127 | Fear and reward BLA-mPFC network dynamics during memory reconsolidation and extinction

Cognition, Behavior, and Memory

Author: Santiago Abel Merlo | Email: santiabelmerlo@gmail.com

Santiago Abel Merlo , Emiliano Merlo , Maria Eugenia Pedreira , Mariano Belluscio

1° IFIByNE, UBA-CONICET, Buenos Aires, Argentina
2° School of Psychology, University of Sussex, Falmer, United Kingdom
3° CONICET – Universidad de Buenos Aires. Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay). Buenos Aires, Argentina

The basolateral nucleus of the amygdala (BLA) and the medial prefrontal cortex (mPFC) have been implicated in fear-related responses and reward-seeking behaviours. In the BLA, different positive and negative valence neuronal subpopulations are known to be activated during fear memory acquisition, reconsolidation or extinction. At the same time, these subpopulations are differentially connected to mPFC prelimbic (PL) and infralimbic (IL) subdivisions. Here, we record local field potentials (LFP) and neuronal activity simultaneously in the BLA and mPFC of rats during appetitive or aversive memory acquisition, reconsolidation and extinction. Since the LFP is a proxy for population-based neural activity and given that there is evidence that the retrieval of positive or negative memories differs in the coupling and power of the theta (4-10 Hz) and gamma (40-120 Hz) oscillations in both the BLA and the mPFC, we explore the dynamics of theta and gamma oscillations synchronization between the PL or IL subdivisions of the mPFC and the BLA. In particular, we studied how the transition between memory reconsolidation and extinction occurs, in terms of BLA-mPFC network dynamics when successive conditioned stimuli are presented in the absence of the unconditioned stimulus.