How seals sleep with only half their brain at a time

How seals sleep with only half their brain at a time

How seals sleep with only half their brain at a time.

A new study led by an international team of biologists has identified some of the brain chemicals that allow seals to sleep with half of their brain at a time.

The study was published this month in the Journal of Neuroscience and was headed by scientists at UCLA and the University of Toronto. It identified the chemical cues that allow the seal brain to remain half awake and asleep.

Findings from this study may explain the biological mechanisms that enable the brain to remain alert during waking hours and go off-line during sleep. Acetylcholine – an important brain chemical – was at low levels on the sleeping side of the brain but at high levels on the waking side.

This finding suggests that acetylcholine may drive brain alertness on the side that is awake. But, the study also showed that another important brain chemical – serotonin – was present at the equal levels on both sides of the brain whether the seals were awake or asleep. This was a surprising finding because scientist long thought that serotonin was a chemical that causes brain arousal.