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

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Psychology

Background:

• Fear memory is crucial for survival but must be regulated to remain adaptive.
• The brain mechanisms underlying the balance between fear maintenance and extinction are not fully understood.

Purpose of the Study:

• To investigate the role of the insular cortex in regulating fear memory.
• To explore how bodily feedback influences fear extinction and maintenance.

Main Methods:

• Used a mouse model to study fear conditioning and extinction.
• Manipulated insular cortex activity and vagus nerve stimulation.
• Measured behavioral responses and neural activity.

Main Results:

• Insular cortex activity correlated with the certainty of threat prediction.
• Heart rate decelerations during freezing provided negative bodily feedback, attenuating insular cortex activity.
• Disrupting body-brain communication or insular cortex function impaired the balance between fear extinction and maintenance.

Conclusions:

• The insular cortex integrates sensory and interoceptive signals to control fear.
• Bodily feedback plays a critical role in maintaining adaptive fear responses.
• The insular cortex acts as a key regulator for gating fear extinction and ensuring functional fear equilibrium.