Hippocampal cells multiplex positive and negative engrams
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE208137 | GEO | 2022/07/19
REPOSITORIES: GEO
Similar Datasets
Project description:The hippocampus is involved in processing a variety of mnemonic computations including the spatiotemporal components, as well as the corresponding emotional dimensions, of contextual memory.1-3 Recent studies have demonstrated vast structural and functional heterogeneity along the dorsal-ventral axis1,5 of the hippocampus, and while much is known about how the dorsal hippocampus processes spatial-temporal content, much less is known about whether or not the ventral hippocampus (vHPC) partitions positive and negative experiences into distinct sets of cells.4-9 Here, we combine transgenic and all-virus based activity-dependent tagging strategies to visualize multiple valence-specific engrams in the vHPC and demonstrate two partially segregated cell populations and projections that respond to positive and negative experiences. Next, using an RNA sequencing approach, we find that vHPC positive and negative engram cells display distinct transcriptional programs compared to a neutral engram population. Additionally, while optogenetic manipulation of tagged cell bodies in vHPC is not sufficient to drive preference or avoidance, stimulation of tagged vHPC terminals projecting to the amygdala and nucleus accumbens (NAc), but not the prefrontal cortex (PFC), drives preference and avoidance. These terminals also can undergo a “switch” or “reset” in their capacity to drive either, thereby demonstrating their flexible contributions to behavior. We conclude that the vHPC contains genetically, cellularly, and behaviorally distinct populations of cells processing positive and negative memory engrams. Together, our findings provide a novel means by which to visualize multiple engrams within the same brain and point to their unique genetic signatures as reference maps for the future development of new therapeutic strategies.
2022-07-13 | GSE198731 | GEO
Project description:Hippocampal cells multiplex positive and negative engrams
| PRJNA858461 | ENA
Project description:Hippocampal cells multiplex positive and negative engrams
| PRJNA816561 | ENA
Project description:The ventral hippocampus (vHPC) is a critical hub in networks that process emotional information. While recent studies have indicated that vHPC projection neurons are functionally dissociable, the basic principles of how the inputs and outputs of the vHPC are organized remain unclear. Here we used viral and sequencing approaches to define the logic of the extended vHPC circuit. Through molecular profiling of vHPC projection neurons, we show that vHPC neurons with distinct projection targets differ in their transcriptional signatures.
2020-08-03 | GSE150869 | GEO
Project description:Engrams are considered to be substrates for memory storage, and the functional dysregulation of the engrams leads to cognition impairment.However, the cellular basis for these maladaptive changes lead to the forgetting of memories remains unclear. Here we found that the expression of autophagy protein 7 (Atg7) mRNA was dramatically upregulated in aged DG engrams, and led to the forgetting of contextual fear memory and the activation of surrounding microglia.To determine mechanism by which autophagy in DG engrams activates the surrounding microglia, mice were co-injected AAV-RAM-Cre either with AAV-Dio-Atg7-Flag or AAV-Dio- EYFP in dorsal dentate gyrus to overexpress ATG7 in the DG memory engrams. Microglia were separated using magnetic-activated cell sorting and subjected to RNA-Seq in dorsal hippocampus .Bioinformatics analysis shown overexpression of Atg7 in dorsal DG memory engrams caused an increase in the expression of Tlr2 in the surrounding microglia.Depletion of Toll-like receptor 2/4 (TLR2/4) in DG microglia prohibited excessive microglial activation and synapse elimination induced by the overexpression of ATG7 in DG engrams, and thus prevented forgetting. Furthermore, the expression of Rac1, a Rho-GTPases which regulates active forgetting in both fly and mice, was upregulated in aged engrams. Optogentic activation of Rac1 in DG engrams promoted the autophagy of the engrams, the activation of microglia, and the forgetting of fear memory. Invention of the Atg7 expression and microglia activation attenuated forgetting induced by activation of Rac1 in DG engrams. Together, our findings revealed autophagy-dependent synapse elimination of DG engrams by microglia as a novel forgetting mechanism.
