May 8, 2018
Sleep is one of our most essential needs, but we don't know precisely how it happens.
Specifically, researchers don't understand how adult humans consolidate their sleep into a single, approximately eight-hour bout.
Now, a University of Michigan researcher is part of an international team that received a $1 million grant from the Human Frontier Science Program to investigate how this works. Daniel Forger, professor of mathematics, will receive the award along with collaborators at the University of Tokyo and University of Zurich.
"Rats or mice don't sleep in a consolidated eight-hour block: They go in between awake and asleep a lot more often," Forger said. "One of the key things we'd really like to understand is the architecture of sleep."
Neuroscientists do know that the consolidation of sleep is controlled by a region of the hypothalamus called the suprachiasmatic nuclei, or SCN. The SCN is the home of the circadian clock, the central biochemical clock in all animals that regulates a host of biological processes, including when to eat, an organism's body temperature, hormonal release and sleep-wake cycles.
The SCN also controls the activity of ion channels in the brain to regulate sleep along signaling pathways, but this is not well understood.
Three different research teams will offer three different components to help the group map these pathways. The Japanese group has devised a way to breed mice very quickly that have these different ion channels knocked out. That way, researchers can study how a particular ion channel might be involved in sleep.
The Swiss group has developed a way to directly record what is happening in the brain. Using tiny skull-mounted microscopes, the group can examine the firing patterns of groups of neurons repeatedly over successive days of sleep and wake.
The U-M group will use computational analysis to understand the data and develop a unified theory of sleep.
"What makes sleep very hard to study is that it's really a whole brain phenomenon," Forger said. "Many regions of the brain play an important role in controlling when and how we sleep."
Forger's fellow researchers include Steven Brown with the Chronobiology and Sleep Research Group at the University of Zurich, and Hiroki Ueda with Systems Pharmacology at the University of Tokyo Graduate School of Medicine. The Human Frontiers Science Program was founded in the late 1980s to connect international researchers conducting leading-edge science.