Microglia Activation, Herpes Infection, and NMDA Receptor Inhibition: Common Pathways to Psychosis?

Abstract

Microglia are the resident macrophages of the brain. Microglia play important housekeeping roles during brain development and during exposure to psychostxial stress, toxins, and infectious pathogens. The hippocampus is a vulnerable brain region in response to these external stressors. In patients with psychosis, we found a major activation of microglia in the hippocampus, which could explain in part the volume loss of the hippocampus after a psychotic episode of patients. Recent research suggests low-grade replication of herpes simplex virus (HSV) as a potential environmental trigger of microglia activation in schizophrenia. A common mechanism of psychosis is proposed that involves activation of microglia by toxic, auto-immune, or infectious factors, converging to a blockade of the NMDA-NRI receptor in the hippocampus. (PsycINFO Database Record (c) 2018 APA, all rights reserved)