This study was performed to assess serum testosterone alterations induced by paradoxical sleep deprivation （PSD） and to verify their attenuation during sleep recovery （SR） based on different durations and ages. Wi...This study was performed to assess serum testosterone alterations induced by paradoxical sleep deprivation （PSD） and to verify their attenuation during sleep recovery （SR） based on different durations and ages. Wistar male rats aged 12 weeks for the younger group and 20 weeks for the elder group were randomly distributed into one of the following groups： a control group （cage and platform）, 3-day SD, 5-day SD, 7-day SD, 1-day SR, 3-day SR and 5-day SR groups. For PSD, the modified multiple platform method was used to specifically limit rapid eye movement （REM） sleep. Differences in the testosterone and luteinizing hormone levels between the younger group and the elder group according to duration of PSD and SR recovery were analysed. Testosterone continued to fall during the sleep deprivation period in a time-dependent manner in both the younger （P=-0.001, correlation coefficient r=-0.651） and elder groups （P=0.001, correlation coefficient r=-0.840）. The elder group showed a significantly lower level of testosterone compared with the younger group after PSD. Upon SR after 3 days of PSD, the testosterone level continued to rise for 5 days after sleep recovery in the younger group （P=0.013）, whereas testosterone concentrations failed to recover until day 5 in the elder group. PSD caused a more detrimental effect on serum testosterone in the elder group compared to the younger group with respect to decreases in luteinizing hormone （LH） levels. The replenishment of serum testosterone level was prohibited in the elder group suggesting that the effects of SD/SR may be age-dependent. The mechanism by which SD affects serum testosterone and how age may modify the process are still unclear.展开更多
BACKGROUND： Complex learning tasks result in a greater number of paradoxical sleep phases, which can improve memory. The effect of paradoxical sleep deprivation, induced by ＂flower pot＂ technique, on spatial refere...BACKGROUND： Complex learning tasks result in a greater number of paradoxical sleep phases, which can improve memory. The effect of paradoxical sleep deprivation, induced by ＂flower pot＂ technique, on spatial reference memory and working memory require further research. OBJECTIVE： To observe the effect of progressive paradoxical sleep deprivation in rats, subsequent to learning, on memory using the Morris Water Maze. DESIGN, TIME AND SETTING： Controlled observation experiment. The experiment was performed at the Laboratory of Neurobiology, Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Lanzhou University from December 2006 to October 2007. MATERIALS： Twenty-eight, male, Wistar rats, 3-4 months old, were provided by the Experimental Animal Center of Lanzhou University. The Morris Water Maze and behavioral analyses system was purchased from Genheart Company, Beijing, China. METHODS： All animals, according to a random digits table, were randomly divided into paradoxical sleep deprivation, tank control, and home cage control groups. Paradoxical sleep deprivation was induced by the ＂flower pot＂ technique for 72 hours, housing the rats on small platforms over water. Rats in the ＂tank control＂ and ＂home cage control＂ groups were housed either in a tank with large platforms over the water or in normal cages without paradoxical sleep deprivation. MAIN OUTCOME MEASURES： Morris Water Maze was employed for task learning and spatial memory testing. Rats in all groups were placed at six random starting points each day for four consecutive days. Each placement was repeated for two trials; the first trial represented reference memory and the second working memory. Rats in the first trial were allowed to locate the submerged platform within 120 seconds. Data, including swimming distance, escape latency, swimming velocity, percentage of time in correct quarter, and memory scores were recorded and analyzed automatically by behavioral analyses systems for Morris Water Maze. RESULTS： Twenty-eight rats were included in the final analysis, without any loss. In the first trial, between day 2 and 4, escape latency and swimming distance increased significantly in the paradoxical sleep deprivation group compared to the home cage control and tank control groups （P 〈 0.01）; percentage of time in correct quarter and memory scores, however, decreased in the paradoxical sleep deprivation group compared to the home cage control and tank control groups （P 〈 0.01）. The escape latency, swimming distance, percentage of time in correct quarter, and memory scores in the second trial was not significantly different among the three groups （P 〉 0.05）. CONCLUSION： Paradoxical sleep deprivation inhibits spatial reference memory, but not working memory.展开更多
