Topic: memory reactivation

Through the process of reconsolidation, consolidated memories can be reactivated and temporarily labialized, allowing them to be updated in strength and content. In the framework of reconsolidation, a prediction error (PE) is proposed as the key mechanism that triggers the process. Generally speaking, a PE is a mismatch between expected (based on prior experience) and current events. Previous associative memory reconsolidation studies show that incomplete reminders (IR) are a subtype of prediction error that strengthen memory trace. These reminders consist in an incomplete trial that ends abru

Memory reconsolidation is the mechanism by which consolidated memories are updated in strength and/or content. Thus, memory reactivation can enhance the retention of reactivated items at long delays. An underlying hypothesis to these findings suggests that reconsolidation would be “reactivation specific”, implying that only the reactivated elements after consolidation would be susceptible to modifications. However, episodic memories are intrinsically associative, which implies that they are integrated into interconnected- networks between its elements and the acquisition context. Reactivation

Every day we make decisions critical for adaptation and survival. We repeat actions with known consequences. But we can also infer associations between loosely related events to infer and imagine the outcome of entirely novel choices. In the first part of the talk I will show that during successful inference, the mammalian brain uses a hippocampal prospective code to forecast temporally structured learned associations. Moreover, during periods of rest, co-activation of hippocampal cells in sharp-wave/ripples represent inferred relationships that include reward, thereby “joining-the-dots” betwe

The brain continuously encodes new information as memories. At the synaptic level, memory formation is enabled by adjusting connections between activated excitatory neurons in the cortex, with mirroring inhibitory activity ensuring stable storage. Particularly, synaptic plasticity occurs as memory reactivation takes place during sleep, contributing to increased memory stability. However, the mechanism by which reactivation mediates plasticity to balance network currents for stable memory storage remains unclear. Here, we investigated whether a newly proposed form of codependent plasticity coul

The interaction between sleep function and memory processing is widely observed in both animals and humans, especially in how sleep supports memory consolidation and forgetting. However, whether memory activity during sleep has any regulatory effect on sleep processes is poorly investigated. Here we find that sensory stimuli-triggered emotional memory reactivation significantly affects sleep strategies after learning, as negative memory promotes alertness in sleep while positive memory protects sleep from perturbation. By combining EEG/EMG recording and engram cell activity tracing, our data r

The fundamental assumption of a functional system for encoding spatial information lies in the stability and preserved integrity of neural representations. In extreme cases, such as psychotic states in schizophrenia, there is a disruption of this stability, often resulting in the fusion of distinct neural representations. In this study, both familiar (F) and novel (N) linear mazes were utilized to assess the quality of neural coding across various time scales in 3-6 months old rats (N = 12). Lower (0.1 mg/kg) and higher doses (0.15 mg/kg) of MK-801 were administered. We observed disrupted spat