Matching Items (24)
Description
Chromatin is the dynamic structure of proteins and nucleic acids into which eukaryotic genomes are organized. For those looking to engineer mammalian genomes, chromatin is both an opportunity and an obstacle. While chromatin provides another tool with which to control gene expression, regional density can lead to variability in genome editing efficiency by CRISPR/Cas9 systems. Many groups have attempted to de-silence chromatin to regulate genes and enhance DNA's accessibility to nucleases, but inconsistent results leave outstanding questions. Here, I test different types of activators, to analyze changes in chromatin features that result for chromatin opening, and to identify the critical biochemical features that support artificially generated open, transcriptionally active chromatin.
I designed, built, and tested a panel of synthetic pioneer factors (SPiFs) to open condensed, repressive chromatin with the aims of 1) activating repressed transgenes in mammalian cells and 2) reversing the inhibitory effects of closed chromatin on Cas9-endonuclease activity. Pioneer factors are unique in their ability to bind DNA in closed chromatin. In order to repurpose this natural function, I designed SPiFs from a Gal4 DNA binding domain, which has inherent pioneer functionality, fused with chromatin-modifying peptides with distinct functions.
SPiFs with transcriptional activation as their primary mechanism were able to reverse this repression and induced a stably active state. My work also revealed the active site from proto-oncogene MYB as a novel transgene activator. To determine if MYB could be used generally to restore transgene expression, I fused it to a deactivated Cas9 and targeted a silenced transgene in native heterochromatin. The resulting activator was able to reverse silencing and can be chemically controlled with a small molecule drug.
Other SPiFs in my panel did not increase gene expression. However, pretreatment with several of these expression-neutral SPiFs increased Cas9-mediated editing in closed chromatin, suggesting a crucial difference between chromatin that is accessible and that which contains genes being actively transcribed. Understanding this distinction will be vital to the engineering of stable transgenic cell lines for product production and disease modeling, as well as therapeutic applications such as restoring epigenetic order to misregulated disease cells.
I designed, built, and tested a panel of synthetic pioneer factors (SPiFs) to open condensed, repressive chromatin with the aims of 1) activating repressed transgenes in mammalian cells and 2) reversing the inhibitory effects of closed chromatin on Cas9-endonuclease activity. Pioneer factors are unique in their ability to bind DNA in closed chromatin. In order to repurpose this natural function, I designed SPiFs from a Gal4 DNA binding domain, which has inherent pioneer functionality, fused with chromatin-modifying peptides with distinct functions.
SPiFs with transcriptional activation as their primary mechanism were able to reverse this repression and induced a stably active state. My work also revealed the active site from proto-oncogene MYB as a novel transgene activator. To determine if MYB could be used generally to restore transgene expression, I fused it to a deactivated Cas9 and targeted a silenced transgene in native heterochromatin. The resulting activator was able to reverse silencing and can be chemically controlled with a small molecule drug.
Other SPiFs in my panel did not increase gene expression. However, pretreatment with several of these expression-neutral SPiFs increased Cas9-mediated editing in closed chromatin, suggesting a crucial difference between chromatin that is accessible and that which contains genes being actively transcribed. Understanding this distinction will be vital to the engineering of stable transgenic cell lines for product production and disease modeling, as well as therapeutic applications such as restoring epigenetic order to misregulated disease cells.
