Parkinson’s disease signature symptoms are tremors, rigidity, and impaired movement associated with the progressive loss of motor skills. Currently, L-DOPA is the only relief of the common symptoms experienced by Parkinson’s disease patients, but it can cause prominent side effects that counteract its effectiveness.

Paul Greengard, Rockefeller University, and colleagues in Sweden, have found evidence that serotonin also plays a crucial role in Parkinson’s disease. Using a mouse model of the disease the researchers were able to block the side effects of L-DOPA by manipulating a specific serotonin receptor.

The neuro transmitter dopamine has several functions in the brain, including the regulation of movement. Parkinson’s disease is characterized by a progressive degeneration of dopamine-producing neurons, causing the tremors and other disease characteristics. These neurons project from the midbrain to an area of the brain called the corpus striatum. Although dopamine signaling is impaired in Parkinson’s patients, serotonin production remains strong.