Publications

2009
E. Spangler, D. M. Cote, A. M. J. Anacker, G. P. Mark, and A. E. Ryabinin. “Differential sensitivity of the perioculomotor urocortin-containing neurons to ethanol, psychostimulants and stress in mice and rats.” Neuroscience, 160, 1, Pp. 115–125. Abstract
The perioculomotor urocortin-containing population of neurons (pIIIu: otherwise known as the non-preganglionic Edinger-Westphal nucleus) is sensitive to alcohol and is involved in the regulation of alcohol intake. A recent study indicated that this brain region is also sensitive to psychostimulants. Since pIIIu has been shown to respond to stress, we investigated how psychostimulant-induced pIIIu activation compares to stress- and ethanol-induced activation, and whether it is independent from a generalized stress response. Several experiments were performed to test how the pIIIu responds to psychostimulants by quantifying the number of Fos immunoreactive nuclei after acute i.p. injections of saline, 10-30 mg/kg cocaine, 5 mg/kg methamphetamine, 5 mg/kg amphetamine, 2.5 g/kg ethanol, 2 h of restraint stress, 10 min of swim stress, or six applications of mild foot shock in male C57BL/6 J mice. We also compared Fos immunoreactivity in pIIIu after acute (20 mg/kg cocaine) and repeated cocaine exposure (7 days of 20 mg/kg cocaine) injections in male C57BL/6 J mice in order to investigate the potential habituation of this response. Finally, we quantified the number of Fos immunoreactive nuclei in pIIIu after administration of saline, 2.5 g/kg ethanol, 20 mg/kg cocaine, or 2 h of restraint stress in male Sprague-Dawley rats. We found that exposure to psychostimulants and ethanol induced significantly higher Fos levels in pIIIu compared to stress in mice. Furthermore, repeated cocaine injections did not decrease Fos immunoreactivity as would be expected if this response were due to stress. In rats, exposure to ethanol, psychostimulant and restraint stress all induced pIIIu Fos immunoreactivity compared to saline-injected controls. In both mice and rats, ethanol- and cocaine-induced Fos immunoreactivity occurred exclusively in urocortin 1-positive, but not in tyrosine hydroxylase-positive, cells. These results provide evidence that the pIIIu Fos-response to psychostimulants is independent of a generalized stress in mice, but not rats. They additionally show that the pIIIu response to stress differs significantly between species.
Zachary A. Rodd, Richard L. Bell, Kelly A. Kuc, James M. Murphy, Lawrence Lumeng, and William J. McBride. “Effects of concurrent access to multiple ethanol concentrations and repeated deprivations on alcohol intake of high-alcohol-drinking (HAD) rats.” Addiction Biology, 14, 2, Pp. 152–164. Abstract
High-alcohol-drinking rats, given access to 10% ethanol, expressed an alcohol deprivation effect (ADE) only after multiple deprivations. In alcohol-preferring (P) rats, concurrent access to multiple ethanol concentrations combined with repeated cycles of EtOH access and deprivation produced excessive ethanol drinking. The current study was undertaken to examine the effects of repeated alcohol deprivations with concurrent access to multiple concentrations of ethanol on ethanol intake of HAD replicate lines of rats. HAD-1 and HAD-2 rats received access to 10, 20 and 30% (v/v) ethanol for 6 weeks. Rats from each replicate line were assigned to: (1) a non-deprived group; (2) a group initially deprived of ethanol for 2 weeks; or (3) a group initially deprived for 8 weeks. Following the restoration of the ethanol solutions, cycle of 2 weeks of ethanol exposure and 2 weeks of alcohol deprivation was repeated three times for a total of four deprivations. Following the initial ethanol deprivation period, deprived groups significantly increased ethanol intakes during the initial 24-hour re-exposure period. Multiple deprivations increased ethanol intakes, shifted preference to higher ethanol concentrations and prolonged the duration of the elevated ethanol intakes for up to 5 days. In addition, repeated deprivations increased ethanol intake in the first 2-hour re-exposure period as high as 5-7 g/kg (which are equivalent to amounts consumed in 24 hours by HAD rats), and produced blood ethanol levels in excess of 150 mg%. The results indicate that HAD rats exhibit 'loss-of-control' of alcohol drinking with repeated deprivations when multiple ethanol concentrations are available.
