Neurotoxin

Definition

A toxin that disrupts, damages, or destroys neural tissue or impairs nervous system function, typically by interfering with ion channels, neurotransmitter release or reception, or axonal conduction. In arthropod biology, neurotoxins figure prominently as venom components that rapidly immobilize prey or deter predators.

Etymology

From Greek neuron (nerve, sinew) + Latin toxicum (poison)

Example

The venom of the black widow spider (Latrodectus spp.) contains latrotoxins, potent neurotoxins that trigger massive vesicular release of acetylcholine and norepinephrine at vertebrate synapses, causing painful muscle cramping and autonomic dysfunction in envenomated mammals.

Synonyms

• neurotoxicant

Related Terms

• venom
• toxin
• Acetylcholine
• ion channel
• Synapse
• alpha-latrotoxin
• tetrodotoxin
• botulinum toxin
• chemical ecology

Usage Notes

Distinguished from cytotoxins (cell-destroying) and hemotoxins (blood-affecting). In entomology, 'neurotoxin' also describes insecticide classes (organophosphates, carbamates, pyrethroids) that target the insect nervous system—usage that is functional rather than etymological, as these are synthetic rather than biological toxins. Some endogenous compounds (glutamate, nitric oxide) are neurotoxic only at pathological concentrations, blurring the exogenous/endogenous boundary.