Good Sleep May Be All in Your Head
Scientists are discovering that the workings of certain cells in the brains of mice may ultimately help improve the quality of human sleep -- particularly for those suffering from sleep disorders.
While working with mice, Johns Hopkins neuroscientist Dr. Seth Blackshaw discovered cells that express a gene, called Lhx6, which is selectively active during sleep.
His team was able to show that by removing Lhx6, animals slept substantially less.
When his team selectively manipulated these cells, they observed that turning Lhx6 “on” made mice go to sleep, and turning them “off” kept the mice awake.
These cells are found in the hypothalamus, the region of the brain that oversees sleep along with things like metabolism, hunger and thirst. They don’t appear to interfere with other things like hunger or mood.
“The neurons we identified are some of the only ones known to selectively promote sleep,” Blackshaw says. “And although our work is done in mice, these cells are found in other vertebrate animals, including humans.”
Cells That Turn Sleep On and Off
“As far as we can tell, when we selectively block the function of Lhx6 cells or modulate their activity, the main effects we see are on sleep,” Blackshaw says. “What this allows us to do, really, is selectively turn sleep on and off.”
What the Discovery of Lhx6 May Mean for Humans
In the future, Blackshaw plans to further pinpoint the specifics of how these cells do what they do.
His team hopes to find out whether these cells have a similar role in humans, whether they are affected in patients that have chronic sleep disorders and whether they lose function as we age.
“By showing that these cells inhibit the activity of wake-promoting neurons, we also know at least in part how they are able to do this. This now lets us look to see if defects in Lhx6-expressing neurons might underlie human sleep disorders,” Blackshaw says.
While results in humans may take years, Blackshaw is optimistic. Modulating the activity of these cells could allow scientists to selectively promote sleep or wakefulness, he says.
”Now that we know that these cells are important for regulating sleep, we can search for drugs that selectively increase or decrease their activity.”