Structural plasticity of hippocampal dendritic spines following contextual fear memory reactivation

MEDINA, CANDELA; OJEA RAMOS, SANTIAGO; FELD, MARIANA; POZZO-MILLER L; ROMANO, ARTURO; DE LA FUENTE, VERÓNICA

Virtual

Congreso; XXXVI Reunión Anual de la Sociedad Argentina de Investigación en Neurociencias; 2021

Sociedad Argentina de Investigación en Neurociencias

The processes of learning and long-term memory formation have been associated with changes in synapticefficacy, which, in turn, tightly correlate with morphological alterations in dendritic spines. This structuralplasticity can occur on previously existing or newly formed spines, thus allowing new information to beencoded. But, what happens with spine morphology when a consolidated memory trace is reactivated? Using acontextual fear conditioning paradigm in mice, we studied long-term morphological changes associated to theprocess of reconsolidation, by assessing spine density and morphology in pyramidal neurons of the dorsalhippocampus CA1 area. For this purpose, we modulated memory reconsolidation by inhibiting nuclear factorκB (NF-κB), a transcription factor that not only has a well described role in synaptic plasticity and memory, butwhich is also an important regulator of activity-induced synaptogenesis. Measuring multiple morphologicalvariables (total spine length, neck width, head diameter and head volume) and using a semi-automatic highthroughputmethodology, we classified dendritic spines according to their maturity and related their structuralplasticity with memory recall and restabilization.