It has been known for some time that the antidepressant drug Prozac treats depression by causing more brain cells to be born.
However, researchers at the Cold Spring Harbor Laboratory in Long Island, New York have found a previously unknown piece of the puzzle: just how Prozac does this.
The researchers analyzed proteins produced by different cells in the brains of mice and were able to track the steps involved in converting an immature stem cell into a mature, specialized brain cell, or neuron.
They found that Prozac acted on the second step of this process, triggering the production of an immature brain cell called ANPs (amplifying neural progenitors).
ANPs ultimately develop into mature brain cells, which lead to increased numbers of neurons in a region of the brain called the dentate gyrus.
The researchers are testing other antidepressants and new drugs to determine if they have the same effect. They are hoping to identify alternative drugs for depression that may be more potent, or have less side effects, than Prozac, along with new treatments for neurodegenerative diseases such as Alzheimer's disease.