1,721,225 research outputs found
Effects of n-di-propylacetate on aggressive behavior and brain GABA level in isolated mice.
No full textn-di-Propylacetate (nDPA, valproate) a GABA-T inhibitor, injected IP at the dose of 300 mg/kg antagonized agonistic behavior of isolated DBA/2 mice in a time-dependent fashion in parallel to an increase of GABA levels in olfactory bulb, striatum, posterior colliculus and septum. After 75 min, aggressive responses were higher than those after 15 to 45 min and significantly lower in comparison with those of saline injected mice. After 120 min aggressive behavior was not different from that of control mice. The concentration of GABA in the striatum and olfactory bulb returned to control value 75 and 120 min after drug administration, respectively. After 120 min GABA levels in posterior colliculus and septum were lower than those after 15 to 75 min, although significantly higher in comparison with those of saline injected mice. The results are discussed in terms of the possible involvement of olfactory bulb and striatum in GABA-mediated control of isolation-induced aggressive behavior in mice
Effects of opiate antagonists on social and aggressive behavior of isolated mice
No full textOpiate antagonists naloxone (1 and 1.5 mg/kg IP) and naltrexone (2.5 and 5 mg/kg IP) inhibit aggressive responses of DBA/2 isolated mice, while increasing the duration of some social activities such as sniff-body, sniff-nose, and following. At the doses employed naloxone and naltrexone did not affect motor activity and self-grooming of paired mice. These findings are discussed in terms of the endogeneous opioids system involvement in arousability, in the response of the organism to stressful events, in the motivational mechanisms which control social behavior and in the functioning of some neurotransmitter systems which are known to play an important role in the control of isolation-induced aggressive behavior
gamma-Aminobutyric acid in brain areas of isolated aggressive or non-aggressive inbred strains of mice.
No full textIn order to investigate the effects of social isolation on aggressive behavior and GABA levels in different brain areas, inbred mice of the C57 Bl/6 and the DBA/2 strains were housed individually over a period of 8 weeks. Social isolation induced a clear increase of aggressive responses only in the DBA/2 strain and a decrease of GABA levels in septum, striatum, olfactory bulb and posterior colliculus in both the C57Bl/6 and in the DBA/2 strains. An increase of neurotransmitter concentration was observed in amygdala of DBA mice. DBA mice when compared to C57 mice showed significantly lower levels of GABA in olfactory bulb and striatum. These results are discussed in light of several previous studies which have pointed out a correlation between a deficiency of GABA mediated inhibition in some brain areas and different kinds of aggressive behavior as well as the possibility of a blockade of aggressive behavior by potentiation of GABAergic mediated inhibition. A possible suggestion emerging from our results is that the aggressive responses exhibited by isolated DBA mice but not by isolated C57 mice may be related to lower levels of the inhibitory neurotransmitter in the olfactory bulb and striatum
Effects of sodium n-dipropylacetate, muscimol hydrobromide and (R,S) nipecotic acid amide on isolation-induced aggressive behavior in mice
No full textAn inhibitor of GABA-T (sodium n-dipropylacetate), a GABA agonist (muscimol hydrobromide) and an inhibitor of GABA uptake (R,S) nipecotic acid amide were administered to DBA/2 isolated aggressive mice throughout three successive daily experimental sessions. Aggressive responses, measured by an automated device, were inhibited by the highest doses of the three drugs in each daily session. At the lowest doses, sodium n-dipropylacetate and nipecotic acid amide failed to inhibit aggression in the first session while they were effective in the subsequent sessions. Muscimol was effective in the first session but did not differ significantly from saline in the second and third session. The highest doses of these three drugs did not affect spontaneous motor activity, indicating that the observed drug effects are rather specific
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
Circadian variations of noradrenaline, 5-hydroxytryptamine and dopamine in specific brain areas of C57Bl/6 and BALB/c mice.
No full textDaily variations in noradrenaline, 5-hydroxytryptamine and dopamine turnover were evident in two strains of mice (C57Bl/6 and BALB/c) subjected to 12-12 h light-dark cycles. These fluctuations were also evident under continuous light (L-L) in C57Bl/6 mice only, a strain which is characterized by clear-cut circadian wheel running activity in the absence of external synchronizers
Involvement of the GABAergic system on shock-induced aggressive behavior in two strains of mice
No full textThe effects of drugs that antagonize or potentiate the action of brain γ-aminobutyric acid (GABA) on shock-induced aggressive behavior in mice were investigated. In previous studies it has been shown that in C57 BL/6 strain shock-induced aggressive behavior is absent up to the 10th week of age and rises to the highest intensity after the 20th week, while at the same ages aggressive responses are lowest or absent in DBA/2 strain. GABA antagonist, picrotoxin and glutamic acid decarboxylase (GAD) inhibitor, D,L-allylglycine induced aggressive responses in non-aggressive 10 week old C57 BL/6 and 20 week old DBA/2 mice. GABA agonist muscimol hydrobromide, and GABA-T inhibitor sodium n-dipropylacetate inhibited aggressive responses in 20 week old C57 BL/6 mice. These effects were not related to changes in shock sensitivity and motor activity. The results strongly suggest that the GABAergic system is involved in the control of shock-induced aggressive behavior in mice and that this control is related to developmental and genetic factors. Copyright © 1981 ANKHO International Inc
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