Ethical approval has been granted for researchers to insert pig cells into people's brains in a bid to cure Parkinson's disease.
The process has been tested successfully in rats and monkeys, but never in humans.
Four people suffering from the incurable disease will be recruited to take part in the 18-month trial, which could get under way next year.
Health Minister Tony Ryall gave Living Cell Technologies the go-ahead in October to test the safety and clinical effect of NTCELL in New Zealand.
Brain cells from Auckland Island pigs were used as they could help protect the brain and repair damaged nerve tissue.
Living Cell Technologies chief executive Dr Andrea Grant said the trail was approved by the Health and Disability Ethics Committee, which is part of the Health Ministry.
"We are extremely pleased to have received ethical approval in such an efficient timeframe.''
About 10,000 New Zealanders have Parkinson's, which is the second-most-common neurodegenerative disorder worldwide, after Alzheimer's.
Reduced dopamine levels in the brain lead to symptoms such as tremor, rigidity and slowness of movement.
The effectiveness of current treatments, which focus on dopamine replacement, declines as the disease progresses. There is no way to reverse or slow the degeneration of the brain.
WHAT WILL HAPPEN
Brain cells from the disease-free Auckland Island pig herd will be transplanted into a person's brain via a catheter.
When transplanted, the naturally occurring "support" cells may help protect the brain and repair damaged nerve tissue.
The cells will be encapsulated with a substance to prevent rejection.
Living Cell Technologies chief executive Andrea Grant said that unlike previous trials, this one would put a "mixture of different neurons" into the dead part of the brain.
"We're encouraging all of these different cell types to grow back, rather than just one."
Four people will receive the pig cells, which help produce cerebrospinal fluid as well as nerve growth factors. They will be assessed every two weeks.
At six months they will have a brain scan to see if there are any changes at the cellular level.
Clinicians will then decide what to do: another implant, deep brain stimulation or nothing.
This will be followed up by another scan at 12 months.
- The Dominion Post