Rapid eye movement sleep deprivation: a central-neural change during wakefulness

Three adult cats were deprived of rapid eye movement sleep for six separate periods of up to 32 days. Animals were allowed normal amouints of sleeping time during which rapid eye movement sleep was interrupted, whenever it occurred, by human observers who continually monitored the animals and their electrocortical activity. Cortical responses evoked by pairs of acoustic clicks were recorded during wakefulness. Recovery functions derived from these data were facilitated during periods of deprivation of rapid eye movement sleep and returned to base-line values when animals were allowed normal amounts of this sleep phase. This change was noted repeatedly within, as well as between, subjects. It did not occur during control periods when non-rapid eye movement sleep was interrupted on identical schedules, nor did it occur when the cats were deprived of all sleep for 22 hours a day for 5 days.     

Breakdown of cortical effective connectivity during sleep

When we fall asleep, consciousness fades yet the brain remains active. Why is this so? To investigate whether changes in cortical information transmission play a role, we used transcranial magnetic stimulation together with high-density electroencephalography and asked how the activation of one cortical area (the premotor area) is transmitted to the rest of the brain. During quiet wakefulness, an initial response (approximately 15 milliseconds) at the stimulation site was followed by a sequence of waves that moved to connected cortical areas several centimeters away. During non-rapid eye movement sleep, the initial response was stronger but was rapidly extinguished and did not propagate beyond the stimulation site. Thus, the fading of consciousness during certain stages of sleep may be related to a breakdown in cortical effective connectivity.     

速溶芦笋粉改善睡眠作用研究

[目的]评价以芦笋为原料开发的功能食品速溶芦笋粉改善睡眠的功效。[方法]通过60名志愿者试食试验,每日食用1次,1次2袋(24 g),连续食用60 d,进行睡眠状况评估,同时测定安全性指标及失眠相关内分泌指标,观察速溶芦笋粉对人体睡眠障碍的改善作用。[结果]速溶芦笋粉可明显增加有失眠困扰测评者的有效睡眠时间,由5.1 h延长至6.1 h;缩短入睡时间,由50.4 min缩短到25.3 min;醒后再入睡时间明显减少,平均时间由46.5 min减少至19.5 min,食用前后差异显著(P0.05),测评者对睡眠质量改善满意度较高。食用后无肝肾功能影响,具有较好的安全性。速溶芦笋粉可以降低皮质醇、去甲肾上腺素水平,提高5-羟色胺、多巴胺水平。[结论]速溶芦笋粉有改善睡眠质量作用,安全有效,其改善睡眠作用可能与调节HPA轴或5-羟色胺分泌相关。     

Response during Sleep with Intervening Waking Amnesia

During stage 1 sleep, subjects responded to suggestions on two or more nights, up to 5 months apart. While they were awake they did not recall the material to which they successfully responded while asleep on a subsequent night.     

速溶芦笋粉改善睡眠作用研究

[目的]评价以芦笋为原料开发的功能食品速溶芦笋粉改善睡眠功效.[方法]通过60名志愿者试食实验,每日食用一次,一次两袋(24G),连续食用60d,进行睡眠状况评估,同时测定安全性指标及失眠相关内分泌指标,观察速溶芦笋粉对人体睡眠障碍的改善作用.[结果]速溶芦笋粉可明显增加有失眠困扰测评者有效睡眠时间,由5.1 h延长至6.1 h;缩短人睡时间,由50.4 min缩短到25.3 min;醒后再入睡时间明显减少,平均时间由46.5 h减少至19.5 h,食用前后差异显著(P＜0.05),测评者对睡眠质量改善满意度较高.食用后无肝肾功能影响,具有较好的安全性.速溶芦笋粉可以降低皮质醇、去甲肾上腺素水平,提高5-羟色胺、多巴胺水平.[结论]人体试食试验表明,速溶芦笋粉有改善睡眠质量作用,安全有效,其改善睡眠作用可能与调节HPA轴或调节5-羟色胺分泌相关.     

Sleep stage characteristics of long and short sleepers

The possibility of different sleep stage characteristics being associated with different sleep lengths was explored by comparing two groups of high school seniors, who characteristically slept 6(1/2) hours or less or who slept 8(1/2) hours or more, with an age-matched control group not selected on the basis of sleep length. All-night electroencephalography was used to examine the sleep stage characteristics of these groups. Compared with the unselected age-matched group, the short sleepers showed no significant diminution in their stage 4 (deep) or rapid eye movement (dream) sleep. The long sleepers were observed to obtain significantly more rapid eye movement sleep than did the other groups.     

