The findings were published online in the journal cell and from their findings and research, they derived this conclusion that a hormone that rules over the sleep and jet lag in humans can also derive the mass migration of plankton in the ocean.
“The fascinating picture emerges that human biology finds its roots in some deeply conserved, fundamental aspects of ocean ecology that dominated life on the Earth since ancient evolutionary times,” A lead researcher from the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, Detlev Arendt says. “We found that a group of multitasking cells in the brains of these larvae that sense light also run an internal clock and make melatonin at night.”
Melatonin is a hormone in the human body which is responsible for maintaining daily rhythm in sleep, and they also discovered that it governs the nightly migration of a plankton species from the surface to deeper waters. In Addition to it, Arendt further explained, “So we think that melatonin is the message these cells produce at night to regulate the activity of other neurons that ultimately drive day-night rhythmic behaviour.”
In order to find out other roles of melatonin in other species and how it evolved to promote the task of sleep, the researchers turned to the marine ragworm Platynereis dumerilii. They have also discovered a particular type of neuron that responds to melatonin. Using modern muscular sensors they were able to visualise the activity of these neurons in the human brain, and found that it changes radically from day to night. In the night, the production of melatonin drives changes in these neurons.
The research strongly suggests that the light-sensing, melatonin-producing cells at the heart of this larva’s nightly migration have evolutionary relatives in the human brain.