scholarly journals Human sensory Long-Term Potentiation (LTP) predicts visual memory performance and is modulated by the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism

2018 ◽  
Author(s):  
M.J. Spriggs ◽  
C.S. Thompson ◽  
D Moreau ◽  
N.A. McNair ◽  
C.C. Wu ◽  
...  
Keyword(s):  
Visual Memory ◽  
Memory Performance ◽  
Memory Function ◽  
Human Memory ◽  
Long Term Potentiation ◽  
Long Term Memory ◽  
Term Memory ◽  
Term Potentiation ◽  
The Relationship

BackgroundLong-Term Potentiation (LTP) is recognised as a core neuronal process underlying long-term memory. However, a direct relationship between LTP and human memory performance is yet to be demonstrated. The first aim of the current study was thus to assess the relationship between LTP and human long-term memory performance. With this also comes an opportunity to explore factors thought to mediate the relationship between LTP and long-term memory, and to gain additional insight into variations in memory function and memory decline. The second aim of the current study was to explore the relationship between LTP and memory in groups differing with respect to BDNF Val66Met; a single nucleotide polymorphism implicated in memory function.Methods28 participants (15 female) were split into three genotype groups (Val/Val, Val/Met, Met/Met) and were presented with both an EEG paradigm for inducing LTP-like enhancements of the visually-evoked response, and a test of visual memory.ResultsThe magnitude of LTP 40 minutes after induction was predictive of long-term memory performance. Additionally, the BDNF Met allele was associated with both reduced LTP and reduced memory performance.ConclusionsThe current study not only presents the first evidence for a relationship between sensory LTP and human memory performance, but also demonstrates how targeting this relationship can provide insight into factors implicated in variation in human memory performance. It is anticipated that this will be of utility to future clinical studies of disrupted memory function.

scholarly journals Deletion of novel protein TMEM35 alters stress-related functions and impairs long-term memory in mice

2016 ◽  
Vol 311 (1) ◽  
pp. R166-R178 ◽  
Author(s):  
Bruce C. Kennedy ◽  
Jiva G. Dimova ◽  
Srikanth Dakoji ◽  
Li-Lian Yuan ◽  
Jonathan C. Gewirtz ◽  
...  
Keyword(s):  
Hpa Axis ◽  
Pathway Analysis ◽  
Transmembrane Protein ◽  
Long Term Potentiation ◽  
Synaptic Proteins ◽  
Molecular Networks ◽  
Long Term Memory ◽  
Term Memory ◽  
Term Potentiation

The mounting of appropriate emotional and neuroendocrine responses to environmental stressors critically depends on the hypothalamic-pituitary-adrenal (HPA) axis and associated limbic circuitry. Although its function is currently unknown, the highly evolutionarily conserved transmembrane protein 35 (TMEM35) is prominently expressed in HPA circuitry and limbic areas, including the hippocampus and amygdala. To investigate the possible involvement of this protein in neuroendocrine function, we generated tmem35 knockout (KO) mice to characterize the endocrine, behavioral, electrophysiological, and proteomic alterations caused by deletion of the tmem35 gene. While capable of mounting a normal corticosterone response to restraint stress, KO mice showed elevated basal corticosterone accompanied by increased anxiety-like behavior. The KO mice also displayed impairment of hippocampus-dependent fear and spatial memories. Given the intact memory acquisition but a deficit in memory retention in the KO mice, TMEM35 is likely required for long-term memory consolidation. This conclusion is further supported by a loss of long-term potentiation in the Schaffer collateral-CA1 pathway in the KO mice. To identify putative molecular pathways underlying alterations in plasticity, proteomic analysis of synaptosomal proteins revealed lower levels of postsynaptic molecules important for synaptic plasticity in the KO hippocampus, including PSD95 and N-methyl-d-aspartate receptors. Pathway analysis (Ingenuity Pathway Analysis) of differentially expressed synaptic proteins in tmem35 KO hippocampus implicated molecular networks associated with specific cellular and behavioral functions, including decreased long-term potentiation, and increased startle reactivity and locomotion. Collectively, these data suggest that TMEM35 is a novel factor required for normal activity of the HPA axis and limbic circuitry.