2021-08-24 | GSE169019 | GEO
Project description:The hippocampus is involved in processing a variety of mnemonic computations specifically the spatiotemporal components and emotional dimensions of contextual memory. Recent studies have demonstrated cellular heterogeneity along the hippocampal axis. The ventral hippocampus has been shown to be important in the processing of emotion and valence. Here, we combine transgenic and all-virus based activity-dependent tagging strategies to visualize multiple valence-specific engrams in the vHPC and demonstrate two partially segregated cell populations and projections that respond to appetitive and aversive experiences. Next, using RNA sequencing and DNA methylation sequencing approaches, we find that vHPC appetitive and aversive engram cells display different transcriptional programs and DNA methylation landscapes compared to a neutral engram population. Additionally, optogenetic manipulation of tagged cell bodies in vHPC is not sufficient to drive appetitive or aversive behavior in real-time place preference, stimulation of tagged vHPC terminals projecting to the amygdala and nucleus accumbens (NAc), but not the prefrontal cortex (PFC), showed the capacity drive preference and avoidance. These terminals also were able to change their capacity to drive behavior. We conclude that the vHPC contains genetically, cellularly, and behaviorally segregated populations of cells processing appetitive and aversive memory engrams.
| S-EPMC9512908 | biostudies-literature
Project description:Memory engrams are a subset of learning activated neurons critical for memory recall, consolidation, extinction and separation. While the transcriptional profile of engrams after learning suggests profound neural changes underlying plasticity and memory formation, little is known about how memory engrams are selected and allocated. As epigenetic factors suppress memory formation, we developed a CRISPR screening in the hippocampus to search for factors controlling engram formation. We identified histone lysine-specific demethylase 4a (Kdm4a) as a novel regulator for engram formation. Kdm4a is downregulated after neural activation and controls the volume of mossy fiber boutons. Mechanistically, Kdm4a anchors to the exonic region of Trpm7 gene loci, causing the stalling of nascent RNAs and allowing burst transcription of Trpm7 upon the dismissal of Kdm4a. Furthermore, the YTH domain containing protein 2 (Ythdc2) recruits Kdm4a to the Trpm7 gene and stabilizes nascent RNAs. Reducing the expression of Kdm4a in the hippocampus via genetic manipulation or artificial neural activation facilitated the ability of pattern separation in rodents. Our work indicates that Kdm4a is a negative regulator of engram formation and suggests a priming state to generate a separate memory.
2024-06-12 | GSE269325 | GEO
Project description:The Hippocampus Consortium data set provides estimates of mRNA expression in the adult hippocampus of 99 genetically diverse strains of mice including 67 BXD recombinant inbred strains, 13 CXB recombinant inbred strains, a diverse set of common inbred strains, and two reciprocal F1 hybrids. The hippocampus is an important and intriguing part of the forebrain that is crucial in memory formation and retrieval, and that is often affected in epilepsy, Alzheimer's disease, and schizophrenia. Unlike most other parts of the brain, the hippocampus contains a remarkable population of stems cells that continue to generate neurons and glial cells even in adult mammals (Kempermann, 2005). This genetic analysis of transcript expression in the hippocampus (dentate gyrus, CA1-CA3) is a joint effort of 14 investigators that is supported by numerous agencies described in the acknowledgments section.
2016-07-26 | GSE84767 | GEO
Project description:People with schizophrenia show hyperactivity in the ventral hippocampus (vHipp) and we have previously demonstrated distinct behavioral roles for vHipp cell populations. Here, we test the hypothesis that parvalbumin (PV) and somatostatin (SST) interneurons differentially innervate and regulate hippocampal pyramidal neurons based on their projection target. First, we use eGRASP to show that PV-positive interneurons form a similar number of synaptic connections with pyramidal cells regardless of their projection target while SST-positive interneurons preferentially target nucleus accumbens (NAc) projections. To determine if these anatomical differences result in functional changes, we used in vivo opto-electrophysiology to show that SST cells also preferentially regulate the activity of NAc-projecting cells. These results suggest vHipp interneurons differentially regulate that vHipp neurons that project to the medial prefrontal cortex (mPFC) and NAc. Characterization of these cell populations may provide potential molecular targets for the treatment schizophrenia and other psychiatric disorders associated with vHipp dysfunction.
2023-11-09 | GSE244159 | GEO
Project description:We analyzed the binding profiles of MEF2D, a member of MEF2 family transcription factors, in rat hippocampal neurons. Keywords: ChIP-chip We used custom-designed rat genome tiling array manufactured by Nimblegen Systems, Inc . This array contains probes that represent the following rat genomic regions: 182 genes identified by mRNA profiling experiments, 86 genes whose expression was decreased by both KCl-mediated depolarization and MEF2 RNAi, and 40 control genes whose expression was not altered by MEF2 RNAi or MEF2-VP16-ER. The array not only covers the entire gene regions but also contains probes that correspond to the 40 kb 5â²and 3â² to each gene. Repeatmasking was conducted by Nimblegen to ensure that repetitive elements were not tiled on the microarray. Probe length and spacing between the probes were 50-75mer and 50 bp, respectively.
2010-05-06 | E-GEOD-13551 | biostudies-arrayexpress