Glia were long considered to be the support structure of the brain, outnumbering neurons by approximately 10 to 1. In the heady rush to map and categorize neural networks, glia were frequently regulated to the position of scaffolding in our conceptualization of the brain, the chassis to the brain's engine.
Research has shown that our conceptualization of glia is in need of revision. There are many subtypes of glia that fulfill vital functions in the brain, including some that may facilitate communication in previously-unknown ways in the brain. As Dr. Fikrey Birey, post-doc at Stanford University, explains below, new studies are slowly demonstrating a strong correlation between the newly-discovered NG2-subtype of glia and mood disorders.
Find additional research on the subject here.