As is obvious from their name, Nerve Agents interfere with the proper functioning of a person's nerves. It is necessary to know the basics of nerve functioning in order to understand how nerve agents interefere with this. Basically, a nerve transmits an electrical impulse along itself. When the impulse reaches the end of the nerve, a chemical (neurotransmitter) is transmitted across the gap between nerves (synapse). This chemical binds to the receptor site on the next nerve along the line, which creates another electrical impulse. Then, an enzyme breaks down the neurotransmitter.
Nerve agents interfere with this process. They prevent the neurotransmitter acetylcholine from breaking down, by affecting the enzyme which breaks down acetylcholine, acetylcholinesterase. The reaction that should take place is:
Enzyme-OH + CH3C(=O)-O-(CH2)2-N+(CH3)3
reacts with the release of choline to produce
Enzyme-O-C(=O)-CH3. This is quickly hydrolysed into
Enzyme-OH + CH3COOH, and the Enzyme-OH can start the process over again. This normally happens about 15,000 times per second.
Nerve agents bind to the enzyme, neutralizing it. This means that nerve cells will be continually stimulated. A low exposure will cause such symptoms as difficulty seeing, drooling, headache, tiredness, slurred speech, and a feeling of tightness in the chest. Even a low exposure can be fatal if corrective measures aren't taken immediately, as the effect is cumulative. A higher exposure will cause the subject to lose control of all body functions. The subject may convulse, or become paralyzed. Hallucinations and delusions are possible. The immediate cause of death will be suffocation or heart failure, as the heart or lungs become paralyzed.
OUR FRIEND, SARIN
Sarin (CH3-P(=O)(-F)(-OCH(CH33)2) is the easiest nerve agent to manufacture. In its pure state, it is a colorless liquid. In weapons, it may be mixed with any number of delivery agents, and is frequently misted, and dropped onto the target from above. There are two ways to deliver it- unitary and binary. The unitary method is easier, but less safe. It delivers premade sarin to the attack site. The binary method is preferred. In it, two harmless chemicals are stored separately. They combine to form sarin upon use of the weapon.
TREATMENT
In treating a person attacked with nerve agents, the first action must be to minimize exposure, and decontaminate. Antidotes are available, but must be used immediately. Many nations make available to their soldiers a kit consisting of 2 auto-injectors: HI-6, and atropine. Atropine helps with the symptoms, and HI-6 halts the spread of the agent. Neither, however, does much to fix any damage already done.