The Science of Waking Up is Actually Pretty Simple

In an exciting new finding that could potentially lead to treatments for body clock disorders, scientists at Northwestern University say they’ve unlocked some of the secrets of why we wake up when we do.

The body clock mechanism, it turns out, is much like a light switch. In a study of brain circadian neurons that govern the daily sleep-wake cycle’s timing, the researchers found that high sodium channel activity in these neurons during the day turn the cells on and ultimately awaken an animal, and high potassium channel activity at night turn them off, allowing the animal to sleep. Investigating further, the researchers were surprised to discover the same sleep-wake switch in both flies and mice.

Better understanding of this mechanism could lead to new drug targets to address sleep-wake trouble related to jet lag, shift work and other clock-induced problems. Eventually, it might be possible to reset a person’s internal clock to suit his or her situation.

The researchers call this a “bicycle” mechanism: two pedals that go up and down across a 24-hour day, conveying important time information to the neurons. That the researchers found the two pedals — a sodium current and potassium currents — active in both the simple fruit fly and the more complex mouse was unexpected.

The findings were published today in the Aug. 13 issue of the journal Cell.