Long-term memory

…cortex, facilitating integration into long-term memory networks. Our recent study showed that the precise temporal dynamics of cross-area coupling between prefrontal cortex (PFC) and primary motor cortex (M1) can demarcate the transition to cortical stabilization and task performance, reducing involvement of the hippocampus. Here, we demonstrate the causal role of precise coupling in PFC-M1 sleep slow oscillation (SO) for motor memory stabilization. Using a s

Memory consolidation is promoted by sleep. However, there is also evidence for consolidation into long-term memory during wakefulness via processes that preferentially affect nonhippocampal representations. We compared, in rats, the effects of 2-h postencoding periods of sleep and wakefulness on the formation of long-term memory for objects and their associated environmental contexts. We employed a novel-object recognition (NOR) task, using object exploration and exploratory rearing as behavioral indicators of these memories. Remote recall testing (after 1 wk) confirmed significant long-term N

…plasticity and is important for long-term memory. However, the direct effects of dopamine on protein synthesis rates and the functional implications of the newly synthesized proteins remain largely unknown. Here, we show that dopamine increases the rate of protein synthesis in hippocampal neurons in CA1, enabling dopamine-dependent long-term potentiation (DA-LTP). Neuronal activity is required for the dopamine-induced increase in protein synthesis, and we found that DA-LTP is mediated by t

The consolidation of long-term memory is thought to critically rely on sleep. However, first evidence from a study in drosophila suggests that hunger as another brain state can benefit memory consolidation as well. Here, we report two human (within-subjects crossover) experiments examining the effects of fasting (versus satiated conditions) during a 10-hour post-encoding consolidation period on later recall of declarative and procedural memories in healthy men. In Experiment 1, participants (n = 16), after an 18.5-hour fasting period, encoded 3 memory tasks (verbal word paired associates, a vi

…extensively researched; learning and memory have not studies. Moreover, the consequences connected to gender are not clearly discussed. You therefore made the decision to contrast and investigate spatial memory in male and female rats.In the present study, we assessed the short

It is challenging to create chemical-induced models of Alzheimer’s disease without using genetically bred animals. Intracerebroventricular (ICV) streptozocin (STZ) administration at a sub-diabetogenic dose can serve as a viable model for cognitive impairment associated with Alzheimer's disease via a disruption of glucose and energy metabolism in the brain, accompanied by oxidative stress and a concurrent impact on cognitive function. The aim of this study is to evaluate the behavioral results of once or twice injections of the ICV STZ administration methods. ICV guide cannulas were placed unil

…was generated showed impairment in long-term memory and an absence of this gene in the Cortex and CA1 regio

The brain parenchyma undergoes several structural changes throughout life that significantly impact on its physiology, and are reflected in changes in cognitive abilities. The aim of this healthy ageing study was to investigate how age-related microstructural alterations affect the degree of preserved cognition in the elderly. We sought to identify brain region- and age-specific patterns that contribute to the physiological decline in cognition. To this end, we compared behavioral and microstructural MRI biomarkers in adult (6 months) and old (1.5 years) Wistar rats. Additionally, we analyzed

…neurogenesis, a pivotal constituent of long-term memory, and its susceptibility to stress. The ongoing hypothesis is that stress, by impeding neurogenesis, contributes to symptoms associated with post-traumatic stress disorder (PTSD). Our work explores the potential of delta-9-tetrahydrocannabinol (THC), the psychoactive constituent of cannabis, in mitigating stress-induced gene expression alterations in astrocytes, thereby fostering neurogenesis. The initial phase involves inducing cellular stress in an astrocyte-

Sleep benefits memory consolidation, especially the first hours following learning, as shown in humans and rodents. However, the effect of sex on both memory performance and its dependency on sleep remains poorly investigated. To investigate the interaction between sex and sleep on memory consolidation, we employed the Novel Object Recognition Test (NORT) in rodents, a task reliant on post-learning sleep for consolidation. Six-month-old male and female mice (n=10/group) were trained with two objects, followed by either undisturbed sleep (control group) or 5 hours of sleep deprivation (SD grou

…and neurons underlies spatial memory in vivo remains unknown, as does its potential link to AD's pathogenesis.To address these challenges, we developed a spatial memory task where mice, tracked with DeepLabCut automated

…can show large effects on learning and memory. Dopaminergic projections to the hippocampus play an important role in the formation of long-term memories. For example, previous studies have employed a reward anticipation manipulation during memory formation, eliciting dopaminergic responses in the midbrain and subsequently enhancing the encoding of memories. Until now, the origin of these dopaminergic projections has been attributed to the ventral tegmental area/substantia nigra

