masterThesis
Reconsolidação e extinção de memórias: uma abordagem computacional
Fecha
2018-08-20Registro en:
SANTIAGO, Rodrigo Marques de Melo. Reconsolidação e extinção de memórias: uma abordagem computacional. 2018. 83f. Dissertação (Mestrado em Neurociências) - Universidade Federal do Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Natal, 2018.
Autor
Santiago, Rodrigo Marques de Melo
Resumen
The reconsolidation and extinction of aversive memories and their boundary
conditions have been extensively studied in order to outline better strategies for the
treatment of fear and anxiety related disorders. In 2011, Osan et al. developed a
computational model for exploring such phenomena based on attractors dynamics, Hebbian
plasticity and synaptic degradation induced by prediction error. This model was able to
explain in a single formalism several experimental findings regarding the freezing behavior
of rodents submitted to paradigms of contextual fear memory consolidation,
reconsolidation and extinction. In 2017, Radiske et al., based on experiments in rats
subjected to the inhibitory avoidance task, found that the previous knowledge of the
current aversive context as non-aversive is a boundary condition for the reconsolidation of
the shock memory experienced in that context. In the present work, we aimed to
investigate whether the formalism introduced by Osan et al. (2011) is sufficiently general to
explain the behavioral results described by Radiske et al. (2017). To do so, we first
implemented Osan et al.'s (2011) model in an open programming language (Python) and
validated it through the replication of the main results reported in the original publication
regarding contextual fear conditioning. Then, we adapted the model to simulate
experimental protocols in the inhibitory avoidance task employed by Radiske et al. (2017).
The results show that the boundary condition found by Radiske et al. (2017) is compatible
with the dynamics of an attractor network that supports a synaptic labilization system
common to reconsolidation and extinction. Finally, by exploring some model parameters –
such as the levels of protein synthesis and degradation –, we provide behavioral predictions
in the inhibitory avoidance task that can be tested experimentally.