Long-Term Memory Performance in Adult ADHD

2016 ◽  
Vol 21 (4) ◽  
pp. 267-283 ◽  
Author(s):  
Timo Skodzik ◽  
Heinz Holling ◽  
Anya Pedersen
Keyword(s):  
Visual Memory ◽  
Adult Adhd ◽  
Memory Performance ◽  
Meta Analysis ◽  
Long Term Memory ◽  
Term Memory ◽  
Memory Tests ◽  
Memory Acquisition ◽  
Meta Analyses

Objective: Memory problems are a frequently reported symptom in adult ADHD, and it is well-documented that adults with ADHD perform poorly on long-term memory tests. However, the cause of this effect is still controversial. The present meta-analysis examined underlying mechanisms that may lead to long-term memory impairments in adult ADHD. Method: We performed separate meta-analyses of measures of memory acquisition and long-term memory using both verbal and visual memory tests. In addition, the influence of potential moderator variables was examined. Results: Adults with ADHD performed significantly worse than controls on verbal but not on visual long-term memory and memory acquisition subtests. The long-term memory deficit was strongly statistically related to the memory acquisition deficit. In contrast, no retrieval problems were observable. Conclusion: Our results suggest that memory deficits in adult ADHD reflect a learning deficit induced at the stage of encoding. Implications for clinical and research settings are presented.

scholarly journals Neural correlates of episodic memory modulated by temporally delayed rewards

2019 ◽  
Author(s):  
Jungsun Yoo ◽  
Seokyoung Min ◽  
Seung-Koo Lee ◽  
Sanghoon Han
Keyword(s):  
Memory Performance ◽  
Long Term Potentiation ◽  
Neural Correlates ◽  
Temporal Distance ◽  
Long Term Memory ◽  
Memory Encoding ◽  
Term Potentiation ◽  
Subjective Value ◽  
Behavioral Memory

AbstractWhen a stimulus is associated with an external reward, its chance of being consolidated into long-term memory is boosted via dopaminergic facilitation of long-term potentiation in the hippocampus. Given that higher temporal distance (TD) has been found to discount the subjective value of a reward, we hypothesized that memory performance associated with a more immediate reward will result in better memory performance. We tested this hypothesis by measuring both behavioral memory performance and brain activation using functional magnetic resonance imaging (fMRI) during memory encoding and retrieval tasks. Contrary to our hypothesis, both behavioral and fMRI results suggest that the TD of rewards might enhance the chance of the associated stimulus being remembered. The fMRI data demonstrate that the lateral prefrontal cortex, which shows encoding-related activation proportional to the TD, is reactivated when searching for regions that show activation proportional to the TD during retrieval. This is not surprising given that this region is not only activated to discriminate between future vs. immediate rewards, it is also a part of the retrieval-success network. These results provide support for the conclusion that the encoding-retrieval overlap provoked as the rewards are more delayed lead to better memory performance of the items associated with the rewards.

scholarly journals Endophilin A1 drives acute structural plasticity of dendritic spines in response to Ca2+/calmodulin

2021 ◽  
Vol 220 (6) ◽  
Author(s):  
Yanrui Yang ◽  
Jiang Chen ◽  
Xue Chen ◽  
Di Li ◽  
Jianfeng He ◽  
...  
Keyword(s):  
Learning And Memory ◽  
Dendritic Spines ◽  
Actin Polymerization ◽  
Structural Plasticity ◽  
Long Term Potentiation ◽  
Membrane Dynamics ◽  
Long Term Memory ◽  
Term Memory ◽  
Term Potentiation