Intracranial self-stimulation and wakefulness: effect of manipulating ambient brain catecholamines

Rats were given disulfiram, an inhibitor of norepinephrine biosynthesis, to see if norepinephrine is a transmitter for motivation in electrical stimulation of the brain. Animals given the drug paused in bar pressing, appearing asleep or sedated; if replaced on the bar, they always resumed pressing at normal rates. The decrease in bar pressing may result from a direct or indirect effect of the drug on wakefulness rather than on reward.     

An hPer2 phosphorylation site mutation in familial advanced sleep phase syndrome

Familial advanced sleep phase syndrome (FASPS) is an autosomal dominant circadian rhythm variant; affected individuals are "morning larks" with a 4-hour advance of the sleep, temperature, and melatonin rhythms. Here we report localization of the FASPS gene near the telomere of chromosome 2q. A strong candidate gene (hPer2), a human homolog of the period gene in Drosophila, maps to the same locus. Affected individuals have a serine to glycine mutation within the casein kinase Iepsilon (CKIepsilon) binding region of hPER2, which causes hypophosphorylation by CKIepsilon in vitro. Thus, a variant in human sleep behavior can be attributed to a missense mutation in a clock component, hPER2, which alters the circadian period.     

Control of sleep by cyclin A and its regulator

How and why the brain reversibly switches from a waking to a sleep state remain among the most intriguing questions in biology. We show that cyclin A (CycA) and regulator of cyclin A1, essential cell cycle factors, function in postmitotic neurons to promote sleep in Drosophila melanogaster. Reducing the abundance of CycA in neurons delayed the wake-sleep transition, caused multiple arousals from sleep, and reduced the homeostatic response to sleep deprivation. CycA is expressed in ~40 to 50 neurons in the adult brain, most of which are intermingled with circadian clock neurons, suggesting functional interactions among neurons controlling sleep and circadian behavior.     

Circadian activity rhythm of the deer mouse, Peromyscus: effect of deuterium oxide

Chemical modification of a vertebrate activity rhythm, the circadian (approximately 24-hour) rhythm of Peromyscus leucopus noveboracensis, has been demonstrated. Activity in a running wheel was used to measure the rhythms of mice kept individually in conditions of continuous darkness. Deuterium oxide was presented in the drinking water. The length of the periods of rhythm increased directly and linearly with the increase in concentration of deuterium oxide. There is no threshold for this effect, and the maximum concentration of deuterium oxide (30 percent) that was presented resulted in a 6 percent lengthening of the period of circadian rhythm. The mice reverted to rhythms similar in period length to control values after deuterium oxide was withdrawn from their drinking water.     

Facilitation of spindle-burst sleep by conditioning of electroencephalographic activity while awake

A slow-wave electroencephalographic rhythm recorded from the sensorimotor cortex of the waking cat has been correlated behaviorally with the suppression of movement. Facilitation of this rhythm through conditioning selectively enhances a similar pattern recorded during sleep, the familiar spindle burst. The training also produced longer epochs of undisturbed sleep. The specific neural mechanism manipulated during wakefulness appears to function also in sleep and to be involved with the regulation of phasic motor behavior.     

Odor cues during slow-wave sleep prompt declarative memory consolidation

Sleep facilitates memory consolidation. A widely held model assumes that this is because newly encoded memories undergo covert reactivation during sleep. We cued new memories in humans during sleep by presenting an odor that had been presented as context during prior learning, and so showed that reactivation indeed causes memory consolidation during sleep. Re-exposure to the odor during slow-wave sleep (SWS) improved the retention of hippocampus-dependent declarative memories but not of hippocampus-independent procedural memories. Odor re-exposure was ineffective during rapid eye movement sleep or wakefulness or when the odor had been omitted during prior learning. Concurring with these findings, functional magnetic resonance imaging revealed significant hippocampal activation in response to odor re-exposure during SWS.     

