A new study on mice has found that the simple act of running in an exercise wheel may delay the onset of some symptoms of Huntington's disease.
Researchers from the University of Oxford and the Howard Florey Institute, University of Melbourne, have offered new insights into the pathogenesis of this fatal disease and suggested possible preventive therapeutic targets.
Huntington's disease affects up to one person in every 10 000, but clusters in families and certain populations. Affected people develop clusters of a defective protein in their neurons and shrinkage of brain areas linked to movement. The disorder causes disability and eventually death, but is not normally evident until people have had children, allowing the disease gene to be passed on.
"Although Huntington's disease is considered the epitome of genetic determinism, environmental factors are increasingly recognised to influence the disease progress", wrote the researchers.
The findings indicate that a genetic mutation causes Huntington's in humans. The researchers said that just as mentally stimulating these mice by enriching their environment had previously been shown to delay onset and progression of motor symptoms, so does the simple physical activity of running in a wheel.
"Of particular interest was the fact that the wheel exercise was started in juvenile mice, much earlier than in a previous study that showed more limited protective effects of physical activity," said lead author Anthony Hannan of the Howard Florey Institute.
He added that the finding suggests that the protective effect has a specific time window.
"Physical activity did not postpone all the motor symptoms delayed by environmental enrichment, which suggests that sensory stimulation, mental exercise, and physical activity could all be used for the benefit of human sufferers," he said.
As genetic diagnosis is possible, in the same way early intervention is also possible in people who will develop Huntington's.
Density of protein aggregates in neurons and shrinkage in brain regions in mice that had benefited from physical activity were as advanced as in those raised without wheels.
Thus, the authors suggest that benefits stem from stimulation of neuronal receptors and other molecules that prolong normal function and delay motor deficits.
The study is published in the open-access journal BMC Neuroscience.