In this study, we determined whether the calcium-dependent protein kinase (PKC) signaling pathway is involved in the improvement of fear memory reconsolidation induced by the intrahippocampal administration of spermidine in rats. Male Wistar rats were trained in a fear conditioning apparatus using a 0.4-mA footshock as an unconditioned stimulus. Twenty-four hours after training, animals were re...

After reactivation, apparently stable memories can become sensitive to modifications again, requiring another phase of stabilization, called reconsolidation. Recent evidence shows that repeated reactivations strengthen memories and that stronger memories are more resistant to alterations during reconsolidation. Therefore, we asked whether multiple reactivations make memories less vulnerable to ...

Memory reconsolidation is a central process enabling adaptive memory and the perception of a constantly changing reality. It causes memories to be strengthened, weakened or changed following their recall. A computational model of memory reconsolidation is presented. Unlike Hopfield-type memory models, our model introduces an unbounded number of attractors that are updatable and can process real...

A new memory is initially labile and becomes stabilized through a process of consolidation, which depends on gene expression. Stable memories, however, can again become labile if reactivated by recall and require another phase of protein synthesis in order to be maintained. This process is known as reconsolidation. The functional significance of the labile phase of reconsolidation is unknown; o...

In fear conditioning, aversive stimuli are readily associated with contextual features. A brief reexposure to the training context causes fear memory reconsolidation, whereas a prolonged reexposure induces memory extinction. The regulation of hippocampal gene expression plays a key role in contextual memory consolidation and reconsolidation. However, the mechanisms that determine whether memory...

The activity-regulated cytoskeletal-associated protein (Arc/Arg3.1) is an immediate-early gene that has been widely implicated in synaptic plasticity and in the consolidation of a variety of hippocampal- and amygdala-dependent memory tasks. The functional role of Arc/Arg3.1 in memory reconsolidation processes, however, has not been systematically studied. In the present study, we examined the r...

It is becoming increasingly clear that the processes of memory formation and storage are exquisitely dynamic. Elucidating the nature and temporal evolution of the biological changes that accompany encoding, storage, and retrieval is key to understand memory formation. For explicit or medial temporal lobe-dependent memories that form after a discrete event and are stored for a long time, the phy...

Stress enhances memory consolidation, in particular for emotional material. When reactivated, consolidated memories return to a fragile state again and thus require another period of stabilization, called reconsolidation. Rodent studies suggest that memory reconsolidation is impaired by stress. Here we examined in healthy humans the effect of stress on the reconsolidation of autobiographical me...

Schiller and Phelps (2011) have provided a thoughtful and comprehensive review in the May issue of Frontiers in Behavioral Neurosciences entitled, “Does reconsolidation occur in humans?” This scholarly paper captures many of the challenges in translating the animal research on reconsolidation to humans. We agree with their main argument that there is little published evidence in humans that mee...