SYDNEY, Oct. 10 (Xinhua) -- Differences in brain activity when people are asleep and awake are key to bringing balance back to cell connections in the major organ, offering the latest evidence of why sleep is crucial for survival, according to an Australian research.

Although the exact purpose of sleep remains largely unknown, studies have pointed to its restorative purpose involving brain synaptic connections, a statement on the latest findings by University of Sydney researchers said on Wednesday.

The researchers, using large-scale plasticity modeling and analysis, reported how brain activity during sleep and wakefulness can also cause significant changes in the neurological connections, with the suggestion that being awake boosts activity in brain cell links while sleep brings "everything back to a baseline so that those circuits don't get overloaded."

Both wake and sleep are thus "necessary, and together are able to stabilize connection weights over the daily cycle," they wrote in the Royal Society Open Science scientific journal.

Their latest findings help "explain more clearly how and why both wake and sleep are necessary to stabilize connection strengths in the brain on multi-day time scales and longer" and provide new support to the function and importance of sleep.