Project description:To identify the activity-induced gene expression programs in inhibitory and excitatory neurons, we analyzed RNA extracted from cultured E14 mouse MGE- and CTX-derived neurons (DIV 10) after these cultures were membrane-depolarized for 0, 1 and 6 hrs with 55mM extracellular KCl. To identify the gene programs regulated in these cells by the activity-induced early-response transcription factor Npas4, we repeated the same experiment in the MGE- and CTX-cultures lacking Npas4 (Npas4-KO). Littermate mouse E14 MGE- or CTX-derived neurons (WT or KO for Npas4) were cultured for 9 days, quieted overnight with TTX and AP-5 and then membrane-depolarized for 0, 1 or 6 hours by raising the extracellular KCl-concentration to 55mM. RNA was then extracted and analyzed using Affymetrix GeneChip Mouse Expression Set 430 2.0 microarray platform.
Project description:To identify the activity-induced gene expression programs in inhibitory and excitatory neurons, we analyzed RNA extracted from cultured E14 mouse MGE- and CTX-derived neurons (DIV 10) after these cultures were membrane-depolarized for 0, 1 and 6 hrs with 55mM extracellular KCl. To identify the gene programs regulated in these cells by the activity-induced early-response transcription factor Npas4, we repeated the same experiment in the MGE- and CTX-cultures lacking Npas4 (Npas4-KO).
Project description:we used DNA microarray analysis to identify genes that are induced by neuronal activity in excitatory neurons at the time when inhibitory synapses are forming and maturing on them. Experiment Overall Design: We cultured cortical neurons for 7 DIV until the process of inhibitory synapse development was underway, and then depolarized the neurons with 50 mM of KCl to activate L-type voltage-sensitive calcium channels (L-VSCCs) for 0, 1 or 6 hours, the cells were lysed, mRNA isolated and hybridized to Affymetrix arrays. Data were collected from 3 independent experiments.
Project description:This SuperSeries is composed of the following subset Series:; GSE11256: KCl depolarization-regulated genes in mouse cortical neurons; GSE11258: Npas4-regulated genes in mouse hippocampal neurons Experiment Overall Design: Refer to individual Series
Project description:Use of addictive substances often creates powerful and enduring associations with external cues that act as relapse triggers in individuals recovering from a substance use disorder (SUD). In the reward-associated brain region, the nucleus accumbens (NAc), drug use or drug-associated cue exposure activates a subset of D1 dopamine receptor-expressing medium spiny neurons (D1-MSNs), which typically promotes drug seeking, and a smaller subset of D2 dopamine receptor-expressing MSNs (D2-MSNs), which typically opposes drug seeking. The activity-regulated transcription factor, Neuronal PAS Domain Protein 4 (NPAS4), is activated in a small subset of NAc neurons during cocaine conditioning, and NAc NPAS4 is required for drug-context memories. Using a new Npas4-TRAP mouse combined with chemogenetics, we found that the during cocaine conditioning, the NPAS4-positive ensemble is required for drug-context associations. Single-cell transcriptomic analyses and in situ hybridization of NAc tissues from drug-conditioned mice revealed that NPAS4 is expressed predominantly in MSNs, and using cell type-specific molecular genetic approaches, we found that NPAS4 in D2-MSNs, but not D1-MSNs, was required for both drug-context associations and cue-reinstated cocaine seeking. Similarly, NPAS4 in NAc D2-MSNs, but not D1-MSNs, blocked cocaine experience-dependent strengthening of glutamatergic prefrontal cortical (PFC) inputs onto D2-MSNs. Analysis of differential gene expression in D2-MSNs revealed that NPAS4 and cocaine conditioning influence a gene expression program associated with synapses, dendrites, neuronal projections, dopamine, and cocaine. Together, our data reveal that NPAS4 functions during active cocaine use to maintain the imbalance of D1-MSN:D2-MSN activation and cue-induced drug seeking by suppressing excitatory drive onto relapse-opposing NAc D2-MSN circuits.
Project description:Astrocytes are implicated in neuronal development, particularly excitatory synaptogenesis, but their genome-wide impact is unclear. Using cell-type specific RNA-seq we show that cortical astrocytes induce widespread transcriptomic changes in developing cortical neurons. Rat cortical neurons were maintained in the presence or absence of mouse astrocytes, RNA-seq performed, and mixed-species RNA-seq reads sorted according to species. Cultures were also treated with TTX to abolish neuronal firing activity, to investigate the effects of the presence or absence activity-dependent signalling.
Project description:The stable formation of remote fear memories is thought to require neuronal gene induction in cortical ensembles that are activated during learning. However, the set of genes expressed specifically in these activated ensembles is not known; knowledge of such transcriptional profiles may offer insights into the molecular program underlying stable memory formation. Here we use RNA-Seq to identify genes whose expression is enriched in activated cortical ensembles labeled during associative fear learning. We first establish that mouse temporal association cortex (TeA) is required for remote recall of auditory fear memories. We then perform RNA-Seq in TeA neurons that are labeled by the activity reporter Arc-dVenus during learning. We identify 944 genes with enriched expression in Arc-dVenus+ neurons. These genes include markers of L2/3, L5b, and L6 excitatory neurons but not glial or inhibitory markers, confirming Arc-dVenus to be an excitatory neuron-specific, layer non-specific activity reporter. Cross comparisons to other transcriptional profiles show that 125 of the enriched genes are also activity-regulated in vitro or induced by visual stimulus in the visual cortex, suggesting that they may be induced generally in the cortex in an experience-dependent fashion. Prominent among the enriched genes are those encoding potassium channels that down-regulate neuronal activity, suggesting the possibility that part of the molecular program induced by fear conditioning may initiate homeostatic plasticity.