%0 Generic
%A Krzywkowski, Piotr
%C Heidelberg
%D 2020
%F heidok:29193
%K Neuroscience
%R 10.11588/heidok.00029193
%T Understanding the neural dynamics of ventromedial hypothalamus in defence and aggression
%U https://archiv.ub.uni-heidelberg.de/volltextserver/29193/
%X Fear and aggression are evolutionary conserved emotional responses that can be evoked by different stimuli. One of these stimuli is exposure to a threatening conspecific that depending on the context and history of previous encounters can elicit either defence and avoidance or approach and aggression. The ventrolateral division of the ventromedial hypothalamus (VMHvl) has been recently identified as a structure involved in both behaviours. Neural activity in the ventromedial hypothalamus has been shown to be necessary for defensive and aggressive behavioural responses to conspecific threats. In male mice, inhibition of neural activity in VMHvl reduces avoidance behaviour following exposure to an aggressive male, as well as attack behaviour following exposure to a subordinate male. However, whether the same or different neurons in VMHvl are responsible for defence and aggression toward social threat, how experience affects these responses and the identity of defence neurons in VMHvl remains unknown. Here we performed serial cFos labelling experiments and found that defence and aggression recruited partially overlapping populations in VMHvl. Using in vivo calcium endoscopy of VMHvl neuron activity during social defence and aggression we found that strong calcium responses were elicited upon exposure to the social stimulus and these were further modulated as the animal exhibited defensive or aggressive behaviours. Notably, specific neuronal calcium responses were identified that were correlated with defensive behaviours, some of these neurons were reacted to more than one behaviour, showing complex patterns of activity during aggression and defence. Moreover, calcium recordings over several days of either defence or aggression revealed a change in the ensemble activity between defence and aggression and this effect was dependent on the previous experience of an animal. At the same time we performed a series of functional manipulation experiments blocking or activating neuronal activity in different cell types of the VMHvl. We found separate populations of VMHvl Esr1+ and Nos1+ neurons that were able to modulate defensive responses to social threat. Together, these results demonstrate that the VMHvl encodes and controls both specific and overlapping features of defensive and aggressive behavioural responses to social threat.