ContributorsBarrett, Cassandra M (Author) / Haynes, Karmella A (Thesis advisor) / Rege, Kaushal (Committee member) / Mills, Jeremy (Committee member) / Kiani, Samira (Committee member) / Arizona State University (Publisher)
Created2019
Description
Parkinson’s disease (PD) is a progressive neurodegenerative disorder, diagnosed late in
the disease by a series of motor deficits that manifest over years or decades. It is characterized by degeneration of mid-brain dopaminergic neurons with a high prevalence of dementia associated with the spread of pathology to cortical regions. Patients exhibiting symptoms have already undergone significant neuronal loss without chance for recovery. Analysis of disease specific changes in gene expression directly from human patients can uncover invaluable clues about a still unknown etiology, the potential of which grows exponentially as additional gene regulatory measures are questioned. Epigenetic mechanisms are emerging as important components of neurodegeneration, including PD; the extent to which methylation changes correlate with disease progression has not yet been reported. This collection of work aims to define multiple layers of PD that will work toward developing biomarkers that not only could improve diagnostic accuracy, but also push the boundaries of the disease detection timeline. I examined changes in gene expression, alternative splicing of those gene products, and the regulatory mechanism of DNA methylation in the Parkinson’s disease system, as well as the pathologically related Alzheimer’s disease (AD). I first used RNA sequencing (RNAseq) to evaluate differential gene expression and alternative splicing in the posterior cingulate cortex of patients with PD and PD with dementia (PDD). Next, I performed a longitudinal genome-wide methylation study surveying ~850K CpG methylation sites in whole blood from 189 PD patients and 191 control individuals obtained at both a baseline and at a follow-up visit after 2 years. I also considered how symptom management medications could affect the regulatory mechanism of DNA methylation. In the last chapter of this work, I intersected RNAseq and DNA methylation array datasets from whole blood patient samples for integrated differential analyses of both PD and AD. Changes in gene expression and DNA methylation reveal clear patterns of pathway dysregulation that can be seen across brain and blood, from one study to the next. I present a thorough survey of molecular changes occurring within the idiopathic Parkinson’s disease patient and propose candidate targets for potential molecular biomarkers.
the disease by a series of motor deficits that manifest over years or decades. It is characterized by degeneration of mid-brain dopaminergic neurons with a high prevalence of dementia associated with the spread of pathology to cortical regions. Patients exhibiting symptoms have already undergone significant neuronal loss without chance for recovery. Analysis of disease specific changes in gene expression directly from human patients can uncover invaluable clues about a still unknown etiology, the potential of which grows exponentially as additional gene regulatory measures are questioned. Epigenetic mechanisms are emerging as important components of neurodegeneration, including PD; the extent to which methylation changes correlate with disease progression has not yet been reported. This collection of work aims to define multiple layers of PD that will work toward developing biomarkers that not only could improve diagnostic accuracy, but also push the boundaries of the disease detection timeline. I examined changes in gene expression, alternative splicing of those gene products, and the regulatory mechanism of DNA methylation in the Parkinson’s disease system, as well as the pathologically related Alzheimer’s disease (AD). I first used RNA sequencing (RNAseq) to evaluate differential gene expression and alternative splicing in the posterior cingulate cortex of patients with PD and PD with dementia (PDD). Next, I performed a longitudinal genome-wide methylation study surveying ~850K CpG methylation sites in whole blood from 189 PD patients and 191 control individuals obtained at both a baseline and at a follow-up visit after 2 years. I also considered how symptom management medications could affect the regulatory mechanism of DNA methylation. In the last chapter of this work, I intersected RNAseq and DNA methylation array datasets from whole blood patient samples for integrated differential analyses of both PD and AD. Changes in gene expression and DNA methylation reveal clear patterns of pathway dysregulation that can be seen across brain and blood, from one study to the next. I present a thorough survey of molecular changes occurring within the idiopathic Parkinson’s disease patient and propose candidate targets for potential molecular biomarkers.
ContributorsHenderson, Adrienne Rose (Author) / Huentelman, Matthew J (Thesis advisor) / Newbern, Jason (Thesis advisor) / Dunckley, Travis L (Committee member) / Jensen, Kendall (Committee member) / Wilson, Melissa (Committee member) / Arizona State University (Publisher)
Created2019
Description
Synthetic manipulation of chromatin dynamics has applications for medicine, agriculture, and biotechnology. However, progress in this area requires the identification of design rules for engineering chromatin systems. In this thesis, I discuss research that has elucidated the intrinsic properties of histone binding proteins (HBP), and apply this knowledge to engineer novel chromatin binding effectors. Results from the experiments described herein demonstrate that the histone binding domain from chromobox protein homolog 8 (CBX8) is portable and can be customized to alter its endogenous function. First, I developed an assay to identify engineered fusion proteins that bind histone post translational modifications (PTMs) in vitro and regulate genes near the same histone PTMs in living cells. This assay will be useful for assaying the function of synthetic histone PTM-binding actuators and probes. Next, I investigated the activity of a novel, dual histone PTM binding domain regulator called Pc2TF. I characterized Pc2TF in vitro and in cells and show it has enhanced binding and transcriptional activation compared to a single binding domain fusion called Polycomb Transcription Factor (PcTF). These results indicate that valency can be used to tune the activity of synthetic histone-binding transcriptional regulators. Then, I report the delivery of PcTF fused to a cell penetrating peptide (CPP) TAT, called CP-PcTF. I treated 2D U-2 OS bone cancer cells with CP-PcTF, followed by RNA sequencing to identify genes regulated by CP-PcTF. I also showed that 3D spheroids treated with CP-PcTF show delayed growth. This preliminary work demonstrated that an epigenetic effector fused to a CPP can enable entry and regulation of genes in U-2 OS cells through DNA independent interactions. Finally, I described and validated a new screening method that combines the versatility of in vitro transcription and translation (IVTT) expressed protein coupled with the histone tail microarrays. Using Pc2TF as an example, I demonstrated that this assay is capable of determining binding and specificity of a synthetic HBP. I conclude by outlining future work toward engineering HBPs using techniques such as directed evolution and rational design. In conclusion, this work outlines a foundation to engineer and deliver synthetic chromatin effectors.
