1,720,972 research outputs found
Modeling Anorexia Nervosa
No full textAlthough the pathophysiology underlying anorexia nervosa (AN) has not been fully elucidated, inflammation appears to be a critical component of its course and progression. Eicosanoids (eiCs) are bioactive signaling lipids primarily derived from arachidonic acid which have gained considerable biological relevance for their involvement in central and peripheral inflammatory processes. They were first described as pro-inflammatory mediators, and only afterward their anti-inflammatory and pro-resolution activities were also highlighted. Recent findings suggest that alterations in eiCs signaling could contribute to the dysregulated inflammatory status observed in AN. In this chapter we will first overview the most important immunological functions of the eiCs, including the regulation of neuroinflammatory processes, and then we will summarize the current knowledge on their possible implication in the pathophysiology of AN, with a focus on animal models
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
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
PEROXISOME PROLIFERATOR-ACTIVATED RECEPTORS ALPHA AGONISTS ANTIDEPRESSANT-LIKE EFFECT: BEHAVIORAL CHARACTERIZATION IN RATS
No full textDepression is a chronic and recurrent severe mood disorder that affectsa high percentage of the worldwide population. Unfortunately at least 40% of patients do not respond to the treatment. Therefore, considerable effort is invested in the development of alternative therapeutic approaches for the pharmacotherapy of depression. Peroxisome proliferator-activated receptorsalpha (PPAR-α) are widely expressed in the brain andare activated by endogenous ligands likethe fatty acid amides N-palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), which are involved in the regulation of different physiological function such as inflammation and neuroprotection.Only few studies have been published onPPAR-α mediated behavioral effects, whichsuggests that PEA exerts anxiolytic and antidepressant-like effect in mice(Crupi et al., 2013, Yu et al., 2011).Thus, the aim of our study was to characterize the pharmacological profile of endogenous and synthetic PPAR-α agonists as PEA, OEA and clofibrate by motor activity test to evaluate possible motor impairments, the forced swim test (FSI) for the antidepressant activity,the elevated plus maze (EPM)and the social interaction test (SI)for anxiolytic like effects.
The compounds,tested at different doses and regimen(sub-chronically and chronically) significantly decreased immobility time and increased swimming in the FST test as compared to vehicle treated animals. Theseantidepressant-likeeffectswere reverted the acute administration of the specific PPAR-α antagonist MK886 and of the CB1 antagonist/inverse agonist rimonabant, demonstrating an involvementof thePPAR-α receptor but also an entourage effect of the endocannabinoid system.Moreover,none of thePPAR-αagonists injected subchronically, produced anxiolytic or anxiogenic-like behaviors in the EMP test, while an anxiogenicprofile was observed after acute treatment in the SI test, with a reduction of the total time spent in social interactions but an unaltered numbers of contacts.In conclusion, thesedata show that both endogenous and synthetic PPAR-α ligandsproduce antidepressant-like effects in an experimental animal model, an effect that is specifically mediated via PPAR-α activation but that also involve the endocannabinoid system. PPAR-α agonists, and in particular clofibrate that is still prescribed for the treatment of primary hypercholesterolemia, mixed dyslipidemia, and hypertriglyceridemia, deserve further characterization as a new candidate for the pharmacotherapy of depression.
Crupi R. et al. (2013) CNS Neurol Disord Drug Targets;12(7):989-1001.
Yu HL. et al (2011) Pharmacol Rep.;63(3):834-9
CB2 antagonist AM630, monoacylglycerol lipase inhibitor JZL184 and cannabidiol did not affect hedonic properties of food in rats with binge eating behavior
No full textBEHAVIORAL EFFECTS OF ACUTE ADMINISTRATION OF THE PPAR-α AGONIST PALMITOYLETHANOLAMIDE IN RATS
No full textN-palmitoylethanolamide (PEA), the amide of palmitic acid and ethanolamine is an endogenous ligand of peroxisome proliferator-activated receptor-alpha (PPAR-α) that possesses effects on metabolism, feeding, inflammation and pain (Pistis and Melis, 2010).
Our previous investigations have shown that PEA induces a dose-dependent antidepressant-like effect with a behavioral profile similar to that of the tricyclic antidepressant amitriptyline (unpublished data). This effect was reversed by the PPAR-α antagonist MK886, showing that it is specifically mediated via PPAR-α activation. Scope of this study was to characterize the pharmacological effects of an acute intraperitoneal (ip) administration of PEA (1 and 2 mg/kg) on anxiety, social interactions and spontaneous motor activity. Anxiety-like behavior has been evaluated by means of the elevated plus maze (EPM) test, that is based on the conflict between the animal’s instinct to explore its environment and its innate fear for open spaces: classical anxiolytic drugs elevate the time spent in the open compartments and the number of entries (Pellow and File, 1986). In the EPM test, we found that PEA (1 and 2 mg/kg ip) does not modify the percentage of either the open arm entries and the time spent in the open arms as compared with vehicle-treated controls. Social behavior was evaluated by means of the social interactions (SI) test that could provide another measure of anxiety (File and Seth, 2003), with time spent in social interactions being usually elevated by anxiolytic drugs. Animals acutely treated with 1 mg/kg (ip) of PEA significantly decrease the total time spent in social interaction but do not modify the total numbers of contacts with respect to vehicle-treated controls thus revealing an anxiogenic-like response. In the spontaneous motor activity test, evaluated using the Digiscan Animal Activity Analyser (Omnitech Electronics, USA), no difference has been found between treatment groups. Our results suggest an anxiogenic-like effect of PEA after acute administration, in agreement with the notion that several antidepressants show an anxiogenic profile after acute treatment. On the basis of these results it will be important to investigate the pharmacological and behavioral profile of PEA on anxiety–like behavior after chronic regime of treatment.
