Rapid behavioural diagnosis of domoic acid toxicosis in California sea lions

• Published in: Biology letters (2005) Vol. 7; no. 4; pp. 536 - 538
• Main Authors: Cook, Peter, Reichmuth, Colleen, Gulland, Frances
• Format: Journal Article
• Language: English
• Published: England The Royal Society 23.08.2011
• Subjects: Animal Behaviour; Animals; Behavior, Animal - drug effects; Behavioural Diagnostics; Domoic Acid; Habituation; Hippocampus; Kainic Acid - analogs & derivatives; Kainic Acid - toxicity; Marine; Marine Mammals; ROC Curve; Sea Lions; Sea Lions - psychology; Zalophus californianus; INE, USA, California
• ISSN: 1744-9561; 1744-957X; 1744-957X
• DOI: 10.1098/rsbl.2011.0127

Domoic acid is a neurotoxic metabolite of widely occurring algal blooms that has caused multiple marine animal stranding events. Exposure to high doses of domoic acid, a glutamate agonist, may lead to persistent medial temporal seizures and damage to the hippocampus. California sea lions (Zalophus californianus) are among the most visible and frequent mammalian victims of domoic acid poisoning, but rapid, reliable diagnosis in a clinical setting has proved difficult owing to the fast clearance of the toxin from the blood stream. Here, we show that the behavioural orienting responses of stranded sea lions diagnosed with domoic acid toxicosis habituate more slowly to a series of non-aversive auditory stimuli than do those of sea lions with no apparent neurological deficits. A signal detection analysis based on these habituation measures was able to correctly identify 50 per cent of subjects with domoic acid toxicosis while correctly rejecting approximately 93 per cent of controls, suggesting potential diagnostic merit.