"The neurons affected in Parkinson's disease don't live in isolation in the brain," said Przedborski. "You must understand the brain environment as a whole to understand disease. For many years, people had a neuron-centric view of neurodegenerative diseases. But more and more scientists are realizing that if you wish to understand the process of neurodegeneration, you must take into account the astrocytes, the microglia, as well as the neurons. Astrocytes maintain an intimate relationship with neurons, and to understand one, you have to understand the other."
The team also analyzed brain tissue from people who died of Parkinson's disease and found that oct3 is active in astrocytes in the brain region affected by Parkinson's disease. They found the same thing in mice, where the absence of oct3 correlated exactly to areas of the brain where neurons were not damaged.
The team also showed that oct3 plays a role in the brain's response to methamphetamine. Oct3 is critical for helping astrocytes soak up excess dopamine in the space around neurons. When dopamine isn't removed as quickly or thoroughly as usual, people can feel euphoric, but they can also experience brain damage. The finding that oct3 may play a role matches other scientists' observations that people in whom oct3 activity is reduced have a higher potential for addiction.
The molecule might also offer a new target for treating depression. Many anti-depressants work by allowing the brain chemical serotonin to stay available in the brain longer than it otherwise would. Since one of oct3's functions is to remove serotonin from the brain, blocking it may offer a new avenue to treat depression.
The chemicals that the team used to block oct
|Contact: Tom Rickey|
University of Rochester Medical Center