Christian Keysers

Gast Spreker:
Associate Professor Dr. Ewelina Knapska.
Director Laboratory of Emotions Neurobiology
Nencki Institute of Experimental biology,
Warszawa, Poland.

Title: How does the brain respond to others’ fear? The role of the central amygdala.

Abstract

Building relationships and adapting to the social environment is based on interacting with others and understanding their emotions. However, these essential processes’ neural and behavioral mechanisms are still insufficiently understood. Our studies focused on the central amygdala (CeA), an integrative hub converting emotionally relevant sensory information into behavioral and physiological responses. We discovered that in rats, the circuits within the CeA, characterized by their connectivity with other brain structures, play a crucial role in orchestrating responses to the fearful behavior of social interaction partners. Further, we found that the fearful behavior of others provides information about the imminence of the threat; depending on the threat’s imminence, the respective socially triggered responses recruit different neuronal circuits in the CeA. Finally, we found that rats are able to sense human fear, as indicated by the risk assessment behavior and amygdala activation. Notably, the amygdalar circuits involved in cross- and within-species fear transmission are similar. In particular, in rats interacting with a fearful caregiver and humans observing fear of another human, the homologous parts of the amygdala are activated, including the CeA. These results support the hypothesis that fear contagion evolved to enable individuals to receive information essential for survival while avoiding the risk of first-hand dangerous experiences. They also challenge a commonly adopted theory that derives emotional contagion from offspring care.