Parkinson's disease may originate in the gut

An international team of experts led by the Karolinska Institutet has found evidence to suggest that Parkinson’s disease originates in the gut. The researchers identified cells from the gut’s nervous system that are involved in an early stage of Parkinson’s.

The nervous system is composed of hundreds of different types of cells with unique functions. By understanding which cells influence a particular brain disorder, experts can develop new treatments to target those cells. 

The research team combined mice gene expression studies with human genetics to map out the cell types involved in various neurological and psychiatric disorders, including Parkinson’s disease. This neurodegenerative disorder is characterized by nerve cell damage in the brain that causes dopamine levels to drop.

“As expected, we found that dopaminergic neurons were associated with Parkinson’s disease,” said study co-author Professor Patrick Sullivan. “More surprisingly, we found that enteric neurons also seem to play an important role in the disorder, supporting the hypothesis that Parkinson’s disease starts in the gut.”

The researchers compared brain tissue from healthy individuals to people with various stages of Parkinson’s disease. The experts were surprised to find that a group of specialized brain cells called oligodendrocytes were affected early on in the progression of the disease.

“The fact that the animal studies pointed us to oligodendrocytes and that we were then able to show that these cells were also affected in patients suggests that the results may have clinical implications,” said study co-author Jens Hjerling-Leffler.

The team found evidence that oligodendrocytes are affected even before the loss of dopaminergic neurons. “This makes them an attractive target for therapeutic interventions in Parkinson’s disease,” said study co-first author Julien Bryois.

The study is published in the journal Nature Genetics.

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By Chrissy Sexton, Earth.com Staff Writer