Immune cells in the brain influence anxiety
Scientists have discovered that two types of immune cells in the brain regulate anxiety in different ways: some increase it, while others suppress it. This finding could lead to new approaches in the treatment of mental disorders.
Salus
The University of Utah has reported the discovery of two distinct populations of microglia in mice, each regulating anxiety-related behavior in different ways. Non-Hoxb8 microglia increase anxiety (the "gas pedal" effect), while Hoxb8 microglia reduce it (the "brake" effect). When both groups are present, their actions balance each other out.
These findings were obtained through experiments in which specific types of microglia were transplanted into mice lacking their own microglial cells. Animals with non-Hoxb8 microglia showed pronounced anxiety (frequent grooming, avoidance of open spaces), whereas those with Hoxb8 microglia did not. Blocking all microglia at once did not trigger anxious behavior, indicating that the subtypes have opposing functions.
The authors believe this discovery shifts the focus from neurons to immune cells in the brain as key regulators of anxiety. Similar microglial populations exist in humans. The prospects include developing therapies aimed at enhancing the "braking" Hoxb8 microglia or weakening the "accelerating" non-Hoxb8 microglia. However, researchers emphasize that clinical application is still a long way off.