An article recently published in the journal Science details how domoic acid (a potent neurotoxin produced by the planktonic algae Pseudonitzschia) damages the hippocampus of sea lions and disrupts an important neural network.
"We were able to correlate the extent of the hippocampal damage to specific behavioral impairments relevant to the animals' survival in the wild," said lead author Peter Cook, postdoctoral fellow in the Center of Neuropolicy at Emory University. "Our research provides a way to model the behavioral and biological effects of this toxin in large-brain mammal," said Cook. "Better understanding of these effects may also help us identify subtle effects in humans that may be at risk."
Sea lions offer scientists an excellent view of overall ocean health; the large mammals often swim to shore when ill, unlike other large ocean animals, allowing their neurobiology to be measured in detail. They also eat fish and shellfish, animals which in turn feed on algae, allowing the domoic acid to bioaccumulate.
The damage done to the sea lions also resembles dementia; their ability to form episodic memories (memories of events and experiences) is impaired.
"This is the first evidence of changes to brain networks in exposed sea lions, and suggests that these animals may be suffering a broad disruption of memory, not just spatial memory deficits," said Cook.
For the full article from futurity.org click here or on the link below.