Research has revealed that exposure to loud noise may exacerbate symptoms in early-stage Parkinson’s disease. A study led by Pei Zhang from the Huazhong University of Science and Technology in Wuhan, China, published in PLOS Biology, shows that high-volume noise adversely affects motor functions in a mouse model of the disease. The findings suggest a significant connection between auditory processing and movement regulation in the brain.
To explore this relationship, the researchers subjected mice with early-stage Parkinson’s disease to either acute or chronic noise levels ranging from 85 to 100 decibels, similar to the sound of a power mower or a blender. After only one hour of exposure, the mice exhibited slower movement and impaired balance compared to control subjects. Notably, the affected mice showed recovery after a day, but those exposed to one hour of noise daily for a week demonstrated persistent motor deficits.
The study further examined the inferior colliculus, a brain region responsible for processing sound. The researchers found that this area has connections to the substantia nigra pars compacta, a critical region in Parkinson’s disease that produces dopamine and is often severely damaged in patients. By chronically stimulating the inferior colliculus, the team observed effects akin to those caused by noise exposure, which included a decrease in the protein VMAT2, essential for dopamine transport, and the death of dopamine-producing cells in the substantia nigra.
In contrast, inhibiting the inferior colliculus or increasing VMAT2 levels appeared to reverse the adverse effects induced by both acute and chronic noise exposure in the mice. While the study’s conclusions are based on animal models, they suggest a vital link between environmental factors such as noise and the progression of Parkinson’s disease symptoms.
The authors state, “Our study reveals that environmental noise exposure changes the IC-SNc circuit, leading to motor deficits and increased neuronal vulnerability in a Parkinson’s disease mouse model.” They also highlight the significance of their findings: “It was particularly fascinating to observe how the environmental noise-induced dopaminergic neurodegeneration and motor deficit, offering new insights into non-genetic risk factors for Parkinson’s disease.”
These results underscore the potential impact of environmental noise on the development and exacerbation of Parkinson’s disease symptoms, highlighting the need for further exploration of how such factors may influence neurodegenerative conditions.
For more detailed information, refer to the study: Cui C, et al. Environmental noise-induced changes to the IC-SNc circuit promote motor deficits and neuronal vulnerability in a mouse model of Parkinson’s Disease, PLOS Biology, March 2025. DOI: 10.1371/journal.pbio.3003435.
