key term - Domoic Acid

Definition

Domoic acid is a potent neurotoxin produced by certain species of marine algae, particularly diatoms of the genus Pseudo-nitzschia. It is known for its ability to accumulate in the food chain, leading to serious health consequences in humans and marine wildlife upon consumption.

5 Must Know Facts For Your Next Test

1. Domoic acid is a potent agonist of the AMPA and kainate receptors in the brain, leading to excitotoxicity and neuronal damage.
2. Exposure to domoic acid can occur through the consumption of contaminated seafood, such as mussels, clams, and anchovies.
3. Domoic acid poisoning can cause Amnesic Shellfish Poisoning (ASP), which can lead to symptoms ranging from gastrointestinal distress to permanent short-term memory loss and even death.
4. Regulatory agencies monitor the levels of domoic acid in seafood to ensure food safety and prevent outbreaks of ASP.
5. Warming ocean temperatures and increased nutrient pollution can contribute to the proliferation of Pseudo-nitzschia and the production of domoic acid.

Review Questions

• Explain the mechanism by which domoic acid exerts its neurotoxic effects.
  • Domoic acid is a potent agonist of the AMPA and kainate receptors in the brain, which are involved in excitatory neurotransmission. Upon binding to these receptors, domoic acid causes excessive stimulation and leads to excitotoxicity, resulting in neuronal damage and death. This mechanism of action is responsible for the severe neurological symptoms associated with domoic acid poisoning, such as seizures, memory loss, and cognitive impairment.
• Describe the process of bioaccumulation of domoic acid in the marine food chain.
  • Domoic acid is produced by certain species of marine diatoms, particularly those in the genus Pseudo-nitzschia. These diatoms are consumed by small marine organisms, such as zooplankton and bivalve mollusks, which then accumulate the toxin in their tissues. As these contaminated organisms are eaten by larger predators, the domoic acid concentration increases up the food chain, a process known as bioaccumulation. This is why the consumption of seafood, especially higher-trophic-level species, is the primary route of human exposure to domoic acid and the development of Amnesic Shellfish Poisoning.
• Analyze the potential environmental factors that may contribute to the increased production of domoic acid by marine algae.
  • Warming ocean temperatures and increased nutrient pollution are two key environmental factors that can contribute to the proliferation of Pseudo-nitzschia and the production of domoic acid. Warmer waters can provide more favorable conditions for the growth of these diatoms, while nutrient pollution, such as from agricultural runoff or sewage discharge, can stimulate algal blooms. These changes in the marine environment can lead to the increased presence of domoic acid-producing algae, heightening the risk of bioaccumulation in the food chain and the potential for outbreaks of Amnesic Shellfish Poisoning. Understanding these environmental factors is crucial for developing strategies to mitigate the impact of domoic acid on marine ecosystems and human health.

Related terms

Pseudo-nitzschia:

A genus of marine diatoms that are capable of producing domoic acid, a neurotoxin that can bioaccumulate in the food chain.

Amnesic Shellfish Poisoning (ASP): A type of food poisoning caused by the consumption of seafood contaminated with domoic acid, leading to symptoms such as short-term memory loss, disorientation, and seizures.

Bioaccumulation: The process by which a substance, such as domoic acid, accumulates in the tissues of living organisms, often increasing in concentration as it moves up the food chain.