London, Oct 2 : There's some good news for students with feeble memories. A nasal spray developed by German scientists promises to boost late night cram sessions, provided a good night's sleep follows.

The scientists have shown how a molecule from the body's immune system (interleukin-6) when administered through the nose helps the brain retain emotional and procedural memories during rapid eye movement (REM) sleep. It is linked to dreaming.

"Sleep to remember, a dream or reality?" said Lisa Marshall, study co-author, neuroendocrinologist at the University of Lubeck in Germany.

"Here, we provide the first evidence that the immunoregulatory signal interleukin-6 plays a beneficial role in sleep-dependent formation of long-term memory in humans."

Marshall and colleagues had healthy young men spend two nights in the lab. On each night after reading either an emotional or neutral short story, they sprayed a fluid into their nostrils which contained either interleukin-6 or a placebo fluid, said a Lubec release.

The subsequent sleep and brain electric activity was monitored throughout the night. The next morning subjects wrote down as many words as they could remember from each of the two stories. Those who received the dose of IL-6 could remember more words.

"If a nasal spray can improve memory, perhaps we're on our way to giving some folks a whiff of common sense, such as accepting the realities of evolution," said Gerald Weissmann, editor-in-chief of The FASEB Journal, which featured these findings.(IANS)