A new study, led by Prof Tara Spires-Jones and Dr Declan King (UK DRI at Edinburgh), has identified molecular changes in the brain associated with maintaining healthy cognitive abilities in old age. The study, published in the journal Alzheimer’s & Dementia, could provide a new therapeutic approach to improving cognition in people with Alzheimer’s disease.
Using post-mortem brain samples, a team of researchers examined synapses – the connection points between brain cells. They compared samples from three cohorts: people in mid-life, people who had aged without dementia, and people who had Alzheimer’s disease.
The researchers found that the number of synapses was lowest in people with Alzheimer’s, and highest in people in mid-life. They found that toxic proteins such as amyloid beta and tau accumulated at highest levels in people with Alzheimer’s compared with the other cohorts.
The authors were surprised to find that in aged people without dementia, the expression of genes involved in the function of synapses were turned down in people who had maintained cognitive function, compared with those who had age-associated cognitive decline that did not reach the severity of dementia symptoms.
