The origins of anxiety-related conditions, including obsessive-compulsive spectrum disorder (OCSD), are becoming clearer due to a study from University of Utah Health scientists.
They've discovered that microglia, a minor cell type in the brain, play a significant role in controlling anxiety-related behaviors in laboratory mice, challenging the traditional belief that neurons are the main controllers of behavior.
Specific populations of microglia were found to activate or dampen anxiety and OCSD behaviors, and they communicate with neurons to trigger these behaviors.
The findings, published in Molecular Psychiatry, could pave the way for targeted therapies.
Nobel Laureate Mario Capecchi, the senior author of the study, highlights the importance of moderate anxiety, which can motivate and propel us forward, but excessive anxiety can be overwhelming, leading to physical symptoms and mental confusion.
The research focuses on maintaining healthy behavior ranges under normal circumstances, with the mechanisms potentially causing debilitating behaviors under pathological conditions.
The study revealed that microglia, which constitute only 10% of brain cells, are not just "trash collectors" responsible for clearing dead neurons and abnormal proteins.
Using optogenetics, a technique combining genetic engineering and laser light, the researchers could activate anxiety-related behaviors with precision.
By stimulating different subpopulations of microglia, the mice displayed anxiety, excessive grooming, or freezing behavior.
The study underscores the importance of microglia type and location in modulating anxiety and OCSD behaviors.
These findings can help unravel the complex communication between neurons and microglia, potentially leading to therapeutic targets for excessive anxiety in patients.