ContributorsTekel, Stefan (Author) / Haynes, Karmella (Thesis advisor) / Mills, Jeremy (Committee member) / Caplan, Michael (Committee member) / Brafman, David (Committee member) / Arizona State University (Publisher)
Created2019
Description
Alzheimer’s disease (AD) is characterized by the degeneration of cholinergic basal forebrain (CBF) neurons in the nucleus basalis of Meynert (nbM), which provides the majority of cholinergic input to the cortical mantle and together form the basocortical cholinergic system. Histone deacetylase (HDAC) dysregulation in the temporal lobe has been associated with neuronal degeneration during AD progression. However, whether HDAC alterations play a role in cortical and cortically-projecting cholinergic nbM neuronal degeneration during AD onset is unknown. In an effort to characterize alterations in the basocortical epigenome semi-quantitative western blotting and immunohistochemistry were utilized to evaluate HDAC and sirtuin (SIRT) levels in individuals that died with a premortem clinical diagnosis of no cognitive impairment (NCI), mild cognitive impairment (MCI), mild/moderate AD (mAD), or severe AD (sAD). In the frontal cortex, immunoblots revealed significant increases in HDAC1 and HDAC3 in MCI and mAD, followed by a decrease in sAD. Cortical HDAC2 levels remained stable across clinical groups. HDAC4 was significantly increased in prodromal and mild AD compared to aged cognitively normal controls. HDAC6 significantly increased during disease progression, while SIRT1 decreased in MCI, mAD, and sAD compared to controls. Basal forebrain levels of HDAC1, 3, 4, 6 and SIRT1 were stable across disease progression, while HDAC2 levels were significantly decreased in sAD. Quantitative immunohistochemistry was used to identify HDAC2 protein levels in individual cholinergic nbM nuclei immunoreactive for the early phosphorylated tau marker AT8, the late-stage apoptotic tau marker TauC3, and Thioflavin-S, a marker of mature neurofibrillary tangles (NFTs). HDAC2 nuclear immunoreactivity was reduced in individual cholinergic nbM neurons across disease stages, and was exacerbated in tangle-bearing cholinergic nbM neurons. HDAC2 nuclear reactivity correlated with multiple cognitive domains and with NFT formation. These findings identify global HDAC and SIRT alterations in the cortex while HDAC2 dysregulation contributes to cholinergic nbM neuronal dysfunction and NFT pathology during the progression of AD.
ContributorsMahady, Laura Jean (Author) / Mufson, Elliott J (Thesis advisor) / Bimonte-Nelson, Heather A. (Thesis advisor) / Coleman, Paul (Committee member) / Bowser, Robert (Committee member) / Arizona State University (Publisher)
Created2018
Description
Epigenetic mechanisms such as DNA methylation have been found to affect metabolic processes, which leads to conditions like type 2 diabetes and obesity. The aim of this project was to validate differentially methylated cytosines (DMCs) identified in skeletal muscle from seven obese, non-diabetic women pre- and 3 months post- Roux-en-Y gastric bypass surgery. DNA samples extracted from skeletal muscle were sent to the Mayo Genotyping Core to undergo reduced representation bisulfite sequencing (RRBS). Differentially methylated cytosines at chr14.105353824 of the gene CEP170B, chr19.16437949 of the KLF2 gene, chr7.130126082 of MEST, and chr15.62457572 of C2CD4B were captured from the RRBS analysis using MethylSig. Bisulfite sequencing PCR (BSP) was performed on all DMCs listed above which resulted in no significant changes in methylation post-surgery. It was concluded that an alternate, more precise method should be used for validation of the RRBS, such as pyrosequencing.
