The H1N1 influenza virus — also known as the swine flu — made mice predisposed to developing pathologies mimicking Parkinson's disease, according to research published in npj Parkinson's Disease.
"This study has provided more evidence to support the idea that environmental factors, including influenza, may be involved in Parkinson's disease," said Richard Smeyne, PhD, professor of neuroscience in the Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia. "Here we demonstrate that even mice who fully recover from the H1N1 influenza virus responsible for the previous pandemic … are later more susceptible to chemical toxins known to trigger Parkinson's in the lab."
MPTP is a toxin that induces Parkinson's-like symptoms in humans and mice. When mice were infected with H1N1, they were very susceptible to the MPTP toxin and had more severe symptoms than those that were not infected with the virus.
Further, mice that were vaccinated against the flu or that received antiviral medications like Tamiflu at the time of infection were not sensitive to MPTP.
Dr. Smeyne said the results provide "good reason to investigate this relationship further in light of the simple and potentially powerful impact that seasonal flu vaccination could have on long-term brain health."