The YouTube staple series for explaining chemistry to the masses, The Periodic Table of Videos, takes time today to explain to us exactly how Sarin and other nerve gases work to disrupt bodily functions, using handmade chemical models in the hands of a researcher who works to understand neurotransmitters, Rob Stockman. Professor Martyn Poliakoff also takes some time to demonstrate a gas mask and how it functions, with the discussion rounding out with antidotes and the reason chemical warfare is considered much worse than targeted explosive types of warfare.
For a muscle to contract, it must receive a signal from nerves in the form of the neurotransmitting chemical, acetylcholine, which activates contraction. When it is time for the muscle to stop contracting, acetylcholine MUST be cleared out or the muscle will continue to contract. This clearing out role is performed by Acetylcholine esterase (AChE). Sarin interferes with the functioning of AChE.
When acetylcholine esterase is no longer available to negate the function of acetylcholine, as is the case when Sarin competes for the same active site that AChE uses on acetylcholine, several bodily functions will persist to the victims' detriment due to continuous signals arriving for muscles to contract. In the presence of acetylcholine and absence of AChE, inspiration (breathing in), for instance, would not be countered by expiration (breathing out), and victims remain permanently in one mode or the other, which is the primary reason Sarin victims perish.
But, let's have our experts explain:
Thank you, Professor Martyn, Brady and Professor Stockton for your helpful and timely explanation!