On Thursday 2nd November, Dr Chris Green came to Marlborough to deliver a talk to Hundred and Sixth Form biologists titled ‘Venoms, Toxins and Nerves: Science for Defence’.
To begin with, Dr Green gave us a background of his studies at university, explaining that he specialised in the torpedo (an electric eel), in which he explored the anatomy of its nervous system and electric organs. During his studies, Dr Green gained an extensive understanding about the nervous system and in particular, synapses, which lead him to his current work at the Defence Science and Technology Laboratory at Porton Down. Here he works to understand how toxins and venoms can harm our nervous systems, with the aim of finding ways to defend against the effects of such toxins.
Dr Green went on to gives us a brief outline of how our brain sends messages to our body. He explained that at synapses (gaps between our neurons), calcium channels form, causing vesicles containing acetylcholine to be excreted, these then diffuse across the synaptic cleft and are received by acetylcholine receptors. This information was vital to help us understand how exactly the toxins affect the activity of our nervous system.
He explained that there are varying types of toxins that can have different effects at synapses. The first being a variety of toxins that bind to the calcium channels with the aim of blocking the release of neurotransmitters. Another being toxins that instead, block the receptors from receiving acetylcholine; and finally, toxins that inhibit the clearance of the secreted neurotransmitters. Dr Green also provided many examples of where such toxins may be found, including conotoxins found in snails and toxins from spiders such as the black widow.
Finishing with an experiment, Dr Green used an app to help us visualise the effects of toxins on the activity levels of the receptors. By programming the addition of certain toxins, we could see a clear drop in the levels of neurotransmitter that the receptors received; whilst the addition of other toxins caused levels to increase, because they were affecting the proteins that clear the neurotransmitters.
Overall, Dr Green gave us a clear insight into the biology behind how different toxins may influence the ability of our bodies to send nervous signals and the way in which his work may help prevent the catastrophic effects these toxins may have. His talk was both fascinating and informative and gave everyone who attended a better understanding of a topic of which they otherwise may not have been aware.
Review by Xanthe H-E