Navegando por Palavras-chave "habituation"

Agora exibindo 1 - 3 de 3
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Acoustic arousal responses in children with obstructive sleep apnea
    (Wiley-Blackwell, 2005-10-01) Moreira, G. A.; Tufik, Sergio [UNIFESP]; Nery, L. E.; Lutz, J.; Verfaille, K.; Luan, X. Q.; Marcus, C. L.; Univ Penn; Johns Hopkins Univ; Universidade Federal de São Paulo (UNIFESP)
    Our objectives were to study the arousal responses to nonrespiratory (acoustic) stimuli in children with obstructive sleep apnea syndrome (OSAS). the acoustic arousal response was studied in children with OSAS due to adenotonsillar hypertrophy compared to normal, age-matched children. Acoustic stimuli were delivered incrementally from 30-100 dB during stage 2, slow wave sleep, and rapid eye movement (REM) sleep. the percentage of children who aroused in response to acoustic stimuli, and the arousal threshold (i.e., sound level at which arousal occurred), were compared between groups and sleep stages. the percentage of children who aroused was similar between children with OSAS and controls. the percentage of children who aroused was lower during slowwave sleep than REM sleep and stage 2 in both OSAS and controls. There were no statistically significant differences in acoustic arousal threshold between OSAS and control children. There was no difference in arousal response to moderate acoustic stimulation between children with OSAS and controls. These results contrast with previous data showing blunted arousal responses to hypercapnia and upper airway loading during sleep in children with OSAS, suggesting that children with OSAS have an arousal deficit specific to respiratory stimuli. However, further studies evaluating arousal to both respiratory and nonrespiratory stimuli in the same subjects are needed.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Acute 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.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Chronic amphetamine transforms the emotional significance of a novel but not a familiar environment: implications for addiction
    (Cambridge Univ Press, 2011-08-01) Fukushiro, Daniela Fukue [UNIFESP]; Frussa Filho, Roberto [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Both drug-induced locomotor sensitization and reactivity to novelty in rodents have been related to drug-craving mechanisms in humans. We investigated whether the exposure to a completely novel environment would modulate the expression of locomotor sensitization induced by repeated administration of amphetamine (Amp) in mice. in addition to locomotion, different open-field behavioural parameters were used to evaluate the possible involvement of anxiogenic-like effects induced by Amp, novelty or a combination of the two. in order to avoid misinterpretations due to different locomotor baseline conditions, we used an open-field illumination condition in which previous exposure to the apparatus did not modify locomotion (although it reliably increased grooming behaviour). Acute Amp administration increased locomotion in mice previously habituated to the open field (Hab) but not in mice exposed to the apparatus for the first time (Nov). This absence of Amp-induced locomotor activation in Nov mice may be related to higher anxiety-like levels, because these animals displayed longer freezing duration. However, only Nov mice developed locomotor sensitization. Because Amp challenge in Amp pre-treated Nov mice did not induce an increase in freezing behaviour, the locomotor sensitization in Nov mice might be related to the tolerance of Amp-induced anxiogenic-like behaviour in novel environments. Repeated Amp administration increased motivation to explore the environment in Nov mice in that these animals presented a within-session locomotion-habituation deficit. Our data suggest that a complex and plastic interaction between the anxiogenic and motivational properties of both novelty and Amp can critically modify the behavioural expression of craving-related mechanisms.