Activity-dependent genetic labeling during behavioral learning shows Fragile-X syndrome model mice exhibit impaired hippocampal engram reactivation, and that enriched environment experience improves fear memory retrieval by enhancing engram reactivation efficacy.

Prelimbic cortical inputs are differentially recruited during early memory consolidation, with claustrum projections involved at encoding and insular cortex projections recruited for recent recall.

Current findings help reconcile the contradictory reports regarding the role of infralimbic cortex in the environmental control of appetitive behavior.

Flies can optimally recall a memory with high specificity by comparing options close in time, or default to generalization when they cannot.

Functionally refined organization of learned and innate threat encoding in the cholinergic basal forebrain.

Consistent with an existing computational model of hippocampal function, using real-time feedback to drive artificial memories at the trough of the hippocampal theta rhythm improves apparent recall.

Ensemble fluidity, observed as synaptic turnover and temporal drift in neuronal patterns, supports memory-updating and flexibility while maintaining memory stability.

The combination of juxtacellular recordings with optogenetics in freely moving mice enables the targeting of genetically defined cell classes for high-resolution, single-cell structure–function analysis.