文摘This study was performed to assess serum testosterone alterations induced by paradoxical sleep deprivation （PSD） and to verify their attenuation during sleep recovery （SR） based on different durations and ages. Wistar male rats aged 12 weeks for the younger group and 20 weeks for the elder group were randomly distributed into one of the following groups： a control group （cage and platform）, 3-day SD, 5-day SD, 7-day SD, 1-day SR, 3-day SR and 5-day SR groups. For PSD, the modified multiple platform method was used to specifically limit rapid eye movement （REM） sleep. Differences in the testosterone and luteinizing hormone levels between the younger group and the elder group according to duration of PSD and SR recovery were analysed. Testosterone continued to fall during the sleep deprivation period in a time-dependent manner in both the younger （P=-0.001, correlation coefficient r=-0.651） and elder groups （P=0.001, correlation coefficient r=-0.840）. The elder group showed a significantly lower level of testosterone compared with the younger group after PSD. Upon SR after 3 days of PSD, the testosterone level continued to rise for 5 days after sleep recovery in the younger group （P=0.013）, whereas testosterone concentrations failed to recover until day 5 in the elder group. PSD caused a more detrimental effect on serum testosterone in the elder group compared to the younger group with respect to decreases in luteinizing hormone （LH） levels. The replenishment of serum testosterone level was prohibited in the elder group suggesting that the effects of SD/SR may be age-dependent. The mechanism by which SD affects serum testosterone and how age may modify the process are still unclear.
基金the National Natural Science Foundation of China, No.30670677
文摘BACKGROUND： Complex learning tasks result in a greater number of paradoxical sleep phases, which can improve memory. The effect of paradoxical sleep deprivation, induced by ＂flower pot＂ technique, on spatial reference memory and working memory require further research. OBJECTIVE： To observe the effect of progressive paradoxical sleep deprivation in rats, subsequent to learning, on memory using the Morris Water Maze. DESIGN, TIME AND SETTING： Controlled observation experiment. The experiment was performed at the Laboratory of Neurobiology, Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Lanzhou University from December 2006 to October 2007. MATERIALS： Twenty-eight, male, Wistar rats, 3-4 months old, were provided by the Experimental Animal Center of Lanzhou University. The Morris Water Maze and behavioral analyses system was purchased from Genheart Company, Beijing, China. METHODS： All animals, according to a random digits table, were randomly divided into paradoxical sleep deprivation, tank control, and home cage control groups. Paradoxical sleep deprivation was induced by the ＂flower pot＂ technique for 72 hours, housing the rats on small platforms over water. Rats in the ＂tank control＂ and ＂home cage control＂ groups were housed either in a tank with large platforms over the water or in normal cages without paradoxical sleep deprivation. MAIN OUTCOME MEASURES： Morris Water Maze was employed for task learning and spatial memory testing. Rats in all groups were placed at six random starting points each day for four consecutive days. Each placement was repeated for two trials; the first trial represented reference memory and the second working memory. Rats in the first trial were allowed to locate the submerged platform within 120 seconds. Data, including swimming distance, escape latency, swimming velocity, percentage of time in correct quarter, and memory scores were recorded and analyzed automatically by behavioral analyses systems for Morris Water Maze. RESULTS： Twenty-eight rats were included in the final analysis, without any loss. In the first trial, between day 2 and 4, escape latency and swimming distance increased significantly in the paradoxical sleep deprivation group compared to the home cage control and tank control groups （P 〈 0.01）; percentage of time in correct quarter and memory scores, however, decreased in the paradoxical sleep deprivation group compared to the home cage control and tank control groups （P 〈 0.01）. The escape latency, swimming distance, percentage of time in correct quarter, and memory scores in the second trial was not significantly different among the three groups （P 〉 0.05）. CONCLUSION： Paradoxical sleep deprivation inhibits spatial reference memory, but not working memory.
