Scientists have said it may be possible to reverse memory loss caused by insomnia

The loss of memory from a lack of sleep may be reversible, according to scientists who say their findings could present a new approach to treating the effects of insomnia.

Millions of people regularly fail to get enough sleep, which can lead to both short and long-term memory and learning problems.

The research, published in the science journal Nature, lays the groundwork for the development of new treatments to improve the effects of sleep deprivation, the scientists said.

Prof Ted Abel and colleagues found that sleep deprivation in mice affected a key molecular pathway known as the hippocampus, a region of the brain which is important for memory and learning.

The sleep-deprived mice showed increased levels of the enzyme PDE4 and reduced levels of the molecule cAMP, which is crucial in forming new connections as a result of learning.

Prof Abel and his team at the University of Pennsylvania, Philadelphia, found that by giving the mice an inhibitor of PDE4, the decrease in cAMP concentration was also reversed.

They also found that the reversal helped rescue the synaptic connections and counteract some of the memory loss caused by the sleep deprivation.

The scientists said their experiments were "the first, to our knowledge, to rescue synaptic plasticity and memory deficits produced by a brief period of sleep deprivation".

Prof Abel said: "These findings demonstrate that brief sleep deprivation disrupts hippocampal function by interfering with cAMP signalling through increased PDE4 activity. Thus, drugs that enhance cAMP signalling may provide a new therapeutic approach to counteract the cognitive effects of sleep deprivation."

He said a "major challenge" in the field of sleep research was to determine how "sleep disruptions associated with neurological and psychiatric disorders, ageing and everyday living affect cognitive function".