Encoding of Contextual Fear Memory Requires De Novo Proteins in the Prelimbic Cortex
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE61529 | GEO | 2017/01/06
SECONDARY ACCESSION(S): PRJNA261396
REPOSITORIES: GEO
Similar Datasets
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:Encoding of Contextual Fear Memory Requires De Novo Proteins in the Prelimbic Cortex
| PRJNA261396 | ENA
Project description:The suppression of fear memory in the absence of danger (fear extinction) requires coordinated neural activity within the amygdala and medial prefrontal (prelimbic and infralimbic) cortex. Any behavior has a transcriptomic signature that is modified by environmental experiences, and specific genes are involved in functional plasticity and synaptic wiring during fear memory and extinction. In the present study, we investigated the effects of optogenetic manipulations of prelimbic pyramidal neurons on amygdala gene expression to analyze the specific transcriptional pathways involved in fear extinction. To this aim, transgenic mice (Thy1-COP4) having cortical and amygdala pyramidal neurons optogenetically excitable were (or not) fear-conditioned. During the extinction phase, the mice received optogenetic (or sham) stimulations to maintain the activation of the prelimbic pyramidal neurons and impair fear extinction. At the end of behavioral testing, electrophysiological (Excitatory Post-Synaptic Currents) and morphological (spinogenesis) correlates were evaluated in the pyramidal neurons of prelimbic cortex. Furthermore, transcriptomic cell-specific RNA-analyses (differential gene expression profiling and functional enrichment analyses) were performed in amygdala pyramidal neurons. Results demonstrate that pyramidal neurons of prelimbic cortex are involved in modulation of the fear responses during extinction phase and their optogenetic stimulation in fear-conditioned mice results in strong modifications of the amygdala transcriptome. Understanding the transcriptomic architecture of fear extinction may facilitate the comprehension of fear-related disorders.
2021-01-14 | GSE162417 | 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.
2014-06-16 | GSE58510 | GEO
Project description:The role of transfer (t)RNA cytosine methyl-transferases as epitranscriptomic regulators of brain proteomes remains unexplored. We report that fear memory and antidepressant-like behaviors are highly sensitive to bi-directional changes in Nsun2 tRNA methyltransferase activity in prefrontal cortex (PFC) neurons. Nsun2-deficient mutant cortex showed a selective deficit in multiple glycine tRNAs, resulting in codon-specific shifts in translational efficiencies and a distorted proteomic landscape with deficits in glycine-rich neuronal proteins impacting synaptic signaling and behavior.
2021-07-02 | PXD023437 | Pride
Project description:Epitranscriptomic mechanisms linking the brain proteome to cognition and complex behaviors essentially remain unexplored. Here, we describe bi-directional changes in depression-related behaviors after genetic disruption of neuronal tRNA cytosine methylation, including conditional ablation and transgene-derived overexpression of NOL1/NOP2/SUN domain 2 (Nsun2) in the prefrontal cortex (PFC). Neuronal Nsun2-deficiency was associated with a sharp drop in tRNA m5C levels, resulting in significant deficits in expression of 70% (7/10) of tRNAGlyGCC, GlyCCC GlyTCC isodecoders, while expression changes in non-glycinergic tRNAs were minimal (4/152). Altogether, 1488/5820 proteins were sensitive to neuronal Nsun2-deficiency, in conjunction with GCC and CCC codon-specific defects in translational efficiencies and loss of Gly-rich proteins critical for glutamatergic neurotransmission, resulting in impaired synaptic signaling at PFC pyramidal neurons and impairments in contextual fear memory. These distortions in the neuronal translatome were associated with an adaptive, 2.46-fold up-regulation in PFC glycine levels with increased expression of multiple enzymes in the glycine biosynthetic pathway. These findings highlight the methylation sensitivity of glycinergic tRNAs in the adult PFC and link synaptic plasticity and complex behaviors to epitranscriptomic regulation of cognate tRNAs and the proteomic homeostasis associated with specific amino acids.
