Cellular and Systems Neurobiology

Rosalina_Alvarez

Rosalina Fonseca

Principal Investigator
Degree in Biology, Science School, University of Lisbon
MD in Medicine, University of Lisbon
PhD in Neurosciences, Ludwig-Maximillians

CV

 

Location:

NOVA Medical School|Faculdade de Ciências Médicas
Edifício do Biotério - Piso 1
Campo Mártires da Pátria, 130
1169-056 Lisboa, Portugal

Phone: (+351) 218 803 101
Fax: (+351) 218 851 920
E-mail: rosalina.fonseca(at)nms.unl.pt

Main Interests:

Memory formation is a key brain feature in which our human nature relies. It is now clear that memories evolve over time. Upon learning, memories are initially labile and become stabilized by consolidation. Interestingly, reactivation of previous consolidated memories renders them in an active, unstable state and therefore susceptible to perturbation. If memory acquisition leads to the reactivation of a previously acquired memory, it is possible that different temporal events can re-enforce or interfere with each other. Recently, it was shown that novelty exposure, prior or after, weak training in a spatial recognition task, can lead to the formation of a long-term memory of the spatial recognition. This suggests a cooperative interaction in memory acquisition but leaves innumerous open questions. How are memory cooperation and competition orchestrated and what are the rules that determine whether a particular memory is re-enforced or lost by a new learning event? We are interested in understanding how memories evolve and the rules underlying this constant updating.

Cellular models of plasticity share similar features to memory acquisition. We found that long-lasting forms of plasticity, such as LTP and LTD, display synaptic cooperation and competition. Synaptic cooperation and competition rely on the distribution of plasticity-related proteins within activated synapses, similarly to memory cooperation. Our studies show that modulation of the actin cytoskeleton is involved in the capture of proteins in activated synapses necessary for the maintenance of LTP and LTD. We have also found that activation of CB1 endocannabinoid receptors can restrict the time window of synaptic cooperation in amygdala synapses. We are currently addressing the molecular mechanisms involved in synaptic cooperation and competition by using super-resolution imaging of actin and CaMKII in neurons. We are also addressing whether such cellular mechanism is involved in discriminative learning using amygdala-dependent behavioral tasks aiming to mirror synaptic rules into memory acquisition.

 
 

Discover more:

- First prize on Audio Slides from Elsevier - Endocannabinoid signaling and memory dynamics: A synaptic perspective.

- Medalhas de Honra L’Oréal Portugal para as Mulheres na Ciência 2006

- Saber como os neurónios reagem a vários estímulos

- Como se formam as nossas memórias?

- Poderemos eliminar memórias traumáticas?

- A conquista da memória

 
 

Projects:

2017-2020 Role: PI, “Synaptic competition and cooperation in reward learning: the role of hippocampal and prefrontal inputs to the nucleus accumbens” Bial Foundation

2017-2019 Role: PI, “Fear not to remember: Impact of acute stress in amygdala synaptic cooperation, NARSAD Young Investigator Grant, Brain and Behavior Research Foundation.

2016-2019 Role: PI, Rules of memory allocation: the role of actin dynamics in synaptic cooperation and competition, Fundação para a Ciência e Tecnologia (FCT – Portuguese Research Council).

2015-2018 Role: PI, The synaptic tag: a structural hypothesis, Fundação para a Ciência e Tecnologia.

Publications:

Collaborations

• Dr. U. Valentin Nägerl, Morphological aspects of synaptic plasticity, Synaptic Plasticity and Super-resolution Microscopy, Université de Bordeaux, France.

• Dr. Gal Richter-Levin, Cellular plasticity in a model of post-traumatic stress disorder, Haifa University, Israel.

• Dr. Stephen Martin, Division of Neuroscience, University of Dundee.

Team photos

Motivated students (Undergraduate, Master and PhD) are encouraged to apply. Interested candidates, please send your CV, a letter explaining your interests and the name/contact information for 1-3 references to rosalina.fonseca(at)nms.unl.pt.