs. Distribute cans of soft drink. Allow
Page 79
students time to work through the instructions on the master.
Step 5
88
What the Teacher Does
Procedure
reference
Discuss the results of the investigation with the class. Use the
Pages 79–80
following questions to guide the discussion.
Step 6
• Did your heart rate go up, down, or stay the same after you
drank a caffeinated soft drink?
• If you drank a caffeine-free soft drink, how did your heart
rate change?
• What happened if you drank water?
• Why was it important that some students drink the same
amount of a caffeine-free soft drink? Why did some students
drink water?
• How long did the effect of caffeine last?
• Did all the members of the class have exactly the same results
when they drank a caffeinated soft drink?
• Why do people respond differently to caffeine?
• What could your results from the caffeine investigation tell you
about how individuals respond to drugs of abuse?
If you have several classes, you may wish to pool data to have a
Page 80
larger sample size for analysis.
Step 7
Discuss how the dose of caffeine may affect the response.
Page 80
Encourage students to design an experiment to investigate this.
Step 8
Activity 3: Routes of Administration
Give each student one copy of Master 3.6. Have students work in
Pages 81–83
groups of three for this step.
Steps 1–2
Display a transparency of Master 3.7. Discuss as a class why one
Page 83
action may be more appropriate than others.
Step 3
= Involves copying a master.
= Involves making a transparency.
89
Student Lesson 3
L E S S O N 4
Explain/Elaborate
Drug Abuse
and Addiction
Photo: Corel
Overview
At a Glance
Students examine data from animal experiments, play a card game, and
examine a case study. They learn that although the initial decision to take