Ronnie Dhaher, Deborah A. Finn, Denesa L. Oberbeck, Naomi Yoneyama, Christopher C. Snelling, Weiran Wu, and Robert J. Hitzemann. “Electrolytic lesions of the medial nucleus accumbens shell selectively decrease ethanol consumption without altering preference in a limited access procedure in C57BL/6J mice.” Pharmacology Biochemistry and Behavior, 92, 2, Pp. 335–342. Publisher's Version Abstract
The central extended amygdala (cExtA) is a limbic region proposed to play a key role in drug and alcohol addiction and to contain the medial nucleus accumbens shell (MNAc shell). The aim of this study was to examine the involvement of the MNAc shell in ethanol and sucrose consumption in a limited and free access procedure in the C57BL/6J (B6) mouse. Separate groups of mice received bilateral electrolytic lesions of the MNAc shell or sham surgery, and following recovery from surgery, were allowed to voluntarily consume ethanol (15% v/v) in a 2 h limited access 2-bottle-choice procedure. Following 1 week of limited access ethanol consumption, mice were given 1 week of limited access sucrose consumption. A separate group of lesioned and sham mice were given free access (24 h) to ethanol in a 2-bottle choice procedure and were run in parallel to the mice receiving limited access consumption. Electrolytic lesions of the MNAc shell decreased ethanol (but not sucrose) consumption in a limited access procedure, but did not alter free access ethanol consumption. These results suggest that the MNAc shell is a component of the underlying neural circuitry contributing to limited access alcohol consumption in the B6 mouse.
Richard L. Bell, Mark W. Kimpel, Jeanette N. McClintick, Wendy N. Strother, Lucinda G. Carr, Tiebing Liang, Zachary A. Rodd, R. Dayne Mayfield, Howard J. Edenberg, and William J. McBride. “Gene expression changes in the nucleus accumbens of alcohol-preferring rats following chronic ethanol consumption.” Pharmacology, biochemistry, and behavior, 94, 1, Pp. 131–147. Publisher's Version Abstract
The objective of this study was to determine the effects of binge-like alcohol drinking on gene expression changes in the nucleus accumbens (ACB) of alcohol-preferring (P) rats. Adult male P rats were given ethanol under multiple scheduled access (MSA; three 1-hr dark-cycle sessions/day) conditions for 8 weeks. For comparison purposes, a second ethanol drinking group was given continuous/daily alcohol access (CA; 24 hr/day). A third group was ethanol-naïve (W group). Average ethanol intakes for the CA and MSA groups were approximately 9.5 and 6.5 g/kg/day, respectively. Fifteen hr after the last drinking episode, rats were euthanized, the brains extracted, and the ACB dissected. RNA was extracted and purified for microarray analysis. The only significant differences were between the CA and W groups (p \textless 0.01; Storey false discovery rate = 0.15); there were 374 differences in named genes between these 2 groups. There were 20 significant Gene Ontology (GO) categories, which included negative regulation of protein kinase activity, anti-apoptosis, and regulation of G-protein-coupled receptor signaling. Ingenuity® analysis indicated a network of transcription factors, involving oncogenes (Fos, Jun, Junb had higher expression in the ACB of the CA group), suggesting increased neuronal activity. There were 43 genes located within rat QTLs for alcohol consumption and preference; 4 of these genes (Tgfa, Hspa5, Mtus1 and Creb3l2) are involved in anti-apoptosis and increased transcription, suggesting that they may be contributing to cellular protection and maintaining high alcohol intakes. Overall, these findings suggest that chronic CA drinking results in genomic changes that can be observed during the early acute phase of ethanol withdrawal. Conversely, chronic MSA drinking, with its associated protracted withdrawal periods, results in genomic changes that may be masked by tight regulation of these genes following repeated experiences of ethanol withdrawal.
