March 27, 2018

expert reaction to study looking at dopamine-firing cells and signs of cognitive decline

Researchers examine dopamine-firing cells and whether they could reveal the earliest signs of Alzheimer’s disease in a new study, published in Journal of Alzheimer’s Disease.

Dr Sara Imarisio, Head of Research at Alzheimer’s Research UK, said:

“While people are only diagnosed with Alzheimer’s disease once they start to show symptoms, we know that underlying brain changes get underway many years earlier.  A test that could identify people in the earliest stages of Alzheimer’s would present a window of opportunity for prospective treatments to be most effective, before too much damage has been done.

“This study links a loss of nerve cells in an area of the brain involved in producing the chemical dopamine, with lower scores in memory tests and brain changes associated with Alzheimer’s disease.  Researchers didn’t find a link between this brain region and memory deficits in people with Alzheimer’s disease, only in those without any diagnosis of cognitive decline.

“The study did not investigate whether healthy people with nerve cell loss in this region of the brain were more likely to develop Alzheimer’s disease.  Without studying those with the disease, it’s too early to tell if these kinds of brain scans could give doctors clues as to who will go on to develop Alzheimer’s.

“This is interesting early-stage research that is building on previous findings that have emerged from studies in mice.  While this study points to brain changes that may play a role in the early development of Alzheimer’s, it does not present any means by which we could screen for Alzheimer’s in the general population.”

Dr James Pickett, Head of Research at Alzheimer’s Society, said:

“Dementia set to be the 21st century’s biggest killer, but we know over 200,000 people across the UK are living without a dementia diagnosis.  A simple memory evaluation to diagnose dementia can be hard to get in some areas of the UK, so with their high price tag, it’s a stretch to suggest this new type of brain scan could revolutionise dementia screening.

“The study does throw up an interesting new avenue for Alzheimer’s research – showing for the first time in humans that a brain area, already known to be affected in Parkinson’s, is also likely involved in Alzheimer’s.  With further research this new evidence could shine light on common features of the two conditions, and open up new treatment opportunities.

“As this is an early stage proof-of-concept study, the researchers’ findings would need to be confirmed with studies of larger groups, including people at various stages of dementia, rather than just people with mild cognitive impairment.”

* ‘Volume and connectivity of the Ventral Tegmental Area are linked to neurocognitive signatures of Alzheimer’s disease in humans’ by Matteo De Marco and Annalena Venneri published in the Journal of Alzheimer’s Disease on Tuesday 27 March 2018.

Declared interests

None received.