Efeitos imediatos e tardios da privação de sono em camundongos pré-púberes: implicações em comportamentos tipo-afetivos

Abstract

Sleep deprivation in children and adolescents of school age is associated with a series of behavioral disorders, such as anxiety disorders, depression and poor school performance. Animal studies suggest that sleep deprivation during development interferes with a series of processes that influence the formation and maturation of neural circuitry, such as synaptogenesis, synaptic refinement, myelination and protein synthesis. Thus, it is reasonable to assume that sleep deprivation during childhood or the prepubertal period (a period marked by intense synaptogenesis in several brain regions) can lead to neurobehavioral impairments for a long period. However, there are few studies investigating the behavioral consequences of deprivation in rodents. The objective of this study was to test the hypothesis that sleep deprivation during the prepubertal period affects anxiety-like behavior and the ability to cope with stress. Form P23 (P1 = day of birth) to P26, Swiss mice of both sexes were sleep-deprived (REMd group) by the multiple platforms method or submitted to control procedures (CONT group) or remained in their rearing cages (NAÏVE group). The anxiety-like behavior and the coping with stress were assessed, respectively, in the elevated plus maze (EPM) and in the forced swim test (FST). Mice were tested immediately after sleep deprivation at P26 or 10 days after sleep deprivation, at P36. In EPM, the percentage of entries into the open arms of CONT and REMd groups was greater than that NAÏVE group, at P26. However, in P36, differences were not observed between groups. In FST, no differences were observed between the NAIVE, CONT and REMd groups in the animals tested at P26. However, at P36, the REMd group showed a greater swimming activity than the CONT and NAÏVE groups, which did not differ from each other. The EPM results suggest that, in the short term, both sleep deprivation and control procedures can transiently decrease anxiety levels. In FST, sleep deprivation did not affect swimming activity in the short term, but 10 days later, it promoted a marked hyperactivity, which is suggestive of an inability to deal with the stressful situation of the test. Based on these results, we can conclude that sleep deprivation during the prepubertal period is able to affect, in the short term, anxiety-like behavior and, in the long term, the ability to deal with stress