Light-dark cycle synchronization of circadian rhythm in blind primates

In this study, the authors evaluated the photoresponsiveness of the circadian system of these blind marmosets.

Study: Length of children's sleep duration varies; can influence their weight, behavior

The duration of a child's sleep can vary, depending on the time of day, week and year

Studies find stable sleep patterns and regular routines may improve outcomes in bipolar disorder

Bipolar disorder, commonly known as manic-depressive disorder, is highly influenced by the circadian system - the body's internal clock

Altered sex hormone levels, higher body temp affects sleep quality in postmenopausal women

In an examination of potential relationships between objective sleep measures, nocturnal sex hormone levels, and the nocturnal course of body temperature of older postmenopausal women

Key Found To Moonlight Romance

An international team of Australian and Israeli researchers has discovered what could be the aphrodisiac for the biggest moonlight sex event on Earth.

Feeling sleepy is all in your genes

Genes responsible for our 24 hour body clock influence not only the timing of sleep, but also appear to be central to the actual restorative process of sleep

Study identifies pathway required for normal reproductive development

Gene defects cause infertility, lack of sense of smell in humans and mice

Simplest circadian clocks operate via orderly phosphate transfers

3 proteins in a test tube, fueled by ATP, maintain accurate circadian rhythm for weeks

Researchers propose new molecule to explain circadian clock

The internal clock in living beings that regulates sleeping and waking patterns -- usually called the circadian clock -- has often befuddled scientists due to its mysterious time delays.

Mouse vision has a rhythm all its own

In the eyes of mammals, visual information is processed on a daily schedule set within the eyes themselves-not one dictated by the brain

Acute Sleep Deprivation Leads To Changes In Nighttime Urine

Lack of sleep causes men to produce more urine than women, making "bathroom breaks" likely

Rotating shift workers have lower levels of serotonin

People who work rotating shifts have significantly lower levels of serotonin

Cicardian system suffers and protects from prenatal cocaine exposure

The circadian factors, including the principal circadian hormone melatonin, can attenuate the prenatal effects of cocaine.

Advanced cancer patients prone to poor sleep quality, daytime sleepiness, Emory study shows

Patients with advanced-stage cancer experience very poor sleep quality and often have troubling staying awake

Late weekend sleep among teens may lead to poor academic performance

Teenagers who stay up late on school nights and make up for it by sleeping late on weekends are more likely to perform poorly in the classroom

A computational model for functional mapping of genes that regulate intra-cellular circadian rhythms

The authors present a statistical model for mapping and characterizing specific genes or quantitative trait loci (QTL) that affect variations in rhythmic responses.

The Association between Morning Hypertension and Metabolic Syndrome in Hypertensive Patients

In this study, the authors investigated the frequency of metabolic syndrome and Morning hypertension in hypertensive patients, and evaluated their association.

System-Driven and Oscillator-Dependent Circadian Transcription in Mice with a Conditionally Active Liver Clock

In this study, the authors describe their attempt to engineer a mouse strain with conditionally active hepatocyte circadian clocks.

Chronobiology: An Internal Clock for All Seasons (part 2)

Current Research on Seasonal Affective Disorder and Phototherapy

Chronobiology An Internal Clock for All Seasons (part 1)

This essay (the first of two parts) discusses chronobiology, the study of these biological clocks. Biological periodicities may range from ultradian and circadian to circahmar and circasrnualcycles