domoic acid

Domoic acid (DA), the neurotoxin that causes amnesic shellfish poisoning (ASP), is a kainic acid analog, heterocyclic amino acid associated with certain harmful algal blooms. [...]
In mammals, including humans, domoic acid acts as a neurotoxin, causing short-term memory loss, brain damage and, in severe cases, death.
Source: Wikipedia
See IHCP's disclaimer on linked sites