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Actively Frozen - contextual modulation of freezing and its neuronal basis

Project description

Research could reveal what guides fearful animals to flee or freeze

When faced with a threat, an animal must decide whether to freeze, thereby reducing its chances of being noticed, or flee to a safe refuge. This choice largely depends on the context in which the threat occurs. Although recent research has made great strides in identifying the pre-motor circuits and their inputs that control the freezing behaviour of rodents, it has provided poor insight into how contextual information guides their choice. Researchers working on the EU-funded A-FRO project are studying how fruit flies integrate information stemming from the environment and how this information guides their choice of whether to freeze or not in the face of a threat.


When faced with a threat, an animal must decide whether to freeze, reducing its chances of being noticed, or to flee to the safety of a refuge. Animals from fish to primates choose between these two alternatives when confronted by an attacking predator, a choice that largely depends on the context in which the threat occurs. Recent work has made strides identifying the pre-motor circuits, and their inputs, which control freezing behavior in rodents, but how contextual information is integrated to guide this choice is still far from understood. We recently found that fruit flies in response to visual looming stimuli, simulating a large object on collision course, make rapid freeze/flee choices that depend on the social and spatial environment, and the fly’s internal state. Further, identification of looming detector neurons was recently reported and we identified the descending command neurons, DNp09, responsible for freezing in the fly. Knowing the sensory input and descending output for looming-evoked freezing, two environmental factors that modulate its expression, and using a genetically tractable system affording the use of large sample sizes, places us in an unique position to understand how a information about a threat is integrated with cues from the environment to guide the choice of whether to freeze (our goal). To assess how social information impinges on the circuit for freezing, we will examine the sensory inputs and neuromodulators that mediate this process, mapping their connections to DNp09 neurons (Aim 1). We ask whether learning is required for the spatial modulation of freezing, which cues flies are using to discriminate different places and which brain circuits mediate this process (Aim 2). Finally, we will study how activity of DNp09 neurons drives freezing (Aim 3). This project will provide a comprehensive understanding of the mechanism of freezing and its modulation by the environment, from single neurons to behaviour.



Net EU contribution
€ 1 969 750,00
Avenida brasilia, centro de investigacao da fundacao champalimaud
1400-038 Lisboa

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Continente Área Metropolitana de Lisboa Área Metropolitana de Lisboa
Activity type
Research Organisations
Other funding
€ 0,00

Beneficiaries (1)