Project description:Animal models provide opportunity to study neurobiological aspects of human alcoholism. Changes in gene expression have been implicated in mediating brain function, including reward system and addiction. The current study aimed to identify novel genes that may underlie ethanol preference. Microarray analysis comparing gene expression in nucleus accumbens (NAc), hippocampus (HP) and prefrontal medial cortex (mPFC) was performed in two rat strains selected for extreme levels of ethanol preference - Warsaw High Preferring (WHP) and Warsaw Low Preferring (WLP). The identified candidate genes may underlie differential ethanol preference in rat model of alcoholism. This is analysis of 18 RNA samples, including 9 technical replicates. Two strains of rats selected for extreme levels of ethanol preference (low preferring WLP and high preferring WHP) were compared. Three brain areas (nucleus accumbens, prefrontal medial cortex and hippocampus) were studied. For each brain area, 6 RNA samples (including 3 technical replicates) were analyzed. Each RNA sample consist of of equal amounts of total RNA from 3 male rats. Comparisons: Nucleus accumbens of WHP vs. Nucleus accumbens of WLP; Prefrontal medial cortex of WHP vs. Prefrontal medial cortex of WLP; Hippocampus of WHP vs. Hippocampus of WLP. 3 biological replicates in each comparison.
Project description:An increase in opioid-overdose deaths was evident before the COVID-19 pandemic, and has escalated since its onset. Fentanyl, a highly potent synthetic opioid, is the primary driver of these recent trends. The current study used two inbred mouse strains, C57BL/6 J and A/J, to investigate the genetics of behavioral responses to fentanyl. Mice were tested for conditioned place preference and fentanyl-induced locomotor activity. C57BL/6J mice formed a conditioned place preference to fentanyl injections and fentanyl increased their activity. Neither effect was noted in A/J mice. We conducted RNA-sequencing on the nucleus accumbens of mice used for fentanyl-induced locomotor activity. Surprisingly, we noted few differentially expressed genes using treatment as the main factor. However many genes differed between strains. We validated differences in two genes: suppressor APC domain containing 1 (Sapcd1) and Glyoxalase 1 (Glo1), with quantitative PCR on RNA from the nucleus accumbens and prefrontal cortex. In both regions A/J mice had significantly higher expression of both genes than did C57BL/6 J. In prefrontal cortex, fentanyl treatment decreased Glo1 mRNA. Glyoxalase 1 catalyzes the detoxification of reactive alpha-oxoaldehydes such as glyoxal and methylglyoxal, is associated with anxiety and activity levels, and its inhibition reduces alcohol intake. We suggest that future studies assess the ability of Glo1 and related metabolites to modify opioid intake.
Project description:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.
Project description:We examined microRNA expression profiles in amygdala (AMY), nucleus accumbens (NAC) and prefrontal cortex (PFC) of male C57BL/6J mice exposed to 4 cycles of chronic intermittent ethanol (CIE) vapor. Animals were sacrificed at 0, 8, and 120 hr following the last ethanol exposure.
Project description:We examined global gene expression profiles in amygdala (AMY), nucleus accumbens (NAC), prefrontal cortex (PFC) and Liver of male C57BL/6J mice exposed to 4 cycles of chronic intermittent ethanol (CIE) vapor. Animals were sacrificed at 0, 8, and 120 hr following the last ethanol exposure.
Project description:Here, we identify persistent and substantial variation in ethanol drinking behavior within an inbred mouse strain and utilize this model to identify gene networks influencing such non-genetic variation in ethanol intake. C57BL/6NCrl mice showed persistent inter-individual variation of ethanol intake in a two-bottle choice paradigm over a three week period, ranging from less than 1 g/kg to over 14 g/kg ethanol in an 18h interval. Whole genome microarray expression analysis in nucleus accumbens, prefrontal cortex and ventral tegmental area of individual animals identified gene expression patterns correlated with ethanol intake. Results included several gene networks previously implicated in ethanol behaviors, such as glutamate signaling, BDNF and genes involved in synaptic vesicle function. Additionally, genes functioning in epigenetic chromatin or DNA modifications such as acetylation and/or methylation also had expression patterns correlated with ethanol intake. Our results thus implicate specific brain regional gene networks, including chromatin modification factors, as potentially important mechanisms underlying individual variation in ethanol intake. Voluntary two-bottle choice drinking was performed as described previously (Khisti et al. 2006). Briefly, two bottles containing 10%(w/v) ethanol (Aaper Alcohol and Chemical Co. Shelbyville, KY) or tap water were placed into the home cage at the beginning of the dark cycle. Tube position was varied every two days (L, L, R, R). Drinking sessions lasted 18 hours/day followed by 6 hours access to water only. Mice had four consecutive drinking sessions followed by four days of abstinence repeated four times to give 16 total drinking sessions. Three brain regions were harvested 6 days after the last drinking session: prefrontal cortex (PFC), nucleus accumbens (NAc) and ventral tegmental area (VTA) as previously described (Kerns et al. 2005). Labeled cRNA from individual animals (n=19) was hybridized to a single microarray for each brain region (n=58 total microarrays).
Project description:Transcriptional alterations in dorsolateral prefrontal cortex and nucleus accumbens implicate neuroinflammation and synaptic remodeling in opioid use disorder. Transcriptomic profile of 20 control subjects and 20 OUD subjects in brain region DLPFC and NAC