Navegando por Palavras-chave "Behavioural sensitization"
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- ItemSomente MetadadadosAcute and chronic ethanol differentially modify the emotional significance of a novel environment: implications for addiction(Cambridge Univ Press, 2012-09-01) Fukushiro, Daniela Fukue [UNIFESP]; Josino, Fabiana de Souza [UNIFESP]; Saito, Luis Paulo [UNIFESP]; Berro, Laís Fernanda [UNIFESP]; Morgado, Fiorella [UNIFESP]; Frussa-Filho, Roberto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Using open-field behaviour as an experimental paradigm, we demonstrated a complex interaction between the rewarding/stimulating effects and the anxiogenic/stressful effects of both novelty and acute or chronic amphetamine in mice. As a consequence of this interaction, acute amphetamine-induced hyperlocomotion was inhibited, whereas the expression of its sensitization was facilitated in a novel environment. in the present study, we aimed to investigate the interactions between exposure to a novel environment and the acute and chronic effects of ethanol (Eth), a drug of abuse known to produce anxiolytic-like behaviour in mice. Previously habituated and non-habituated male Swiss mice (3 months old) were tested in an open field after receiving an acute injection of Eth or following repeated treatment with Eth. Acute Eth administration increased locomotion with a greater magnitude in mice exposed to the apparatus for the first time, and this was thought to be related to the attenuation of the stressful effects of novelty produced by the anxiolytic-like effect of acute Eth, leading to a subsequent prevalence of its stimulant effects. However, locomotor sensitization produced by repeated Eth administration was expressed only in the previously explored environment. This result might be related to the well-known tolerance of Eth-induced anxiolytic-like behaviour following repeated treatment, which would restore the anxiogenic effect of novelty. Our data suggest that a complex and plastic interaction between the emotional and motivational properties of novelty and drugs of abuse can critically modify the behavioural expression of addiction-related mechanisms.
- ItemSomente MetadadadosDisulfiram impairs the development of behavioural sensitization to the stimulant effect of ethanol(Elsevier B.V., 2010-03-05) Kim, Andrezza Kyunmi [UNIFESP]; Oliveira Souza-Formigoni, Maria Lucia [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Background: Although disulfiram has been used in the treatment of alcoholism due to the unpleasant sensations its concomitant ingestion with ethanol provokes, some patients reported stimulant effects after its ingestion. This issue has not been addressed in studies with animals. in mice, the stimulant effect of ethanol has been associated with increased locomotor activity and behavioural sensitization. This study sought to analyze the influence of disulfiram on the development of behavioural sensitization to the stimulant effect of ethanol.Methods: Male Swiss mice pre-treated with vehicle or disulfiram (15 mg/kg) received saline or ethanol (2.0 g/kg) every other day, for 5 days. Forty-eight hours afterwards mice were challenged with Saline, and 48 h later they received Disulfiram, or Disulfiram + Ethanol or Ethanol.Results: the co-administration of disulfiram (15 mg/kg) blocked the development of behavioural sensitization induced by ethanol (2.0 g/kg). Although the acute administration of disulfiram did not alter the locomotor activity, its acute administration-induced higher levels of locomotor activity in mice previously sensitized to ethanol than in controls which received saline.Conclusions: Our data suggest that besides the known psychological effects (fear of aversive effects) disulfiram efficacy on alcohol dependency treatment could also be due to its pharmacological interference in the brain neurotransmission. (C) 2009 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosNucleus accumbens dopamine D-1 receptors regulate the expression of ethanol-induced behavioural sensitization(Cambridge Univ Press, 2011-03-01) Abrahao, Karina Possa [UNIFESP]; Quadros, Isabel Marian Hartmann; Souza-Formigoni, Maria Lucia Oliveira de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Tufts UnivRepeated ethanol administration may induce behavioural sensitization, defined as a progressive potentiation of locomotor stimulant effects. This process is associated with neuroadaptations in the mesolimbic pathway and the nucleus accumbens. the aim of the present study was to analyse dopamine D-1 receptor (D1R) participation in locomotor response to an agonist and an antagonist of the D1R in mice with different levels of sensitization to ethanol. in three separate experiments, mice received administrations of 2.2 g/kg ethanol or saline every other day for 10 d. According to their locomotor response on the last day, ethanol-treated animals were classified into two groups : sensitized or non-sensitized. After the treatment, mice were challenged with 4 or 8 mg/kg SKF-38393 (i.p.), a D1R agonist (expt 1); or with 0.01 or 0.1 mg/kg SCH-23390 (i.p.), a D1R antagonist, followed by 2.2 g/kg ethanol (i.p.) administration (expt 2). in expt 3, mice were challenged with intra-accumbens (intra-NAc) SKF-38393 (1 mu g/side, in 0.2 mu l), and with intra-NAc SCH-23390 (3 mu g/side, in 0.2 mu l) followed by 2.2 g/kg ethanol (i.p.). Although the i.p. administration of SKF-38393 did not affect the locomotion of mice, the intra-NAc administration of SKF-38393 significantly increased the locomotor activity in sensitized mice, suggesting that sensitized mice present functionally hyperresponsive D(1)Rs in the NAc. Both i.p. and intra-NAc administration of SCH-23390 blocked the expression of ethanol sensitization, suggesting that the activation of NAc D(1)Rs seems to be essential for the expression of ethanol sensitization.