Dear All,

This Thursday (December 3rd) at 3pm, Kacper Kondrakiewicz, who is a PhD student working at the Neurobiology of Emotions Laboratory, under the supervision of prof. Ewelina Knapska, will give a lecture entitled: Central amygdala circuits activated by social transfer of fear.

Abstract

When exposed to danger, animals display rich repertoire of defensive responses, such as flight or freezing (cessation of any movement when no escape routes are available). In social species these reactions can be additionally influenced by the behavior of fearful conspecifics, which is known as ‘emotional contagion’. To study this phenomenon, we developed an experimental paradigm in which information about threat is transmitted between rats.

In the paradigm one animal (called ‘demonstrator’) receives mild electric foot-shocks, which evokes robust freezing reaction. The other rat (‘observer’) does not receive any foot-shocks, but can witness behavior of the demonstrator from behind a perforated wall. This interaction with the fearful demonstrator is enough to evoke freezing also in the observer rat. Interestingly, observers do not mimic the behavior of demonstrators on a moment-to-moment basis, but rather display freezing across time independently from their partners.

To study how contact with fearful demonstrators influences brain activity, we focused on the central nucleus of the amygdala (CeA), which is known to regulate defensive responses in single-subjects. Specifically, we used custom-made viral vectors to tag the population of CeA cells which are activated by the interaction with the fearful demonstrator, and reactivate them during a different behavioral test. Such ‘reverse engineering’ approach allowed us to demonstrate that the studied neuronal population promotes passive defensive reactions (freezing, immobility), but does not influence social interactions per se. Additional experiments indicated that the studied CeA population is most probably driven by the input from basolateral amygdala (BLA). When compared to literature, the results strongly suggest that socially-triggered and first-hand defensive responses are controlled by similar brain circuitry.

ZOOM link:

https://zoom.us/j/91262243656?pwd=eUt5WGg1OHlrb1NuV0RQQmtPRUl2Zz09
Meeting ID: 912 6224 3656
Passcode: 485625
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Best regards,
Aleksandra Pękowska