Depression is more than just sadness. You may lose interest in favorite activities or lose motivation to complete routine tasks. You may also lose some brain cells, say University of Mississippi Medical Center neuroscientists.
According to a study in the March issue of Neuroscience, people with major depressive disorder (MDD) may have fewer glial cells called astrocytes in some parts of the brain's hippocampus.
Glia, from the Greek for “glue,” were long thought to be just structural cells keeping everything stuck together. But Dr. Grazyna Rajkowska, professor of psychiatry and human behavior, was one of the first scientists to show the connection between fewer glia and depression.
“People thought depression had to do with neurons. No one thought about glia,” Rajkowska said. “The decrease in glial density is much more dramatic than the changes in neurons.”
“She's the grandmother of glia and depression,” joked Dr. Craig Stockmeier, professor of psychiatry and human behavior.
But Stockmeier is also serious about studying the brain.
“Seeing the struggles and tragedy of mental illness in acquaintances and extended family is a deep personal motivation for my work,” he said.
For more than 15 years, Rajkowska, Stockmeier and Dr. Jose Miguel-Hidalgo, associate professor of psychiatry and human behavior, together have studied the brain's cellular and biochemical changes in mental illness, including this recent study.
The team collected brain tissue from 17 recently deceased people with a history of MDD symptoms, then matched each sample with a non-MDD control by age and sex.