Unusually brainy mice could hold the key to developing treatments for conditions such as Alzheimer's disease, schizophrenia and post-traumatic stress disorder (PTSD), scientists have found.
Researchers have created mice with an altered gene to inhibit an enzyme that is present in many organs of the body, including the brain.
The study, led by the University of Leeds and Mount Sinai Hospital in Toronto, found that these mice learn faster, have a longer memory and solve complex exercises better than ordinary mice.
They were also found to be less likely to feel anxiety or recall fear, a discovery that could help researchers looking for treatments for pathological fear, such as PTSD.
Researchers are now working on developing drugs that will specifically inhibit the enzyme - known as phosphodiesterase-4B (PDE4B) - and potentially help people with cognitive disorders.
Tests found that the mice showed a better ability than ordinary mice to recognise another mouse they had been introduced to the day before. They were also quicker at learning the location of a hidden escape platform in a maze.
The mice showed less recall of a fearful event after several days and less fear and anxiety - spending more time in open, brightly-lit spaces than ordinary mice and showing a decreased fear response to cat urine.
Dr Steve Clapcote, lecturer in pharmacology in the University of Leeds' School of Biomedical Sciences, said: "Cognitive impairments are currently poorly treated, so I'm excited that our work using mice has identified phosphodiesterase-4B as a promising target for potential new treatments."
Dr Alexander McGirr, a psychiatrist in training at the University of British Columbia, added: "In the future, medicines targeting PDE4B may potentially improve the lives of individuals with neurocognitive disorders and life-impairing anxiety, and they may have a time-limited role after traumatic events."
Dr Laura Phipps of Alzheimer's Research UK said there is currently a lack of effective treatments for dementia but further investigation was needed to know if the findings of this study could have implications for Alzheimer's disease.
Dr Phipps said: "With so many people affected by dementia, it is important that there is research into a wide array of treatment approaches to have the best chance of helping people sooner."
The study, which was funded by the UK Medical Research Council, has been published in the Neuropsychopharmacology journal.