Correlates of sleep and waking in Drosophila melanogaster

Drosophila exhibits a circadian rest-activity cycle, but it is not known whether fly rest constitutes sleep or is mere inactivity. It is shown here that, like mammalian sleep, rest in Drosophila is characterized by an increased arousal threshold and is homeostatically regulated independently of the circadian clock. As in mammals, rest is abundant in young flies, is reduced in older flies, and is modulated by stimulants and hypnotics. Several molecular markers modulated by sleep and waking in mammals are modulated by rest and activity in Drosophila, including cytochrome oxidase C, the endoplasmic reticulum chaperone protein BiP, and enzymes implicated in the catabolism of monoamines. Flies lacking one such enzyme, arylalkylamine N-acetyltransferase, show increased rest after rest deprivation. These results implicate the catabolism of monoamines in the regulation of sleep and waking in the fly and suggest that Drosophila may serve as a model system for the genetic dissection of sleep.     

Alcohol and caffeine: effect on inferred visual dreaming

In seven subjects, a large amount of alcohol, taken at bedtime, reduced the total duration of stage 1 electroencephalographic-rapid-eye-movement periods in the first 5 hours of sleep; a moderate amount of caffeine produced no significant change.     

Study on Phenological Character in Seedling Period of Introduced Populus deltoids Clones

为了探索美洲黑杨物候性状遗传变异水平与利用潜力,开展基因资源评价,提供杨树定向遗传改良育种材料,对60个引种美洲黑杨无性系苗期的8个物候期进行观测分析。结果表明：①各无性系物候特征存在较大差异,展叶盛期差异最大,变异系数为14.97%,最小的是落叶末期,为3.83%;②展叶盛期出现的时间最分散,落叶末期相对集中,苗木生长前期物候特征是影响生长期长短的主要因素;③通过主成分分析将物候期分为3类典型,即萌芽期、展叶盛期和落叶期;④对各无性系物候出现时间变量进行聚类分析,将60个无性系分成4类。     

半夏不同溶剂提取物镇静催眠活性比较

[目的]研究比较半夏不同溶剂提取物的镇静、催眠作用。[方法]采用连续溶剂提取法制备半夏不同溶剂提取物,通过行为药理学试验,考察半夏不同溶剂提取物对小鼠自主活动和戊巴比妥诱导睡眠的影响。[结果]半夏浓度95%乙醇提取物和浓度60%乙醇提取物能显著抑制小鼠的自主活动;对戊巴比妥诱导的睡眠表现出协同作用,不仅显著增加了催眠剂量戊巴比妥小鼠的入睡只数,而且显著缩短了睡眠剂量戊巴比妥小鼠的入睡潜伏期,延长了其睡眠时间,具有明显的镇静、催眠作用。[结论]半夏醇提物为其镇静、催眠活性部位。     

Human growth hormone release: relation to slow-wave sleep and sleep-walking cycles

Release of human growth hormone during sleep is significantly related to slow, synchronized stages of sleep and therefore would seem to be controlled by related neural mechanisms. When sleep-waking cycles are reversed by 12 hours, the release of growth hormone with sleep is reversed; thus release does not follow an inherent circadian rhythm independent of sleep.     

Sleep and memory

Two experiments demonstrated that memory over an interval with relatively high amounts of rapid eye movement (REM) sleep was inferior to memory over an interval with relatively high amounts of stage 4 sleep. The results suggest that, at least for humans, REM sleep does not facilitate memory consolidation and that stage 4 sleep may be beneficial to memory.     

茶尺蠖幼虫在茶叶和人工饲料上的取食行为

 茶尺蠖五龄幼虫的取食活动是不连续的,在室内无昼夜节律。此文对取食行为作了定性和定量的描述,区分出两种类型的取食间隔,证明了取食的开始与终止不是随机的,并提出了取食行为的动机模型,以解释取食行为和与之相关的的某些行为的发生。幼虫在人工饲料上与在茶叶上的取食行为表现出相似的时间模式,但在一些具体的指标上差异显著。     

Differential rescue of light- and food-entrainable circadian rhythms

When food is plentiful, circadian rhythms of animals are powerfully entrained by the light-dark cycle. However, if animals have access to food only during their normal sleep cycle, they will shift most of their circadian rhythms to match the food availability. We studied the basis for entrainment of circadian rhythms by food and light in mice with targeted disruption of the clock gene Bmal1, which lack circadian rhythmicity. Injection of a viral vector containing the Bmal1 gene into the suprachiasmatic nuclei of the hypothalamus restored light-entrainable, but not food-entrainable, circadian rhythms. In contrast, restoration of the Bmal1 gene only in the dorsomedial hypothalamic nucleus restored the ability of animals to entrain to food but not to light. These results demonstrate that the dorsomedial hypothalamus contains a Bmal1-based oscillator that can drive food entrainment of circadian rhythms.