Gz_bjREP
Ontology highlight
ABSTRACT:
PROVIDER: EGAD00010001528 | EGA |
REPOSITORIES: EGA
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Project description:Aging is a complex biological process that compromises brain function and neuronal network activity, leading to cognitive decline and synaptic dysregulation. In recent years, a cyclic Ketogenic Diet (KD) has emerged as a potential treatment to ameliorate cognitive decline by improving memory in aged mice after long-term administration. However, whether short-term cyclic KD administration later in life preserves memory has not been addressed in detail. Accordingly, here we investigated how a short-term cyclic KD starting at 20-23 months-old regulates brain function of aged mice. Behavioral testing and long-term potentiation (LTP) recordings revealed that a cyclic KD improves working memory and hippocampal LTP in 24-27 months-old mice after 16 weeks of treatment. Moreover, the diet also promotes higher dendritic arborization complexity and dendritic spine density in the prefrontal cortex. Furthermore, to elucidate the molecular mechanisms underlying the memory improvements elicited by a cyclic KD, cortical synaptosomes of aged mice fed with this diet for 1 year were analyzed by mass spectrometry. Bioinformatics analysis revealed that long-term cyclic KD administration predominantly modulates the presynaptic compartment by inducing changes in the cAMP/PKA signaling pathway, the synaptic vesicle cycle and the actin/microtubule cytoskeleton. To test these findings in vivo, synaptic proteins from cortices of 24-27 month-old mice fed with control or cyclic KD for 16 weeks were analyzed by western blot. Interestingly, increased Brain Derived Neurotrophic Factor abundance, MAP2 phosphorylation and PKA activity were observed. Overall, we show that a cyclic KD regulates brain function and memory even when it is administered at late mid-life and significantly triggers several molecular features of long-term administration, including the PKA signaling pathway and cytoskeleton dynamics, thus promoting synaptic plasticity at advanced age.
2023-08-08 | MSV000092626 | MassIVE
Project description:The hippocampus plays an important role in spatial memory and the conversion of short-term to long-term memory. Several studies have reported the presence of a peripheral oscillator in the hippocampus, and have highlighted the importance of circadian regulation in memory formation. In this study we performed global quantitative phosphoproteome analyses of the murine hippocampus across the circadian cycle, applying spiked-in labeled reference and high accuracy mass spectrometry.
2017-04-11 | PXD005669 | Pride
Project description:Molecular mechanism of long-term memory has been extensively studied in the context of hippocampus-dependent recent memory examined within several days; however, months-old remote memory maintained in the cortex for long-term has not much been investigated at molecular levels yet. Various epigenetic mechanisms are known to be important for long-term memory, but how 3D chromatin architecture and its regulator molecules contribute to neuronal plasticity and memory consolidation are still largely unknown. To assess memory upon perturbation of 3D chromatin structure, we chose CCCTC-binding factor (CTCF), a seven-zinc finger protein well known for its role as a transcription factor and a chromatin regulator, and created the conditional knockout (cKO) mice, in which CTCF is lost in neurons during adulthood. Our CTCF cKO mice showed normal recent memory in contextual fear conditioning and spatial water maze task. However, they showed remarkable impairments in remote memory in both tasks. Underlying the remote memory-specific phenotypes, we found that loss of CTCF disrupts cortical long-term potentiation (LTP) but not hippocampal LTP. Through RNA-sequencing, we found that CTCF KD cultured cortical neurons have altered the expression of hundreds of genes, some of which we uncovered to be regulated by neuronal activity. These results suggest that remote memory storage in the cortex requires CTCF-mediated chromatin regulation in neurons while recent memory formation in the hippocampus does not.
2018-05-21 | GSE99230 | GEO
Project description:The circadian clock is an endogenous oscillator that drives daily rhythms in physiology, behavior and gene expression. The underlying mechanisms of circadian timekeeping are cell-autonomous and involve interconnecting transcription-translation feedback loops. The hippocampus plays an important role in spatial memory and the conversion of short-term to long-term memory. Several studies have reported the presence of a peripheral oscillator in the hippocampus, and have highlighted the importance of circadian regulation in memory formation. In this study we performed global quantitative proteome and phosphoproteome analyses of the murine hippocampus across the circadian cycle, applying spiked-in labeled reference and high accuracy mass spectrometry.
