Carl Zimmer
December 28, 2015
Throughout the day, a clock ticks inside our bodies. It rouses us in the morning and makes us sleepy at night. It raises and lowers our body temperature at the right times, and regulates the production of insulin and other hormones.
The body’s circadian clock even influences our thoughts and feelings. Psychologists have measured some of its effects on the brain by having people take cognitive tests at different times of day.
“Sleep and activity cycles are a very big part of psychiatric illnesses,” said Huda Akil, a neuroscientist at the University of Michigan.
Yet neuroscientists have struggled to understand exactly how the circadian clock affects our minds. After all, researchers can’t simply pop open a subject’s skull and monitor his brain cells over the course of each day.
A few years ago, Dr. Akil and her colleagues came up with an idea for the next best thing.