Glial deal in mood disorders.

People who suffer from either major depression or manic depression and who also have family members with these mood disturbances display strikingly low numbers of glial cells--but not neurons--in a brain area implicated in emotional behavior and stress responses, a new study suggests.

Glia affect biological processes that aid neurons in this region, located just behind the eyes. Glial losses play a role in the emergence or expression of mood disorders that run in families, propose neurobiologist Dost Ongur of Washington University in St. Louis and his coworkers.

The scientists conducted microscopic analyses of a total of 73 brain specimens from human cadavers, representing nearly equal numbers of people with major depression, manic depression (also known as bipolar disorder), schizophrenia, or no history of psychiatric ailments. In the brain area called the subgenual prefrontal cortex, unusually low numbers of glia characterized those who had been diagnosed with one of the two mood disorders and who had at least one close relative with either of these conditions, the researchers report in the Oct. 27 Proceedings of the National Academy of Sciences.

Psychiatric drug use didn't seem to have caused the glial losses. Participants who were the only members of their families with major depression or manic depression had taken the same medications as those who had familial mood disorders but who displayed no comparable glial reductions, the investigators say.