1,720,961 research outputs found
Synthetic cannabinoid JWH-018 impairs object recognition memory in mice: behavioral and electrophysiological evidence
No full textIntroduction:
JWH-018 (1-pentyl-3-(1-naphthoyl) indole) is a synthetic CB1 and CB2 agonist illegally marketed in 'Spice' and “herbal blend” for its psychoactive effects similar to those produced by Cannabis. In rodents JWH-018 reproduces the typical effects of THC as hypothermia, analgesia, hypolocomotion and akinesia, while its effects on memory functions are still unknowns. Behavioral and in vitro electrophysiological studies were undertaken to investigated the effects of acute JWH-018 administration on novel object recognition memory and hippocampal LTP formation in CD-1 male mice.
Methods and Results:
The novel object recognition task is a one-trial learning paradigm allowing the assessment of acquisition, consolidation or retrieval of (object) information separately. JWH-018 (0.1-1 mg/Kg i.p.) dose-dependently impaired both short (2 hours after training section) and long (24 hours after training section) memory retention in mice by CB1 receptor stimulation, since JWH-018 effect was prevented by the selective CB-1 receptor antagonist AM251 (3 mg/Kg).
Electrically evoked Schaffer area fEPSP has been extracellularly recorded from stratum radiatum of mouse dorsal hippocampal transversal slices. A stimulus–response curve was recorded before and after JWH-018 contact. At this time, an LTP stimulation paradigm was applied. JWH-018 (10-1000 nM) dose-dependently reduced LTP in hippocampal slices and abolished it at higher concentrations (300 and 1000 nM).
Conclusion:
These results show that JWH-018 impairs cognitive function in mice possibly by impairing hippocampal memory formation. This aspect should be carefully investigated since chronic consumption of THC impairs cognitive function not only in animal models but in particular in human consumers by altering brain neurodevelopment (http://www.dronet.org/monografia.php?monografie=93)
Powerful cocaine-like action of MDPV on aggressive behaviour in isolated mice
No full textMDPV (3,4-methylenedioxypyrovalerone) is a synthetic cathinone illegally marketed as “bath salts” or “plant food” and consumed for its psychostimulant effects similar to those produced by cocaine, amphetamines and MDMA. Clinical reports indicate that MDPV produce euphoria, increase alertness and at high doses it causes agitation, psychosis, tachycardia and even death (1). In particular, the second leading cause of death induced by MDPV and other cathinones is associated with self-harm, risky and violent behavior (2, 3). Anecdotal reports suggests that MDPV increases violent aggressive behavior in men similar to that reported for alcohol and cocaine consumption (4).
In rodents, MDPV reproduces the typical physiological effects of psychostimulant drugs, showing a greater potency compared to cocaine (5). Nevertheless, its role on aggressive behavior is still unknowns. Therefore, the aim of this study was to evaluate the effect of MDPV on aggressive behavior in mice and to compare its action with that induced by cocaine.
The Resident-Intruder paradigm in isolated mice (6) was undertaken to investigate the effect of MDPV and cocaine on aggressive behavior. Saline administration causes an increase in aggressive behavior in 7% of total mice (n=50) with an increase of bite frequency of +52±1% respect to control baseline. Systemic MDPV administration (i.p.) at 0.1 and 10 mg/Kg causes an increased aggressive behavior in 46% and 55 % of total mice (n=50 for each treatment) with an increased frequency of bites of +134±22% and +155±18 % respectively. Similarly, cocaine administration (i.p.) at 0.1 and 10 mg/Kg causes an increased aggressive behavior in 13% and 27 % of total mice (n=50 for each treatment) with an increased frequency of bites of +82±8% and +132±11 % respectively, proving to be less potent than MDPV in inducing aggressive behavior in mice. The aggressive effect caused by MDPV is consistent with the positive modulation on catecholamine release (5) and its powerful action may reflect its stronger ability to inhibit dopamine and norepinephrine uptake respect to cocaine (5). These results show for the first time that MDPV enhance aggressive behavior in mice with grater potency compared to cocaine. This aspect should be carefully investigated for the prevention of interpersonal violence in human induced by novel psychoactive drug consumption.
(1) Prosser J.M. and Nelson L.S. (2012) J Med Toxicol. 8: 33-42.
(2) Marinetti L.J. and Antonides H.M. (2013) J. Anal. Toxicol. 37: 135-146.
(3) Schifano F., Corkery J. and Ghodse A.H. (2012) J. Clin. Psychopharmacol. 32: 710-714.
(4) Chermack S.T. and Blow F.C. (2002) Drug Alcohol Depend. 58: 43-54.
(5) Baumann M.H., Partilla J.S., Lehener K.R. et al., (2013) Neuropsychopharmacology 38:552-562.
(6) Miczec K.A. and O’Donnel J.M. (1978) Psychopharmacology 57: 47-5
Acute intoxication cases related to methoxetamine consumption in Italy: clinical and toxicological evidences
No full textAccording to European directives, in 2008 the Department for Antidrug Policies of the Italian Presidency of the Council of Ministers activated the National Early Warning System aimed at monitoring new psychoactive substances and at implementing actions to prevent health consequences related to their consumption. Among new drugs registered, methoxetamine was identified in seized materials and was related to two acute intoxication cases notified by the poison control centers in Pavia and Florence
Rapid analysis of caffeine in "smart drugs" and "energy drinks" by microemulsion electrokinetic chromatography (MEEKC)
No full textA novel method based on microemulsion electrokinetic chromatography (MEEKC) with diode array detection (DAD) for rapid determination of caffeine in commercial and clandestine stimulants, known as "energy drinks" and "smart drugs", is described. Separations were carried out in 50 cm × 50 μm (ID) uncoated fused silica capillaries. The optimized buffer electrolyte was composed of 8.85 mM sodium tetraborate pH 9.5, SDS 3.3% (w/v), n-hexane 1.5% (v/v) and 1-butanol 6.6% (v/v). Separations were performed at a voltage of 20 kV. Sample injection conditions were 0.5 psi, 3 s. Diprofilline was used as internal standard. The determination of the analytes was based on the UV signal recorded at 275 nm, corresponding to the maximum wavelength of absorbance of caffeine, whereas peak identification and purity check was performed on the basis of the acquisition of UV radiation between 200 and 400 nm wavelengths. Under the described conditions, the separation of the compounds was achieved in 6 min without any interference from the matrix. Linearity was assessed within a caffeine concentration range from 5 to 100 μg/mL. The intra-day and inter-day precision values were below 0.37% for migration times and below 9.86% for peak areas. The present MEEKC method was successfully applied to the direct determination of caffeine in smart drugs and energy drinks
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
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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