neu·​ro·​tox·​in ˌnu̇r-ō-ˈtäk-sən How to pronounce neurotoxin (audio)
: a poisonous substance (such as tetrodotoxin or saxitoxin) that acts on the nervous system and disrupts the normal function of nerve cells

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The nervous system is almost all-powerful in the body: all five senses depend on it, as do breathing, digestion, and the heart. So it's an obvious target for poisons, and neurotoxins have developed as weapons in many animals, including snakes, bees, and spiders. Some wasps use a neurotoxin to paralyze their prey so that it can be stored alive to be eaten later. Snake venom is often neurotoxic (as in cobras and coral snakes, for example), though it may instead be hemotoxic (as in rattlesnakes and coppermouths), operating on the circulatory system. Artificial neurotoxins, called nerve agents, have been developed by scientists as means of chemical warfare; luckily, few have ever been used.

Examples of neurotoxin in a Sentence

Recent Examples on the Web As described above, the procedure involves using a needle to inject neurotoxin into the trapezius muscle—two common injection sites, according to Dr. Alexiades, are at the slope of the neck and just before the shoulder. Brian Underwood, Women's Health, 31 Aug. 2023 The neurotoxins in puffers responsible for illness and death are tetrodotoxin and saxitoxin, which adversely affect the human central nervous system. Joe Cermele, Outdoor Life, 23 Aug. 2023 Here’s why, and here’s how San Diegans can help July 2, 2023 The neurotoxin was first found in waters off Santa Barbara and Ventura counties in early June, resulting in reports of sea lions and dolphins dying off by the hundreds. Emily Alvarenga, San Diego Union-Tribune, 5 Aug. 2023 The cosmetic treatment involves injecting botulinum toxin, or a similar muscle-paralyzing neurotoxin, into the trapezius muscles, or traps, with the intent of flattening the shoulders to give the appearance of a longer neck. USA TODAY, 2 Aug. 2023 Some contain neurotoxins that can cause tingling and numbness. Amanda Gokee,, 18 July 2023 More than 100 sea lions have likely been poisoned by domoic acid, a neurotoxin produced by large algae blooms, according to a joint news release from the Department of Beaches and Harbors, the Department of Public Health, and the Department of Animal Care and Control. Laura Studley, CNN, 3 July 2023 The technique entails getting a neurotoxin such as Botox (Botulinum toxin) injected into the trapezius muscle. Maggie O'Neill, Health, 22 June 2023 Experts suspect the animals are victims of domoic acid, a neurotoxin produced by the algae Pseudo-nitzschia, according to NOAA Fisheries. USA TODAY, 23 June 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'neurotoxin.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


borrowed from French névrotoxine, from névro- neuro- + toxine toxin

First Known Use

1902, in the meaning defined above

Time Traveler
The first known use of neurotoxin was in 1902

Dictionary Entries Near neurotoxin

Cite this Entry

“Neurotoxin.” Dictionary, Merriam-Webster, Accessed 27 Sep. 2023.

Medical Definition


neu·​ro·​tox·​in -ˈtäk-sən How to pronounce neurotoxin (audio)
: a poisonous substance (such as tetrodotoxin or saxitoxin) that acts on the nervous system and disrupts the normal function of nerve cells

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