Chemical warfare neurotoxins

Wild, JR USDA To develop an effective and complete biological remediation system capable of hydrolyzing organophosphorous neurotoxins from agricultural and chemical warfare munitions, contaminations, and wastes. 

A striking feature of the toxic compounds considered so far is that many of them are neurotoxic to vertebrates or invertebrates or both. The nervous system of animals appears to be a particularly vulnerable target in chemical warfare. Not altogether surprisingly, all the major types of insecticides that have been commercially successful are also neurotoxins. Indeed, in 2003, neurotoxic insecticides accounted for over 70% of total insecticide sales globally (Nauen 2006). 

Cellular and molecular mechanisms of neurotoxicity are also influenced by the fact that neurons are postmitotic and do not divide. Thus, the capacity for replacement of damaged cells does not exist in the nervous system, whereas most other organ systems have a well-established capacity for regeneration. Many neurotoxins can cause encephalopathy and an important concept in neurotoxicology is the delayed manifestation of symptoms sometimes up to years after the exposure started. Several agents show a lag time between exposure and neurotoxicity. Examples are the organophosphate chemical warfare agents [245], bismuth intoxications [246] and methylmercury... 

Adler, M., Oyler, G., Apland, J.P. et al. (2008). Mechanism of action of botulism neurotoxin and overview of medical countermeasures for intoxication In Chemical Warfare Agents Chemistry, Pharmacology, Toxicology, and Therapeutics (Romano, J.A., Jr., Lukey, B.J., Salem, H., eds), pp. 389-422. CRC Press, Boca Raton, FL. 

Organophosphates and their family of conqmunds are potent neurotoxins that share structural similarities to chemical warfare agents such as sarin, soman and VX. Organophosphates are cholinesterase inhibitors and exposure to OP compounds leads to increased neurotransmitter accumulation. Classical synq)toms of OP exposure include salivation, lacrimination, urination and defecation. E q)osure to OP con )ounds can cause Ettigue, dizziness, vomiting, paralysis and even death (2). 

Chemical Abstracts Service Registry Number CAS 14277-97-5. Domoic acid, a glutamic acid analog that is resistant to temperature extremes, is an excitatory neurotoxin produced by a diatom and concentrated in shellfish. Ingestion leads to amnesic shellfish poisoning, which can also include seizures. Its relevance to use in warfare and terrorism, apart from its being unfamiliar to most disaster-response personnel, is that it is also easily absorbed by inhalation and across mucous membranes. No specific antitoxin is available, and treatment is supportive. 

Biological toxins typically are of lesser molecular weight and size, and are thus more soluble and more easily penetrate the skin than chemical weapon agents. Biological toxins can be categorized based upon their mode of action, such as neurotoxins (disrupt nerve impulses) and cytotoxins (disrupt cell respiration and metabolism). Known biological toxins that are warfare or terror agents include aflatoxin, botuli-num toxins, ricin, and T2 mycotoxin. 

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