Creating true and false memories from forgotten information in Drosophila

Recovering forgotten memories is a double-edged sword. While regaining access to forgotten information can be beneficial, targeted memory recovery carries the risk of generating false memories. The current understanding of neuronal circuits governing memory recovery or false memory implantation remains limited. We find in fruit flies that a reminder can recover forgotten aversive memories. This recovery requires a silent memory to recruit a specific pair of dopaminergic neurons. Modifying the reminder can mislead the recovery process and implant a false aversive memory. The effectiveness of this false memory implantation depends on the contextual boundaries of the training event. Compared to memory recovery, false memory implantation recruits a distinct dopamine pathway. Understanding these distinctions between true and false memory formation is essential for preventing and rectifying the acquisition of misleading information.