Pesticide Rotenone Exposure Alters Brain Gene Activity Linked to Parkinson's Disease

Recent research has shown that exposure to the pesticide rotenone can cause lasting changes in gene expression in specific brain regions associated with Parkinson's disease. Conducted by scientists from the UK Dementia Research Institute, King's College London, and the University of Pittsburgh, the study focused on how such exposure affects rats at the epigenetic level, shedding light on potential mechanisms behind environmental contributions to Parkinson's.

During the experiment, rats were administered rotenone daily for three weeks. Their brain tissues, particularly from the substantia nigra and motor cortex—areas critically involved in Parkinson's—were examined after exposure. The findings revealed that in the substantia nigra, genes related to the immune response, especially those involved with microglia activation, were significantly upregulated. This suggests that chronic pesticide exposure primes brain immune cells, possibly setting the stage for neurodegeneration.

In the motor cortex, researchers observed notable alterations in genes responsible for synaptic communication, indicating disrupted neuronal connectivity and signaling pathways. These molecular changes highlight how rotenone may impair brain function and contribute to Parkinsonian symptoms.

Rotenone, a naturally occurring pesticide, is known to impair mitochondrial function and induce oxidative stress, leading to cellular damage. Although banned in the UK and Europe, it is still used in the US and Canada for controlling fish populations, raising concerns about environmental exposure risks.

This study supports epidemiological links between pesticide exposure and increased Parkinson's risk, especially among agricultural workers. Understanding how pesticides influence gene regulation and brain pathology can pave the way for new preventive strategies and therapeutic targets. The researchers aim to further explore how different brain cell types respond to environmental toxins, enhancing our understanding of environmental factors in neurodegenerative diseases.

Lead researcher Dr. Sarah Marzi emphasized that their findings offer vital insights into the long-term impact of low-grade pesticide exposure, particularly how it creates cellular 'memory' that predisposes individuals to Parkinson’s. Co-author Dr. Emily Rocha added that uncovering these region-specific gene changes helps explain why dopamine-producing neurons in the substantia nigra are especially vulnerable, providing crucial clues for future interventions.

This research illustrates the importance of environmental health policies and highlights the need for ongoing investigation into how toxic exposures influence neurodegenerative disease development.

Source: https://medicalxpress.com/news/2025-07-exposure-pesticide-rotenone-disrupts-genes.html