The harmful algal bloom (HAB) toxin domoic acid (DA) contaminates marine food webs in the western United States, and acts as a potent glutamate receptor agonist following ingestion. As HAB events increase in spatial range, duration, and frequency, it is increasingly important that we characterize risk for human seafood consumers. New data suggest that the elderly may be regularly exposed to DA year-round, and historical epidemiological data indicate that the elderly are disproportionately overrepresented among those hospitalized following DA events. In addition, canonical indicators of aging like increased levels of inflammation and oxidative stress have been associated with DA toxicity. We are using a mouse model to assess possible increased susceptibility of the elderly to the toxic effects of DA exposure.