ContributorsKelley, Conley Lane (Author) / Coletta, Dawn K. (Thesis director) / Roust, Lori R. (Committee member) / School of Human Evolution and Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Evidence from the 20th century demonstrated that early life stress (ELS) produces long lasting neuroendocrine and behavioral effects related to an increased vulnerability towards psychiatric illnesses such as major depressive disorder, post-traumatic stress disorder, schizophrenia, and substance use disorder. Substance use disorders (SUDs) are complex neurological and behavioral psychiatric illnesses. The development, maintenance, and relapse of SUDs involve multiple brain systems and are affected by many variables, including socio-economic and genetic factors. Pre-clinical studies demonstrate that ELS affects many of the same systems, such as the reward circuitry and executive function involved with addiction-like behaviors. Previous research has focused on cocaine, ethanol, opiates, and amphetamine, while few studies have investigated ELS and methamphetamine (METH) vulnerability. METH is a highly addictive psychostimulant that when abused, has deleterious effects on the user and society. However, a critical unanswered question remains; how do early life experiences modulate both neural systems and behavior in adulthood? The emerging field of neuroepigenetics provides a potential answer to this question. Methyl CpG binding protein 2 (MeCP2), an epigenetic tag, has emerged as one possible mediator between initial drug use and the transition to addiction. Additionally, there are various neural systems that undergo long lasting epigenetics changes after ELS, such as the response of the hypothalamo-pituitary-adrenal (HPA) axis to stressors. Despite this, little attention has been given to the interactions between ELS, epigenetics, and addiction vulnerability. The studies described herein investigated the effects of ELS on METH self-administration (SA) in adult male rats. Next, we investigated the effects of ELS and METH SA on MeCP2 expression in the nucleus accumbens and dorsal striatum. Additionally, we investigated the effects of virally-mediated knockdown of MeCP2 expression in the nucleus accumbens core on METH SA, motivation to obtain METH under conditions of increasing behavioral demand, and reinstatement of METH-seeking in rats with and without a history of ELS. The results of these studies provide insights into potential epigenetic mechanisms by which ELS can produce an increased vulnerability to addiction in adulthood. Moreover, these studies shed light on possible novel molecular targets for treating addiction in individuals with a history of ELS.
ContributorsLewis, Candace (Author) / Olive, M. Foster (Thesis advisor) / Hammer, Ronald (Committee member) / Neisewander, Janet (Committee member) / Sanabria, Federico (Committee member) / Arizona State University (Publisher)
Created2015
Description
Gene delivery is a broadly applicable tool that has applications in gene therapy, production of therapeutic proteins, and as a study tool to understand biological pathways. However, for successful gene delivery, the gene and its carrier must bypass or traverse a number of formidable obstacles before successfully entering the cell’s nucleus where the host cell’s machinery can be utilized to express a protein encoded by the gene of interest. The vast majority of work in the gene delivery field focuses on overcoming these barriers by creative synthesis of nanoparticle delivery vehicles or conjugation of targeting moieties to the nucleic acid or delivery vehicle, but little work focuses on modifying the target cell’s behavior to make it more amenable to transfection.
In this work, a number of kinase enzymes have been identified by inhibition to be targets for enhancing polymer-mediated transgene expression (chapter 2), including the lead target which appears to affect intracellular trafficking of delivered nucleic acid cargo. The subsequent sections (chapters 3 and 4) of this work focus on targeting epigenetic modifying enzymes to enhance polymer-mediated transgene expression, and a number of candidate enzymes have been identified. Some mechanistic evaluation of these targets have been carried out and discussion of ongoing experiments and future directions to better understand the mechanistic descriptions behind the phenomena are discussed. The overall goal is to enhance non-viral (polymer-mediated) transgene expression by modulating cellular behavior for general gene delivery applications.
In this work, a number of kinase enzymes have been identified by inhibition to be targets for enhancing polymer-mediated transgene expression (chapter 2), including the lead target which appears to affect intracellular trafficking of delivered nucleic acid cargo. The subsequent sections (chapters 3 and 4) of this work focus on targeting epigenetic modifying enzymes to enhance polymer-mediated transgene expression, and a number of candidate enzymes have been identified. Some mechanistic evaluation of these targets have been carried out and discussion of ongoing experiments and future directions to better understand the mechanistic descriptions behind the phenomena are discussed. The overall goal is to enhance non-viral (polymer-mediated) transgene expression by modulating cellular behavior for general gene delivery applications.
