Exploring glia in schizophrenia and depression

In recent years, researchers in the neurosciences have changed their focus of attention from neurons to glia. This “glial turn” has revealed new approaches and hypotheses for the healthy brain and its disorders. Recently, mood disorders, namely major depression, have been described as diseases mainly affecting glia and particularly astrocytes. We have validated the glial hypothesis of mood disorders in humans by measuring serum markers with meta-analyses, and cell culture models. We were able to show that the glial marker protein S100B is elevated in major depression. These elevations seem to be related to the severity of depression and might be used as treatment markers. In contrast, the neuronal marker protein neuron-specific enolase (NSE) is unchanged. However, increases of S100B are not specific for mood disorders. We and others detected the same alterations in schizophrenia that were particularly related to the “deficit syndrome” characterized by “negative symptoms”. Now, cell culture models of astrocytes, which we have also previously used to investigate the blood-brain barrier, are underway exploring drug effects specifically.