The Default Mode Network (DMN), Microglia Dysfunction, and Neuropsychiatric Disorders: A Neuroimmune Interface
The Default Mode Network (DMN) is a central player in how the human brain processes internal thoughts, memories, emotions, and self-referential thinking. Its dysfunction has been increasingly associated with a variety of psychiatric and neurological conditions, from schizophrenia to hepatic encephalopathy, and even neurodegenerative diseases like Alzheimer's. But what underlies these dysfunctions? Recent research points to an unlikely suspect: microglia, the brain's resident immune cells. Understanding the Default Mode Network (DMN) The DMN is most active when the brain is at rest, such as during daydreaming, self-reflection, or when not focused on external tasks. It deactivates during goal-oriented behaviors. Major hubs of the DMN include: Medial prefrontal cortex (mPFC) Posterior cingulate cortex (PCC) Hippocampus These structures are heavily involved in autobiographical memory, emotional regulation, and self-awareness. The DMN operates as a “switchboard” — ...