ContributorsChristensen, Matthew David (Author) / Rege, Kaushal (Thesis advisor) / Nielsen, David (Committee member) / Green, Matthew (Committee member) / Haynes, Karmella (Committee member) / Muthuswamy, Jitendran (Committee member) / Arizona State University (Publisher)
Created2016
Description
Within the primate lineage, skeletal traits that contribute to inter-specific anatomical variation and enable varied niche occupations and forms of locomotion are often described as the result of environmental adaptations. However, skeletal phenotypes are more accurately defined as complex traits, and environmental, genetic, and epigenetic mechanisms, such as DNA methylation which regulates gene expression, all contribute to these phenotypes. Nevertheless, skeletal complexity in relation to epigenetic variation has not been assessed across the primate order. In order to gain a complete understanding of the evolution of skeletal phenotypes across primates, it is necessary to study skeletal epigenetics in primates. This study attempts to fill this gap by identifying intra- and inter-specific variation in primate skeletal tissue methylation in order to test whether specific features of skeletal form are related to specific variations in methylation. Specifically, methylation arrays and gene-specific methylation sequencing are used to identify DNA methylation patterns in femoral trabecular bone and cartilage of several nonhuman primate species. Samples include baboons (Papio spp.), macaques (Macaca mulatta), vervets (Chlorocebus aethiops), chimpanzees (Pan troglodytes), and marmosets (Callithrix jacchus), and the efficiencies of these methods are validated in each taxon. Within one nonhuman primate species (baboons), intra-specific variations in methylation patterns are identified across a range of comparative levels, including skeletal tissue differences (bone vs. cartilage), age cohort differences (adults vs. juveniles), and skeletal disease state differences (osteoarthritic vs. healthy), and some of the identified patterns are evolutionarily conserved with those known in humans. Additionally, in all nonhuman primate species, intra-specific methylation variation in association with nonpathological femur morphologies is assessed. Lastly, inter-specific changes in methylation are evaluated among all nonhuman primate taxa and used to provide a phylogenetic framework for methylation changes previously identified in the hominin lineage. Overall, findings from this work reveal how skeletal DNA methylation patterns vary within and among primate species and relate to skeletal phenotypes, and together they inform our understanding of epigenetic regulation and complex skeletal trait evolution in primates.
ContributorsHousman, Genevieve (Author) / Stone, Anne (Thesis advisor) / Quillen, Ellen (Committee member) / Kusumi, Kenro (Committee member) / Stojanowski, Christopher (Committee member) / Arizona State University (Publisher)
Created2017
Description
Obesity and its underlying insulin resistance are caused by environmental and genetic factors. DNA methylation provides a mechanism by which environmental factors can regulate transcriptional activity. The overall goal of the work herein was to (1) identify alterations in DNA methylation in human skeletal muscle with obesity and its underlying insulin resistance, (2) to determine if these changes in methylation can be altered through weight-loss induced by bariatric surgery, and (3) to identify DNA methylation biomarkers in whole blood that can be used as a surrogate for skeletal muscle.
Assessment of DNA methylation was performed on human skeletal muscle and blood using reduced representation bisulfite sequencing (RRBS) for high-throughput identification and pyrosequencing for site-specific confirmation. Sorbin and SH3 homology domain 3 (SORBS3) was identified in skeletal muscle to be increased in methylation (+5.0 to +24.4 %) in the promoter and 5’untranslated region (UTR) in the obese participants (n= 10) compared to lean (n=12), and this finding corresponded with a decrease in gene expression (fold change: -1.9, P=0.0001). Furthermore, SORBS3 was demonstrated in a separate cohort of morbidly obese participants (n=7) undergoing weight-loss induced by surgery, to decrease in methylation (-5.6 to -24.2%) and increase in gene expression (fold change: +1.7; P=0.05) post-surgery. Moreover, SORBS3 promoter methylation was demonstrated in vitro to inhibit transcriptional activity (P=0.000003). The methylation and transcriptional changes for SORBS3 were significantly (P≤0.05) correlated with obesity measures and fasting insulin levels. SORBS3 was not identified in the blood methylation analysis of lean (n=10) and obese (n=10) participants suggesting that it is a muscle specific marker. However, solute carrier family 19 member 1 (SLC19A1) was identified in blood and skeletal muscle to have decreased 5’UTR methylation in obese participants, and this was significantly (P≤0.05) predicted by insulin sensitivity.
