Abstract Survey and laboratory studies suggest that several factors, such as social academic demands, part-time jobs irregular school schedules, affect the sleep-wake cycle of college students. In this study, we examined pattern role played by schedules individual characteristics on performance. The subjects were 36 medical students (male = 21 female 15), mean age 20.7 years, SD 2.2. All attended same schedule, from Monday to Friday. volunteers answered a morningness-eveningness...

Circadian rhythmicity in humans has been well studied using actigraphy, a method of measuring gross motor movement. As actigraphic technology continues to evolve, it is important for data analysis keep pace with new variables and features. Our objective study the behavior two variables, interdaily stability intradaily variability, describe rest activity rhythm. Simulated actigraphy humans, rats, marmosets were used this study. We modified calculation IV IS by modifying time intervals...

Chronotype is an established concept designed to identify distinct phase relationships between the expression of circadian rhythms and external synchronizers in humans. Although it has been widely accepted that chronotype subjected ontogenetic modulation, there no consensus on interaction age gender. This study aimed determine relationship age- gender-related changes morningness-eveningness character a large sample people. A total 14,650 volunteers were asked complete Brazilian version Horne...

Abstract The rotation of the Earth around its own axis and sun determines characteristics light/dark cycle, most stable ancient 24 h temporal cue for all organisms. Due to tilt in earth’s relation plane orbit sun, sunlight reaches differentially depending on latitude. timing circadian rhythms varies among individuals a given population biological environmental factors underlie this variability. In present study, we tested hypothesis that latitude is associated regulation rhythm humans. We...

The sleep-wake cycle of students is characterized by delayed onset, partial sleep deprivation and poor quality. Like other circadian rhythms, the influenced endogenous environmental factors. aim present study was to determine effects different class starting times on pattern 27 medical students. data were collected during two school semesters having times. All subjects answered Portuguese version Horne Östberg Morningness/Eveningness Questionnaire, Pittsburgh Sleep Quality Index (PSQI) kept...

Aging changes sleep patterns in most elderly people. Frailty shares a number of characteristics with disorders and leads to similar results. However, their relationship residents long-stay institutions remains unclear. Thus, the present study aimed evaluate between frailty syndrome institutions.This was cross-sectional 69 institutionalized city João Pessoa, Brazil. The Pittsburg Sleep Quality Index, actimetry specific tests for phenotype variables were used. Pearson's χ(2)-test, one-way...

Abstract Sleep plays a crucial role in the regulation of body homeostasis and rhythmicity mammals. Recently, specific component sleep structure has been proposed as part its homeostatic mechanism, named micro-arousal. Here, we studied unique progression dynamic behavior cortical hippocampal local field potentials (LFPs) during slow-wave sleep-related to motor-bursts (micro-arousals) mice. Our main results comprised: (i) an abrupt drop LFP amplitude preceding micro-arousals which persisted...

OBJECTIVE: To evaluate excessive daytime sleepiness in patients with depressive disorder and to examine its association the severity of depression suicidal ideation. METHOD: Seventy were interviewed assessed by Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI) for Suicidal Ideation (SSI). Descriptive analysis, Pearson correlations Student's t-test used data analyses. RESULTS: Most (57.1%) obtained high scores on ESS. Correlation was positive strongly significant between ESS BDI...

Mammals exhibit daily anticipatory activity to cycles of food availability. Studies on such (FAA) have been conducted mainly in nocturnal rodents. They identified FAA as the behavioral output a entrained oscillator (FEO), separate known light (LEO) located suprachiasmatic nucleus (SCN) hypothalamus. Here we briefly review main characteristics FAA. Also, present results four topics anticipation: (1) possible input signals FEO, (2) FEO substrate, (3) importance canonical clock genes for FAA,...

Several lines of evidence converge to the idea that rapid eye movement sleep (REMS) is a good model foster our understanding psychosis. Both REMS and psychosis course with internally generated perceptions lack rational judgment, which attributed hyperlimbic activity along hypofrontality. Interestingly, some individuals can become aware dreaming during REMS, particular experience known as lucid (LD), whose neurobiological basis still controversial. Since frontal lobe plays role in...

There are several determinants of mental health symptoms, ranging from individual characteristics to social factors. Consistent with patterns in the general population, students evening tend exhibit more anxiety symptoms and poorer sleep quality compared morning students. Meal timing also appears affect may be associated symptoms. In this context, aim present study was investigate association main last meals day levels, according chronotype university This conducted colleges São Paulo,...

Abstract Melatonin receptors MT 1 and 2 are G protein-coupled that mediate the effects of melatonin, a hormone involved in circadian rhythms other physiological functions. Understanding molecular interactions between these their ligands is crucial for developing novel therapeutic agents. In this study, we used docking, dynamics simulations, quantum mechanics calculation to investigate binding modes affinities three ligands: melatonin (MLT), ramelteon (RMT), 2-phenylmelatonin (2-PMT) with...

During sleep, humans experience the offline images and sensations that we call dreams, which are typically emotional lacking in rational judgment of their bizarreness. However, during lucid dreaming (LD), subjects know they dreaming, may control oneiric content. Dreaming LD features have been studied North Americans, Europeans Asians, but not among Brazilians, largest population Latin America. Here investigated dreams characteristics a Brazilian sample (n=3,427; median age=25 years) through...

Dream reports collected after rapid eye movement sleep (REM) awakenings are, on average, longer, more vivid, bizarre, emotional and story-like compared to those non-REM. However, a comparison of the word-to-word structural organization dream is lacking, traditional measures that distinguish REM non-REM dreaming may be confounded by report length. This problem amenable analysis as non-semantic directed word graphs, which provide assessment oral reports, while controlling for individual...

Alterations in circadian rhythms are present the presymptomatic stage of Alzheimer's disease (AD), possibly contributing to its pathogenesis. However, it is unknown whether such alterations associated with worse outcomes once individuals diagnosed symptomatic disease. We aimed evaluate association between rest-activity pattern and AD-related features patients mild-moderate AD.We assessed consecutive AD through actigraphy for 14 days. Cerebrospinal fluid was obtained determine levels...

Three experiments examined students' long-term retention of knowledge learned in college courses. In Experiment 1 was measured 4 and 11 months after the term ended. Students retained a great deal what they originally learned, there were no differential forgetting effects as function level original learning. 2 compared for recall test items 3 types multiple-choice items: recognition, comprehension, mental skills. performed poorer on items, but differences among multiple- choice measuring...

Several structures of the central nervous system are essential in sleep–wake regulation process. This study aimed to identify which actigraphic parameters cycle (SWC) compromised after stroke and determine whether low-level physical activity can influence expression sleep-cycle temporal variation, order discuss implications for clinical practice patient rehabilitation. The assessed 22 patients (55 ± 12 years) 24 healthy individuals (57 11 years), both sexes. instruments used were...