2017-04-11 | PXD005668 | Pride
Project description:Working memory is a form of short-term memory that involves maintaining and updating task relevant information toward goal-directed pursuits. Classical models posit persistent activity in prefrontal cortex (PFC) as a primary neural correlate, but emerging views suggest additional mechanisms may exist. We screened ~200 genetically diverse mice on a working memory task and identified a genetic locus on Chromosome 5 that contributes to a substantial proportion (17%) of the phenotypic variance. Within the locus, we identified a gene encoding an orphan G-protein coupled receptor, Gpr12, which is sufficient to drive substantial and bi-directional changes in working memory. Molecular, cellular, and imaging studies revealed that Gpr12 enables high thalamus-PFC synchrony to support memory maintenance and choice accuracy. These findings identify a novel orphan receptor as a potent modifier of short-term memory, and supplement classical PFC-based models with an emerging thalamus-centric framework for the mechanistic understanding of working memory.
2020-10-01 | GSE156836 | GEO
Project description:Understanding the mechanisms by which long-term memories are formed and stored in the brain represents a central aim of neuroscience. Prevailing theory suggests that long-term memory encoding involves early plasticity within hippocampal circuits, while reorganization of the neocortex is thought to occur weeks to months later to subserve remote memory storage. Here we report that long-term memory encoding can elicit early transcriptional, structural and functional remodeling of the neocortex. Parallel studies using genome-wide RNA-sequencing, ultrastructural imaging, and whole-cell recording in wild-type mice suggest that contextual fear conditioning initiates a transcriptional program in the medial prefrontal cortex (mPFC) that is accompanied by rapid expansion of the synaptic active zone and postsynaptic density, enhanced dendritic spine plasticity, and increased synaptic efficacy. To address the real-time contribution of the mPFC to long-term memory encoding, we performed temporally precise optogenetic inhibition of excitatory mPFC neurons during contextual fear conditioning. Using this approach, we found that real-time inhibition of the mPFC inhibited activation of the entorhinal-hippocampal circuit and impaired the formation of long-term associative memory. These findings suggest that encoding of long-term episodic memory is associated with early remodeling of neocortical circuits, identify the prefrontal cortex as a critical regulator of encoding-induced hippocampal activation and long-term memory formation, and have important implications for understanding memory processing in healthy and diseased brain states. 4 biological replicates per group were analyzed. The material analyzed was medial prefrontal cortex (mPFC; anterior cingulate cortex subregion) from both brain hemispheres, from which total RNA was extracted.
2014-06-16 | E-GEOD-58510 | biostudies-arrayexpress
Project description:Elite Long-Term Nonprogressors are asymptomatic HIV-infected individuals who display long-term virtually undetectable viremia, stable CD4 T cell counts and extremeley low levels of HIV reservoir, in the absence of antiretroviral therapy. We conducted a whole-genome transcriptional profiling study of sorted resting CD4 T cell subsets (naive, central memory, transitional memory and effector memory) in 7 Elite Long-Term Nonprogressors, 7 HIV-infected viremic and 7 uninfected individuals. HIV-1 cellular DNA levels were quantified in each sorted CD4 T cell subset
2015-01-10 | E-MTAB-1480 | biostudies-arrayexpress
Project description:Antimicrobial peptides modulate long-term memory
| PRJNA450853 | ENA
Project description:Remembrances of traumata range among the most enduring forms of memories. Despite the elevated lifetime prevalence of anxiety disorders, effective strategies to attenuate long-term traumatic memories are scarce. The most efficacious treatments to diminish recent (i.e., day-old) traumata capitalize on memory updating mechanisms during reconsolidation that are initiated upon memory recall. Here, we show that in mice successful reconsolidation-updating paradigms for recent memories fail to attenuate remote (i.e., month-old) ones. We find that whereas recent memory recall induces a limited period of hippocampal neuroplasticity mediated, in part, by S-nitrosylation of HDAC2 and histone acetylation, such plasticity is absent for remote memories. However, by using an HDAC2-targeting inhibitor (HDACi) during reconsolidation, even remote memories can be persistently attenuated. This intervention epigenetically primes the expression of neuroplasticity-related genes as revealed by whole genome RNA sequencing, which is accompanied by higher metabolic, synaptic and structural plasticity. Thus, applying HDACis during memory reconsolidation might constitute a treatment option for remote traumata. 3 biological replicates per group were analyzed. The material analyzed was whole hippocampi from one brain hemisphere, from which total RNA was extracted.
2014-01-04 | E-GEOD-53794 | biostudies-arrayexpress
Project description:Dynamics of hippocampal protein expression during long-term spatial memory formation
2015-12-01 | PXD002176 | Pride