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NOVA scienceNOW: Of Mice and Memory
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Viewing Ideas
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Before Watching
Note: Some students might have trouble
discussing this topic because they may have a family member with
Alzheimer's disease.
Model
a nerve cell. Explain to
students that the nervous system functions as the body's communication
and control system. Alzheimer's disease symptoms result from damage to
the nervous system, particularly brain damage and a disruption in nerve
communication. Nerve cells (neurons) are a main component of the nervous
system, and their unique structure allows rapid communication between the brain
and parts of the body. Explain the functions of each part of a nerve cell and
how information (electrical impulses) travels through nerve cells.
Dendrites
deliver information to the nerve cell. Information (electrical impulses)
travels down the axon towards the axon terminals. Axons are surrounded by a
myelin sheath, which protects the axon and helps the nerve impulse travel
faster. (Nerve impulses travel down the axon in only one direction.) At the
axon terminal, the nerve communicates with a nerve dendrite or other body cell
by releasing chemicals called neurotransmitters. Pair
students and provide each one with two basic diagrams: one of a typical nerve
cell and one of a typical body cell. The nerve diagram should include the cell
body, nucleus, dendrites, axon, axon terminals, Schwann cells, and myelin
sheath. Tell students that even though nerve cells vary in size and shape, most
have the same specialized parts as those in the diagram. Have pairs list some
ways nerve cells are similar to and different from body cells. Have them share
their list with the class. (Similar: They have a nucleus containing DNA, a
cell membrane, and cytoplasm.
Different: They have a very different shape, and long extensions with
terminals that connect to other cells.)
Give
pairs different colored pipe cleaners. Have them use the diagram to construct a
nerve cell model. Then have them tape their models to a piece of paper and
label the cell body, nucleus, dendrites, axon, axon terminals, and myelin
sheath.
Model
a neural pathway. Review
with students how nerve impulses travel (see Question 1). Then tell the class
they will model a traveling nerve impulse representing multiple neurons
consecutively firing to trigger a response far from the initial stimulus. Have
students form a line, standing side to side, an arm's length apart.
Initiate a nerve impulse by tapping the right hand of the first student. That
student should, with their left hand, then tap the next students' right
hand, and so on down the line. Continue until the last person in line performs
an action, such as picking up a book. Process the activity by asking the
following questions:
Which
body part represented the dendrite? (Right hand/arm) The cell body? (Body trunk) The axon? (Left arm) The axon terminal? (Left Hand) How
many neurons were part of the nerve pathway? (The number of students plus
the teacher) How
many directions did the impulse travel in? (One, always down the axon,
toward the last student in line) What
would have happened if a nerve cell axon, dendrite, or cell body was destroyed?
(The impulse would have stopped, preventing the communication. In this
example, the book would not have been picked up.) What
would happen if the damaged nerve pathway, as occurs in Alzheimer's,
related to retrieving a memory? (The memory would not be retrieved.)
After Watching
Discuss
ethical questions related to genetic testing for Alzheimer's Disease. Have student groups discuss the
questions below and summarize their ideas. Then, conduct a class discussion.
If
tests could predict that a person is likely to get a disease in the future,
such as Alzheimer's, what are some advantages and disadvantages related
to early detection? What
are the pros and cons of being required to be tested for debilitating diseases,
such as Alzheimer's? Who
do you think should be allowed or not allowed to see a person's test
results? Explain your reasoning.
Prepare
a poster and presentation about Alzheimer's disease. Discuss with students basic information
about Alzheimer's disease (i.e., it results in a loss of memory, mental
functions, and includes behavioral and personality changes). Then make teams of
students, and have each one research an aspect of the disease listed below. Ask
teams to prepare a poster and short presentation on their topic.
What
is Alzheimer's disease and what are its symptoms? What evidence exists
for the causes? What are some treatments and/or lifestyle changes that help
slow the progress of the disease? What actions appear to delay the onset of the
disease? Who
most often gets Alzheimer's disease? How prevalent is the disease?
Generate a bar graph representative of disease statistics and age of onset of
the disease. Be able to explain the graph. (Get Alzheimer statistics at www.alz.org/documents/national.) What
are Alzheimer's care centers doing to ease the symptoms of people living
with Alzheimer's disease? What are some things caregivers, friends, and
relatives can do to make daily life for people living with Alzheimer's
more enjoyable?
Investigate
the effects of the environment and lifestyle on memory and learning. In the segment, experiments with mice
showed that enriched environments resulted in improved memory and stimulated
the growth of neurons with more branches. In comparison, brain neurons of mice
in sterile environments had a bare appearance with little branching. The
segment also discussed how people with Alzheimer's disease had improved
memory when moved from a sterile to an enriched environment. As a class,
brainstorm factors, both positive and negative that students believe contribute
or detract from their ability to remember and learn. (Possible
answers—Positive: healthy diet; comfortable temperature; sufficient
sleep; low levels of stress; mental engagement; comforting music; able to focus
without interruption. Negative: poor diet; hunger; too cold or too hot; lack of
sleep; boredom; stress; pain; lack of mental engagement or motivation; loud
noise; constant interruption; inability to focus or concentrate) Have each student make a list of the
features he or she would want to have in his or her ideal environment—one
that would stimulate the memory and maximize learning. Have students describe
these ideal learning environment.
Web Sites
NOVA scienceNOW
www.pbs.org/wgbh/nova/sciencenow
Offers
Alzheimer's-related resources, including additional activities, streamed
video, and reports by experts.
AFA Teens
www.afateens.org
Provides
information for teens about Alzheimer's disease symptoms and causes.
Alzheimer's Disease
kidshealth.org/kid/grownup/conditions/alzheimers.html
Describes
how Alzheimer's Disease changes the brain, and the site includes links to
related articles for kids and teens.
Brain Structures and their Functions
www.serendip.brynmawr.edu/bb/kinser/Structure1.html
Describes
the parts and functions of the nervous system and includes diagrams and
pictures.
Neuroscience for Kids: Alzheimer's Disease
faculty.washington.edu/chudler/alz.html
Presents
basic information about Alzheimer's as well as scientific theories
regarding its causes.
Books
The Human Body
Book
by Steve Parker. Dorling Kindersley, 2004.
Provides information on and diagrams of different body
systems including the brain and nervous systems.
The Human Brain
Coloring Book
by Marion C. Diamond and Arnold B.
Scheibel. Oxford University Press, 1996.
Presents brain anatomy in coloring book form for students.
Activity Author
WGBH Outreach staff
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