ABSTRACT
Domoic acid is an excitatory amino acid that has been implicated as the toxin responsible for the outbreak of amnesic shellfish poisoning in Canada in 1987. Domoic acid is a highly potent and selective agonist at a subpopulation of the AMPA/kainate subtype of excitatory amino acid receptor. These receptors are found in high densities in the mammalian hippocampal formation. Activation of these receptors leads to seizures and degeneration of neurons due to excitotoxicity. Hippocampal neurons are particularly sensitive to this toxin. Long-term consequences of domoic acid administration include disturbances of learning and memory, which can be explained by damage to the hippocampus. The clinical syndrome in individuals afflicted by amnesic shellfish poisoning can be understood in terms of the neuropharmacology of domoic acid, and appropriate antidotes proposed.
