US study indicates memory loss in the elderly can be reversed

Aug 8, 2011, 12:52 GMT

New Haven, Connecticut/London - A team of US scientists say a chemical substance in the brain that slows down the rate of neuron activity is the source of forgetfulness in elderly people. Their findings, which have been published in the journal Nature, show that treatments may be developed one day to reverse the process.

Tests with elderly people are already in the planning.

Older brains have weaker connections between their neurons. Additionally, the neurons themselves are slower to fire signals.

Amy Arnsten and her team of colleagues from Yale University School of Medicine say this leads to forgetfulness in seniors. The scientists are the first to have carried out research into age-induced change in nerve cells in the frontal area of the cerebral cortex, which is responsible for the cognitive function of the brain.

These neurons are constantly firing off impulses in order to keep information 'fresh' in the memory. This helps to remember things such as where you last left your car keys.

It's also the basis for abstract thinking, multitasking and the suppression of 'inappropriate' thoughts. But for this form of 'random access memory' to work properly it must be constantly updated.

Arnsten and her team studied the rate at which neurons fired in laboratory animals. They found that neurons signalled slower in elderly animals but that the frequency could be increased when the neurons' chemical environment was matched to that of a younger animal.

The scientists discovered that the frontal lobes of elderly brains had too high a concentration of what are known as cMAP molecules. These molecules slow the rate of neuron activity by opening the walls of the nerve cells and allowing electrically charged particles in.

Arnsten and her team believe cMAP blockers could reverse memory loss. The substance Guanfacine appears to be an effective cMAP inhibitor and clinical trials with the chemical are in the planning stage.