A new study published in Science Translational Medicine found that dormant viruses in the human body can be reactivated and stimulate the development of motor neuron disease, according to The Guardian.

Human endogenous retroviruses (HERVs) are the result of microbial remnants combining with our chromosomes after years of repeated infections throughout human evolution. Although typically dormant, the study found that the reactivation of a specific virus, HERV-K, can lead to neurodegeneration in the brain and spinal cord and cause amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease.

"A key question is whether the increased expression of HERV-K in the brains of ALS patients is a cause or a consequence of the disease," said Jeremy Garson, a virologist who has also studied the connection between ALS and retroviruses, according to Chemical & Engineering News.

Garson stated that he believes that these new findings "have gone some way to answering this by demonstrating not only that elevated HERV-K expression can cause neurotoxicity but also that the elevated expression is not just a nonspecific consequence of neuronal injury."

Although the results are promising, further research needs to look at large samples of ALS patients and confirm the prevalence of HERV-K activation, and then link it to the cause of the disease.

"But if the virus is important in triggering the disease, then it would certainly be easier to target a viral infection of the nervous system than it is to target a neurodegenerative process that we still don't fully understand," said Stephen Scelsa, a neurologist who has studied retroviruses and ALS.

The research team that conducted the study will now be studying whether retrovirus treatment can help treat HERV-K in order to find a potential treatment for ALS, according to UPI.