In recent years, Parkinson's research has advanced to the point that halting the progression of PD, restoring lost function, and even preventing the disease are all considered realistic goals.  While the ultimate goal of preventing PD may take years to achieve, researchers are making great progress in understanding and treating PD.

One of the most exciting areas of PD research is genetics.  Studying the genes responsible for inherited cases can help researchers understand both inherited and sporadic cases of the disease. Identifying gene defects can also help researchers understand how PD occurs, develop animal models that accurately mimic the neuronal death in human PD, identify new drug targets, and improve diagnosis.

Several genes have been definitively linked to PD in some people.  Researchers also have identified a number of other genes that may play a role and are working to confirm these findings.  In addition, several chromosomal regions have been linked to PD in some families.  Researchers hope to identify the genes located in these chromosomal regions and to determine which of them may play roles in PD.

Researchers funded by the National Institute of Neurological Disorders and Stroke (NINDS) are gathering information and DNA samples from hundreds of families with PD and are conducting large-scale gene expression studies to identify genes that are abnormally active or inactive in PD.  They also are comparing gene activity in PD with gene activity in similar diseases such as progressive supranuclear palsy. 

Some scientists have found evidence that specific variations in the DNA of mitochondria – structures in cells that provide the energy for cellular activity — can increase the risk of getting PD, while other variations are associated with a lowered risk of the disorder. They also have found that PD patients have more mitochondrial DNA (mtDNA) variations than patients with other movement disorders or Alzheimer's disease. Researchers are working to define how these mtDNA variations may lead to PD.

In addition to identifying new genes for PD, researchers are trying to learn how known PD genes function and how the gene mutations cause disease.  For example, a 2005 study found that the normal alpha-synuclein protein may help other proteins that are important for nerve transmission to fold correctly.  Other studies have suggested that the normal parkin protein protects neurons from a variety of threats, including alpha-synuclein toxicity and excitotoxicity.

Scientists continue to study environmental toxins such as pesticides and herbicides that can cause PD symptoms in animals.  They have found that exposing rodents to the pesticide rotenone and several other agricultural chemicals can cause cellular and behavioral changes that mimic those seen in PD.  Other studies have suggested that prenatal exposure to certain toxins can increase susceptibility to PD in adulthood.  An NIH-sponsored program called the Collaborative Centers for Parkinson's Disease Environmental Research (CCPDER) focuses on how occupational exposure to toxins and use of caffeine and other substances may affect the risk of PD.

Another major area of PD research involves the cell's protein disposal system, called the ubiquitin-proteasome system. If this disposal system fails to work correctly, toxins and other substances may build up to harmful levels, leading to cell death.  The ubiquitin-proteasome system requires interactions between several proteins, including parkin and UCH-L1. Therefore, disruption of the ubiquitin-proteasome system may partially explain how mutations in these genes cause PD.

Other studies focus on how Lewy bodies form and what role they play in PD.  Some studies suggest that Lewy bodies are a byproduct of degenerative processes within neurons, while others indicate that Lewy bodies are a protective mechanism by which neurons lock away abnormal molecules that might otherwise be harmful.  Additional studies have found that alpha-synuclein clumps alter gene expression and bind to vesicles within the cell in ways that could be harmful.