organisation - the Instituto Gulbenkian de Ciência

BEHAVIOURAL
NEUROSCIENCE
THIS GROUP IS A MEMBER OF THE CHAMPALIMAUD NEUROSCIENCE PROGRAMME AT THE IGC
Marta Moita Principal Investigator
PhD in Neuroscience, Universidade do Porto, Portugal
Post-doctoral Fellow, Cold Spring Harbor Laboratory, USA
Principal Investigator at the IGC since 2004
link to external website
We are interested in understanding the neural mechanisms underlying behavioural
plasticity using a combination of behavioural, pharmacological, molecular
and electrophysiological tools. In particular, we are studying how prior experience
and how social interactions shape behaviour. To this end, we are studying
fear; both how animals learn to fear cues that are predictive of aversive events
or threats, and how fear can be socially transmitted, i.e. how animal respond to
the distress of con-specifics. We chose fear learning since it is conserved across
species, entailing fast robust learning and very long lasting memories. We are
also studying decision-making in the context of social interactions, using game
theory to test how rats learn and evaluate the payoffs that result from the interaction
with another individual.
NEURAL MECHANISMS OF TRACE AUDITORY FEAR CONDITIONING
This project focuses on the role of different memory systems in trace auditory
fear conditioning (tAFC). We hypothesised that the mechanism underlying the
association between a tone and a shock depends on the length of the trace
interval memory and in the case of long intervals they rely on episodic memory
between the two stimuli, where in the case of a short interval rats rely on working
memory.
GROUP MEMBERS
Kensaku Nomoto (Post-doc)
Ana Pereira (PhD student)
Andreia Pereira (PhD student)
Elizabeth Rickenbacher (PhD student)
Marta Guimarãis (PhD student)
Scott Rennie (PhD student)
COLLABORATORS
Hugh Blair (University of California Los Angeles (UCLA), USA)
Alfonso Renart (Champalimaud Foundation, Portugal)
Susana Lima (Champalimaud Neuroscience Programme, Portugal)
FUNDING
Fundação para a Ciência e a Tecnologia (FCT), Portugal
Champalimaud Foundation, Portugal
We have tested the role of contextual learning in auditory trace fear conditioning.
We found that decreasing the saliency of the training environment disrupts
learning to fear a tone that precedes shock by several seconds and that inactivating
the hippocampus does not decrease it further. In addition we are studying
the role prefrontal cortex in trace conditioning by performing single-unit
recordings in this structure during learning.
COOPERATION IN SOCIAL DILEMMAS IN RATS
Game theory has constituted a powerful tool in the study of the mechanisms of
reciprocity. Having shown that, in a Prisoner’s Dilemma game, 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.
We tested whether rats learn to coordinate in a game where coordination with a
conspecific leads to highest number of rewards. We have found that rats learn to
coordinate and that they are not simply following the other rat, since decreasing
the reward for coordinating leads to a significant decrease in coordination.
NEURAL MECHANISMS OF SOCIAL TRANSMISSION OF FEAR IN RATS
This project aims at investigating the mechanisms underlying social transmission
of fear (STF) in rats, i.e. how rats respond to the fear displayed by a
conspecific. In order to unravel the neural circuit underlying STF, we will first
determine how prior self-experience with shock contributes to STF and what
are the sensory cues that mediate this process.
We found that rats do not rely on visual cues, alarm calls or short range chemical
signals to detect fear in a conspecific. Instead, they use auditory cues which are
likely to signal the sudden transition from motion to immobility. Through sound
playback experiments, we found that the absence of movement-evoked sound
was necessary and sufficient to induce fear in rats. In addition we have found that
prior experience with shock is necessary, but not sufficient for vicarious fear.
IGC ANNUAL REPORT ‘11
RESEARCH GROUPS
53