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Drawing of a brain cut in half, showing areas of the
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cerebral cortex and their functions.
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Source: National Institute on Drug Abuse (1997). Mind Over Matter: The Brain’s Response to Drugs, Teacher’s Guide.
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Master 1.5
What Happened to Phineas Gage?
Name(s)______________________________________________________________ Date ______________
Due to an accident while he was working, Phineas Gage made a contribution to the understanding of
how the brain works. In 1848, 25-year-old Phineas Gage worked for the Rutland and Burlington Railroad
Company laying railroad tracks across Vermont. Before railroad track could be laid, however, the uneven
ground needed to be leveled. Gage and coworkers had to drill holes in the stone, put explosive in the
holes, cover the explosive with sand, and then use a fuse and tamping iron to trigger an explosion. One
day, an accident occurred that changed Gage’s life forever. The explosive went off early, sending the
tamping iron, which was 1.25 inches in diameter and 43 inches long, shooting into Gage’s face, through
his skull and brain, and out the top of his head. The tamping iron landed about 25 yards away. Gage
regained consciousness within a few minutes. Amazingly, he not only survived the blast, but he was able
to talk and to walk! His coworkers took him to the doctor, who cleaned and bandaged the wounds, the
standard medical treatment at the time.
Although Gage survived the physical injuries from the blast, he was a changed man. He appeared to
be just as intelligent as before the accident, and he did not have any impairment in movement, speech,
or memory. But, something was different. Before the accident, he was a responsible, intelligent, and
likeable person. After the accident, he was irresponsible, used profanity extensively, and demonstrated
09. no respect for social customs. His friends commented that “Gage was no longer Gage.” He could not hold
20 the responsible jobs that he had before the accident and apparently wandered for the next several years.
ated Phineas Gage ended up in San Francisco in the custody of his family, where he died approximately
dp 12 years after the accident.
se. Uu Twenty years after the accident, the physician who treated Gage correlated the behavioral changes with damage to the frontal region of the brain. At the time, the brain was thought to control language and
classroom movement, but the suggestion that the brain functioned to process emotions and social behavior was new.
for In addition, scientists at the time believed the brain lacked localized functions. Unknowingly, Phineas Gage contributed to our understanding of how the brain processes information.
granted
In the 1990s, scientists used their improved understanding of brain function, computer modeling
ission techniques, and new data from Gage’s skull. On the basis of this information, they found that the accident damaged both hemispheres of the frontal lobe, which is the part of the brain that influences social
behavior. Today, physicians see patients with damage to the frontal lobe that has occurred through motor
vehicle accidents, gun accidents, or major falls. These individuals, like Phineas Gage, often have dramatic
changes in their emotional and decision-making abilities.
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Master 1.6
The Reward System �
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Drawing of a brain cut in half, showing the reward system.
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Source: National Institute on Drug Abuse (1997). Mind Over Matter: The Brain’s Response to Drugs, Teacher’s Guide.
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Master 1.7
Anatomy of a Neuron �
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Master 2.1
Neurons Interact with Other
Neurons through Synapses �
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Master 2.2
How Do Neurons Communicate? �
Name(s)______________________________________________________________ Date ______________
1
2
3
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Master 2.3
Neurons Communicate
by Neurotransmission
Neurons communicate using both electrical signals and chemical messages.
Information in the form of an electrical impulse is carried away from the
neuron’s cell body along the axon of a presynaptic neuron toward the axon
terminals. When the electrical signal reaches the terminal, it cannot cross
the synaptic space, or synaptic cleft, to reach the postsynaptic neuron.
