1,720,985 research outputs found
Effect of medial prefrontal cortex 6-OHDA lesions on behavioral and neurochemical responses to gustatory stimuli
Full text linkAppetitive sweet tastes increase dopamine (DA) in the nucleus accumbens (NAc) shell and core and in the medial prefrontal cortex (mPFC) in relation to their motivational valence, salience and novelty; the DA increase in the NAc shell is subjected to single trial habituation while in the NAc core and in the mPFC is not. Recently it was shown that sensitization to morphine can reverse these phenomena in the NAc shell and in the mPFC; abolishment of the habituation phenomenon was observed in the NAc shell while in the mPFC single trial habituation took place. Medial prefrontal cortex is an area well known to interact with subcortical areas such as the VTA and the NAc and it has been proposed that DA depletion in the mPFC can alter the mode of function of subcortical areas, including the NAc DAergic responses to pharmacological and environmental challenges of the system. In fact, 6-OHDA lesions of the mPFC have been shown to produce sensitization to the neurochemical and behavioral responses to cocaine and to alter the NAc DAergic transmission in response to natural reinforcers. In the present thesis it was studied the effect of 6-OHDA lesions in the mPFC in the NAc DAergic response to a taste stimulus (sweet chocolate) using in vivo microdialysis. Moreover, behavioral taste reactivity and motor behavior studies were held out to investigate whether the lesions influence this type of behaviors. As in sensitized to morphine animals, lesions produced abolishment of habituation in the NAc shell in the pre-exposed to taste animals, while in the NAc core produced a higher and delayed increase in DA in the naive animals. No differences between lesioned and sham operated animals where observed in naive and pre-exposed animals in the DAergic response of NAc shell and core, respectively. No differences were observed between the groups in taste reactivity test and in the motor activity studies. TH immunoreactivity studies were performed and tissue neurotransmitter levels were quantified in order to evaluate the extension and percentage of the lesions in the mPFC
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
Neurocircuitry of Reward and Addiction : Potential Impact of Dopamine-Glutamate Co-release as Future Target in Substance Use Disorder
No full textDopamine-glutamate co-release is a unique property of midbrain neurons primarily located in the ventral tegmental area (VTA). Dopamine neurons of the VTA are important for behavioral regulation in response to rewarding substances, including natural rewards and addictive drugs. The impact of glutamate co-release on behaviors regulated by VTA dopamine neurons has been challenging to probe due to lack of selective methodology. However, several studies implementing conditional knockout and optogenetics technologies in transgenic mice have during the past decade pointed towards a role for glutamate co-release in multiple physiological and behavioral processes of importance to substance use and abuse. In this review, we discuss these studies to highlight findings that may be critical when considering mechanisms of importance for prevention and treatment of substance abuse
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Two Different Real-Time Place Preference Paradigms Using Optogenetics within the Ventral Tegmental Area of the Mouse
No full textUnderstanding how neuronal activation leads to specific behavioral output is fundamental for modern neuroscience. Combining optogenetics in rodents with behavioral testing in validated paradigms allows the measurement of behavioral consequences upon stimulation of distinct neurons in real-time with high spatial and temporal selectivity, and thus the establishment of causal relationships between neuronal activation and behavior. Here, we describe a step-by-step protocol fora real-time place preference (RT-PP) paradigm, a modified version of the classical conditioned place preference (CPP) test. The RT-PP is performed in a three-compartment apparatus and can be utilized to answer if optogenetic stimulation of a specific neuronal population is rewarding or aversive. We also describe an alternative version of the RT-PP protocol, the socalled neutral compartment preference (NCP) protocol, which can be used to confirm aversion. The two approaches are based on extensions of classical methodology originating from behavioral pharmacology and recent implementation of optogenetics within the neuroscience field. Apart from measuring place preference in real time, these setups can also give information regarding conditioned behavior. We provide easyto-follow step-by-step protocols alongside examples of our own data and discuss important aspects to consider when applying these types of experiments
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