We thank Dunsmoor et al. [1] for their timely and comprehensive examination of how salient events, including novelty and emotion, can save mundane memories from oblivion when encountered in close temporal proximity – an effect sometimes referred to as ‘memory’s penumbra’. We specifically applaud their efforts in linking neurobiological mechanisms as identified in rodents to emerging behavioral findings in humans, while explaining these in light of existing memory models. They address the synaptic-tagging-and-capture hypothesis – for which two conditions are indispensable: (i) local setting of synaptic tags generated by appropriate synaptic activity; and (ii) availability of plasticity-related proteins (PRPs) that are synthesized as a result of the activation of neuromodulatory systems in a time-dependent manner [2] – to explain how on a neuronal level an initially weak memory trace becomes stable when a salient event is experienced during a critical time window around it.
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