SMARTER UK – RESOURCES FOR SCHOOLS

1. 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.

2. Neurotoxins What are they and what do they do?

3. many poisons are neurotoxins Most of them work by interfering with control of muscle contractions They cause death because they stop the heart and lungs from working Smarter UK

4. 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 acetylcholine muscle Smarter UK

5. Within the neurone itself, different neurotoxins work in different ways… many make it impossible for the neurone to fire its electrical signal neurotoxins that work like this are found in: some snake and spider venom; poison arrow frogs; many scorpion stings and… Smarter UK

6. Within the neurone itself, different neurotoxins work in different ways… many make it impossible for the neurone to fire its electrical signal 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 Puffer fish for sale at KuromonIchiba market, Osaka, Japan Credit: Nate Gray Smarter UK

7. 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 Credit: SaleemHameed Smarter UK

8. Other neurotoxins you may have heard of… Botox http://www.flickr.com/photos/ajc1/533224941/ Botulinumtoxin (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

9. 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 Smarter UK L0058962CreditScience Museum, London, Wellcome Images 

10. Other neurotoxins you may have heard of… Curare 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 Smarter UK