Relationship between sleep architecture and severity of obstructive sleep apnea / 浙江大学学报·医学版

OBJECTIVE@#To investigate the effect of obstructive sleep apnea (OSA) on different sleep stages, and the relationship between N3 stage of non-rapid eye movement sleep and respiratory abnormal events.@*METHODS@#A total of 188 adult patients who underwent overnight polysomnography(PSG)monitoring in Sir Run Run shaw Hospital of Zhejiang University from June 24th to December 26th 2019 were enrolled in the study. OSA patients were classified into 3 groups (mild, moderate and severe) according to the apnea-hypopnea index (AHI). PSG data, AHI and the lowest SPO in each stage of sleep were compared among three groups.@*RESULTS@#There was no significant difference in total sleep time and sleep efficiency among patients with different severity of OSA (all >0.05). The proportion of N3 stage in moderate and severe OSA groups were significantly smaller than that in mild OSA group (all <0.05). The proportion of N3 stage in severe OSA group was also smaller than that in moderate OSA group (<0.05). In addition, severe OSA group had a longer latency of N3 stage than mild and moderate OSA groups (all <0.05). The latency of N3 stage in moderate OSA group was longer than that in mild OSA group (<0.05). The AHI in N3 stage was markedly lower than that in other sleep stages (all <0.01), regardless of the severity of OSA. Supine AHI in N3 stage in mild and moderate groups was significantly lower than that in N1, N2 and rapid eye movement (REM) stages (all <0.01). Supine AHI in N3 stage in severe group was also lower than that in N2 and REM stages (<0.05 or <0.01). The lowest SPO in N3 stage was significantly higher than that in N1, N2 and REM stages (<0.05 or <0.01), regardless of the severity of OSA.@*CONCLUSIONS@#s The proportion of N3 stage is lower in OSA patients, and N3 stage has less sleep respiratory events than non-N3 stages. The results suggest that the increased N3 stage proportion may indicate less severity of OSA.

Sueño, memoria y aprendizaje / Sleep, memory and learning

Las investigaciones recientes demuestran que mientras estamos tranquilamente durmiendo nuestro cerebro está muy ocupado procesando la información obtenida a lo largo del día. Asimismo, la falta de sueño ocasiona problemas en la consolidación de la memoria. El sueño juega un papel fundamental en el adecuado desarrollo del cerebro en crecimiento y muchos de los fenómenos de plasticidad cerebral ocurren durante el sueño. A nivel celular, los ciclos circadianos coordinan complejos mecanismos de "encender y apagar" genes y estructuras que regulan individualmente y colectivamente las funciones de cada célula del organismo y a su vez de cada órgano, cada sistema fisiológico, para finalmente producir un perfecto equilibrio en el funcionamiento mental, emocional y sistémico del individuo. El sueño influye en los procesos de memoria, aprendizaje, estados de ánimo y comportamiento, en las respuestas inmunológicas, procesos metabólicos, niveles de hormonas, digestión y muchas más funciones fisiológicas. Aquí presentamos una breve revisión de tres aspectos fundamentales relacionados con el sueño, enfocado especialmente en el efecto que tienen en procesos de aprendizaje y memoria: a. actividad eléctrica cerebral durante el sueño y correlación neuroanatómica con los mecanismos fisiológicos de memoria y aprendizaje; b. ciclos circadianos y su importancia en el funcionamiento de diferentes sistemas fisiológicos; c. algunos ejemplos de trastornos clínicos asociados con trastornos del sueño y sus repercusiones en aprendizaje y memoria.

Recent studies have demonstrated that while we are sleeping, our brain is very busy processing all information we have acquired along the day. Lack of sleep has shown to produce deficits in memory consolidation and plays an important role in brain development and brain plasticity in the several developmental stages of the human brain. At the cellular level, circadian cycles coordinate complex mechanism that "turn on and off" genes and cellular structures regulating individual cell functions to impact global organ and systems physiological activities. At the end a perfect and coordinated equilibrium in the mental, emotional and physiological is the goal of this complex process. Sleep impacts memory, learning, mood, behavior, immunological responses, metabolism, hormone levels, digestive process and many more physiological functions. We present a review of three basic aspects related with sleep: a. brain electrical activity during the sleep and neuroanatomic correlation with mechanism related with memory and learning; b. circadian cycles and impact in several physiological systems; c some examples of clinical disorders associated with sleep disorders and impact in learning and memory.

Poria cocos ethanol extract and its active constituent, pachymic acid, modulate sleep architectures via activation of GABA(A)-ergic transmission in rats / 동물의과학연구지

Poria cocos is a well-known traditional Chinese traditional medicine (TCM) that grows around roots of pine trees in China, Korea, Japan, and North America. Poria cocos has been used in Asian countries to treat insomnia as either a single herb or part of an herbal formula. In a previous experiment, pachymic acid (PA), an active constituent of Poria cocos ethanol extract (PCE), increased pentobarbital-induced sleeping behaviors. The aim of this experiment was to evaluate whether or not PCE and PA modulate sleep architectures in rats as well as whether or not their effects are mediated through GABA(A)-ergic transmission. PCE and PA were orally administered to individual rats 7 days after surgical implantation of a transmitter, and sleep architectures were recorded by Telemetric Cortical encephalogram (EEG) upon oral administration of test drugs. PCE and PA increased total sleep time and non-rapid eye movement (NREM) sleep as well as reduced numbers of sleep/wake cycles recorded by EEG. Furthermore, PCE increased intracellular chloride levels, GAD65/67 protein levels, and alpha-, beta-, and gamma-subunits of GABA(A) receptors in primary cultured hypothalamic neuronal cells. These data suggest that PCE modulates sleep architectures via activation of GABA(A)-ergic systems. Further, as PA is an active component of PCE, they may have the same pharmacological effects.

Characteristics of sleep-wake cycles in mice lacking prostanoid DP receptors / 中国临床药理学与治疗学

AIM: To investigate the effect of prostanoid DP receptors (DPR) on sleep-wake regulation in mice. METHODS: Under pentobarbital anesthesia, mice were chronically implanted with electroencephalogram (EEG) and electromyogram (EMG) electrodes for polysomnographic recordings. The spontaneous sleep-wake cycles were monitored continuously by EEG/EMG recording system for 24 h beginning at 800 p.m. and analyzed by SLEEPSIGN software in DPR knock out (KO) and wild type (WT) mice. RESULTS: DPR-KO mice exhibited a similar circadian rhythm of sleep-wake cycles to WT mice. The amounts of rapid eye movement (REM) sleep or non-REM (NREM) sleep during both the light and dark periods were identical between the DPR-KO and WT mice. Whereas, an increase in the episode number of wakefulness and a shortage in the duration of NREM sleep were found in DPR-KO mice during the light period compared with WT mice. Moreover, DPR-KO mice showed lower activity in delta-wave component in NREM sleep and higher activity in theta-wave component in REM sleep than WT mice. CONCLUSION: DPR plays a crucial role in mediating the prostaglandin D2-induced sleep. Deficiency of DPR results in the low intensity and fragmented diurnal NREM sleep and the high vigilance REM sleep, with the normal circadian rhythm of sleep in mice.