Domoic Acid

Domoic acid (DomA) is an excitatory amino acid that can accumulate in shellfish and finfish under certain environmental conditions. It is a potent neurotoxin. In humans and nonhuman primates, oral exposure to a few milligrams per kilogram DomA elicits gastrointestinal effects, whereas slightly higher doses cause neurological symptoms, seizures, memory impairment, and limbic system degeneration. In rodents, which appear to be less sensitive than humans or nonhuman primates, oral doses cause behavioral abnormalities (e.g., hindlimb scratching), followed by seizures and hippocampal degeneration. Similar effects are seen in other species (from sea lions to zebrafish), indicating that DomA exerts similar neurotoxic effects across species. The neurotoxicity of DomA is ascribed to its ability to interact and activate the (. S)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl) propionic acid/kainate receptors, a subfamily of receptors for the neuroexcitatory neurotransmitter glutamate.