Process for Weakening Unused Brain Connections Disrupted in Parkinson’s

A study in mice has found that the brain weakens unused neural connections in the striatum, a brain region involved in movement and decision-making, through a process that relies on nitric oxide. This process seems to malfunction in Parkinson’s disease. Researchers believe these findings could shed light on the causes of Parkinson’s symptoms and may help guide the development of new treatments. Dr. D. James Surmeier from Northwestern University explained that new tools are helping scientists better understand how Parkinson's affects the brain and how fixing disrupted nitric oxide signaling might improve symptoms. In the brain, neurons strengthen or weaken connections as part of learning and habit formation. In the striatum, certain neurons communicate through a process dependent on nitric oxide. This process, called nitric oxide-dependent long-term depression (NO-LTD), mainly affects inactive connections, allowing the brain to fine-tune its network. The study found that in Parkinson’s disease, NO-LTD is disrupted due to a lack of nitric oxide, which may lead to movement problems. However, restoring a balance of certain brain chemicals, like dopamine and acetylcholine, helped bring back NO-LTD in mice. This suggests that targeting these brain processes could help reduce Parkinson’s symptoms.