Induction of long-term potentiation (LTP) in excitatory neurons triggers a large transient increase in the volume of dendritic spines followed by decays to sustained size expansion, a process termed structural LTP (sLTP) that contributes to the cellular basis of learning and memory. Although mechanisms regulating the early and sustained phases of sLTP have been studied intensively, how the acute spine enlargement immediately after LTP stimulation is achieved remains elusive. Here, we report that endophilin A1 orchestrates membrane dynamics with actin polymerization to initiate spine enlargement in NMDAR-mediated LTP. Upon LTP induction, Ca2+/calmodulin enhances binding of endophilin A1 to both membrane and p140Cap, a cytoskeletal regulator. Consequently, endophilin A1 rapidly localizes to the plasma membrane and recruits p140Cap to promote local actin polymerization, leading to spine head expansion. Moreover, its molecular functions in activity-induced rapid spine growth are required for LTP and long-term memory. Thus, endophilin A1 serves as a calmodulin effector to drive acute structural plasticity necessary for learning and memory.

scholarly journals Information Loss over Time Defines the Memory Defect of Propofol

2004 ◽  
Vol 101 (4) ◽  
pp. 831-841 ◽  
Author(s):  
Robert A. Veselis ◽  
Ruth A. Reinsel ◽  
Vladimir A. Feshchenko ◽  
Ray Johnson
Keyword(s):  
Drug Administration ◽  
Memory Performance ◽  
Memory Function ◽  
Recognition Task ◽  
Long Term Memory ◽  
Drug Induced ◽  
Term Memory ◽  
Median Split ◽  
Hypnotic Drugs

Background Sedative-hypnotic drugs impair memory, but details regarding the nature of this effect are unknown. The influences of propofol, thiopental, and dexmedetomidine on the performance of a task that isolates specific components of episodic memory function were measured. Methods Working (1 intervening item, 6 s) and long-term memory (10 intervening items, 33 s) were tested using auditory words in a continuous recognition task before and during drug administration. Eighty-three volunteer participants were randomly assigned to receive a constant target concentration of drug or placebo, producing sedative effects from imperceptible to unresponsiveness. Responsive participants were categorized as high or low performers, using a median split of long-term memory performance during drug administration. Recognition of words at the end of the study day was assessed. Results High performers had acquisition of material into long-term memory when drug was present at the same level as placebo. Retention of this material at 225 min was significantly less for propofol (39 +/- 23% loss of material) than for other drugs (17-23% loss; P < 0.01). Greater sedation in low performers was evident in multiple measures. Memory for words presented before drug was no different from that associated with placebo for all groups. Conclusions Lack of retention of material acquired into long-term memory during propofol administration, associated with minimal sedation, seems to define drug-induced amnesia. Sedation seems to impair the acquisition or encoding of material into long-term memory. Therefore, the putative targets of drug-induced amnesia by propofol are processes associated with retention of material in long-term memory.

scholarly journals Sustained Attention and Spatial Attention Distinctly Influence Long-term Memory Encoding

2021 ◽  
pp. 1-17
Author(s):  
Megan T. deBettencourt ◽  
Stephanie D. Williams ◽  
Edward K. Vogel ◽  
Edward Awh
Keyword(s):  
Spatial Attention ◽  
Sustained Attention ◽  
Memory Performance ◽  
Stimulus Onset ◽  
Long Term Memory ◽  
Attention And Memory ◽  
Memory Encoding ◽  
Term Memory ◽  
The Relationship

Abstract Our attention is critically important for what we remember. Prior measures of the relationship between attention and memory, however, have largely treated “attention” as a monolith. Here, across three experiments, we provide evidence for two dissociable aspects of attention that influence encoding into long-term memory. Using spatial cues together with a sensitive continuous report procedure, we find that long-term memory response error is affected by both trial-by-trial fluctuations of sustained attention and prioritization via covert spatial attention. Furthermore, using multivariate analyses of EEG, we track both sustained attention and spatial attention before stimulus onset. Intriguingly, even during moments of low sustained attention, there is no decline in the representation of the spatially attended location, showing that these two aspects of attention have robust but independent effects on long-term memory encoding. Finally, sustained and spatial attention predicted distinct variance in long-term memory performance across individuals. That is, the relationship between attention and long-term memory suggests a composite model, wherein distinct attentional subcomponents influence encoding into long-term memory. These results point toward a taxonomy of the distinct attentional processes that constrain our memories.

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