Influência do exercício físico no comportamento e alterações neuroquímicas induzidas pela privação do sono em camundongos

Abstract

Sleep is essential for survival and its absence is associated with cardiovascular and metabolic diseases and early mortality. Exercise improves memory and mobility in conditions of health and disease. Conversely, sleep deprivation (SD) impairs mood, cognition and functional performance. The objective of this study is to evaluate the effects of exercise in mice submitted to total SD (6hTSD) and REMSD (72h-REMSD). Methods: Experimental groups were mice submitted to 6hTSD by gentle handling or 72h-REMSD by multiple platform method. Studied groups were controls (home cage), exercise (treadmill for 8 weeks); exercise followed by 6hTSD or 72h-REMSD. Behavioral tests included the elevated plus-maze, open field, Y-maze test and tail-suspension. Dopamine (DA), Serotonin (5-HT) and Norepinephrine (NE) and metabolites were determined in the striatum using high-performance liquid chromatography. Results: O grupo submetido somente a exercício físico comparado ao grupo com PS apresentou aumento do desempenho da memória de trabalho. In both models of SD (6hTSD or 72h-REMSD) depressive behavior was increased and previous exercise hindered it. Animals subjected to either, SD or exercise, showed high NA levels. Exercise previous to SD reduced NA levels. Animals subjected to either, SD or exercise, showed increased 5-HT turnover (5-HIAA/5-HT). Exercise previous to SD reduced 5-HT turnover. Sleep deprivation increased 3,4-dihydroxyfenylacetic acid (DOPAC) e reduced the relation DOPAC/Dopamine. As compared to control, exercised animals showed less depressive symptoms and better working memory. Sleep deprivation increased depressive behavior and impaired working memory; previous exercise reversed these behaviors. Sleep deprivation and exercise groups presented high NE levels. Previous exercise reduced NA levels after SD. Exercise and SD were associated with increased 5-HT turnover. Exercise before SD reduced 5-HT turnover. Sleep deprivation increased 3,4-Dihydroxyphenylacetic acid and e DOPAC/Dopamine ratio. Exercise only and exercise before SD reduced DOPAC levels. Conclusion: Exercise alone improved working memory and mice subjected to 72h-REMSD showed the worst performance. Previous exercise increased 5-HT and reduced striatal levels of NE and DOPAC. The present findings confirm the effects of exercise on behavior and neurochemical alterations associated with SD and provide avenues to understand the mechanistic of exercise.