Neural mechanisms of social empathy in the anterior cingulate cortex

Empathy is a prosocial behavior that perceives the emotional state of others, expresses similar perceptions that match those of others, and mediates different social behaviors. Empathic behaviors for pain and fear also exist in primates and rodents. In the past decades, the neural mechanisms of empathy have been defined as a result of various sensations and perceptions, such as visual and hearing stimuli, which cause mirror activations in brain regions, such as the insular, the inferior frontal, and the medial frontal cortices, among which the anterior cingulate cortex (ACC) has been identified as a core region of the neural network that is associated with the empathic activity in mammals. Most studies on the neural mechanisms underlying empathy have been based on rodent models, which allowed for single-cell resolution mapping of neuronal activity; moreover, the application of optogenetic techniques in rodent models has led to a deeper delineation of neural circuits. Here, we review the role of the ACC in two behavioral paradigms, pain and fear empathy, in rodents at the neuronal and neural circuit levels. Understanding how the ACC mediates empathic behavior in the brain will provide new targets in the treatment for neuropsychiatric disorders characterized by empathic disorders.