Dayne R Mayfield and Adron R Harris. “Gene expression profiling in blood: new diagnostics in alcoholism and addiction?.” Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 34, 1, Pp. 250–251. Publisher's Version
Boris Tabakoff, Laura Saba, Morton Printz, Pam Flodman, Colin Hodgkinson, David Goldman, George Koob, Heather N. Richardson, Katerina Kechris, Richard L. Bell, Norbert Hübner, Matthias Heinig, Michal Pravenec, Jonathan Mangion, Lucie LeGault, Maurice Dongier, Katherine M. Conigrave, John B. Whitfield, John Saunders, Bridget Grant, and Paula L. Hoffman. “Genetical genomic determinants of alcohol consumption in rats and humans.” BMC Biology, 7, Pp. 70. Publisher's Version Abstract
We have used a genetical genomic approach, in conjunction with phenotypic analysis of alcohol consumption, to identify candidate genes that predispose to varying levels of alcohol intake by HXB/BXH recombinant inbred rat strains. In addition, in two populations of humans, we assessed genetic polymorphisms associated with alcohol consumption using a custom genotyping array for 1,350 single nucleotide polymorphisms (SNPs). Our goal was to ascertain whether our approach, which relies on statistical and informatics techniques, and non-human animal models of alcohol drinking behavior, could inform interpretation of genetic association studies with human populations.
Nicole A. R. Walter, Daniel Bottomly, Ted Laderas, Michael A. Mooney, Priscila Darakjian, Robert P. Searles, Christina A. Harrington, Shannon K. McWeeney, Robert Hitzemann, and Kari J. Buck. “High throughput sequencing in mice: a platform comparison identifies a preponderance of cryptic SNPs.” BMC genomics, 10, Pp. 379. Abstract
BACKGROUND: Allelic variation is the cornerstone of genetically determined differences in gene expression, gene product structure, physiology, and behavior. However, allelic variation, particularly cryptic (unknown or not annotated) variation, is problematic for follow up analyses. Polymorphisms result in a high incidence of false positive and false negative results in hybridization based analyses and hinder the identification of the true variation underlying genetically determined differences in physiology and behavior. Given the proliferation of mouse genetic models (e.g., knockout models, selectively bred lines, heterogeneous stocks derived from standard inbred strains and wild mice) and the wealth of gene expression microarray and phenotypic studies using genetic models, the impact of naturally-occurring polymorphisms on these data is critical. With the advent of next-generation, high-throughput sequencing, we are now in a position to determine to what extent polymorphisms are currently cryptic in such models and their impact on downstream analyses. RESULTS: We sequenced the two most commonly used inbred mouse strains, DBA/2J and C57BL/6J, across a region of chromosome 1 (171.6 - 174.6 megabases) using two next generation high-throughput sequencing platforms: Applied Biosystems (SOLiD) and Illumina (Genome Analyzer). Using the same templates on both platforms, we compared realignments and single nucleotide polymorphism (SNP) detection with an 80 fold average read depth across platforms and samples. While public datasets currently annotate 4,527 SNPs between the two strains in this interval, thorough high-throughput sequencing identified a total of 11,824 SNPs in the interval, including 7,663 new SNPs. Furthermore, we confirmed 40 missense SNPs and discovered 36 new missense SNPs. CONCLUSION: Comparisons utilizing even two of the best characterized mouse genetic models, DBA/2J and C57BL/6J, indicate that more than half of naturally-occurring SNPs remain cryptic. The magnitude of this problem is compounded when using more divergent or poorly annotated genetic models. This warrants full genomic sequencing of the mouse strains used as genetic models.
Natalie M Zahr, Dirk Mayer, Shara Vinco, Juan Orduna, Richard Luong, Edith V Sullivan, and Adolf Pfefferbaum. “In Vivo Evidence for Alcohol-Induced Neurochemical Changes in Rat Brain Without Protracted Withdrawal, Pronounced Thiamine Deficiency, or Severe Liver Damage.” Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 34, 6, Pp. 1427–1442. Publisher's Version Abstract
Magnetic resonance spectroscopy (MRS) studies in human alcoholics report decreases in N-acetylaspartate (NAA) and choline-containing (Cho) compounds. Whether alterations in brain metabolite levels are attributable to alcohol per se or to physiological effects of protracted withdrawal or impaired nutritional or liver status remains unclear. Longitudinal effects of alcohol on brain metabolites measured in basal ganglia with single-voxel MRS were investigated in sibling pairs of wild-type Wistar rats, with one rat per pair exposed to escalating doses of vaporized alcohol, the other to vapor chamber air. MRS was conducted before alcohol exposure and twice during exposure. After 16 weeks of alcohol exposure, rats achieved average blood alcohol levels (BALs) of \textasciitilde 293 mg per 100 ml and had higher Cho and a trend for higher glutamine + glutamate (Glx) than controls. After 24 weeks of alcohol exposure, BALs rose to \textasciitilde 445 mg per 100 ml, and alcohol-exposed rats had higher Cho, Glx, and glutamate than controls. Thiamine and thiamine monophosphate levels were significantly lower in the alcohol than the control group but did not reach levels low enough to be considered clinically relevant. Histologically, livers of alcohol-exposed rats exhibited greater steatosis and lower glycogenosis than controls, but were not cirrhotic. This study demonstrates a specific pattern of neurobiochemical changes suggesting excessive membrane turnover or inflammation, indicated by high Cho, and alterations to glutamate homeostasis in the rat brain in response to extended vaporized alcohol exposure. Thus, we provide novel in vivo evidence for alcohol exposure as causing changes in brain chemistry in the absence of protracted withdrawal, pronounced thiamine deficiency, or severe liver damage.
