A new study found the chemicals in a seal's brain that allows them to sleep while half their brain remains awake.
A study conducted by an international team of biologists from UCLA and the University of Toronto have found the chemical that facilitates seals to sleep with half their brain awake.
"Seals do something biologically amazing -- they sleep with half their brain at a time," said Professor John Peever of the University of Toronto. "The left side of their brain can sleep while the right side stays awake. Seals sleep this way while they're in water, but they sleep like humans while on land. Our research may explain how this unique biological phenomenon happens."
The discovery was made after the study's co-author and University of Toronto PhD student, Jennifer Lapierre, studied the working of all chemicals in the brain and how they work differently in the sleeping and awake half of a seal's brain.
She discovered that acetylcholine, which is an important brain chemical, was at low levels on the sleeping side of the brain but at high levels on the waking side. The finding suggested that acetylcholine may drive brain alertness on the side that is awake.
It was also discovered that another important brain chemical, serotonin, was present in equal levels on both sides of the brain whether the seals were awake or asleep. This came as a surprise discovery because it was believed that serotonin was responsible for waking up the brain.
These findings can also be applied to the human brain as "about 40% of North Americans suffer from sleep problems and understanding which brain chemicals function to keep us awake or asleep is a major scientific advance. It could help solve the mystery of how and why we sleep" says the study's senior author, Jerome Siegel of UCLA's Brain Research Institute.
