An update on memory reconsolidation updating

TL;DR: In this article , a group of adult smoking volunteers engaged in a period of desire thinking before performing an associative learning task in which neutral words (cues) were shown along with images (smoking-related vs. neutral context) at different frequencies.

TL;DR: A role for delta oscillations in memory reactivation is suggested that should be further investigated, and lower power of delta and strength of delta-gamma oscillations coupling in MS rats, compared to NH, could explain the low Zif268 levels in a subgroup of MS animals.

Abstract: Abstract Recalled memories become transiently labile and require stabilization 1–3 . The mechanism for stabilizing memories of survival-critical experiences, which are often emotionally salient and repeated, remains unclear 4 . Here we identify an astrocytic ensemble that is transcriptionally primed by emotional experience and functionally triggered by repeated experience to stabilize labile memory. Using a novel brain-wide Fos tagging and imaging method, we found that astrocytic Fos ensembles were preferentially recruited in regions with neuronal engrams 5 and were more widespread during fear recall than during conditioning. We established the induction mechanism of the astrocytic ensemble, which involves two steps: (1) an initial fear experience that induces day-long, slow astrocytic state changes with noradrenaline receptor upregulation; and (2) enhanced noradrenaline responses during recall, a repeated experience, enabling astrocytes to integrate coincident signals from local engrams and long-range noradrenergic projections, which induce secondary astrocytic state changes, including the upregulation of Fos and the neuromodulatory molecule IGFBP2. Pharmacological and genetic perturbation of the astrocytic ensemble signalling modulate engrams, and memory stability and precision. The astrocytic ensemble thus acts as a multiday trace in a subset of astrocytes after experience-dependent neural activity, which are eligible to capture future repeated experiences for stabilizing memories.

TL;DR: ........................................................................................................ii Table of Diseases of the Landmarks of Europe and Northern Europe shows the variety of diseases that have affected the landscape over the centuries.

TL;DR: A heated debate has been revitalized on whether memories become labile and must undergo some form of renewed consolidation every time they are activated, and on fundamental issues concerning the nature of the memory trace, its maturation, persistence, retrievability, and modifiability.

TL;DR: The findings indicate that the long-lasting trace of an experience is not completely fixed, consolidated, or coded at the time of the experience, and that any search for the engram or the basis of memory is not going to be successful.

TL;DR: The adaptive role of reconsolidation as a window of opportunity to rewrite emotional memories is demonstrated, and a non-invasive technique that can be used safely in humans to prevent the return of fear is suggested.

TL;DR: The temporal dynamics of memory reconsolidation are dependent on the strength and age of the memory, such that younger and weaker memories are more easily reconsolidated than older and stronger memories.