2021-07-01 | GSE165202 | GEO
Project description:Sparse populations of neurons in the dentate gyrus (DG) of the hippocampus are causally implicated in the encoding of contextual fear memories. However, engram-specific molecular mechanisms underlying memory consolidation remain largely unknown. Here we perform unbiased RNA sequencing of DG engram neurons 24h after contextual fear conditioning to identify transcriptome changes specific to memory consolidation. DG engram neurons exhibit a highly distinct pattern of gene expression, in which CREB-dependent transcription features prominently (P=6.2x10-13), including Atf3 (P=2.4x10-41), Penk (P=1.3x10-15), and Kcnq3 (P=3.1x10-12). Moreover, we validate the functional relevance of the RNAseq findings by establishing the causal requirement of intact CREB function specifically within the DG engram during memory consolidation, and identify a novel group of CREB target genes involved in the encoding of long-term memory.
2019-03-30 | GSE129024 | GEO
Project description:Extinction learning refers to the phenomenon that a previously learned response to an environmental stimulus, for example the expression of an aversive behavior upon exposure to a specific context, is reduced when the stimulus is repeatedly presented in the absence of a previously paired aversive event. Extinction of fear memories has been implicated with the treatment of anxiety disease but the molecular processes that underlie fear extinctionare only beginning to emerge. Here we show that fear extinction initiates up-regulation of hippocampal insulin-growth factor 2 (Igf2) and down-regulation of insulin-growth factor binding protein 7 (Igfbp7). In line with this observation we demonstrate that IGF2 facilitates fear extinction, while IGFBP7 impairs fear extinction in an IGF2-dependent manner. Furthermore, we identify one cellular substrate of altered IGF2-signaling during fear extinction. To this end we show that fear extinction-induced IGF2/IGFBP7-signaling promotes the survival of 17-19 day-old newborn hippocampal neurons. In conclusion, our data suggests that therapeutic strategies that enhance IGF2-signaling and adult neurogenesis might be suitable to treat disease linked to excessive fear memory. We employed mice to investigate fear extinction in the hippocampus-dependent contextual fear conditioning paradigm. To this end, male C57BL/6J mice were exposed to the fear conditioning box (context) followed by an electric foot-shock which elicits the acquisition of conditioned contextual fear. For extinction training animals were repeatedly reexposed to the conditioned context on consecutive days (24h interval) without receiving the footshockagain (extinction trial, E). This procedure eventually results in the decline of the aversive freezing behavior. Mice that were exposed to the conditioning context without receiving fear conditioning training served as control groups. To gain a better understanding of the molecular processes underlying fear extinction we performed a genome-wide analysis of the hippocampal transcriptome during fear extinction. In the employed paradigm fear extinction is a gradual process. To capture the longitudinal course of fear extinction we decided to perform hippocampal microarray analysis at two time points: (1) After the first extinction trial (E1) when animals display high levels of aversive freezing behavior and (2) at the extinction trial on which the freezing behavior was significantly reduced when compared to E1. This extinction trial, in the case of this experiment E5, we termed “extinction trial low freezing” (ELF). Mice that were exposed to the conditioning context without receiving fear conditioning training served as control groups (3). For all three groups we hybridized 5 samples (biological replicates).
2011-08-07 | E-GEOD-31063 | biostudies-arrayexpress
Project description:Dopaminergic modulation of the prefrontal cortex (PFC) circuits is crucial for cognitive processes such as working memory, planning, attention and dysfunction. This system has been linked to cognitive deficits associated with schizophrenia and autism spectrum disorders. Despite its physiological and pathophysiological importance, we are still lacking a clear understanding of the basic principles of dopamine (DA) actions in the PFC. We set out to provide a detailed classification of layer 5 pyramidal neurons mediating the two main streams of DA signaling, namely via DA receptor group 1 (D1) and DA receptor group 2 (D2). To achieve this, we combined electrophysiological whole-cell recordings in acute slices of the prelimbic part (PL) of the medial PFC with single cell RNA sequencing, morphological and immunohistochemical analysis.
2020-07-01 | GSE129125 | GEO
Project description:This experiment uses a transgenic mouse that allows for activity-induced expression of an HA-tagged ribosome in an inducible and cre-dependent manner. This allowed us to assess long-lasting gene-expression changes in neurons active during contextual fear conditioning. Previous studies have used similar systems to look a transient changes in gene expression in these neurons, but we developed a system to look at long lasting changes. The workflow includes tissue dissection of the prefrontal cortex, tissue homogenization followed by an immunoprecipitation of the tagged ribosomes using antibodies against HA. RNA bound to the ribosomes is then purified, a cDNA library is prepared and RNAseq was performed. The experimental group was fear conditioned and the control group was left in their homecage for induction of HA- expression in active neurons.
2020-03-27 | E-MTAB-7836 | biostudies-arrayexpress