Summary: As life expectancy rises in the U.S., and as death rates for diseases like cancer and heart disease drop, more people will die of Parkinson's disease. It is now the 14th leading cause of death.

Comment: These statistics are part of a comprehensive report by the Centers for Disease Control and Prevention.

Summary: The loss of both norepinephrine and dopamine neurons, not just one type of brain cell, is linked with the onset of symptoms associated with Parkinson's disease. Originally, only the loss of dopamine neurons was believed to trigger symptoms.

Comment: Most treatments for Parkinson's disease target only dopamine neurons. This study suggests that a combination of dopamine and norepinephrine might be more effective.

Summary: A study in the Journal of Neuroscience found that mice with a reduced capacity to store dopamine in the brain experienced a degenerative process similar to Parkinson's disease. The mice had too little of the gene VMAT2, causing a chain reaction that damaged their nigrostriatal dopamine system, embedded deep in the brain structure. This damage led to the type movement problem associated with PD.

Comment: Doctors have known for some time that the lack of dopamine triggers PD symptoms. This study provides a model that can be used to test treatments for delaying the onset and progression of the disease.