WVU in the News: What are circadian rhythms?

Much of life on Earth depends on the day and night cycle. For humans, sunlight triggers our internal clock and causes us to wake. When night comes, the same mechanism sends out a hormone called melatonin, which makes us sleepy and helps the body shut down for the day. This is the circadian rhythm.

“Light is the signal,” says William Walker, a postdoctoral fellow in the department of neuroscience, Rockefeller Neuroscience Institute at West Virginia University School of Medicine in Morgantown. Light “regulates all the other clocks in the body.” Without that signal, your circadian rhythm is disrupted.