Sleep Disorders, Circadian Rhythm
Dyssomnias associated with disruption of the normal 24 hour sleep wake cycle secondary to travel (e.g., JET LAG SYNDROME), shift work, or other causes.
An ovoid densely packed collection of small cells of the anterior hypothalamus lying close to the midline in a shallow impression of the OPTIC CHIASM.
Period Circadian Proteins
Circadian Rhythm Signaling Peptides and Proteins
A broad category of proteins that regulate the CIRCADIAN RHYTHM of an organism. Included here are proteins that transmit intracellular and intercellular signals in a chronological manner along with proteins that sense light and time-dependent changes in the environment such as the PHOTOPERIOD.
Basic helix-loop-helix (bHLH) domain-containing proteins that contain intrinsic HISTONE ACETYLTRANSFERASE activity and play important roles in CIRCADIAN RHYTHM regulation. Clock proteins combine with Arntl proteins to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation. This transcriptional activation also sets into motion a time-dependent feedback loop which in turn down-regulates the expression of clock proteins.
Biological mechanism that controls CIRCADIAN RHYTHM. Circadian clocks exist in the simplest form in cyanobacteria and as more complex systems in fungi, plants, and animals. In humans the system includes photoresponsive RETINAL GANGLION CELLS and the SUPRACHIASMATIC NUCLEUS that acts as the central oscillator.
The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.
ARNTL Transcription Factors
Basic helix-loop-helix (bHLH) domain-containing proteins that play important roles in CIRCADIAN RHYTHM regulation. They combine with CLOCK PROTEINS to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation.
A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
Jet Lag Syndrome
A chronobiologic disorder resulting from rapid travel across a number of time zones, characterized by insomnia or hypersomnolence, fatigue, behavioral symptoms, headaches, and gastrointestinal disturbances. (From Cooper, Sleep, 1994, pp593-8)
The absence of light.
Flavoproteins that function as circadian rhythm signaling proteins in ANIMALS and as blue-light photoreceptors in PLANTS. They are structurally-related to DNA PHOTOLYASES and it is believed that both classes of proteins may have originated from an earlier protein that played a role in protecting primitive organisms from the cyclical exposure to UV LIGHT.
Nuclear Receptor Subfamily 1, Group D, Member 1
A DNA-binding orphan nuclear receptor that negatively regulates expression of ARNTL TRANSCRIPTION FACTORS and plays a role as a regulatory component of the circadian clock system. The Nr1d1 nuclear receptor expression is cyclically-regulated by a feedback loop involving its positive regulation by CLOCK PROTEIN; BMAL1 PROTEIN heterodimers and its negative regulation by CRYPTOCHROME and PERIOD PROTEINS.
A light-sensitive neuroendocrine organ attached to the roof of the THIRD VENTRICLE of the brain. The pineal gland secretes MELATONIN, other BIOGENIC AMINES and NEUROPEPTIDES.
Casein Kinase Iepsilon
A casein kinase I isoenzyme with specificity for proteins involved the regulation of the CIRCADIAN RHYTHM.
The adaptation of therapeutic approaches such as pharmacological (DRUG CHRONOTHERAPY), surgical, radiological, or physical to the known variations in biological RHYTHMICITY, such as CIRCADIAN RHYTHMS. The treatment is aimed at supporting normal rhythms, or modifying the timing of therapy to achieve maximal efficacy and minimal adverse effect.
An acetyltransferase with specificity towards the amine group of aromatic alkylamines (arylalkylamines) such as SEROTONIN. This enzyme is also referred to as serotonin acetylase despite the fact that serotonin acetylation can also occur through the action of broad specificity acetyltransferases such as ARYLAMINE N-ACETYLTRANSFERASE.
Seasonal Affective Disorder
A syndrome characterized by depressions that recur annually at the same time each year, usually during the winter months. Other symptoms include anxiety, irritability, decreased energy, increased appetite (carbohydrate cravings), increased duration of sleep, and weight gain. SAD (seasonal affective disorder) can be treated by daily exposure to bright artificial lights (PHOTOTHERAPY), during the season of recurrence.
Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.
Work Schedule Tolerance
Nuclear Receptor Subfamily 1, Group F, Member 1
A DNA-binding orphan nuclear receptor that positively regulates expression of ARNTL TRANSCRIPTION FACTORS and is a regulatory component of the circadian clock system. The protein also has a role in neuron cell survival and differentiation in that loss of function mutations of its gene result in the mouse phenotype referred to as the STAGGERER MOUSE.
