You may have wondered how dolphins, whales, sea otters and certain other marine mammals survive with the low oxygen supply underwater. Researchers at the University of California, Santa Cruz have found an answer.
Humans, even well-trained Olympic swimmers, cannot survive longer than a few minutes underwater because their brains need a constant supply of oxygen that they do not get beneath water.
However, Weddell seals that dive and hunt under the Antarctic sea ice remain unfazed by low levels of oxygen.
Lead researcher Terrie Williams, professor of ecology and evolutionary biology, believes that elevated levels of oxygen-carrying proteins in the marine creature's brain protect it from brain damage.
The researchers measured and compared the amounts of such complex oxygen-carrying proteins, known as globins, in the cerebral cortex of 16 different mammalian species.
They observed that some species had evolved the capacity to protect their brains from conditions of low oxygen, also called hypoxia.
"What was remarkable was the level of variability we found. Some animals had three to 10 times more neuroprotecting type globins than others. These wild species may hold many clues about how to turn on protective mechanisms in the mammalian brain," said Williams.
She said that her team's discovery could have important implications for understanding stroke and aging in humans.
Terrie admitted that her team was yet unsure whether animals of a particular species are born with high amounts of brain globins, or whether their behaviour and environment stimulate the production of globins. She, however, said that in either case, the amounts appeared to be malleable.
She said that the results were significant because it raised hopes that humans could be protected from brain damage due to disease or aging by boosting globin production.
"The mammalian brain appears to have a remarkable capacity for increasing neuroprotective globins--we're seeing that in a comparative way in animals. Could we take advantage of that" Could we retrain the human brain to improve our own survival" We don't know yet, but it's certainly intriguing and worth investigating," she said.
The study entitled 'Running, swimming and diving modifies neuroprotecting globins in the mammalian brain' appears online in the Proceedings of The Royal Society.