Domoic acid is a glutamate analog and potent receptor agonist of AMPA and kainate receptors (20x moreso than kainate at the KA receptor). It is not readily removed from the synapse by transporters, making it extremely toxic. The activation of AMPA/KA receptors causes an influx of calcium into the cell, in turn causing glutamate release and activation of the NMDA receptor causing more calcium influx (excitotoxicity).
It is produced in certain algae and thus enters the food chain. It is known to cause amnesic shellfish poisoning: a condition causing short-term memory loss, brain damage and, rarely, death.
This is a neurotoxin produced by cyanobacteria. It seems to be selective for motor neurons and activates AMPA/KA receptors, as well as inducing over-production of oxygen free-radical species and excitotoxicity.
It has been implicated in rare forms of amyotrophic lateral sclerosis (motor neuron disease)/parkinsonian-dementia complex in a tribe of Guam who eat fruit bats (that eat seeds containing this compound).