File and Seth (2003). Eur J Pharmacol 463: 35-53.
Pellow et al. (1986). Pharmacol Biochem Behav 24: 525-9.
Pistis and Melis (2010). Curr Med Chem 17:1450-6
Acute administration of palmitoylethanolamide: behavioural studies
No full textN-palmitoylethanolamide (PEA), the amide of palmitic acid and ethanolamine, belongs to the family of lipidic mediators that includes endogenous ligands of peroxisome proliferator-activated receptor-alpha (PPAR-α). PEA is broadly demonstrated to possess effects on metabolism, feeding, inflammation and pain (Pistis and Melis, 2010). The discovery that PEA is able to prevent nicotine addiction in rats has highlighted the role of these ligands in the modulation of the rewarding properties of nicotine and indicates that PPAR-α might provide a valuable new target for antismoking medications (Mascia et al., 2010). Furthermore, Mazzola and coworkers (2009) have recently proposed the involvement of PPAR-α in learning and memory thus providing new behavioral evidence of a central role of these nuclear receptors. However, the mechanism of PEA action in the brain is largely unknown. Our previous investigations have shown that PEA induces a dose-dependent antidepressant-like effect with a behavioral profile similar to that of the tricyclic antidepressant amitriptyline (unpublished data). This effect was reversed by the PPARα antagonist MK886 showing that it is specifically mediated via PPAR-α activation. Scope of this study was to characterize the pharmacological effects of an acute intraperitoneal (ip) administration of PEA (1-2mg/kg) on anxiety, social interaction and spontaneous motor activity. Anxiety-like behavior has been evaluated by means of the elevated plus maze (EPM) test, that is based on the conflict between the animal’s instinct to explore its environment and its innate fear for open spaces: classical anxiolytic drugs elevate the time spent in the open compartments and the number of entries (Pellow and File, 1986). In the EPM test, we found that PEA (1-2 mg/kg ip) did not modify the percentage of either the open arm entries and the time spent in the open arms as compared to vehicle-treated controls. The active social behavior was tested by means of the social interaction (SI) test that could provide another measure of anxiety (File and Seth, 2003) with time spent in social interactions being usually elevated by anxiolytic drugs. Animal acutely treated with 1 mg/kg (ip) of PEA significantly decreased the total social interaction time but did not modify the total numbers of contacts with respect to vehicle-treated controls thus revealing an anxiogenic-like response. In the spontaneous motor activity test, evaluated using the Digiscan Animal Activity Analyser (Omnitech Electronics, USA), we found that horizontal, vertical and center locomotor activities significantly decreased over time in both vehicle and PEA-treated rats (1-2 mg/kg ip ) with no difference between treatment groups. Our results add further sustenance to the biological and pharmacological effects demonstrated for PPAR-α agonists, suggesting an anxiogenic-like effect after acute administration. Since several antidepressant drugs show an anxiogenic profile after acute treatment but anxiolytic effects after chronic treatment, it will be important to investigate the pharmacological and behavioral profile of PEA following a chronic regime of treatment.
File SE and Seth P (2003). Eur J Pharmacol 463: 35-53.
Mascia P et al. (2011).Biol Psychiatry69: 633-41.
Mazzola C et al. (2009).Learn Mem 16:332-7.
Pellow S et al. (1986).PharmacolBiochemBehav24: 525-9.
Pistis M and Melis M (2010).Curr Med Chem17:1450-67
Behavioural and neurochemical assessment of salvinorin A abuse potential in the rat
No full textSalvinorin A is a recreational drug derived from Salvia divinorum, a sage species long used as an entheogen. While salvinorin A has potent hallucinogenic properties, its abuse potential has not been assessed consistently in controlled behavioural and neurochemical studies in rodents.
OBJECTIVE:
This study aimed to assess salvinorin A abuse potential by measuring its capacity to establish and maintain self-administration behaviour and to modify dopamine (DA) levels in the nucleus accumbens (NAcc) of rats.
RESULTS:
Male Lister Hooded (LH) and Sprague-Dawley (SD) rats were allowed to self-administer salvinorin A (0.5 or 1.0 μg/kg/infusion) intravenously 2 h/day for 20 days under a continuous schedule of reinforcement and lever pressing as operandum. LH rats discriminated between the active and inactive levers but did not reach the acquisition criterion for stable self-administration (≥12 active responses vs ≤5 inactive responses for at least 5 consecutive days). SD rats discriminated between the two levers at the lower dose only but, like LH rats, never acquired stable self-administration behaviour. Systemic salvinorin A increased extracellular DA in the NAcc shell of both LH (at ≥40 μg/kg) and SD rats (at ≥5 μg/kg), but injection into the ventral tegmental area (VTA) induced no significant change in NAcc DA concentration in LH rats and only brief elevations in SD rats.
CONCLUSIONS:
Salvinorin A differs from other commonly abused compounds since although it affects accumbal dopamine transmission, yet it is unable, at least at the tested doses, to sustain stable intravenous self-administration behaviour
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