Natalie M. Zahr, Elena L. Fasano Crawford, Oliver Hsu, Shara Vinco, Dirk Mayer, Torsten Rohlfing, Edith V. Sullivan, and Adolf Pfefferbaum. “In vivo glutamate decline associated with kainic acid-induced status epilepticus.” Brain Research, 1300, Pp. 65–78. Publisher's Version Abstract
Neurophysiological, biochemical, and anatomical evidence implicates glutamatergic mechanisms in epileptic seizures. Until recently, however, longitudinal characterization of in vivo glutamate dynamics was not possible. Here, we present data using in vivo magnetic resonance spectroscopy (MRS) optimized for the detection of glutamate to identify changes that evolve following kainic acid (KA)-induced status epilepticus. Wild-type male Wistar rats underwent whole-brain MR imaging and single-voxel MRS on a clinical 3 T scanner equipped with a high-strength insert gradient coil. Scanning took place before and then 3 days, 28–32 days, and 42–50 days after induction of status epilepticus. Analyses compared 5 seizure (Sz), 5 no-seizure (NoSz; received KA but did not exhibit seizures), and 6 control (Con) animals. This longitudinal study demonstrated reduced glutamate levels in vivo in the dorsal hippocampus 3 days and 1 month following status epilepticus in Sz animals compared with Con animals. Additionally, previous results were replicated: in the Sz group, computed T2 was higher in the ventral hippocampus and limbic cortex 3 days after seizure activity compared with baseline but resolved in both regions at the 1 month scan, suggesting a transient edema. Three days following seizure activity, N-acetylaspartate (NAA) declined and lactate increased in the dorsal hippocampus of the Sz group compared with the Con and NoSz group; both metabolites approached baseline levels by the third scan. Taken together, these results support the conclusion that seizure activity following KA infusion causes loss of glutamatergic neurons.
Daniel M. Spielman, Dirk Mayer, Yi-Fen Yen, James Tropp, Ralph E. Hurd, and Adolf Pfefferbaum. “In vivo measurement of ethanol metabolism in the rat liver using magnetic resonance spectroscopy of hyperpolarized [1-13C]pyruvate.” Magnetic Resonance in Medicine, 62, 2, Pp. 307–313. Abstract
[1-(13)C]pyruvate is a readily polarizable substrate that has been the subject of numerous magnetic resonance spectroscopy (MRS) studies of in vivo metabolism. In this work (13)C-MRS of hyperpolarized [1-(13)C]pyruvate was used to interrogate a metabolic pathway involved in neither aerobic nor anaerobic metabolism. In particular, ethanol consumption leads to altered liver metabolism, which when excessive is associated with adverse medical conditions including fatty liver disease, hepatitis, cirrhosis, and cancer. Here we present a method for noninvasively monitoring this important process in vivo. Following the bolus injection of hyperpolarized [1-(13)C]pyruvate, we demonstrate a significantly increased rat liver lactate production rate with the coadministration of ethanol (P = 0.0016 unpaired t-test). The affect is attributable to increased liver nicotinamide adenine dinucleotide (NADH) associated with ethanol metabolism in combination with NADH's role as a coenzyme in pyruvate-to-lactate conversion. Beyond studies of liver metabolism, this novel in vivo assay of changes in NADH levels makes hyperpolarized [1-(13)C]pyruvate a potentially viable substrate for studying the multiple in vivo metabolic pathways that use NADH (or NAD(+)) as a coenzyme, thus broadening the range of applications that have been discussed in the literature to date.