Gene Expression Regulation
Light Signal Transduction
The conversion of absorbed light energy into molecular signals.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
Dorsomedial Hypothalamic Nucleus
An aggregation of cells in the middle hypothalamus dorsal to the ventromedial nucleus and bordering the THIRD VENTRICLE.
A form-genus of spherical to rod-shaped CYANOBACTERIA in the order Chroococcales. They contain THYLAKOIDS and are found in a wide range of habitats.
Photoreceptor Cells, Invertebrate
Specialized cells in the invertebrates that detect and transduce light. They are predominantly rhabdomeric with an array of photosensitive microvilli. Illumination depolarizes invertebrate photoreceptors by stimulating Na+ influx across the plasma membrane.
Basic Helix-Loop-Helix Transcription Factors
A family of DNA-binding transcription factors that contain a basic HELIX-LOOP-HELIX MOTIF.
Ocular Physiological Phenomena
A broad category of sleep disorders characterized by either hypersomnolence or insomnia. The three major subcategories include intrinsic (i.e., arising from within the body) (SLEEP DISORDERS, INTRINSIC), extrinsic (secondary to environmental conditions or various pathologic conditions), and disturbances of circadian rhythm. (From Thorpy, Sleep Disorders Medicine, 1994, p187)
Abnormal cardiac rhythm that is characterized by rapid, uncoordinated firing of electrical impulses in the upper chambers of the heart (HEART ATRIA). In such case, blood cannot be effectively pumped into the lower chambers of the heart (HEART VENTRICLES). It is caused by abnormal impulse generation.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Enzymes that oxidize certain LUMINESCENT AGENTS to emit light (PHYSICAL LUMINESCENCE). The luciferases from different organisms have evolved differently so have different structures and substrates.
Casein Kinase Idelta
A casein kinase I isoenzyme that plays a regulatory role in a variety of cellular functions including vesicular transport, CHROMOSOME SEGREGATION; CYTOKINESIS, developmental processes, and the CIRCADIAN RHYTHM.
Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.
Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.
DNA locations with the consensus sequence CANNTG. ENHANCER ELEMENTS may contain multiple copies of this element. E-boxes play a regulatory role in the control of transcription. They bind with basic helix-loop-helix (bHLH) type TRANSCRIPTION FACTORS. Binding specificity is determined by the specific bHLH heterodimer or homodimer combination and by the specific nucleotides at the 3rd and 4th position of the E-box sequence.
Vasoactive Intestinal Peptide
A highly basic, 28 amino acid neuropeptide released from intestinal mucosa. It has a wide range of biological actions affecting the cardiovascular, gastrointestinal, and respiratory systems and is neuroprotective. It binds special receptors (RECEPTORS, VASOACTIVE INTESTINAL PEPTIDE).
Body Temperature Regulation
The processes of heating and cooling that an organism uses to control its temperature.
Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.
Casein Kinase I
A casein kinase that was originally described as a monomeric enzyme with a molecular weight of 30-40 kDa. Several ISOENZYMES of casein kinase I have been found which are encoded by separate genes. Many of the casein kinase I isoenzymes have been shown to play distinctive roles in intracellular SIGNAL TRANSDUCTION.
Conditions characterized by disturbances of usual sleep patterns or behaviors. Sleep disorders may be divided into three major categories: DYSSOMNIAS (i.e. disorders characterized by insomnia or hypersomnia), PARASOMNIAS (abnormal sleep behaviors), and sleep disorders secondary to medical or psychiatric disorders. (From Thorpy, Sleep Disorders Medicine, 1994, p187)
A stage of sleep characterized by rapid movements of the eye and low voltage fast pattern EEG. It is usually associated with dreaming.
Cell Cycle Proteins
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
A phylum of oxygenic photosynthetic bacteria comprised of unicellular to multicellular bacteria possessing CHLOROPHYLL a and carrying out oxygenic PHOTOSYNTHESIS. Cyanobacteria are the only known organisms capable of fixing both CARBON DIOXIDE (in the presence of light) and NITROGEN. Cell morphology can include nitrogen-fixing heterocysts and/or resting cells called akinetes. Formerly called blue-green algae, cyanobacteria were traditionally treated as ALGAE.
Animals, Genetically Modified
Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Receptor, Melatonin, MT2
Gene Expression Regulation, Plant
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
Analysis of Variance
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
An anterior pituitary hormone that stimulates the ADRENAL CORTEX and its production of CORTICOSTEROIDS. ACTH is a 39-amino acid polypeptide of which the N-terminal 24-amino acid segment is identical in all species and contains the adrenocorticotrophic activity. Upon further tissue-specific processing, ACTH can yield ALPHA-MSH and corticotrophin-like intermediate lobe peptide (CLIP).
Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.