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Melatonin
Melatonin, an indoleamine, is a natural compound produced by various organisms, including bacteria and eukaryotes. Its discovery in 1958 by Aaron B. Lerner and colleagues stemmed from the isolation of a substance from the pineal gland of cows that could induce skin lightening in common frogs. This compound was later identified as a hormone secreted in the brain during the night, playing a crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm, in vertebrates. In vertebrates, melatonin's functions extend to Entrainment (chronobiology), synchronizing sleep-wake cycles, encompassing sleep-wake timing and blood pressure regulation, as well as controlling seasonal rhythmicity (circannual cycle), which includes reproduction, fattening, molting, and hibernation. Its effects are mediated through the activation of melatonin receptors and its role as an antioxidant. In plants and bacteria, melatonin primarily serves as a defense mechanism against oxidative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melatonin As A Medication And Supplement
Melatonin is a Natural product, naturally occurring hormone produced in the brain that is also used as a dietary supplement and medication. As a hormone, melatonin is released by the pineal gland and is involved in sleep–wake cycles. As a supplement, it is often used for the short-term treatment of disrupted sleep patterns such as from jet lag or shift work, and is typically taken oral administration, orally. There is evidence of its benefit for insomnia, but the evidence is not strong. A 2017 review found that sleep onset occurred six minutes faster with use on average, but found no change in total time asleep. Side effects from melatonin supplements are minimal at low doses for short durations (the studies reported that side effects occurred about equally for both melatonin and placebo). Side effects of melatonin are rare but may occur in 1 to 10 patients out of 1,000. They may include somnolence, Headache, headaches, nausea, diarrhea, abnormal Dream, dreams, irritability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melatonin Receptors
Melatonin receptors are G protein-coupled receptors (GPCR) which bind melatonin. Three types of melatonin receptors have been cloned. The MT1 (or Mel1A or MTNR1A) and MT2 (or Mel1B or MTNR1B) receptor subtypes are present in humans and other mammals, while an additional melatonin receptor subtype MT3 (or Mel1C or MTNR1C) has been identified in amphibia and birds. The receptors are crucial in the signal cascade of melatonin. In the field of chronobiology, melatonin has been found to be a key player in the synchrony of biological clocks. Melatonin secretion by the pineal gland has circadian rhythmicity regulated by the suprachiasmatic nucleus (SCN) found in the brain. The SCN functions as the timing regulator for melatonin; melatonin then follows a feedback loop to decrease SCN neuronal firing. The receptors MT1 and MT2 control this process. Melatonin receptors are found throughout the body in places such as the brain, the retina of the eye, the cardiovascular system, the live ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melatonin Receptor
Melatonin receptors are G protein-coupled receptors (GPCR) which bind melatonin. Three types of melatonin receptors have been cloned. The MT1 (or Mel1A or MTNR1A) and MT2 (or Mel1B or MTNR1B) receptor subtypes are present in humans and other mammals, while an additional melatonin receptor subtype MT3 (or Mel1C or MTNR1C) has been identified in amphibia and birds. The receptors are crucial in the signal cascade of melatonin. In the field of chronobiology, melatonin has been found to be a key player in the synchrony of biological clocks. Melatonin secretion by the pineal gland has circadian rhythmicity regulated by the suprachiasmatic nucleus (SCN) found in the brain. The SCN functions as the timing regulator for melatonin; melatonin then follows a feedback loop to decrease SCN neuronal firing. The receptors MT1 and MT2 control this process. Melatonin receptors are found throughout the body in places such as the brain, the retina of the eye, the cardiovascular system, the liv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pineal Gland
The pineal gland (also known as the pineal body or epiphysis cerebri) is a small endocrine gland in the brain of most vertebrates. It produces melatonin, a serotonin-derived hormone, which modulates sleep, sleep patterns following the diurnal cycles. The shape of the gland resembles a pine cone, which gives it its name. The pineal gland is located in the epithalamus, near the center of the brain, between the two cerebral hemisphere, hemispheres, tucked in a groove where the two halves of the thalamus join. It is one of the neuroendocrinology, neuroendocrine Circumventricular organs, secretory circumventricular organs in which capillaries are mostly Vascular permeability, permeable to solutes in the blood. The pineal gland is present in almost all vertebrates, but is absent in Protochordata, protochordates in which there is a simple pineal homologue. The hagfish, archaic vertebrates, lack a pineal gland. In some species of amphibians and reptiles, the gland is linked to a light-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melatonin Receptor 1
Melatonin receptor type 1A is a protein that in humans is encoded by the ''MTNR1A'' gene. Function This gene encodes the MT1 protein, one of two high-affinity forms of a receptor for melatonin, the primary hormone secreted by the pineal gland. This receptor is a G protein-coupled, 7-transmembrane receptor that is responsible for melatonin effects on mammalian circadian rhythm and reproductive alterations affected by day length. The receptor is an integral membrane protein that is readily detectable and localized to two specific regions of the brain. The hypothalamic suprachiasmatic nucleus appears to be involved in circadian rhythm while the hypophysial pars tuberalis may be responsible for the reproductive effects of melatonin. Ligands # Melatonin – full agonist # Afobazole – agonist # Agomelatine – agonist See also * Melatonin receptor Melatonin receptors are G protein-coupled receptors (GPCR) which bind melatonin. Three types of melatonin receptors have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleep-wake Cycle