These findings suggest SLC19A1 as a potential blood-based biomarker for obese, insulin resistant states. The collective findings of SORBS3 DNA methylation and gene expression present an exciting novel target in skeletal muscle for further understanding obesity and its underlying insulin resistance. Moreover, the dynamic changes to SORBS3 in response to metabolic improvements and weight-loss induced by surgery.
Assessment of DNA methylation was performed on human skeletal muscle and blood using reduced representation bisulfite sequencing (RRBS) for high-throughput identification and pyrosequencing for site-specific confirmation. Sorbin and SH3 homology domain 3 (SORBS3) was identified in skeletal muscle to be increased in methylation (+5.0 to +24.4 %) in the promoter and 5’untranslated region (UTR) in the obese participants (n= 10) compared to lean (n=12), and this finding corresponded with a decrease in gene expression (fold change: -1.9, P=0.0001). Furthermore, SORBS3 was demonstrated in a separate cohort of morbidly obese participants (n=7) undergoing weight-loss induced by surgery, to decrease in methylation (-5.6 to -24.2%) and increase in gene expression (fold change: +1.7; P=0.05) post-surgery. Moreover, SORBS3 promoter methylation was demonstrated in vitro to inhibit transcriptional activity (P=0.000003). The methylation and transcriptional changes for SORBS3 were significantly (P≤0.05) correlated with obesity measures and fasting insulin levels. SORBS3 was not identified in the blood methylation analysis of lean (n=10) and obese (n=10) participants suggesting that it is a muscle specific marker. However, solute carrier family 19 member 1 (SLC19A1) was identified in blood and skeletal muscle to have decreased 5’UTR methylation in obese participants, and this was significantly (P≤0.05) predicted by insulin sensitivity.
These findings suggest SLC19A1 as a potential blood-based biomarker for obese, insulin resistant states. The collective findings of SORBS3 DNA methylation and gene expression present an exciting novel target in skeletal muscle for further understanding obesity and its underlying insulin resistance. Moreover, the dynamic changes to SORBS3 in response to metabolic improvements and weight-loss induced by surgery.
ContributorsDay, Samantha Elaine (Author) / Coletta, Dawn K. (Thesis advisor) / Katsanos, Christos (Committee member) / Mandarino, Lawrence J. (Committee member) / Shaibi, Gabriel Q. (Committee member) / Dinu, Valentin (Committee member) / Arizona State University (Publisher)
Created2017
Description
The maternal separation (MS) paradigm is an animal model of early life stress. Animals subjected to MS during the first two weeks of life display altered behavioral and neuroendocrinological stress responses as adults. MS also produces altered responsiveness to and self-administration (SA) of various drugs of abuse including cocaine, ethanol, opioids, and amphetamine. Methamphetamine (METH) causes great harm to both the individual user and to society; yet, no studies have examined the effects of MS on METH SA. This study was performed to examine the effects of MS on the acquisition of METH SA, extinction, and reinstatement of METH-seeking behavior in adulthood. Given the known influence of early life stress and drug exposure on epigenetic processes, group differences in levels of the epigenetic marker methyl CpG binding protein 2 (MeCP2) in the nucleus accumbens (NAc) core were also investigated. Long-Evans pups and dams were separated on postnatal days (PND) 2-14 for either 180 (MS180) or 15 min (MS15). Male offspring were allowed to acquire METH SA (0.05 mg/kg/infusion) in 15 2-hr daily sessions starting at PND67, followed by extinction training and cue-induced reinstatement of METH-seeking behavior. Rats were then assessed for MeCP2 levels in the NAc core by immunohistochemistry. The MS180 group self-administered significantly more METH and acquired SA earlier than the MS15 group. No group differences in extinction or cue-induced reinstatement were observed. MS15 rats had significantly elevated MeCP2-immunoreactive cells in the NAc core as compared to MS180 rats. Together, these data suggest that MS has lasting influences on METH SA as well as epigenetic processes in the brain reward circuitry.
ContributorsLewis, Candace (Author) / Olive, Micheal F (Thesis advisor) / Conrad, Cheryl (Committee member) / Neisewander, Janet (Committee member) / Arizona State University (Publisher)
Created2013