Irina Fonareva, Erika Spangler, Nazzareno Cannella, Valentina Sabino, Pietro Cottone, Roberto Ciccocioppo, Eric P. Zorrilla, and Andrey E. Ryabinin. “Increased perioculomotor urocortin 1 immunoreactivity in genetically selected alcohol preferring rats.” Alcoholism, Clinical and Experimental Research, 33, 11, Pp. 1956–1965. Abstract
INTRODUCTION: Urocortin 1 (Ucn 1) is an endogenous peptide related to the corticotropin-releasing factor (CRF). Ucn 1 is mainly expressed in the perioculomotor area (pIII), and its involvement in alcohol self-administration is well confirmed in mice. In other species, the relationship between the perioculomotor Ucn 1-containing population of neurons (pIIIu) and alcohol consumption needs further investigation. The pIII also has a significant subpopulation of dopaminergic neurons. Because of dopamine's (DA) role in addiction, it is important to evaluate whether this subpopulation of neurons contributes to addiction-related phenotypes. Furthermore, the effects of gender on the relationship between Ucn 1 and tyrosine hydroxylase (TH) in pIII and alcohol preference in rats have not been previously assessed. METHODS: To address these issues, we compared 2 Sardinian alcohol-preferring sublines of rats, a population maintained at the Scripps Research Institute (Scr:sP) and a population maintained at University of Camerino-Marchigian Sardinian preferring rats (msP), to corresponding nonselectively bred Wistar rats of both sexes. Ucn 1- and TH-positive cells were detected on coronal midbrain sections from 6- to 8-week-old alcohol-naïve animals using brightfield and fluorescent immunohistochemistry. Ucn 1- and TH-positive cells in pIII were counted in the perioculomotor area, averaged across 2 to 3 sets, and binned into 3 bregma levels. RESULTS: Results demonstrated increased average counts of Ucn 1-positive cells in the middle bregma level in preferring male rats compared to Wistar controls and no difference in TH-positive cell counts in pIII. In addition, fluorescent double labeling revealed no colocalization of Ucn 1-positive and TH-positive neurons. Ucn 1 but not TH distribution was influenced by gender with female animals expressing more Ucn 1-positive cells than male animals in the peak bregma level. CONCLUSIONS: These findings extend previous reports of increased Ucn 1-positive cell distribution in preferring lines of animals. They indicate that Ucn1 contributes to increased alcohol consumption across different species and that this contribution could be gender specific. The results also suggest that Ucn1 regulates positive reinforcing rather than aversive properties of alcohol and that these effects could be mediated by CRF(2) receptors, independent of direct actions of DA.
John C. Crabbe, Pamela Metten, Justin S. Rhodes, Chia-Hua Yu, Lauren Lyon Brown, Tamara J. Phillips, and Deborah A. Finn. “A line of mice selected for high blood ethanol concentrations shows drinking in the dark to intoxication.” Biological Psychiatry, 65, 8, Pp. 662–670. Abstract
BACKGROUND: Many animal models of alcoholism have targeted aspects of excessive alcohol intake (abuse) and dependence. In the rodent, models aimed at increasing alcohol self-administration have used genetic or environmental manipulations, or their combination. Strictly genetic manipulations (e.g., comparison of inbred strains or targeted mutants, selective breeding) have not yielded rat or mouse genotypes that will regularly and voluntarily drink alcohol to the point of intoxication. Although some behavioral manipulations (e.g., scheduling or limiting access to alcohol, adding a sweetener) will induce mice or rats to drink enough alcohol to become intoxicated, these typically require significant food or water restriction or a long time to develop. We report progress toward the development of a new genetic animal model for high levels of alcohol drinking. METHODS: High Drinking in the Dark (HDID-1) mice have been selectively bred for high blood ethanol concentrations (BEC, ideally exceeding 100 mg%) resulting from the ingestion of a 20% alcohol solution. RESULTS: After 11 generations of selection, more than 56% of the population now exceeds this BEC after a 4-hour drinking session in which a single bottle containing 20% ethanol is available. The dose of ethanol consumed also produced quantifiable signs of intoxication. CONCLUSIONS: These mice will be useful for mechanistic studies of the biological and genetic contributions to excessive drinking.
