Animal Models of Parkinson's Disease

Parkinson’s disease is a degenerative disease that affects the nervous system and results from damage to an area of the brain that is involved in passing signals. The causes of Parkinson’s disease are not entirely clear, and it could be due to a combination of environmental and genetic factors. Animal models are for testing to try to improve our understanding of the causes of Parkinson’s disease and to find possible treatments.

Benefits

• Animal models can be altered to mimic the symptoms of a disease, either by using surgery or chemicals to damage body tissues in a way that mirrors the disease or by changing the animals genes to cause a certain disease to develop. Animals allow scientists to get a closer look at what is causing Parkinson’s disease and to test different treatments that could not be tested on people.

Drug-Induced Models

• Using drugs to alter animals is the main method used in Parkinson's disease research. The chemical MPTP is used to cause Parkinson-like symptoms in monkeys by damaging the brain. The more common drug retenone, often used as a pesticide and insecticide, has the same effect as MPTP when used in rats. These models have highlighted the possibility that environmental chemicals used in everyday situations may be responsible for contributing to the development of Parkinson's disease.

Surgery-Induced Models

• Using surgery to damage the signaling part of the brain in rats is another method of mimicking Parkinson’s disease. It is very useful for testing different drug treatments and the various ways of getting these drugs directly into the brain, where they are needed. Scientists believe that this could reduce the numerous side effects associated with these drugs and therefore improve the prognosis for people suffering from Parkinson’s disease.

Genetically Modified Models

• Fruit flies have a similar number of genes to people and therefore are often used to change these genes to see the effects it may have on disease progression. The DJ-1 gene is present in people and fruit flies, and when removed, it increases the speed in which the Parkinson-like symptoms are seen in the fruit fly. This has highlighted the possibility that certain genes that protect us from chemicals may be missing or ineffective in some people, increasing their chances of developing Parkinson's disease.

Considerations

• While there are many different animal models that are used to test different aspects of Parkinson’s disease, there is not one model that accurately mimics the whole condition. Having a variety of different models that are specific to certain stages of the disease can be useful, but there will always be differences between people and the animals used, which may affect the outcome of the research.