Replay articles from across Nature Portfolio

A study of neuronal activity in rats finds that sleep loss adversely affects hippocampal function and memory by dissociating hippocampal sharp-wave ripples from memory replay and reactivation events.

Using a Bayesian learning approach, a study tracks the spatial representations by individual hippocampal cells over time in freely moving rats, and provides insights into how ensemble patterns form and reconfigure during sleep.

Artificial neural networks are known to perform well on recently learned tasks, at the same time forgetting previously learned ones. The authors propose an unsupervised sleep replay algorithm to recover old tasks synaptic connectivity that may have been damaged after new task training.

Sleep is known to promote memory consolidation, but the extent to which this is dependent on the memory’s relevance remains unclear. Here, the authors use a brain decoding approach to show that neural representations of rewarded experiences undergo a privileged reactivation during sleep, favouring their consolidation.

Sleep after learning helps to strengthen new memories. Here, the authors link this memory benefit to the reactivation of learning experiences when two endogenous sleep rhythms—slow oscillations and sleep spindles—coincide.

Learning-activated engram neurons play a critical role in memory recall but the role of these neurons in offline memory consolidation is unclear. The authors show that sleep-associated reactivation of learning-activated sensory neurons is necessary for memory consolidation.

In this Journal Club, Adrien Peyrache highlights a 1998 paper that showed memory formation as a dynamic process involving multiple brain areas.

In rats, CA1 place cells that encode the location of an aversive experience are reactivated during retrieval of the memory of that event.

Head direction cells have been hypothesized to form representations of an animal's spatial orientation through internal network interactions. New data from mice show the predicted signatures of these internal dynamics.