LOS ANGELES, Feb. 18 (Xinhua) -- A new research in mice at the California Institute of Technology (Caltech) shows that a telltale symptom of Parkinson's disease (PD) may originate in the gut and travel to the brain, according to a latest Caltech release.

Postmortem examinations of the brains of people with PD have shown that their brain cells that control movement are littered with aggregates, or clumps, of a protein called alpha-synuclein.

Working with mouse models, Caltech researchers have seeded alpha-synuclein aggregates in neurons in the gut and discovered that these clumps can travel up to affect neurons in the brain. But this process depends on age, according to the release.

Normally, mice produce an enzyme that is able to break down these clumps, but as they get older, they may lose this ability, which could explain why PD develops most often in elderly people.

The researchers showed that injecting mice with systemic delivery vectors carrying genes that encode for this enzyme helped ameliorate some of the clumping and partially restored proper gut function.

A paper describing the research appears in the Feb. 17 issue of the journal Nature Neuroscience.

"The vagus nerve is a physical connection between neurons in the gut and neurons in the brain. If these damaging protein clusters first originate in gut neurons, then in the future we may be able to diagnose PD earlier and potentially use gene delivery to restore functions to the cells so that they can clean up the aggregates," said Collin Challis, former postdoctoral scholar at Caltech and first author on the study.