Efeitos da privação de sono paradoxal na nocicepção e ansiedade em ratos / Effects of paradoxical sleep deprivation in rats on nociception and anxiety

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

22/12/2010

RESUMO

Paradoxical sleep deprivation (PSD) causes several neurochemical and behavioral changes related to alterations in neurotransmitters systems. Increased responses to nociceptive stimuli have been reported in animals deprived of this phase of sleep. The commonly used methods of PSD have been linked to the generation of anxiety in animals, and hyperalgesia could, therefore, be due to anxiety stimuli generated by the method. The purpose of this study was to investigate anxiety induced by the PSD method and the effect of the anxiolytic drug diazepam and analgesic drug acetylsalicylic acid on anxiety and response to thermal nociceptive stimuli. Male Wistar rats of 90 days of life were deprived from sleep for 96 hours and submitted to the nociceptive test on the hot plate (46C). The assessment of anxiety level of animals was performed using the open field test, where they made the link between residence in central and peripheral squares, and also by test of the elevated plus maze, whose endpoint was to quantify the number of times that the animal entered in the open arms of the maze and measure the time spent by the animal in the same arms. PSD animals showed increased rate of locomotion compared to control animals (+314.8%, p <0.05), longer time spent in open arms of elevated plus maze (+319.2%, p <0.05), largest number of entries in the same arms of the maze (+257.1%) and reductions in latency to withdraw the hind paw of the hot plate (-64.2%, p <0.05). The drug diazepam, did not influence the responses made by PSD animals in the open field and hot plate test, but influenced the answers given by these animals in test of the elevated plus maze in both time (+308, p <0.05), or the number of entries (+316.6%, p <0.05). The drug acetylsalicylic acid caused a decline in the rate of locomotion in PSD animals subjected to the open field test that also was administered with diazepam (-99.5%, p <0.05). The results of this study indicated that the method of paradoxical sleep deprivation does not appear to be anxiogenic. The results obtained in this work showed that the PSD method does not induce anxiety and the pharmacological reduction in anxiety does not interfere in the increased algic response induced by paradoxical sleep deprivation.

ASSUNTO(S)

privação de sono paradoxal hiperalgesia ansiedade neuropsicofarmacologia paradoxical sleep deprivation hyperalgesia anxiety

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