New evidence on how Parkinson's disease spreads offers renewed hope for a cure, according to researchers.
In a paper, published today in Scientific Reports - Nature, the study revealed that pathological proteins (known as Lewy bodies) in Parkinson's disease could be spread from cell to cell.
The discovery, made by researchers at the University of Auckland, is the first strong evidence on how Parkinson's develops and will help advance treatment of the disease.
Associate Professor Maurice Curtis, who leads research on Parkinson's disease at the University's Centre for Brain Research, said the new evidence is the first proof, using donated human brains, of the mechanism controlling the spread.
Curtis said it was previously known that the troublesome Lewy bodies accumulated in susceptible cells, but it was not known that the protein could spread from cell to cell, in the same way a straw connects two cups.
The implication was that the Parkinson's spread could be stopped early, Curtis said.
"This new mechanism of pathology spread provides us with new targets to go after for development of Parkinson's disease treatments.
"If the Parkinson's disease pathology spreads then it may be possible to stop it in its tracks."
Curtis said Parkinson's begins in the brain's smell centre and 85 per cent of sufferers have reduced or no sense of smell.
But it took between six and 10 years for more severe symptoms of the disease to strike, such as tremors, slowed movement, rigid muscles, impaired balance, and speech and writing changes.
Curtis said that time was a window of opportunity for the spread to be stopped.
Cells use structures called tunnelling nanotubes that act like conduits between two cells, to spread the Lewy bodies.
The research also showed that cells in the blood vessels called pericytes appear to harbour and spread the Lewy bodies rather than just neurons, Curtis said.
"Most literature suggests that Lewy bodies cause the most problems in neurons but this paper proposes blood vessel pericytes to be significant."
Curtis said while the research had only been conducted in cells and not live brains, he was very proud of his team's work including that of post-doctoral researcher and lead author Dr Victor Dieriks.
The work was made possible by the availability of human brain cells cultured post mortem from people who had donated their brains, as well as through funding from the Neuro Research Charitable Trust founded by Bernie and Kaye Crosby.
The Hamilton couple have pledged $1 million over five years to the trust for research into Parkinson's which Bernie Crosby was diagnosed with 12 years ago.
Crosby said he was "absolutely delighted" with the discovery and that it had been made in New Zealand at a time when other countries were also trying to advance their understanding of the disease.
"It's another instalment in the journey to finding a cure."
Crosby, 66, who with his wife started the successful Prolife Foods company in the 1980s, said no two days were the same for him because of a range of movement and emotional challenges he continued to face.
"I just need to enjoy life."
What is Parkinson's disease?
• A progressive neurodegenerative condition.
• Caused by insufficient quantities of dopamine - a chemical in the brain which enables well co-ordinated movement.
• One in 500 New Zealanders suffers from it.
• Average age for diagnosis is 59.