Scientists in the UK have mapped a pathway that generates "aberrant" forms of proteins at the root of degenerative diseases such as Alzheimer’s and Parkinson’s.

Researchers at the Cambridge University’s Department of Chemistry believe the breakthrough is a vital step closer to increased capabilities for earlier diagnosis of neurological disorders.

The study builds on research established by Cambridge by Professor Christopher Dobson 15 years ago, when he discovered a ‘toxic species’ – the oligomers – that is small enough to spread through the brain and kill neurons.

Under some conditions these proteins can ‘misfold’ and snag surrounding normal proteins, which then tangle and stick together in clumps and build to masses.

The new work, published in the Proceedings of the National Academy of Sciences journal, shows that once a small level of malfunctioning protein ‘clumps’ have formed, a runaway chain reaction is triggered that multiplies exponentially the number of these protein composites, activating new focal points through ‘nucleation’.

"We’ve now established the pathway that shows how the toxic species that cause cell death, the oligomers, are formed."

Lead author of the study Dr Tuomas Knowles said: "There are no disease modifying therapies for Alzheimer’s and dementia at the moment, only limited treatment for symptoms. We have to solve what happens at the molecular level before we can progress and have real impact."

"We’ve now established the pathway that shows how the toxic species that cause cell death, the oligomers, are formed. This is the key pathway to detect, target and intervene – the molecular catalyst that underlies the pathology."

In 2010, the Alzheimer’s Research Trust showed that dementia costs the UK economy over £23bn, more than cancer and heart disease combined.

Last week, Prime Minister David Cameron urged scientists and clinicians to work together to "improve treatments and find scientific breakthroughs" to address "one of the biggest social and healthcare challenges we face."

Image: The amyloid fibril, the type of protein structures that are formed in Alzheimer’s. Courtesy of Dr Tuomas Knowles.