From emotional contagion to resilience – A serotonin echo in the brain

Sarah Mondoloni
Research group of Manuel Mameli
DNF – Département des neurosciences fondamentales
Unil – Université de Lausanne

Abstract: How does the brain compute and integrate others’ emotional state? This question has gained increasing interest over the past few decades as emotional contagion (the ability to react to and share others’ emotions) is a key component of empathy and a master regulator of social interaction. Mice can share emotions and learn from the experiences of conspecifics to ultimately adapt their behaviors and avoid negative consequences. Recent studies on neural circuit mechanisms and dynamics during vicarious experiences have shed light on the circuits overlapping with those associated with human empathy. However, it is not clear whether emotional contagion also better prepares individuals to cope with traumas and which neural substrate might underlies this process.
The lateral habenula (LHb) is a subcortical structure contributing to valence encoding, and its neuronal activity adapts according to the animal’s affective state. For instance, the upregulation of burst activity in LHb neurons, defined as a transitory high frequency of spikes, is associated with despair-like behavior after prolonged stress. The LHb receives inputs from raphe serotonin neurons, a neuromodulatory system involved in mood regulation and social interaction, that likely plays a key role in emotional contagion processing. While the consequences of extended stress experiences on LHb dynamics and subsequent behaviors have been extensively explored, it remains unknown whether emotional contagion has any impact on LHb dynamics, neuromodulation and function.
My postdoctoral research has been focused on understanding the influence of emotional contagion on coping behavior. In this work, we discovered that negative emotional contagion promotes resilience in mice, helping them withstand behavioral despair following an adverse experience. We demonstrated that the protective effect of emotional contagion relies on serotonin release in the lateral habenula that fine-tunes its neuronal burst activity. This work provides essential insights for the neuropsychiatric research field, echoing phenotypes reported in humans, and further highlights a new neurophysiological substrate, the habenula-serotonin system, for emotional contagion.

Invited by Rosa Cossart

Tuesday, September 10th at 11 am – Inmed conference room