Kelli G. Kline and Christine C. Wu. “MudPIT analysis: application to human heart tissue.” Methods in Molecular Biology (Clifton, N.J.), 528, Pp. 281–293. Abstract
Although two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) has been used as the standard proteomic approach for separating proteins in a complex mixture, this technique has many drawbacks. These include a limited molecular mass range, poor separation of highly acidic or basic proteins, and exclusion of the majority of membrane proteins from analysis. Considering the important functions of many membrane proteins, such as receptors, ion transporters, signal transducers, and cell adhesion proteins, it is increasingly important that these proteins are not excluded during the global proteomic analysis of cellular systems. Multidimensional Protein Identification Technology (MudPIT) offers a gel-free alternative to 2D-PAGE for the analysis of both membrane and soluble proteins.The goal of this chapter is to provide detailed methods for using MudPIT to profile both membrane and soluble proteins in complex unfractionated samples. Methods discussed will include tissue homogenization, sample preparation, MudPIT, data analysis, and an application for the analysis of unfractionated total tissue homogenate from human heart.
Yuval Silberman, Michal Bajo, Ann M. Chappell, Daniel T. Christian, Maureen Cruz, Marvin R. Diaz, Thomas Kash, Anna K. Lack, Robert O. Messing, George R. Siggins, Danny Winder, Marisa Roberto, Brian A. McCool, and Jeff L. Weiner. “Neurobiological mechanisms contributing to alcohol-stress-anxiety interactions.” Alcohol (Fayetteville, N.Y.), 43, 7, Pp. 509–519. Abstract
This article summarizes the proceedings of a symposium that was presented at a conference entitled "Alcoholism and Stress: A Framework for Future Treatment Strategies." The conference was held in Volterra, Italy on May 6-9, 2008 and this symposium was chaired by Jeff L. Weiner. The overall goal of this session was to review recent findings that may shed new light on the neurobiological mechanisms that underlie the complex relationships between stress, anxiety, and alcoholism. Dr. Danny Winder described a novel interaction between D1 receptor activation and the corticotrophin-releasing factor (CRF) system that leads to an increase in glutamatergic synaptic transmission in the bed nucleus of the stria terminalis. Dr. Marisa Roberto presented recent data describing how protein kinase C epsilon, ethanol, and CRF interact to alter GABAergic inhibition in the central nucleus of the amygdala. Dr. Jeff Weiner presented recent advances in our understanding of inhibitory circuitry within the basolateral amygdala (BLA) and how acute ethanol exposure enhances GABAergic inhibition in these pathways. Finally, Dr. Brian McCool discussed recent findings on complementary glutamatergic and GABAergic adaptations to chronic ethanol exposure and withdrawal in the BLA. Collectively, these investigators have identified novel mechanisms through which neurotransmitter and neuropeptide systems interact to modulate synaptic activity in stress and anxiety circuits. Their studies have also begun to describe how acute and chronic ethanol exposure influence excitatory and inhibitory synaptic communication in these pathways. These findings point toward a number of novel neurobiological targets that may prove useful for the development of more effective treatment strategies for alcohol use disorders.
Richard L. Bell, Bill J. A. Eiler, Jason B. Cook, and Shafiqur Rahman. “Nicotinic receptor ligands reduce ethanol intake by high alcohol-drinking HAD-2 rats.” Alcohol (Fayetteville, N.Y.), 43, 8, Pp. 581–592. Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) are implicated in the reinforcing effects of many drugs of abuse, including ethanol. The present study examined the efficacy of cytisine, a nAChR partial agonist, and lobeline, a putative nAChR antagonist, on the maintenance of ethanol drinking by HAD-2 rats. Adult male HAD-2 rats were given access to ethanol (15 and 30%, with ad libitum access to water and food) 22 h/day for 12 weeks, beginning at 60 days of age, after which cytisine (0.0, 0.5, and 1.5 mg/kg) was tested for 3 consecutive days. The rats were given an 18-day washout period and were then tested with lobeline (0.0, 1.0, and 5.0 mg/kg) for 3 consecutive days. Ethanol intake was measured at 1, 4, and 22 h postinjection. Rats were injected intraperitoneally just before lights out (1200 h). There was a significant main effect of cytisine treatment on the second test day, with the 1.5 mg/kg dose significantly reducing ethanol intake at the 1- and 4-h time-points, relative to saline, and the 0.5 mg/kg dose inducing a significant reduction at the 4-h time-point. Conversely, lobeline treatment resulted in significant main effects of treatment for all three time-points within each test day, with the 5.0 mg/kg dose significantly reducing ethanol intake, relative to saline, at each time-point within each test day. These findings provide further evidence that activity at the nAChR influences ethanol intake and is a promising target for pharmacotherapy development for the treatment of alcohol dependence and relapse.
