Project description:Circular RNA (circRNA) has recently emerged as a novel type of endogenous non-coding RNA. It plays natural microRNA sponge effect that represses the activity of corresponding miRNAs by binding with them, thus regulating gene expression. Recent studies demonstrate that circRNAs are significantly enriched in the brain and a disproportionate fraction of them is derived from host genes that code for synaptic proteins. In addition, studies have shown that microRNAs are involved in synaptic plasticity, memory formation and cocaine addiction. However, the role of circRNAs in cocaine reward is largely unknown. This study aimed to identify the expression profile of circRNAs in the striatum of mice after cocaine self-administration by using circRNA microarray analysis.
Project description:Circular RNA (circRNA), a novel type of endogenous non-coding RNA, plays natural miRNA sponge effect that represses the activities of corresponding miRNAs through binding with them, thus modulating transcriptional expression of genes. Recent studies indicate that circRNAs are significantly enriched in the brain and some of them are derived from synaptic protein-coding genes. In addition, miRNAs are involved in synaptic plasticity, memory formation, and cocaine addiction. However, the role of circRNAs in cocaine reward is unclear. This study aimed to investigate the expression profile of striatal circRNAs in the mice after cocaine self-administration. By using circRNA microarray analysis, we observed that 90 striatal circRNAs were differentially expressed in cocaine self-administering mice, of which 18 circRNAs were up-regulated and 72 down-regulated. Six circRNAs were selected randomly for validation by using quantitative reverse transcription-PCR, and their expression levels showed consistency with microarray analysis. We backward predicted the circRNAs and their binding sites of miRNAs associated with neuroplasticity. In functional validation test, mmu_circRNA_002381 may modulate the transcription of certain genes associated with neuroplasticity, such as limk1 and bdnf. Taken together, circRNAs may participate in cocaine behavioral effect via interacting with miRNAs. Our findings reveal a potential role of circRNAs in cocaine effect.
Project description:Comparison of gene expression in the dorsal striatum of rats after chronic binge or acute binge cocaine injections or saline treatment
Project description:Comparison of gene expression in the dorsal striatum of rats after chronic binge or acute binge cocaine injections or saline treatment
Project description:Cocaine-dependent genome-wide effects were analyzed, total RNAs were extracted from ventral striatum tissue punches and processed for RNA-seq analyses.
Project description:<p>This project characterizes DNA methylation and gene expression changes that occur in the human brain, specifically in neurons from the rostral striatum. Major advances from NIDA funded initiatives for noninvasive neuroimaging studies have made it possible to study neuroanatomical, neurochemical and functional changes in the human brain that contribute to the vulnerability to abuse drugs, together with the neurotoxic consequences of years of drug misuse. Animal models have been developed to explain the fundamental behavioral and biological mechanisms of addiction, including reward, tolerance and dependence. From these studies, we learned that cocaine abuse not only alters the epigenetic status of genes, but also induces particular epigenetic modifications depending on the frequency of the drug's administration. Certain genes are switched on by infrequent (short-term exposure) administration, while others are switched on only after chronic administration (addiction/dependence). Animal studies have also suggested that cocaine-seeking habits modeling chronic cocaine addiction in humans depend upon dopamine-dependent serial connectivity linking the ventral (nucleus accumbens) with the dorsal striatum (caudate nucleus). The primary goal of this study is to identify DNA methylation and gene expression changes that occur in the transition from recreational cocaine use to cocaine addiction. High throughput sequencing studies were designed to investigate unique postmortem human brain specimens from individuals that met criteria for cocaine dependence, as compared to unaffected age-matched controls.</p> <p>Brain biospecimens were available from the University of Miami Brain Endowment BankTM, from a collection of phenotypically well-characterized postmortem tissues sampled from chronic cocaine abusers that came to autopsy. This biobank of postmortem brain specimens and annotated genomic data serve as a research resource to support NIDA's scientific mission.</p>
Project description:Ablation of the Camk4 gene in dopaminoceptive neurons of the brain was performed using the Cre/loxP system, with the recombinase expressed from a BAC-derived Drd1a promoter. Our goal was to analyze how loss of CaMKIV will affect acitivity-regulated transcription induced by strong stimulation, i.e. cocaine. Experiment Overall Design: Animals were injected i.p. with either 25 mg/kg cocaine or saline and sacrificed after one hour by cervical dislocation. Expression profiling was performed using total RNA isolated from the striatum.
Project description:TRAP translational profiling is a method that allows investigators to genetically characterize specific cell types in complex tissues such as mouse brain. Using this technique we obtained RNA-Seq data from actively translating transcripts present in neurons in the striatum of adult Chat-EGFP/Rpl10a (DW167) mice that were administered either saline or cocaine.
Project description:Drug addiction is a major public health issue that is characterised by continued drug use despite negative consequences. However, the molecular and cellular mechanisms that underlie this behaviour are not well understood. In this study we investigated the role of miR-137, a microRNA that has been previously shown to control the expression of genes necessary for neuronal development and synapse maturation, with common variants in the MIR137 gene linked to a higher risk of schizophrenia. Previously, we revealed that miR-137 expression in cocaine-trained animals exhibited spatial and temporal variability in the dorsal striatum (DS). Building upon this observation, we hypothesised that augmenting miR-137 function in the DS would impact drug-seeking behavior under punishment conditions by modulating molecular targets involved in synaptic plasticity. Male Sprague-Dawley rats were trained to self-administer cocaine and then randomly assigned to receive either lentiviral-mediated overexpression of hsa-miR-137 (miR-137OE) or an empty pCDH-vector (pCDH-EV) control in the dorsomedial striatum (DMS). Once stable cocaine self-administration was achieved, drug-taking was assessed under conditions in which lever presses were associated with a 0.25 probability of foot shock (0.5 mA). During five days of testing, pCDH-EV control animals showed a significant reduction in responding for cocaine, whereas miR-137OE animals displayed greater resistance to the suppression of cocaine responding across foot shock sessions compared to controls. RNA-sequencing analysis of striatal tissue from miR-137OE animals revealed significant enrichment of genes involved in synaptic plasticity and astrocyte signalling compared to control animals. Taken together, these findings provide insight into the mechanisms underlying addiction risk and and contribute to a better understanding of the neural substrates involved in these disorders.