One of the problems of researching cells damaged by Parkinson's disease in a human being? A scientist needs the brain of someone who has died. For a variant of Parkinson's disease, there might no longer be a need to wait.
One in 10 people diagnosed with Parkinson's disease, a progressive neurological disorder, suffers from a hereditary -- or genetic -- version of the disease. Scientists at the University of Buffalo devised a way to grow human brain cells donated by PD patients with the genetic variant.
"This is the first time that human dopamine neurons have ever been generated from Parkinson's disease patients with parkin mutations," said Dr. Jian Feng, professor of physiology and biophysics in the UB School of Medicine and Biomedical Sciences and the study's lead author. He called this discovery a "game-changer".
"Before this, we didn't even think about being able to study the disease in human neurons," he says. "The brain is so fully integrated. It's impossible to obtain live human neurons to study."
Animal neurons are useless in researching this kind of Parkinson's disease, Feng said. Animal models that lack the parkin gene do not develop the disease; thus, human neurons are thought to have "unique vulnerabilities."
"Our large brains may use more dopamine to support the neural computation needed for bipedal movement, compared to quadrupedal movement of almost all other animals," he says.
This research was inspired, Feng said, by a 2007 Japanese breakthrough in which researchers announced they had converted human cells to induced pluripotent stem cells (iPSCs) that could then be converted to nearly any cells in the body, mimicking embryonic stem cells. Embryonic stem cells, the subject of much controversy, have the ability to convert themselves into practically any kind of cell, where other stem cells need to be "coaxed" or "converted" in some way to gain the ability to mimic the cell they are destined to replace.
The discovery would eliminate the need to acquire living human dopamine neurons, which exist in an almost inaccessible part of the living brain. Dopamine is the chemical neurotransmitter that makes smooth muscle movement possible. Parkinson's disease occurs when a person's brain stops making this crucial chemical.
The research was published in the current issue of the online journal Nature Communications.