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BACKGROUND AND AIMS: Human empathy emerges over phylogeny from various behavioral precursors. One of the simplest is emotional contagion, i.e. sharing emotional states between individuals, which can be modelled in rodents. In our model of socially transferred fear we showed that a brief social interaction with a fearful cage mate (demonstrator) promotes aversive learning in an otherwise naïve rat (observer) and activates the amygdala of the observers, especially its central part (CeA). METHODS: To elucidate the role of neuronal circuits in the central amygdala of the observers, we used two methods of functional mapping: transgenic rats expressing in behaviorally activated neurons a PSD-95:Venus fusion protein and injected with anterograde tracer and a combination of retrograde tracing with c-Fos ISH. RESULTS: We have identified several afferent and efferent CeA projections active during socially transferred fear. We discovered strong activation especially in the periaqueductal gray (PAG) and dorsal raphe nuclei (DRN), structures receiving dense projections from the CeA and implicated in fear and anxiety disorders. Moreover, we observed that most of the activated cells are GABA-ergic neurons. To test whether the activated circuits are similar for the socially and non-socially induced emotions, we used double immunodetection for a PSD-95:Venus construct and endogenous c-Fos. About 70% of neurons was activated by both social interaction with fear conditioned partner and subsequent fear conditioning. Moreover, using optogenetics, we showed that specific activation of CeA neurons involved in socially transferred fear results in increased anxiety. CONCLUSIONS: These findings suggest that there exists a group of neurons in the central amygdala that is involved in integrating information about a threat, activated during socially transferred fear and subsequently recruited by learning of fear responses. Part of these cells is probably specifically involved in socially induced anxiety.