Helpline: 0808 800 0303

New genetically engineered mice show non-motor symptoms of Parkinson's

1 July 2009

Genetically engineered mice, which show many of the non-motor symptoms of Parkinson's, have been developed for the first time, according to the Journal of Neuroscience (24 June 2009).

Non-motor symptoms, such as sleep problems, loss of sense of smell and depression, can seriously affect the quality of life for people with Parkinson's. Much current research focuses on how to treat the physical symptoms of Parkinson's such as tremor, stiffness and slow movement.

What did scientists do?

Scientists at the School of Medicine at Emory University, in the USA, genetically engineered mice to be deficient in a protein called VMAT2 that helps to store dopamine. It is the loss of dopamine in brain cells which causes Parkinson's.

Within brain cells, VMAT2 puts neurotransmitters such as dopamine into containers that deliver chemical messages to other cells. When the protein is genetically removed from the mice it is believed that brain cell damage occurs.

The genetically altered mice fell asleep more quickly and lost their sense of smell. In tests used to model depression, mice displayed signs of depression and responded to the use of antidepressants.

This is the first time that non-motor symptoms have been studied in this way. It is hoped that the mice could become new models in the search for drugs which treat the troubling non-motor symptoms of Parkinson's. Most non-motor symptoms do not respond to levodopa, the most widely used medication for the condition.

The Parkinson's Disease Society is currently funding research into the non-motor symptoms of Parkinson's, including sleep, depression and dementia.

More research in this area

Research achievements: more than a movement disorder gives more information about Parkinson's Disease Society research into non-motor symptoms.