CALFA GASTON DIEGO
Congresos y reuniones científicas
Título:
Temporal Dynamic of the Hippocampal Structural Plasticity Associated to Contextual Fear Memory: Influence of the Destabilization/ Reconsolidation Process
Autor/es:
RAMIRO GABRIEL COMAS MUTIS; PABLO JAVIER ESPEJO; IRENE DELIA MARTIJENA; VICTOR ALEJANDRO MOLINA; GASTON DIEGO CALFA
Reunión:
Congreso; Argentine Society for Research in Neurosciences; 2018
Resumen:
Increasing experimental evidence indicates that fear memory
reactivation induces a transient plastic state that presumably
activates the neuronal circuit involved in the encoding of the
long term fear memory. Under certain circumstances, such
reactivation allows the incorporation and integration of new
information to the original memory trace. Here, we evaluated
whether fear memory reactivation impacts on the dendritic
spines remodeling in CA1 region of the dorsal hippocampus
associated with the formation of the contextual fear
memory. In the same way, we tested whether stress exposure
affects such dendritic spine remodeling. Thus, stressed
and control animals were fear conditioned and sacrificed 24
hr postconditioning (preretrieval), 60 min postretrieval or
24 hr postretrieval. A higher dendritic spines density, particularly
mature ones, were observed after fear encoding and
later reduced to basal levels 60 min after fear reactivation,
returning to higher levels 24 hr postretrieval. This temporal
dynamic structural plasticity was prevented by pharmacologically
blocking the destabilization/reconsolidation process in
the basolateral amygdala complex or by a single stress exposure
just before fear memory conditioning. Thus, the destabilization/
reconsolidation process was evidenced by a
change in the hippocampal structural plasticity immediately
following reactivation, a plausible necessary step for the
integration of new information.
reactivation induces a transient plastic state that presumably
activates the neuronal circuit involved in the encoding of the
long term fear memory. Under certain circumstances, such
reactivation allows the incorporation and integration of new
information to the original memory trace. Here, we evaluated
whether fear memory reactivation impacts on the dendritic
spines remodeling in CA1 region of the dorsal hippocampus
associated with the formation of the contextual fear
memory. In the same way, we tested whether stress exposure
affects such dendritic spine remodeling. Thus, stressed
and control animals were fear conditioned and sacrificed 24
hr postconditioning (preretrieval), 60 min postretrieval or
24 hr postretrieval. A higher dendritic spines density, particularly
mature ones, were observed after fear encoding and
later reduced to basal levels 60 min after fear reactivation,
returning to higher levels 24 hr postretrieval. This temporal
dynamic structural plasticity was prevented by pharmacologically
blocking the destabilization/reconsolidation process in
the basolateral amygdala complex or by a single stress exposure
just before fear memory conditioning. Thus, the destabilization/
reconsolidation process was evidenced by a
change in the hippocampal structural plasticity immediately
following reactivation, a plausible necessary step for the
integration of new information.
