Agent VX

Chemical signals are transmitted between nerve cells by means of small molecules called neurotransmitters. One of the most common neurotransmitters in the central and peripheral nervous system is acetylcholine. Under normal conditions, acetylcholine is released from the terminal axon of one nerve cell, crosses the synaptic cleft between nerve cells, and binds with a receptor on the membrane of the post-synaptic nerve cell. Then, the enzyme cholinesterase binds to acetylcholine and inactivates it. This completes the chemical signaling between nerve cells.

When the VX nerve agent is present in the nervous system, it inactivates the enzyme cholinesterase. As a result, the receptor on the post-synaptic nerve cell is indefinitely stimulated by acetylcholine. In addition, the pre-synaptic nerve cell continues to release acetylcholine. Nervous signals are never completed and the nervous system is eventually destroyed.

VX poisoning can occur by exposure to the eyes or skin, inhalation, or ingestion. Symptoms occur within minutes. Autonomic nervous system symptoms include constricted pupils, reduced vision and other visual effects, drooling, sweating, diarrhea, nausea, vomiting, and abdominal pain. Neuromuscular symptoms are twitching, weakness, paralysis, and eventually respiratory failure. Symptoms affecting the central nervous system are headache, confusion, depression, convulsions, coma, respiratory depression, and respiratory arrest.