Cure for ageing brains may be close

The studies raise the possibility of finding a cure for memory loss and fading mental faculties in an ageing population, experts say.

Scientists in the US screened thousands of compounds for their brain-protective properties.

They identified one called P7C3 that had dramatic effects on ageing rats and genetically- engineered mice.

The molecule spurred on the growth of new neurons in a part of the brain vital to memory, according to the research published in the journal Cell.

It significantly improved the ability of ageing rats to swim through a water maze – a standard test of memory-dependent learning – and assisted the birth of brain cells in mice. Further research showed a derivative of the compound, called A20, had an even bigger impact.

The scientists are still trying to find out how the drugs work, though they appear to prevent a process called apoptosis, which causes cells to self-destruct.

Thomas Insel, director of the US body that funded the work, the National Institute of Mental Health (NIMH), said: "This striking demonstration of a treatment that stems age-related cognitive decline in living animals points the way to potential development of the first cures that will address the core illness process in Alzheimer's disease."

A key factor is that P7C3 can be swallowed, rather than having to be injected. A lot more work is needed, however, to develop the early animal research

Dr Steven McKnight, one of the research leaders from the University of Texas Southwestern Medical Center in Dallas, said: "The neuroprotective compound, called P7C3, holds special promise because of its medication-friendly properties.

"It can be taken orally, crosses the blood-brain barrier with long-lasting effects, and is safely tolerated by mice during many stages of development."

The "blood-brain barrier" is a biological "wall" designed to prevent potentially harmful substances entering the brain. Drugs that target the brain have to overcome this obstacle if they are to be effective.

Scientists know that the adult brain is "plastic" and capable of regenerating itself under the right conditions. Nerve growth in the hippocampus, the brain's "memory centre", can potentially stave off mental decline.

But even in a normal brain most of the new neurons die during the month or so it takes them to develop and become "wired in". New hippocampus neurons are known to fare much worse in people with age-related disorders such as Alzheimer's.

The scientists tried to find compounds that might protect vulnerable growing neurons in a key area of the hippocampus.

They found that giving P7C3 to the genetically-engineered adult mice reduced the death of new cells, and prevented other effects by 40 per cent. When the compound was fed to ageing rats they outperformed other rodents in the water maze test.

Alzheimer's is the most common dementia, affecting an estimated 750,000 people in the UK.

Rebecca Wood, chief executive of the Alzheimer's Research Trust, said: "This research seeks to address the fundamental destructive force of Alzheimer's disease: the death of nerve cells in the brain. Any research that moves us towards a way of preserving the life of cells in the brain is worthy of attention.

"This preliminary study, while only in rats, suggests that a protective drug for brain cells could one day be achievable. Steps must now be taken to research whether the compound can be used beneficially and safely in people."