neuronal sodium channels which occurs in paralytic shellfish poisoning produces a flaccid paralysis that leaves its victim calm and conscious through the progression of symptoms. Death often occurs from respiratory failure. Saxitoxin was originally isolated and described by the United States military, who assigned it the chemical weapon designation "TZ". Saxitoxin is listed in schedule 1 of the Chemical Weapons Convention. According to the book Spycraft, U-2 spyplane pilots were provided with needles containing saxitoxin to be used for suicide in the event escape was impossible. Aetokthonotoxin Aetokthonotoxin (abbreviated to AETX) was discovered in 2021 as the cyanobacterial neurotoxin causing vacuolar myelinopathy (VM). As the biosynthesis of aetokthonotoxin depends on the availability of bromide in freshwater systems and requires an interplay between the toxin-producing cyanobacterium Aetokthonos hydrillicola and the host plant it epiphytically grows on (most importantly hydrilla), it took > 25 years to discover aetokthonotoxin as the VM-inducing toxin after the disease has first been diagnosed in bald eagles in 1994. The toxin cascades through the food-chain: Among other animals, it affects fish and waterfowl such as coots or ducks which feed on hydrilla colonized with the cyanobacterium. Aetokthonotoxin is transmitted to raptors, such as the bald eagle, that prey on these affected animals. Vacuolar myelinopathy is characterized by widespread vacuolization of the myelinated axons (intramyelenic edema) in the white matter of the brain and spinal cord. Clinical signs of the intoxication include the severe loss of motor functions and sight. Affected birds fly into objects, lack coordination in swimming, flying and walking, develop tremors of the head and lose their responsiveness. As the toxin has been shown to bioaccumulate, there is concern that it might also be a threat to human health. However, toxicity to mammals has yet to be confirmed experimentally. Lipopolysaccharides Lipopolysaccharides are present in all cyanobacteria. Though not as potent as other cyanotoxins, some researchers have claimed that all lipopolysaccharides in cyanobacteria can irritate the skin, while other researchers doubt the toxic effects are that generalized. Amino acids BMAA The non-proteinogenic amino acid beta-Methylamino-L-alanine (BMAA) is ubiquitously produced by cyanobacteria in marine, freshwater, brackish, and terrestrial environments. The exact mechanisms of BMAA toxicity on neuron cells is being investigated. Research suggests both acute and chronic mechanisms of toxicity. BMAA is being investigated as a potential environmental risk factor for neurodegenerative diseases, including ALS, Parkinson's disease and Alzheimer's disease. Gallery Other cyanotoxins: See also Dinotoxin Microbial