| 1. |
- Augier, Eric, et al.
(författare)
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A Method for Evaluating the Reinforcing Properties of Ethanol in Rats without Water Deprivation, Saccharin Fading or Extended Access Training
- 2017
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Ingår i: Journal of Visualized Experiments. - : JOURNAL OF VISUALIZED EXPERIMENTS. - 1940-087X. ; :119
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Tidskriftsartikel (refereegranskat)abstract
- Operant oral self-administration methods are commonly used to study the reinforcing properties of ethanol in animals. However, the standard methods require saccharin/sucrose fading, water deprivation and/or extended training to initiate operant responding in rats. This paper describes a novel and efficient method to quickly initiate operant responding for ethanol that is convenient for experimenters and does not require water deprivation or saccharin/sucrose fading, thus eliminating the potential confound of using sweeteners in ethanol operant self-administration studies. With this method, Wistar rats typically acquire and maintain self-administration of a 20% ethanol solution in less than two weeks of training. Furthermore, blood ethanol concentrations and rewards are positively correlated for a 30 min self-administration session. Moreover, naltrexone, an FDA-approved medication for alcohol dependence that has been shown to suppress ethanol self-administration in rodents, dose-dependently decreases alcohol intake and motivation to consume alcohol for rats self-administering 20% ethanol, thus validating the use of this new method to study the reinforcing properties of alcohol in rats.
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| 2. |
- Cippitelli, Andrea, et al.
(författare)
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Alcohol-induced neurodegeneration, suppression of transforming growth factor-beta, and cognitive impairment in rats : prevention by group II metabotropic glutamate receptor activation
- 2010
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Ingår i: Biological Psychiatry. - : Elsevier. - 0006-3223 .- 1873-2402. ; 67:9, s. 823-830
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Glutamatergic neurotransmission has been implicated in mechanisms of alcohol-induced neurodegeneration and cognitive impairment, but the underlying mechanism remains unknown. Here, we examined whether the group II metabotropic glutamate receptor agonist LY379268 prevents neuronal death and learning deficits in a rat model of binge-like exposure to alcohol.METHODS: Following 4-day binge alcohol exposure concurrent with LY379268 or vehicle treatment, Fluoro-Jade B and transforming growth factor-beta (TGF-beta) staining were carried out, and reversal learning in the Morris water maze was assessed.RESULTS: Fluoro-Jade B staining indicating neurodegeneration was most extensive in the ventral hippocampus and the entorhinal cortex (EC). LY379268 was potently neuroprotective in the EC but not in the dentate gyrus of the hippocampus. In parallel, binge alcohol exposure suppressed TGF-beta expression in both the EC and dentate gyrus, whereas LY379268 increased TGF-beta in the EC only. Finally, neuroprotective effects of LY379268 were accompanied by prevention of deficits in spatial reversal learning.CONCLUSIONS: Our data support a neuroprotective role for group II metabotropic glutamate receptor agonists and TGF-beta in alcohol-induced neurodegeneration.
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| 3. |
- Cippitelli, Andrea, et al.
(författare)
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Neuropeptide Y (NPY) suppresses yohimbine-induced reinstatement of alcohol seeking
- 2010
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Ingår i: Psychopharmacology. - : Springer. - 0033-3158 .- 1432-2072. ; 208:3, s. 417-426
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Reinstatement of responding to a previously alcohol-associated lever following extinction is an established model of relapse-like behavior and can be triggered by stress exposure. Here, we examined whether neuropeptide Y (NPY), an endogenous anti-stress mediator, blocks reinstatement of alcohol-seeking induced by the pharmacological stressor yohimbine.MATERIALS AND METHODS: NPY [5.0 or 10.0 mug/rat, intracerebroventricularly (ICV)] dose-dependently blocked the reinstatement of alcohol seeking induced by yohimbine (1.25 mg/kg, i.p.) but failed to significantly suppress the maintenance of alcohol self-administration. We then used c-fos expression mapping to examine neuronal activation following treatment with yohimbine or NPY alone or yohimbine following NPY pre-treatment.RESULTS AND DISCUSSION: The analysis was focused on a network of structures previously implicated in yohimbine-induced reinstatement, comprised of central (CeA) and basolateral (BLA) amygdala and the shell of the nucleus accumbens (Nc AccS). Within this network, both yohimbine and NPY potently induced neuronal activation, and their effects were additive, presumably indicating activation of excitatory and inhibitory neuronal populations, respectively.CONCLUSION: These results suggest that NPY selectively suppresses relapse to alcohol seeking induced by stressful events and support the NPY system as an attractive target for the treatment of alcohol addiction.
