All-night cram sessions aren't the answer for students hoping to do well on a test, researchers at Brandeis University have found; they'd do better just to put aside the books and get a good night's sleep.

Previously studies have identified sleep as critical for the conversion of short-term into long-term memory, a process known as known as memory consolidation.

While it has long been understood that there are deep connections between learning, memory and sleep, the exact physiological and anatomical associations between sleep and memory have not been clear.

Most animals have memory problems when they are sleep deprived, so Brandeis graduate students Paula Haynes and Bethany Christmann have investigated the possibility that our memory neurons are actually trying to put us to sleep, inhibiting wakefulness to improve the process of transforming short-term memory to long-term memory.

There are two conflicting schools of thought: One, that memories can be consolidated while we sleep because the brain is quiet, with little activity; or Two, it's the memory consolidation activity of the brain's neurons that actually puts us to sleep.

In a study published in the journal eLife, Haynes and Bethany Christmann of the Griffith Lab at Brandeis suggest it's the latter.

They looked at Drosophila, fruit flies, and focused on well-known memory consolidators known as dorsal paired medial neuron.

When DPM neurons are activated, they found, the flies tended to more, while when those same neurons were deactivated the flies remained awake and busy buzzing about.

It all happens in a region of the fruit fly brain known as the mushroom body, similar to the human brain's hippocampus, where our memories are recorded and stored.

"It's almost as if that section of the mushroom body were [first] saying 'hey, stay awake and learn this,'" says Christmann.

The link between memory and sleep in a simple system like that of the fruit fly and help yield clues to better understanding of learning and memory and the role sleep plays in it, the researchers say.

"Knowing that sleep and memory overlap in the fly brain can allow researchers to narrow their search in humans," Christmann says. "Eventually, it could help us figure out how sleep or memory is affected when things go wrong, as in the case of insomnia or memory disorders."