Monkeys Provide Clues to How Antidepressents Work

Author:  Falishia Sloan

Institution:  Eastern Virginia Medical School
Date:  May 2007

Researchers at Columbia University have found antidepressant treatments in adult monkeys can induce neuron growth in the hippocampus of the brain. This research, published in the May 2 issue of the Journal of Neuroscience, provides new clues into how the antidepressant medication works and how it may work in humans, as well. .

Dr. Tarique Perera, MD and his fellow scientists studied the changes in the number of brain cells in the dentate gyrus region of the hippocampus. In the study, Perera and his colleagues treated the monkey with an animal-version of an electroconvulsive shock (ECS).

Perera observed an increase in the number of new nerve cells present in the hippocampus, most of which became mature neurons over a period of four weeks.

Perera states the changes observed in the brain were not the result of brain damage, in contrast, the ECS treatments were found to increase the production of a protein known as BCL2 that actually protects nerve cells from damage. In addition, the animals exhibited no evidence of increased cell death.

Perera said, "These findings support the hypothesis that induction of neurogenesis is a necessary component in the mechanism of action of antidepressant treatments."

Previous studies in this field have included rodents with similar results. According to Dr. Eric Nestler, MD, PhD of the University of Texas Southwestern Medical Center, the increase of new nerve cells in the hippocampus has previously been though the mechanism by which antidepressants have worked in rodent models.

"However," he states, "the clinical relevance of this action has remained controversial, in part, because of uncertainty as to whether similar neurogenesis occurs in humans. This finding further supports the potential clinical relevance of changes in neurogenesis seen in rodent models."

Written by Falishia Sloan