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| 4. |
- Cippitelli, Andrea, et al.
(författare)
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Pharmacological blockade of corticotropin-releasing hormone receptor 1 (CRH1R) reduces voluntary consumption of high alcohol concentrations in non-dependent Wistar rats
- 2012
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Ingår i: Pharmacology, Biochemistry and Behavior. - : Elsevier. - 0091-3057 .- 1873-5177. ; 100:3, s. 522-529
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A dysregulation of the corticotropin-releasing hormone (CRH) system has been implicated in the development of excessive alcohol consumption and dependence. The aim of the present study was to evaluate whether the CRH system is also recruited when non-dependent Wistar rats escalate to high alcohol intake in the intermittent (alternate days) model of drinking.METHODS: We compared intermittent and continuous access to 20% (v/v) alcohol in a two-bottle free choice drinking paradigm. Following a total of twenty 24-hour exposures for every experimental group, we assessed signs of alcohol withdrawal, including anxiety-like behavior and sensitivity to stress. The selective CRH1 receptor (CRH1R) antagonist antalarmin (0, 10, 20 mg/kg, i.p.) was tested on alcohol consumption.RESULTS: Intermittent access to 20% alcohol led non-selected Wistar rats to escalate their voluntary intake to a high and stable level, whereas continuously exposed animals maintained a lower consumption. These groups did not differ in physical withdrawal signs. In addition, no differences were found when anxiogenic-like behavior was studied, neither under basal conditions or following restraint stress. Nevertheless, sensitivity to the treatment with the CRH1R antalarmin was observed since a reduction of 20% alcohol intake was found in both groups of animals regardless of the regimen of alcohol exposure. In addition, antalarmin was effective when injected to animals exposed to intermittent 10% (v/v) alcohol whereas it failed to suppress 10% continuous alcohol intake.CONCLUSIONS: Pharmacological blockade of CRH1R reduced alcohol drinking when sustained high levels of intake were achieved suggesting that the CRH system plays a key role when high doses of ethanol are consumed by non-dependent subjects. This supports the notion that CRH system not only maintains the dependent state but also engages the transition to dependence.
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| 5. |
- Thorsell, Annika, et al.
(författare)
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Neurokinin-1 receptors (NK1Rs), alcohol consumption, and alcohol reward in mice
- 2010
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Ingår i: Psychopharmacology. - : Springer. - 0033-3158 .- 1432-2072. ; 209:1, s. 103-111
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Tidskriftsartikel (refereegranskat)abstract
- RATIONALE: Reduced voluntary alcohol consumption was recently found in neurokinin-1 receptor (NK1R)-deficient (KO) mice. It remains unknown whether this reflects developmental effects or direct regulation of alcohol consumption by NK1R:s, and whether the reduced consumption reflects motivational effects.OBJECTIVE: The objective of this study is to obtain an expanded preclinical validation of NK1R antagonism as a candidate therapeutic mechanism in alcohol use disorders.METHODS: The NK1R antagonist L-703,606 and NK1R KO mice were used in models that assess alcohol-related behaviors.RESULTS: L-703,606 (3-10 mg/kg i.p.) dose-dependently suppressed alcohol intake in WT C57BL/6 mice under two-bottle free choice conditions but was ineffective in NK1R KO:s, demonstrating the receptor specificity of the effect. Alcohol reward, measured as conditioned place preference for alcohol, was reduced by NK1R receptor deletion in a gene dose-dependent manner. In a model where escalation of intake is induced by repeated cycles of deprivation and access, escalation was seen in WT mice, but not in KO mice. Among behavioral phenotypes previously reported for NK1R mice on a mixed background, an analgesic-like phenotype was maintained on the C57BL/6 background used here, while KO:s and WT:s did not differ in anxiety- and depression-related behaviors.CONCLUSIONS: Acute blockade of NK1R:s mimics the effects of NKR1 gene deletion on alcohol consumption, supporting a direct rather than developmental role of the receptor in regulation of alcohol intake. Inactivation of NK1R:s critically modulates alcohol reward and escalation, two key characteristics of addiction. These data provide critical support for NK1R antagonism as a candidate mechanism for treatment of alcoholism.
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