Scientists have identified a protein that appears not only to be central to the process that causes Parkinson’s disease but could also play a role in muting the high from methamphetamine and other addictive drugs or to treat depression.
In a paper published online this week in the Proceedings of the National Academy of Sciences, scientists at the University of Rochester Medical Center and Columbia University have shown that oct3, a protein that shepherds molecules into and out of cells, plays a critical role, bringing toxic chemicals to the doorstep of the brain cells that die in patients with Parkinson’s disease. The team found that oct3 is involved in the brain’s response to addictive drugs like methamphetamine as well and it may be a way to treat depression.
The team 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 and the need for drug treatment.
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 oct3 in mice would be toxic in people, and there is no drug available for people now that blocks or boosts oct3, Tieu and Przedborski said. But such a drug might be useful for Parkinson’s, drug addiction, and depression and could play a role in a drug treatment program or drug rehab program in the future.