Fear balance is maintained by bodily feedback to the insular cortex in mice

Abstract

How the body regulates fear Although fear is important for survival, it is maladaptive if it is either too strong, as in anxiety disorders, or too weak, as in exaggerated risk taking. Working in mice, Klein et al . observed that the insular cortex has an unparalleled dual role in either enhancing or weakening the extinction of fear, depending on the internal fear state of the animal (see the Perspective by Christianson). This insula function helps to maintain fear within a homeostatic range and depends on bodily feedback signals: Fear-induced freezing behavior is associated with a slowed heart rate, which in turn dampens fear-evoked activity of the insular cortex. Two opposite signals, prediction of threat by fear-associated cues and negative feedback signals from the body, are thus integrated within the insular cortex. —PRS