Exploring New Avenues for Parkinson’s Treatment Through Brain Stimulation

Researchers are delving into the mechanisms of brain function and pinpointing new regions that, when stimulated, could offer therapeutic benefits. For individuals with Parkinson’s disease who progressively lose mobility and may eventually become unable to walk deep brain stimulation (DBS), often described as a “brain pacemaker,” offers a potential lifeline.

In a recent study published on April 12, 2025, in Scientific Reports, scientists from Ruhr University Bochum and Philipps-Universität Marburg investigated whether stimulating a specific brain region could enhance walking ability and improve quality of life. Using optogenetics a technique where light activates or inhibits targeted nerve cells they explored the effect of this stimulation on locomotion.

A New Target Beyond the Basal Ganglia

When medication no longer sufficiently manages mobility issues in advanced Parkinson’s, DBS becomes an alternative. Traditionally, stimulation targets the subthalamic nucleus, a component of the basal ganglia. However, Dr. Liana Melo-Thomas and her team at Philipps-Universität Marburg previously demonstrated in animal models that stimulating the inferior colliculus a region primarily involved in auditory processing can restore movement. This area may activate the mesencephalic locomotor region (MLR), a critical node in initiating motion.

Importantly, the inferior colliculus remains unaffected by Parkinson’s pathology, unlike the basal ganglia. Stimulating it seems to recruit alternate motor pathways that help restore mobility.

Refining Techniques with Optogenetics

To investigate this further, the Marburg team collaborated with Professor Stefan Herlitze’s group at Ruhr University Bochum, experts in optogenetic methodology. By genetically modifying neurons to express light-sensitive proteins, researchers could precisely control their activity using implanted optical fibers. Compared to electrical stimulation, this approach offers significantly improved targeting, minimizing unintended effects on surrounding tissue.

Electrophysiological recordings with a custom multi-electrode system enabled the team to directly observe changes in neuronal activity. This method, combined with behavioral monitoring in awake animals, allowed for detailed analysis while reducing the number of test subjects.

Key Findings: A Functional Link Between Brain Regions

Optogenetic stimulation of the inferior colliculus successfully increased neuronal activity in that area. Simultaneously, most neurons in the MLR also became more active, although about 25% showed inhibition suggesting complex circuit interactions. Notably, the average delay of 4.7 milliseconds between stimulations in the inferior colliculus and responses in the MLR supports a direct synaptic connection.

Implications for Future Therapies

By exploring brain circuits beyond the commonly targeted basal ganglia, this research opens doors to alternative treatments for Parkinson’s-related motor symptoms. The demonstrated link between the inferior colliculus and MLR is a promising target for further therapeutic development.

“Although clinical application may still be years away, foundational studies like this are crucial,” says Dr. Wolfgang Kruse from Ruhr University Bochum. “They not only deepen our understanding of how DBS works but also help us design more effective and precise interventions for Parkinson’s disease in the future.

Source: https://news.rub.de/english/2025-05-15-computer-science-weight-loss-pills-and-depression-tests-kids