Nerve cell miswiring linked to depression
Mouse study identifies gene needed for proper assembly of serotonin circuitry
ALL TANGLED UP In a healthy mouse (left), nerve cells (white) that release serotonin extend through the hippocampus. But when a specific gene is knocked out, those nerve cell wires clump together (right).
T. Maniatis/Columbia's Zuckerman Institute
Researchers have pinpointed a gene that keeps important brain cells in mice from crossing their wires, providing a possible link between brain wiring and mood disorders like depression.
Without the gene, called Pcdhαc2, mice acted more depressed, researchers report April 28 in Science.
Nerve cells, or neurons, that produce the chemical messenger molecule serotonin extend long projections called axons to various parts of the brain. Serotonin released from the tips of the axons signal other neurons in these target areas to influence mood and other aspects of behavior. For efficient signaling, the axon tips must be properly spaced.
In the new work, scientists from New York City, St. Louis and China found that such spacing is disrupted in mice lacking the Pcdhαc2 gene. As a result, serotonin-signaling circuits are not properly assembled and the mice exhibited