Alzheimer’s disease: Connections between brain cells destroyed in early stages of condition, study finds

One in six people over the age of 80 in the UK have dementia

Scientists have taken a step forward in understanding Alzheimer's disease (SEBASTIEN BOZON/AFP/Getty Images)

Scientists have pinpointed how connections in the brain are destroyed in the early stages of Alzheimer’s disease, in a study which it is hoped will help in the development of treatments for the debilitating condition.

At the early stages of the development of Alzheimer’s disease the synapses – which connect the neurons in the brain – are destroyed, according to researchers at the University of New South Wales, Australia.

The synapses are vital for brain function, particularly learning and forming memories.

To make their findings published in the journal 'Nature Communications', scientists used post-mortem brain tissue to study the protein in the brain which connects the membranes of the synapses.

The team found that the levels of the protein - called neural cell adhesion molecule 2, or NCAM2 – were low in those with the disease.

Studies on mice also showed that NCAM2 was broken down by the beta-amyloid protein, which is the main component of the plaques that build up in the brains of people with the disease.

“One of the first signs of Alzheimer’s disease is the loss of synapses – the structures that connect neurons in the brain,” said study leader, Dr Vladimir Sytnyk, of the UNSW School of Biotechnology and Biomolecular Sciences.

“In Alzheimer’s disease, this loss of synapses occurs very early on, when people still only have mild cognitive impairment, and long before the nerve cells themselves die.”

“Our research shows the loss of synapses is linked to the loss of NCAM2 as a result of the toxic effects of beta-amyloid,” says Dr Sytnyk.

“It opens up a new avenue for research on possible treatments that can prevent the destruction of NCAM2 in the brain.”

Alzheimer's is the most common form of dementia, a condition which affects one in six people over the age of 80 and 40,000 younger people, according to the Alzheimer's Society.

The symptoms of dementia include memory loss, difficulties with thinking and problem solving, and can go on to affect a person's movement.