A new research suggests that sleep loss may be more serious than previously thought, causing a permanent loss of brain cells.

In mice, prolonged lack of sleep led to 25% of certain brain cells dying, according to a study in The Journal of Neuroscience.

If the same is true in humans, it may be futile to try to catch up on missed sleep, say scientists at the University of Pennsylvania School of Medicine.

They think it may one day be possible to develop a drug to protect the brain from the side-effects of lost sleep.

Sleep loss may be more serious than previously thought, causing a permanent loss of brain cells

The study looked at lab mice that were kept awake to replicate the kind of sleep loss common in modern life, through night shifts or long hours in the office.

The research team studied certain brain cells which are involved in keeping the brain alert.

After several days of sleep patterns similar to those followed by night workers – three days of night shifts with only four to five hours sleep in 24 hours – the mice lost 25% of the brain cells, in part of the brain stem.

The researchers say this is the first evidence that sleep loss can lead to a loss of brain cells.

But they add that more work needs to be done to find out if people who miss out on sleep might also be at risk of permanent damage.

In the long-term, they think it might be possible to develop a medicine that protects brain cells, by boosting a natural chemical involved in sleep recovery.