Can missing sleep affect memory?

You’ve had a rough night’s sleep – or maybe a string of them – and the result can be some fuzzy thinking the next day. Why is that?

A new study led by the University of Pennsylvania points to a possible role for the brain chemical adenosine, levels of which increase if we lose out on sleep.

“There is accumulating evidence that this adenosine is really the source of a number of the deficits and impact of sleep deprivation, including memory loss and attention deficits,” said researcher Ted Abel.

“One thing that underscores that evidence is that caffeine is a drug that blocks the effects of adenosine, so we sometimes refer to this as ‘the Starbucks experiment’.”

To tease out the effects of adenosine in sleep deprivation, the researchers tested mice to see how they recognised and remembered objects. If they blocked the effects of adenosine in specific ways, mice who were deprived of sleep tended to do better on the test, acting as though they had not lost out on slumber.

In addition, the hippocampus – a key portion of the brain for memory – seemed in better shape in the mice that were protected from adenosine’s effects in sleep deprivation.

“Our sleep deprivation experiments are the equivalent of losing half of a night sleep for a single night,” said Abel.

“Most of us would think that’s pretty minor, but it shows just how critical the need for sleep is for things like cognition.”

The study was published this month online in the Journal of Neurochemistry.