Scientists in Germany have developed a nasal spray containing a molecule from the body’s immune system that they say can help the brain retain memories during sleep.

Researchers with the University of Lubeck had 17 healthy young men read either an emotional or neutral short story before bed. Each also had either a fluid containing the immunoregulatory signal interleukin-6 (IL-6) or a placebo sprayed into their nostrils before going to sleep. 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.

"Here we provide the first evidence that IL-6 plays a beneficial role in sleep-dependent formation of long-term memory in humans," said the study’s co-author Lisa Marshall.

According to experts, IL-6 had previously been considered a by-product of inflammation, not an agent that affects cognition.

Vitamin B12 is said to be a key for improving memory in healthy people, according to The-Vitamin-and-Supplement-Guide.com. Nutritional supplements containing carnitine, coenzyme Q10, DMAE, ginkgo, huperzine A and kava all have special uses in treating age-related memory loss as well.