Project description:Neuroadaptations in the nucleus accumbens (NAc) underlie cue-induced cocaine craving that intensifies (“incubates”) during withdrawal and contributes to persistent relapse vulnerability. Long-lasting gene changes govern perpetual behavioral abnormalities but the role of epigenetic plasticity in cocaine craving during prolonged withdrawal is poorly understood. Here we show that chromatin remodeler INO80 in the NAc mediates cocaine-induced, withdrawal-dependent plasticity and incubated cocaine craving.
Project description:DNA methylation profiling of nucleus Accumbens of rats that self administered cocaine, were subjected to 30 withdrawal days, were treated with aCSF, RG108 or SAM and were subjected to extinction tests. The groups consist of: 1. Rats that self-administered cocaine for 10 days and that were subjected to a withdrawal period of 30 days, were injected in the nucleus accumbens with aCSF and were subjected to an extinction test for assessment of cue-induced cocaine-seeking behavior (aCSF) 2. Rats that self-administered cocaine for 10 days and that were subjected to a withdrawal period of 30 days, were injected in the nucleus accumbens with RG108 and were subjected to an extinction test for assessment of cue-induced cocaine-seeking behavior (RG108) 3. Rats that self-administered cocaine for 10 days and that were subjected to a withdrawal period of 30 days, were injected in the nucleus accumbens with SAM and were subjected to an extinction test for assessment of cue-induced cocaine-seeking behavior (SAM)
Project description:Previous studies in animal models of cocaine craving have delineated broad changes in DNA methylation profiles in the nucleus accumbens. A crucial factor for progress in behavioral and mental health epigenetics is the discovery of epigenetic markers in peripheral tissues. Several studies in primates and humans have associated differences in behavioral phenotypes with changes in DNA methylation in T cells and brain. Herein, we present a pilot study (n=27) showing that the T cell DNA methylation profile differentiates persons with a substance use disorder from controls. Intervention with dehydroepiandrosterone (DHEA), previously shown to have a long-term therapeutic effect on human addicts herein resulted in reversal of DNA methylation changes in behavioral pathways associated with the addictive state.
Project description:DNA methylation profiling of nucleus Accumbens of rats that self administered cocaine and were subjected to 1 or 30 withdrawal days with or without extinction tests.
Project description:The aim of the study was to investigate whether environmental factors like S-adenosylmethionine (SAM) via affecting epigenome could alter cocaine-induced gene expression and locomotor sensitization in mice. Using mouse nucleus accumbens (NAc) tissue, whole-genome gene expression profiling revealed that repeated SAM treatment affected a limited number of genes, but significantly modified cocaine-induced gene expression by blunting nonspecifically the cocaine response. At the gene level, we discovered that SAM modulated cocaine-induced DNA methylation by inhibiting both promoter-associated CpG-island hyper- and hypomethylation in the NAc but not in the reference tissue cerebellum. Total RNA was extracted from the mouse nucleus accumbens (NAc) tissue. Two tissues were combined to a sample, 4 samples per group used. RNA quality and quantity were assessed using the Nano-Drop -1000 spectrophotometer and the Agilent 2100 Bioanalyzer.
Project description:DNA methylation profiling of nucleus Accumbens of rats that self administered cocaine, were subjected to 30 withdrawal days, were treated with aCSF, RG108 or SAM and were subjected to extinction tests.
Project description:Increasing evidence supports a role for altered gene expression in mediating the lasting effects of cocaine on the brain, and recent work has demonstrated the involvement of chromatin modifications in these alterations. However, all such studies to date have been restricted by their reliance on microarray technologies which have intrinsic limitations. Here, we used advanced sequencing methods, RNA-seq and ChIP-seq, to obtain an unprecedented view of cocaine-induced changes in gene expression and associated adaptations in numerous modes of chromatin regulation in the nucleus accumbens, a key brain reward region. We identify unique combinations of chromatin changes, or signatures, that accompany cocaine’s regulation of gene expression, including the dramatic involvement of pre-mRNA alternative splicing in cocaine action. Together, this delineation of the cocaine-induced epigenome in the nucleus accumbens reveals several novel modes of drug regulation, thereby providing new insight into the biological basis of cocaine addiction. More broadly, the combinatorial chromatin and transcriptional approaches that we describe serve as an important resource for the field, as they can be applied to other systems to reveal novel transcriptional and epigenetic mechanisms of neuronal regulation. ChIP-seq of 6 marks (H3K27me3, H3K36me3, H3K4me1, H3K4me3, H3K9me2, RNApolII) were done on mouse nucleus accumbens 24 hr after 7 day daily cocaine ip injection with saline as control. Three replicates for each condition.