A team of researchers led by The Hospital for Sick Children and the University of Toronto has shown that what scientists thought caused neurons to die in inherited neurodegenerative diseases such as Huntington's and Parkinson's is in fact not the case. The scientists propose a new model for neuronal cell death in the July 13 issue of the journal Nature, which will lead to new research into treatments for these types of diseases.
Neurons are the cells of the nervous system that carry information to and from the brain.
Once they have matured, normal neurons live forever, and don't die unless they are damaged. Neurodegenerative diseases are characterized by a progressive loss of cells from one region of the nervous system. Nerve cells cannot be replaced, and humans can only lose a certain number, before they start having noticeable symptoms, such as tremors in Parkinson's patients. Previously, it was believed that the mutant genes in these inherited conditions caused cumulative damage to the neurons, damage from which they eventually died, much like how the aging process leads to death in humans. This study, which used data from patients with retinal degeneration, Huntington's disease and Parkinson's disease, showed that cumulative damage theory was not correct.