1,721,003 research outputs found
Professor Changeux, JP
This record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/435828Professor Changeux, JP: 20 November 2008. Correspondence, articles, 2008257797
Item: [2017.0015.00115] "Professor Changeux, JP
Contribution of nicotinic acetylcholine receptors containing the beta 2-subunit to the behavioural effects of nicotine
INCREASED NEURODEGENERATION DURING AGEING IN MICE LACKING HIGH-AFFINITY NICOTINE RECEPTORS
Involvement of alpha 6 nicotinic receptor subunit in nicotine-elicited locomotion, demonstrated by in vivo antisense oligonucleotide infusion
ENHANCED locomotion in a habituated environment is a well documented effect of nicotine mediated by the mesotelencephalic dopaminergic system. The nicotinic receptor subunit alpha 6 is, among other subunits, strongly expressed in the dopaminergic neurons of the mesencephalon. To examine the functional role of this subunit, we inhibited its expression in vivo using antisense oligonucleotides. lit vitro treatments of embryonic mesencephalic neuron cultures demonstrated that the alpha 6 antisense oligonucleotides caused a marked decrease in the level of alpha 6 subunit protein. In vivo, 1 week infusion of alpha 6 antisense oligonucleotides by osmotic mini-pump reduced the effect of nicotine on locomotor activity in habituated environment by 70%. These data support the notion that the effects of nicotine on the dopaminergic system involve alpha 6 subunit containing nAChRs
A single (-)-nicotine injection causes change with a time delay in the affinity of striatal D2 receptors for antagonist, but not for agonist, nor in the D2 receptor mRNA levels in the rat substantia nigra.
The in vitro and in vivo effects of (-)-nicotine on dopamine D2 receptors in the rat neostriatum have been studied using biochemical binding, in situ hybridization and immunocytochemistry. A single i.p. injection (1 mg/kg) of (-)-nicotine resulted in a reduction of the KD value of the D2 antagonist [3H]raclopride binding sites in rat neostriatal membrane preparations at 12 h without any significant change in the Bmax value. This action of (-)-nicotine was counteracted by pretreatment 15 min earlier with the nicotine antagonist mecamylamine (1 mg/kg, i.p.). However, the KD and the Bmax values of the D2 agonist [3H]NPA binding sites in the rat neostriatal membrane preparations were not significantly affected 0.5-48 h after a single i.p. injection with 1 mg/kg of (-)-nicotine. No significant change in neostriatal D2 receptor mRNA levels was observed at any time interval after the (-)-nicotine injection. No significant change was observed in tyrosine hydroxylase (TH) immunoreactivity in either the substantia nigra or the neostriatum, nor in nigral TH mRNA levels during the time interval studied (4-24 h posttreatment). Furthermore, addition of low (10 nM) or high (1 microM) concentrations of (-)-nicotine in vitro to rat neostriatal membranes did not alter the characteristics of [3H]raclopride or [3H]NPA binding. These results indicate that a single (-)-nicotine injection can produce a selective and delayed increase in the affinity of D2 receptors for the antagonist, but not for the agonist without modifying the levels of D2 receptor mRNA, probably via the activation of central nicotinic receptors
Inhibition of both alpha7* and beta2* nicotinic acetylcholine receptors is necessary to prevent development of sensitization to cocaine-elicited increases in extracellular dopamine levels in the ventral striatum
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Rapid kinetics of agonist binding and permeability response analyzed in parallel on acetylcholine receptor rich membranes from Torpedo marmorata
Heidmann T, Bernhardt J, Neumann E, Changeux JP. Rapid kinetics of agonist binding and permeability response analyzed in parallel on acetylcholine receptor rich membranes from Torpedo marmorata. Biochemistry. 1983;22(23):5452-5459
Variations on the Author
“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
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