Sleep is one of the most essential human activities — so essential, in fact, that if we don’t get enough sleep for even one night, we may struggle to think, react, and otherwise make it through the day. Yet, despite its importance for function and survival, scientists still don’t fully understand how sleep works.
Enter Dragana Rogulja, a neurobiologist on a quest to unravel the basic biology of sleep.

As a self-described latecomer to science, Rogulja found herself drawn to questions she considers “broadly interesting and easy to understand on a basic human level.”
One of these questions…What happens when we sleep?
For Rogulja, an associate professor of neurobiology in the Blavatnik Institute at Harvard Medical School, an intriguing aspect of sleep is the loss of consciousness and awareness it brings, as the outside world disappears and the inner world takes over.
In a conversation with Harvard Medicine News, Rogulja delved into the details of her sleep research, which uses fruit flies and mice to explore why we need to sleep and how we disconnect from the world during sleep.
Harvard Medicine News: What are you studying in the context of sleep?
Rogulja: There are two main questions that my lab has been pursuing for the past several years. The first is why sleep is necessary for survival. Why is it that if you don’t sleep, you will literally die after not too long? The other question is how your brain disconnects from the environment when you fall asleep. How are stimuli prevented from reaching your brain during sleep? Elevating the threshold for sensory arousal is essential for sleep, and we want to understand how that barrier is built around the brain. Sleep is one unified state, but it seems to have multiple components that are regulated through separate mechanisms. We want to understand those mechanisms.