Dorit Ron and Jun Wang. “The NMDA Receptor and Alcohol Addiction.” In Biology of the NMDA Receptor, edited by Antonius M. Van Dongen. Boca Raton (FL): CRC Press/Taylor & Francis. Publisher's Version Abstract
Alcohol addiction is a costly and detrimental chronic relapsing disorder, characterized by compulsive alcohol use despite the negative consequences; it is thought to be associated with aberrant learning and memory processes [1,2]. The NMDA-type glutamate receptor (NMDAR) plays an essential role in synaptic plasticity and learning and memory [3,4]. Not surprisingly, it is well established that the NMDAR is a major target of alcohol (ethanol) in the brain and has been implicated in ethanol-associated phenotypes such as tolerance, dependence, withdrawal, craving, and relapse [5,6]. This chapter focuses on studies elucidating molecular mechanisms that underlie ethanol’s actions on the NMDAR, and discusses the physiological and behavioral consequences of ethanol’s actions. Finally, we summarize information regarding the potential use of modulators of NMDAR function as medication to treat the adverse effects of alcoholism.
Colin N. Haile, Thomas R. Kosten, and Therese A. Kosten. “Pharmacogenetic treatments for drug addiction: cocaine, amphetamine and methamphetamine.” The American Journal of Drug and Alcohol Abuse, 35, 3, Pp. 161–177. Abstract
BACKGROUND: Pharmacogenetics uses genetic variation to predict individual differences in response to medications and holds much promise to improve treatment of addictive disorders. OBJECTIVES: To review how genetic variation affects responses to cocaine, amphetamine, and methamphetamine and how this information may guide pharmacotherapy. METHODS: We performed a cross-referenced literature search on pharmacogenetics, cocaine, amphetamine, and methamphetamine. RESULTS: We describe functional genetic variants for enzymes dopamine-beta-hydroxylase (DbetaH), catechol-O-methyltransferase (COMT), and dopamine transporter (DAT1), dopamine D4 receptor, and brain-derived neurotrophic factor (BDNF). A single nucleotide polymorphism (SNP; C-1021T) in the DbetaH gene is relevant to paranoia associated with disulfiram pharmacotherapy for cocaine addiction. Individuals with variable number tandem repeats (VNTR) of the SLC6A3 gene 3'-untranslated region polymorphism of DAT1 have altered responses to drugs. The 10/10 repeat respond poorly to methylphenidate pharmacotherapy and the 9/9 DAT1 variant show blunted euphoria and physiological response to amphetamine. COMT, D4 receptor, and BDNF polymorphisms are linked to methamphetamine abuse and psychosis. CONCLUSIONS: Disulfiram and methylphenidate pharmacotherapies for cocaine addiction are optimized by considering polymorphisms affecting DbetaH and DAT1 respectively. Altered subjective effects for amphetamine in DAT1 VNTR variants suggest a 'protected' phenotype. SCIENTIFIC SIGNIFICANCE: Pharmacogenetic-based treatments for psychostimulant addiction are critical for successful treatment.
