OVERVIEW

Behaviours that are crucial for survival are likely to have shaped the brain throughout evolution. For example, animals face a multitude of dangers, many of which can be life threatening, such as the encounter with a predator. Therefore, they have evolved several mechanisms of defensive behaviours, of which many are similar across the animal kingdom. Another type of behaviour crucial to the survival of many species is social behaviour. Living in groups provides a number of advantages, including protection against predators, a great example of this is the use of alarm signals from other animals, and division of labor, for example when groups of females take care of their young together. These two different types of behaviour raise many questions such as how animals detect threats in the environment, how they choose which defensive strategy to adopt and  what drives animals to cooperate with each other. Once a threat is detected animals need to choose the appropriate action. While the action an animal displays depends on a number of factors, there is little understanding of how the choice between different defence modules is made. Again the social environment plays a crucial role in regulating defensive responses. Many times defensive behaviors are carried out at the level of the population, such as shoaling in fish. To address the question of the neural mechanisms of social defense responses, the Behavioural Neuroscience group uses a model system that is both amenable to the search for the neural mechanism of behaviour, while at the same time allowing the study of the behaviour of large groups of individuals, the fruit fly. This is the ideal model system, for its large collection of powerful genetic tools, a rapidly increasing number of approaches to study neural circuits and expanding set of behavioural paradigms.

Main Interests

Defensive and Social Behaviour

Methods

Development of behavioural tasks, Optogenetics, Pharmacology and Physiology

Models

Rat and Fruit fly

How do animals use cues from conspecifics?

How do animals select and execute different defensive strategies?

STRATEGY

Overarching loop beh-brain-body.

Detailed behavioral characterization, identification of cues/elements/modules of behavior:

– Develop behavioral tasks,

-perform behavioral manipulations

– quantitative beh analysis and we manipulate brain and body

Neural instantiation

– Circuit mapping

– physiology (electrophysiology and Ca imaging)

Somatic instantiation

– muscle function

We count with the help from the platforms (development versus support a bit more detail)

PROJECTS

Selection between different defensive responses

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Internal state

Modulation by social environment 

Research Team: Ricardo Zacarias, Ricardo Neto Silva, Clara Howcroft Ferreira, Ricardo Vieira, Matheus Farias and Elizabeth Rickenbacher.

Collaborators: Maria Luísa Vasconcelos, Gwyneth Card, Eugenia Chiappe, Regina Sullivan, João Frazão, Scientific Software and Hardware Platforms

Somatic instatiation of defensive behaviors

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Cardiac Function

Postural control

Research Team: Natalia Barrios and Anna Hobbiss.

Collaborators: Cesar Mendes and Michael Dickinson, João Frazão, Pedro Garcia and Scott Rennie

Inferring threat from the alarm of others

A great deal is known about the neural basis of associative fear learning. However, many animal species are able to use social cues to recognize threats, a defense mechanism that may be less costly than learning from self-experience. We have previously shown that rats perceive the cessation of movement-evoked sound as a signal of danger and its resumption as a signal of safety. To study the inference of threat from the behavior of others, we assessed the behavior of an observer rat while witnessing a demonstrator rat display defense responses. With this paradigm we took advantage of the accumulated knowledge on learned fear to investigate the neural mechanisms by which the social environment regulates defense behaviors. We have focused on the amygdala, crucial for fear learning and expression, and its auditory inputs, and we have combined immunohistochemistry, pharmacology and optogenetics, to unravel the neural circuits involved in detecting the transition from movement-evoked sound to silence. Moreover, since observer rats previously exposed to shock display observational freezing, but naive observer rats do not, we have determined the mechanisms by which prior experience contributes to observational freezing.

Research Team: Ana Pereira, Andreia Cruz, Matheus Farias and Mirjam Heinemans.

Collaborators: Susana Lima, Christian Keysers and Valeria Gazzola. 

Cooperation in social dilemmas

Game theory has constituted a powerful tool in the study of the mechanisms of reciprocity. Having shown, in a Prisoner’s Dilemma game, that rats shape their behaviour according to the opponent’s strategy and the relative size of the payoff resulting from cooperative or defective moves, we now aim at dissecting the mechanisms underlying the decision-making process during such social dilemma games. We have designed and set-up an automated maze to study the behavior of rats in different social dilemma games, such as the Stag Hunt and the Snow drift game, which allow for dissection of the factors that govern cooperation between two rats.

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Prosocial behaviour (social feeding)

Collective decision making

Research Team: Scott Rennie, Cristina Marquez, Diana Costa, Alexandra Medeiros, Matheus Farias.

Collaborators: Eric DeWitt, João Frazão, Gonzalo Polavieja and Gonçalo Lopes.