Instead, that electrical signal triggers chemical changes that can cross the
synapse and affect the postsynaptic cell. When the electrical impulse reaches
the presynaptic axon terminal, it causes membranous sacs, called vesicles, to
move toward the membrane of the axon terminal. When the vesicles reach
the membrane, they fuse with the membrane and release their contents into
the synaptic space. The molecules contained in the vesicles are chemical
compounds called neurotransmitters. Each vesicle contains many molecules
of a neurotransmitter. The released neurotransmitter molecules drift across
09. the synaptic cleft and then bind to special proteins, called receptors, on the
20 postsynaptic neuron. A neurotransmitter molecule will bind only to a specific
ated dp kind of receptor. The binding of neurotransmitter to its receptor causes a
se. Uu change in the postsynaptic neuron that in turn causes that neuron to generate
an electrical impulse. The electrical impulse then moves away from the neuron
classroom ending toward the cell body of the receiving neuron. After the neurotransmitter
for binds to the receptor and transmits the signal to the postsynaptic neuron,
granted it comes off, or releases from, the receptor into the synaptic space. Specific
proteins called transporters or reuptake pumps carry the neurotransmitter
ission back into the presynaptic neuron. When the neurotransmitter molecules are
back in the presynaptic axon terminal, they can be repackaged into vesicles
for release the next time an electrical impulse reaches the axon terminal.
iscovery, Inc. Perm Enzymes present in the synaptic space degrade neurotransmitter molecules
ideodV that are not taken back up into the presynaptic neuron.
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Master 2.4
Neurotransmission �
Name(s)______________________________________________________________ Date ______________
1
2
3
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Master 2.5
Recording the Activity of a Neuron �
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Master 2.6
Neurotransmitter Actions �
Name(s)______________________________________________________________ Date ______________
The following diagrams represent recordings of the electrical activity of a neuron over a period of time.
Each vertical line on the diagram represents an electrical impulse, or action potential, occurring in the
neuron. The first diagram represents a neuron at rest. For the other recordings, a solution containing
neurotransmitter was applied to the neuron.
09. 20 1. � Why is saline applied to the resting neuron?
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se. Uu 2. � When the neurotransmitter glutamate is applied to the neuron, how does its activity change?
classroom
for 3. � How does the application of the two neurotransmitters, glutamate and GABA, change the activity of the neuron?
granted
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4. � Predict how the activity of the neuron would change if only GABA was applied to the neuron.
iscovery, Inc. Perm 5. � Do all neurotransmitters affect a neuron in the same way?
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released from that neuron? How would the application of GABA to a neuron change the amount of
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neurotransmitter released from that neuron?
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Master 2.7
Neurons in Series �
Name(s)______________________________________________________________ Date ______________
Using what you have learned about the effects of the neurotransmitters glutamate and GABA, determine
how the different signals that affect Neuron #1 can change the release of the neurotransmitter dopamine
from Neuron #2. Use the chart to help you work through the cases. You can use a down arrow to indicate
a decrease or an up arrow to indicate an increase.
A. The signaling molecule is inhibitory. Neuron #1 releases glutamate as its neurotransmitter.
Neuron #2 releases dopamine as its neurotransmitter.
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classroom r ofd B. The signaling molecule is excitatory. Neuron #1 releases glutamate as its neurotransmitter.
etna
Neuron #2 releases dopamine as its neurotransmitter.
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ideodVd na C. The signaling molecule is inhibitory. Neuron #1 releases GABA as its neurotransmitter.
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Neuron #2 releases dopamine as its neurotransmitter.
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Master 2.8a
D. The signaling molecule is excitatory. Neuron #1 releases GABA as its neurotransmitter. Neuron #2
releases dopamine as its neurotransmitter.
Does the
Is the
amount of
neuro-
Does the
neuro-
What is
transmitter
amount of
Does the
transmitter the name of
released
dopamine
signal
Does the
released
the neuro-
from
Does the
released
molecule
activity of
from
transmitter
Neuron #1
activity of
from
excite or
Neuron #1
Neuron #1
released
excitatory
Neuron #2
Neuron #2
09.
inhibit
increase or increase or
from
or
increase or increase or
20
Case Neuron #1?
decrease?
decrease?
Neuron #1? inhibitory?
decrease?
decrease?