Zhiguo Nie, Eric P. Zorrilla, Samuel G. Madamba, Kenner C. Rice, Marissa Roberto, and George Robert Siggins. “Presynaptic CRF1 receptors mediate the ethanol enhancement of GABAergic transmission in the mouse central amygdala.” TheScientificWorldJournal, 9, Pp. 68–85. Abstract
Corticotropin-releasing factor (CRF) is a 41-amino-acid neuropeptide involved in stress responses initiated from several brain areas, including the amygdala formation. Research shows a strong relationship between stress, brain CRF, and excessive alcohol consumption. Behavioral studies suggest that the central amygdala (CeA) is significantly involved in alcohol reward and dependence. We recently reported that the ethanol augmentation of GABAergic synaptic transmission in rat CeA involves CRF1 receptors, because both CRF and ethanol significantly enhanced the amplitude of evoked GABAergic inhibitory postsynaptic currents (IPSCs) in CeA neurons from wild-type (WT) and CRF2 knockout (KO) mice, but not in neurons of CRF1 KO mice. The present study extends these findings using selective CRF receptor ligands, gene KO models, and miniature IPSC (mIPSC) analysis to assess further a presynaptic role for the CRF receptors in mediating ethanol effects in the CeA. In whole-cell patch recordings of pharmacologically isolated GABAAergic IPSCs from slices of mouse CeA, both CRF and ethanol augmented evoked IPSCs in a concentration-dependent manner, with low EC50s. A CRF1 (but not CRF2) KO construct and the CRF1-selective nonpeptide antagonist NIH-3 (LWH-63) blocked the augmenting effect of both CRF and ethanol on evoked IPSCs. Furthermore, the new selective CRF1 agonist stressin1, but not the CRF2 agonist urocortin 3, also increased evoked IPSC amplitudes. Both CRF and ethanol decreased paired-pulse facilitation (PPF) of evoked IPSCs and significantly enhanced the frequency, but not the amplitude, of spontaneous miniature GABAergic mIPSCs in CeA neurons of WT mice, suggesting a presynaptic site of action. The PPF effect of ethanol was abolished in CeA neurons of CRF1 KO mice. The CRF1 antagonist NIH-3 blocked the CRF- and ethanol-induced enhancement of mIPSC frequency in CeA neurons. These data indicate that presynaptic CRF1 receptors play a critical role in permitting or mediating ethanol enhancement of GABAergic synaptic transmission in CeA, via increased vesicular GABA release, and thus may be a rational target for the treatment of alcohol abuse and alcoholism.
Kelli G. Kline, Greg L. Finney, and Christine C. Wu. “Quantitative strategies to fuel the merger of discovery and hypothesis-driven shotgun proteomics.” Briefings in Functional Genomics and Proteomics, 8, 2, Pp. 114–125. Publisher's Version Abstract
The ultimate goal of most shotgun proteomic pipelines is the discovery of novel biomarkers to direct the development of quantitative diagnostics for the detection and treatment of disease. Differential comparisons of biological samples identify candidate peptides that can serve as proxys of candidate proteins. While these discovery approaches are robust and fairly comprehensive, they have relatively low throughput. When merged with targeted mass spectrometry, this pipeline can fuel hypothesis-driven studies and the development of novel diagnostics and therapeutics.
Mingzhou Joe Song, Chris K. Lewis, Eric R. Lance, Elissa J. Chesler, Roumyana Kirova Yordanova, Michael A. Langston, Kerrie H. Lodowski, and Susan E. Bergeson. “Reconstructing generalized logical networks of transcriptional regulation in mouse brain from temporal gene expression data.” EURASIP journal on bioinformatics & systems biology, Pp. 545176. Abstract
Gene expression time course data can be used not only to detect differentially expressed genes but also to find temporal associations among genes. The problem of reconstructing generalized logical networks to account for temporal dependencies among genes and environmental stimuli from transcriptomic data is addressed. A network reconstruction algorithm was developed that uses statistical significance as a criterion for network selection to avoid false-positive interactions arising from pure chance. The multinomial hypothesis testing-based network reconstruction allows for explicit specification of the false-positive rate, unique from all extant network inference algorithms. The method is superior to dynamic Bayesian network modeling in a simulation study. Temporal gene expression data from the brains of alcohol-treated mice in an analysis of the molecular response to alcohol are used for modeling. Genes from major neuronal pathways are identified as putative components of the alcohol response mechanism. Nine of these genes have associations with alcohol reported in literature. Several other potentially relevant genes, compatible with independent results from literature mining, may play a role in the response to alcohol. Additional, previously unknown gene interactions were discovered that, subject to biological verification, may offer new clues in the search for the elusive molecular mechanisms of alcoholism.

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