1,720,973 research outputs found
Animal models of drug relapse and craving: From drug priming-induced reinstatement to incubation of craving after voluntary abstinence (Chapter 2)
No full textHigh rates of relapse to drug use during abstinence is a defining feature of drug addiction. In abstinent drug users, drug relapse is often precipitated by acute exposure to the self-administered drug, drug-associated cues, stress, as well as by short-term and protracted withdrawal symptoms. In this review, we discuss different animal models that have been used to study behavioral and neuropharmacological mechanisms of these relapse-related phenomena. In the first part, we discuss relapse models in which abstinence is achieved through extinction training, including the established reinstatement model, as well as the reacquisition and resurgence models. In the second part, we discuss recent animal models in which drug relapse is assessed after either forced abstinence (e.g., the incubation of drug craving model) or voluntary (self-imposed) abstinence achieved either by introducing adverse consequences to ongoing drug self-administration (e.g., punishment) or by an alternative nondrug reward using a discrete choice (drug vs. palatable food) procedure. We conclude by briefly discussing the potential implications of the recent developments of animal models of drug relapse after voluntary abstinence to the development of medications for relapse prevention
Animal models of drug relapse and craving: From drug priming-induced reinstatement to incubation of craving after voluntary abstinence
No full textHigh rates of relapse to drug use during abstinence is a defining feature of drug addiction. In abstinent drug users, drug relapse is often precipitated by acute exposure to the self-administered drug, drug-associated cues, stress, as well as by short-term and protracted withdrawal symptoms. In this review, we discuss different animal models that have been used to study behavioral and neuropharmacological mechanisms of these relapse-related phenomena. In the first part, we discuss relapse models in which abstinence is achieved through extinction training, including the established reinstatement model, as well as the reacquisition and resurgence models. In the second part, we discuss recent animal models in which drug relapse is assessed after either forced abstinence (e.g., the incubation of drug craving model) or voluntary (self-imposed) abstinence achieved either by introducing adverse consequences to ongoing drug self-administration (e.g., punishment) or by an alternative nondrug reward using a discrete choice (drug vs. palatable food) procedure. We conclude by briefly discussing the potential implications of the recent developments of animal models of drug relapse after voluntary abstinence to the development of medications for relapse prevention
Sexually dimorphic effects of alcohol self-administration on cognitive processes
No full textChronic alcohol consumption is able to modify cognitive and emotional behaviour in humans. Many studies on gender diversity have identified swingeing differences between man and woman, not only in the propensity for alcohol abuse, but also in their behavioural effects. In this study we investigate in adult male and female rats:
i) alcohol drinking behaviour and preference pattern using a 3-bottle choice paradigm with water, 10% ethanol solution and white wine (10%v/v), along a four-week period;
ii) Alcohol free access (AFA) effects on locomotion and behavioural reactivity in the Open Field;
iii) The influence of AFA on spatial learning and reference memory, employing the Morris Water Maze.
Our results show that:
1) female rats display higher intake of alcoholic beverages compared to males in the first two weeks of the paradigm, while they reduce their alcoholic intake in the last two weeks, drinking the same amounts as males; female rats- as well as males - prefer ethanol 10% than white wine;
2) AFA increases locomotor activity and behavioural reactivity in response to novelty in male rats (p< 0.004); on the contrary, female rats display a decrease in behavioural reactivity and locomotion compared to controls (p< 0.0187);
3) AFA improves spatial information processing in the new-place learning task in male rats, while it has detrimental effects in place learning, reversal learning and reference memory in female rats.
Our results show a sexually dimorphic pattern of alcohol drinking behaviour, highlighting a different sensitivity to the reinforcing properties of ethanol. Both male and female rats are able to self-regulate their alcoholic intake along the four-week paradigm. The sexually dimorphic different behavioural consequences of alcohol free-access indicate that female rats are more vulnerable to the detrimental effects of alcohol and this may be due to the gender-related differences in metabolic and neurochemical pattern
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Evaluation of neuropeptide Y expression during acetaldehyde withdrawal in rats. Focus on hippocampus and nucleus accumbens
No full textStress-related neuropeptides are involved in setting up alcohol addiction. Ethanol is able to acutely induce CRH and ACTH release, while cronically a dampered response of the hypothalamus -pituitary- adrenal (HPA) axis has been observed. Also neuropeptide Y (NPY) has been shown to modulate ethanol consumption, and its central expression seems inversely correlated to ethanol intake. Recent in vivo and in vitro evidence have highlighted the key role of acetaldehyde (ACD), ethanol first metabolite, as a mediator of the central effects of ethanol, even as modulator of the neuropeptidergic transmission in the rat brain.
The aim of this study was to investigate NPY immunoreactivity following a 4-day binge ACD treatment in hippocampus and nucleus accumbens, two areas particulary involved in addictive-related learning and reward processes. Wistar rats have been intragastrically administered with ACD (450mg/kg) five times per day, for four days, and have been sacrificed at early (16h) and late (72h) withdrawal.
Our results show:
i) an increased NPY expression at 16h and 72h after the last administration in hippocampus (p< 0.001; p< 0.001) and nucleus accumbens (p< 0.05; p< 0.001) compared to controls.
ii) an increase in the number of NPY-positive neurons in the hippocampus (p< 0.001) and nucleus accumbens (p< 0.001) in late withdrawal with respect to early withdrawal.
These findings are consistent with the hypothesis that NPY levels increase in a time- and region-specific fashion to reset homeostasis in the brain during withdrawal; and that ACD is able to affect neuropeptidergic transmission as well as ethanol, playing thus a key role in the neuroadaptative changes that characterize ethanol addiction
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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