Location

Portland State University

Start Date

2-5-2018 11:00 AM

End Date

2-5-2018 1:00 PM

Subjects

Binge drinking, Designer drugs, Nucleus accumbens

Abstract

We previously found that stimulating activity in the nucleus accumbens (NAc) reduced binge-like alcohol drinking in mice. We manipulated the NAc using clozapine-n-oxide (CNO) and Designer Receptors Exclusively Activated by Designer Drugs (DREADDs). In a subsequent study, we tested the hypothesis that chronic administration of CNO (to stimulate excitatory DREADDs expressed in the NAc) could produce lasting reductions in binge drinking (as compared with mice receiving vehicle). We observed that 4 weeks of CNO administration resulted in reductions in binge-like drinking that lasted at least 1 week. Based on these results, we hypothesized that transcriptional changes may underlie the observed behavioral plasticity. To test this hypothesis, we conducted a study to further explore the effects of NAc stimulation on behavior and gene expression in mice selectively bred to drink to intoxication (High Drinking in the Dark; HDID mice).

We stereotaxically injected AAVCre and AAV2DIO-hM3Dq into the NAc and subsequently measured ethanol intake for 6 weeks using the Drinking in the Dark (DID) paradigm. We employed 2 experimental conditions [drinking fluid (ethanol or water) and treatment (CNO or vehicle; IP)] with 11-12 mice/group. Vehicle groups were injected with 1% DMSO in saline daily for 6 weeks. For CNO groups, mice were treated with vehicle during weeks 1 (baseline) and 6 (washout) and CNO during weeks 2-5. At the end of the study we isolated NAc RNA and performed RNA Seq.

To explore quantitative changes across samples in the NAc transcriptome and determine target genes associated with binge-like drinking, we performed Differential Expression analysis (DE) and Weighted gene co-expression analysis (WGCNA). RNA-Seq sample reads were aligned to the Mus musculus genome (via STAR aligner), filtered and normalized to produce a count matrix. Using DESeq2, the count matrix was used to determine significantly up or down regulated genes based on p-value threshold. WGCNA was then used to describe correlation patterns among expressed genes. To identify modules (co-regulated genes) and hubs (genes correlating strongly with a significant number of related expressed modules) the count matrix was processed with the WGCNA package in R. By using these analyses, we are working to identify changes in gene expression related to harmful binge-like drinking and CNO/DREADD-induced reductions in binge-drinking. Our results suggest that chronically increasing NAc activity (via CNO/DREADDs) can induce molecular and behavioral plasticity.

Persistent Identifier

http://archives.pdx.edu/ds/psu/25068

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May 2nd, 11:00 AM May 2nd, 1:00 PM

Effects of Chronic Stimulation of Nucleus Accumbens on Binge Drinking and Transcriptome

Portland State University

We previously found that stimulating activity in the nucleus accumbens (NAc) reduced binge-like alcohol drinking in mice. We manipulated the NAc using clozapine-n-oxide (CNO) and Designer Receptors Exclusively Activated by Designer Drugs (DREADDs). In a subsequent study, we tested the hypothesis that chronic administration of CNO (to stimulate excitatory DREADDs expressed in the NAc) could produce lasting reductions in binge drinking (as compared with mice receiving vehicle). We observed that 4 weeks of CNO administration resulted in reductions in binge-like drinking that lasted at least 1 week. Based on these results, we hypothesized that transcriptional changes may underlie the observed behavioral plasticity. To test this hypothesis, we conducted a study to further explore the effects of NAc stimulation on behavior and gene expression in mice selectively bred to drink to intoxication (High Drinking in the Dark; HDID mice).

We stereotaxically injected AAVCre and AAV2DIO-hM3Dq into the NAc and subsequently measured ethanol intake for 6 weeks using the Drinking in the Dark (DID) paradigm. We employed 2 experimental conditions [drinking fluid (ethanol or water) and treatment (CNO or vehicle; IP)] with 11-12 mice/group. Vehicle groups were injected with 1% DMSO in saline daily for 6 weeks. For CNO groups, mice were treated with vehicle during weeks 1 (baseline) and 6 (washout) and CNO during weeks 2-5. At the end of the study we isolated NAc RNA and performed RNA Seq.

To explore quantitative changes across samples in the NAc transcriptome and determine target genes associated with binge-like drinking, we performed Differential Expression analysis (DE) and Weighted gene co-expression analysis (WGCNA). RNA-Seq sample reads were aligned to the Mus musculus genome (via STAR aligner), filtered and normalized to produce a count matrix. Using DESeq2, the count matrix was used to determine significantly up or down regulated genes based on p-value threshold. WGCNA was then used to describe correlation patterns among expressed genes. To identify modules (co-regulated genes) and hubs (genes correlating strongly with a significant number of related expressed modules) the count matrix was processed with the WGCNA package in R. By using these analyses, we are working to identify changes in gene expression related to harmful binge-like drinking and CNO/DREADD-induced reductions in binge-drinking. Our results suggest that chronically increasing NAc activity (via CNO/DREADDs) can induce molecular and behavioral plasticity.