SMARTER UK – RESOURCES FOR SCHOOLS

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

AQA11.3 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 BiologyTopic 5: The body in actionSubtopic 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?

Smarter UK

many poisons are neurotoxinsMost of them work by interfering

with control of muscle contractions

They cause death because they stop the heart and lungs from working

Smarter UK

the point where your muscles and nervous system meet is called the

neuromuscular junction (NMJ)

muscle

Signals sent from your central nervous system to the NMJ tell muscles to move

The synapses at the NMJ use a neurotransmitter called

acetylcholine

Smarter UK

Within the neurone itself, different neurotoxins work in different ways…

neurotoxins that work like this are found in:

some snake and spider venom; poison arrow frogs; many scorpion stings

and…

many make it impossible for the neurone to fire its

electrical signal

Smarter UK

Cred

it: N

ate

Gray

Puffer fish for sale at Kuromon

Ichiba market, Osaka, Japan

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

Within the neurone itself, different neurotoxins work in different ways…

many make it impossible for the neurone to fire its

electrical signal

Cobratoxin blocks acetylcholine receptors

Left untreated, a bite from an Indian Cobra can kill in just 1 hour

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

Smarter UK

Within the neurone itself, different neurotoxins work in different ways…

Some interfere with the action of

acetylcholine at the NMJ

BotoxOther neurotoxins you may have heard of…

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

Smarter UK

Other neurotoxins you may have heard of…

Smarter UK

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

Tetanus

The Strychnine Tree is native to India and SE Asia. Itis related to the curare tree.Strychnine was used by the winner of the 1904 Olympic marathon to improve performanceIt is still banned in sport, but its use rarely detected

Tetanus is caused by the neurotoxin tetanospasmin which comes from comes from a bacterium called Clostridium tetani

Strychnine

Smarter UK

CurareOther neurotoxins you may have heard of…

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