How can short-lived molecules selectively maintain potentiation of synapses to sustain long-term potentiation (late-LTP) and long-term memory? One possibility, suggested by Francis Crick (Nature, 1984), is that continual interaction between synaptic molecules maintains the strengthening of activated synapses in the face of molecular turnover. Here, we tested the hypothesis that continual interaction between KIBRA, a postsynaptic scaffolding protein genetically linked to human memory performance, with the autonomously active, atypical PKC isoform PKMζ, maintains late-LTP and long-term memory. U

The process of memory consolidation involves the transfer of information from short-term memory (STM) to long-term memory (LTM). Memory consolidation requires activation of the dorsal hippocampus (dHP), especially under conditions of high memory load. In this study, we asked whether there is a limit to the memory capacity, that is, the amount of information that can be stored during unique experiences. Using male and female outbred CD1 mice subjected to a modified version of the object recognition test, we found that females, despite having the same 6- object STM capacity as males, appear to t

Exposure to novelty around the time of weak training enhances long-term memory (Ballarini et al., 2009). This enhancement is conserved across rodent models to humans (Fenker et al., 2009). It was proposed that synapses have been ‘tagged’ during the weak training and captured later by the strong event, i.e. novelty exposure (Moncada et al., 2007; Lisman et al., 2011). Concurrently, novelty induces dopamine and noradrenaline release in the hippocampus which similarly enhances memories (Moncada et al., 2011; Duszkiewicz et al., 2019). However, the synaptic and molecular changes induced by novelty

Learning resulting in long-term memory correlates with the formation of new dendritic spines. However, are these newly grown spines only a correlate or a necessity for long-term memory storage? The most direct way to answer this fundamental question is to build a tool to selectively eliminate newly formed dendritic spines, and to then apply this tool in vivo to observe whether a recently acquired long-term memory is destabilized.To this end, we have developed a chemical-genetic selective new spine elimination tool (NSET) in organotypic hippocampal slice cultures. This tool consists of two comp

…retroactive interference - obstructing memory for the initially trained sequence but not for the second. However, in the context of hippocampal-system dependent memories, a poor learning experience, one whose behavioral effects would soon decay, can be enhanced if temporally paired with a ‘strong’, consolidation-triggering, experience. The Synaptic Tagging and Capture hypothesis (STC) explains this paradoxical enhancement by suggesting that synapses specifically engaged in a ‘weak’ learn

…which information is retained in memory. However, memory is not only affected by the amount of time spent viewing a visual scene but also by specific gaze patterns during visual exploration. Revisitations occur when the eye gaze returns to a previously fixated location, resembling retrieval processes and offering another chance to encode. What remains unclear is whether revisitations actually enhance long-term memory formation and how they are associated with hippocampal activity dynamics. In this study, 50 human participant

…stagnalis, epicatechin facilitates memory formation through conditioned taste aversion (CTA) training. These snails were categorized into two groups: "good learner" and "poor learner", based on their feeding behaviour 24hours after CTA training. The "good learner" snails showed at least a 40% reduction in feeding behaviour compared to the pre-test levels, while the others were categorized as "poor learner". This study first investigated the effe

Understanding and potentially reversing memory decline necessitates a comprehensive examination of memory's evolution throughout life. Traditional memory assessments, however, suffer from a lack of comparability across different age groups due to the diverse nature of the tests employed. Addressing this gap, our study introduces a novel, ACT-R model-based memory assessment designed to provide a consistent metric for evaluating memory function across a lifespan, from 5 to 85-year-olds. This approach allows for direct comparison across various tasks and materials tailored to specific age groups.

Visual working memory (VWM) is limited in capacity, but memorizing meaningful objects may refine this limitation. However, meaningless and meaningful stimuli usually differ perceptually and an object’s association with meaning is typically already established before the actual experiment. We applied a strict control over these potential confounds by asking observers (N=45) to actively learn associations of (initially) meaningless objects. To this end, a change detection task presented Chinese characters, which were meaningless to our observers. Subsequently, half of the characters were consist

…first of its kind and scale in which long-term memory effects of blind listeners’ speaker identification abilities are examined. For the empirical investigation, all listeners were evenly assigned to one of n

…and recall of structured knowledge in long-term memory. Specifically, we ask how recurrent neuronal networks can store and retrieve multiple knowledge structures. We model each structure as a set of binary relations between events and attributes (attributes may represent e.g., temporal order, spatial location, role in semantic structure), and map e

We examine consciousness from the perspective of theoretical computer science (TCS), a branch of mathematics concerned with understanding the underlying principles of computation and complexity, including the implications and surprising consequences of resource limitations. We propose a formal TCS model, the Conscious Turing Machine (CTM). The CTM is influenced by Alan Turing's simple yet powerful model of computation, the Turing machine (TM), and by the global workspace theory (GWT) of consciousness originated by cognitive neuroscientist Bernard Baars and further developed by him, Stanislas D