SMARTER UK – RESOURCES FOR SCHOOLS
Please feel free to use this PowerPoint presentation in the classroom. It is intended to support the KS3 & KS4 curriculum and the
Scottish S3-S4 curriculum.
KEY LEARNING:
Introduces students to a range of different neurotoxins, from Cobratoxin to Curare, and their impacts on the nervous system.
Specific curriculum areas include:
KS4 Links to GCSE Biology Syllabuses
AQA
11.3 How do we use/abuse medical and recreational drugs?
• Many drugs derived from natural substances have
been known to indigenous peoples for many years.
Scottish Certificate in Education, Standard Grade Biology
Topic 5: The body in action
Subtopic c: Coordination
• State that the nervous system is composed of the
brain, spinal cord and nerves.
19) Obtain and present information on the flow of information in
the nervous system.
• State that the central nervous system sorts out
information from the senses and sends messages to
those muscles which make the appropriate response.
Neurotoxins
What are they and what do they do?
many poisons are
neurotoxins
Most of them work by interfering
with control of
contractions
muscle
They cause death
because they stop the
heart and lungs from
working
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the point where your muscles and nervous system meet is called the
neuromuscular junction (NMJ)
Signals sent from your central nervous
system to the NMJ tell muscles to move
The synapses at the NMJ
use a neurotransmitter
called
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acetylcholine
neurotoxins work in different ways…
many make it impossible for the neurone to fire its
electrical signal
Within the neurone itself, different
neurotoxins that work
like this are found in:
some snake and
spider venom;
poison arrow
frogs;
many scorpion
stings
and…
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neurotoxins work in different ways…
many make it impossible for the neurone to fire its
electrical signal
Within the neurone itself, different
Puffer fish (or fugu) is a potentially lethal Japanese
treat
One puffer fish contains enough neurotoxin to kill
30 people
Fugu can only be prepared by specially trained chefs
who carefully remove all the parts of the fish that
contain the poison
Eating it can cause an enjoyable, tingly feeling in
your mouth. But this could also be an early sign that
you are being poisoned. Every year in Japan, eating
it kills 30-100 people
There is no known antidote
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Within the neurone itself, different
neurotoxins work in different ways…
Some interfere with the action of
acetylcholine at the NMJ
Cobratoxin blocks acetylcholine receptors
Acetylcholine can’t bind to its receptors, so the
signals that control your muscles are blocked and
your muscles, including your heart and
diaphragm, are paralysed
Left untreated, a bite from an Indian Cobra
can kill in just 1 hour
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Other
neurotoxins you may have heard of…
Botox
Botulinum toxin (Botox) is a neurotoxin produced
by bacteria called Clostridium Botulinum
It is the most powerful neurotoxin yet discovered
and causes poisoning that can be fatal (botulism)
It is used medically to treat muscle spasms and
cosmetically to reduce wrinkles
It works by preventing vesicles containing
neurotransmitter from fusing with the
presynaptic membrane.
This means acetylcholine isn’t released at
the neuromuscular junction, so muscles are
paralysed
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Other
neurotoxins you may have heard of…
Strychnine
The Strychnine Tree is native to India and SE Asia. It
is related to the curare tree.
Strychnine was used by the winner of the 1904 Olympic
marathon to improve performance
It is still banned in sport, but its use rarely detected
Tetanus
Tetanus is caused by the neurotoxin tetanospasmin
which comes from comes from a bacterium called
Clostridium tetani
Both cause poisoning by interfering with they way muscle
contractions are regulated.
Muscles become very sensitive to stimulation and instead
contracting and then releasing, they go into spasm
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neurotoxins you may have heard of…
Curare
Other
Curare is used by some indigenous
South American tribes for poison
darts
It comes from the curare plant
Curare paralyses muscles by blocking
acetylcholine receptors
At the right dose, it has medical uses.
It was one of the first chemicals used
as a muscle relaxant in anaesthesia
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