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Master 2.8b
Cocaine Alters Neurotransmission �
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Master 3.1
Methamphetamine and Nicotine
Disrupt Neurotransmission �
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Master 3.2
How Does Alcohol Affect
Neurotransmission? �
Alcohol absent
GABA
GABA
receptor
Cl–
Cl–
Cl–
GABAreleasing
neuron
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receptor
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Cl– Cl–
Cl– Cl–
Cl–
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Master 3.3
Parent Letter �
Dear Parents,
Next week in biology class, we will investigate the effect of caffeine on the body. Each student will need
to bring in a 12-ounce can of ______________________________. Please provide one can labeled with your
child’s name and class period.
During the activity, students will consume 12 ounces of the above-specified soft drink and measure what
effect it has, if any, on their heart rates.
Students are not to bring in any soft drink other than the one specified. Because the different brands and
flavors vary in their caffeine content, it is important that all students consume the same brand.
Students who choose not to bring in a soft drink, or those without signed permission forms, can
participate in the activity by drinking 12 ounces of water. They will be an important part of the activity
by serving as “controls.”
Thank you for your continued support.
09. 20
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classroom
for My child, ______________________________________, has permission to participate in the caffeine activity in class and will bring in a 12-ounce can of ______________________________ to consume as part of
granted the activity.
ission My child, ______________________________________, has permission to participate in the activity in class and will bring in a 12-ounce can of caffeine-free ______________________________ to consume as part of
the activity.
iscovery, Inc. Perm My child, ______________________________________, will not drink a 12-ounce soft drink during the ideodV activity, but will participate by drinking 12 ounces of water.
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Master 3.4
Caffeine: How Does Your Heart Respond? �
Name(s)______________________________________________________________ Date ______________
MATERIALS FOR EACH TEAM
2 cans of soft drink (caffeinated or caffeine-free)
1 watch or classroom clock with a second hand
PROCEDURE
Do Steps 1 to 3 with your teacher.
1. � When your teacher directs you to do so, find your pulse. You can find it most easily by pressing two
fingers against the artery in your neck or on the inside of your wrist. Practice counting the beats.
2. � When your teacher directs you to start, count the number of beats you feel in 15 seconds. Your
teacher will tell you when to stop. Record the number in the data table on the next page.
3. � Multiply the number of beats you counted in 15 seconds by four to calculate your resting heart rate in
09.
beats per minute.
20
ated Complete the rest of the activity with your partner.
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se. U 4. � Predict what you think might happen to your heart rate after you drink a caffeinated soft drink. What u
might happen after drinking a caffeine-free soft drink? Write your predictions here:
classroom
for
granted 5. � At the same time as your partner, drink your can of soft drink. Write down the time when you started ission
drinking it. For best results, try to drink it quickly, taking less than 10 minutes to finish the can.
Write the type of soft drink at the top of the data table on the next page.
6. � Watch the time. Sit quietly for 5 minutes. You can talk softly with your partner or read, but keep your body still so that you will not change your heart rate due to activity.
iscovery, Inc. Perm
7. � After 5 minutes, have one partner measure his or her pulse rate for 15 seconds. Record the number
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of beats in the data table. The other partner should be the timer, saying “Start” and then “Stop” when
and
the 15-second period is over. Now the partners should switch roles.
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00
times. Record each measurement in the data table.
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Master 3.5a
9. Use the data that you collected to calculate your heart rate in beats per minute.
Name of Drink: ___________________________________ Type (circle one): Caffeinated or Caffeine-Free
Time ( i
m nutes after
Heartbeats counted
Multiply by 4
Heart rate
drinking soft drink)
in 15 seconds
(beats per minute)
0 (resting heart rate)
x 4
5
x 4
7
x 4
9
x 4
11
x 4
13
x 4
15
x 4
17
x 4
19
x 4
21
x 4
09. 20 23
x 4
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x 4
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x 4
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x 4
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x 4
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33
x 4
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35
x 4
Difference between resting heart rate and the highest heart rate after drinking the soft drink: _________ �
iscovery, Inc. Perm Number of minutes after finishing the drink when the heart rate reached its peak: _________
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and Number of minutes after finishing the drink when the heart rate returned to resting rate: _________ �
S