A circadian rhythm (), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., endogenous) and responds to the environment (is entrained by the environment). Circadian rhythms are regulated by a circadian clock whose primary function is to rhythmically co-ordinate biological processes so they occur at the correct time to maximize the fitness of an individual. Circadian rhythms have been widely observed in animals, plants, fungi and cyanobacteria and there is evidence that they evolved independently in each of these kingdoms of life. The term ''circadian'' comes from the Latin ', meaning "around", and ', meaning "day". Processes with 24-hour cycles are more generally called diurnal rhythms; diurnal rhythms should not be called circadian rhythms unless they can be confirmed as endogenous, and not environmental. Although circadian rhythms are endogenous, they are adjuste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circadian Rhythm Sleep Disorders
A circadian rhythm (), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., endogenous) and responds to the environment (is entrained by the environment). Circadian rhythms are regulated by a circadian clock whose primary function is to rhythmically co-ordinate biological processes so they occur at the correct time to maximize the fitness of an individual. Circadian rhythms have been widely observed in animals, plants, fungi and cyanobacteria and there is evidence that they evolved independently in each of these kingdoms of life. The term ''circadian'' comes from the Latin ', meaning "around", and ', meaning "day". Processes with 24-hour cycles are more generally called diurnal rhythms; diurnal rhythms should not be called circadian rhythms unless they can be confirmed as endogenous, and not environmental. Although circadian rhythms are endogenous, they are adjust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insomnia
Insomnia, also known as sleeplessness, is a sleep disorder where people have difficulty sleeping. They may have difficulty falling asleep, or staying asleep for as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, irritability, and a depression (mood), depressed mood. It may result in an increased risk of accidents of all kinds as well as problems focusing and learning. Insomnia can be short term, lasting for days or weeks, or long term, lasting more than a month. The concept of the word ''insomnia'' has two distinct possibilities: insomnia disorder (ID) or insomnia symptoms, and many abstracts of randomized controlled trials and systematic reviews often underreport on which of these two possibilities the word refers to. Insomnia can occur independently or as a result of another problem. Conditions that can result in insomnia include psychological stress, chronic pain, heart failure, hyperthyroidism, heartburn, restless leg syndrome, menopause ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleep Disorder
A sleep disorder, or somnipathy, is a medical disorder affecting an individual's sleep patterns, sometimes impacting physical, mental, social, and emotional functioning. Polysomnography and actigraphy are tests commonly ordered for diagnosing sleep disorders. Sleep disorders are broadly classified into dyssomnias, parasomnias, circadian rhythm sleep disorders involving the timing of sleep, and other disorders, including those caused by medical or psychological conditions. When a person struggles to fall asleep or stay asleep without any obvious cause, it is referred to as insomnia, which is the most common sleep disorder. Other sleep disorders include sleep apnea, narcolepsy, hypersomnia (excessive sleepiness at inappropriate times), sleeping sickness (disruption of the sleep cycle due to infection), sleepwalking, and night terrors. Sleep disruptions can be caused by various issues, including teeth grinding (bruxism) and night terrors. Managing sleep disturbances that are seconda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circannual Cycle
In chronobiology, the circannual cycle is characterized by biological processes and behaviors recurring on an approximate annual basis, spanning a period of about one year. This term is particularly relevant in the analysis of seasonal environmental changes and their influence on the physiology, behavior, and life cycles of organisms. Adaptations observed in response to these circannual rhythms include fur color transformation, molting, migration, breeding, fattening and hibernation, all of which are inherently driven and synchronized with external environmental changes. The regulation of these cycles is linked to internal biological clocks, akin to the circadian rhythm, which respond to external cues such as variations in temperature, daylight length ( photoperiod), and food availability. Such environmental signals enable organisms to anticipate seasonal variations and adjust their behaviors and physiological states, thereby optimizing evolutionary fitness and reproductive succ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indoleamine
Indolamines are a family of neurotransmitters that share a common molecular structure. Indolamines are a classification of monoamine neurotransmitter, along with catecholamines and ethylamine derivatives. A common example of an indolamine is the tryptophan derivative serotonin, a neurotransmitter involved in mood and sleep. Another example of an indolamine is melatonin. In biochemistry, indolamines are substituted indole compounds that contain an amino group. Examples of indolamines include the lysergamides. Synthesis Indolamines are biologically synthesized from the essential amino acid tryptophan. Tryptophan is synthesized into serotonin through the addition of a hydroxyl group by the enzyme ''tryptophan hydroxylase'' and the subsequent removal of the carboxyl group by the enzyme ''5-HTP decarboxylase''.Carlson, Neil R. ''Physiology of Behavior''. 11th ed. Vol. 1. N.p.: Pearson Education, n.d. Print. See also *Indole *Tryptamine Tryptamine is an indolamine me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entrainment (chronobiology)
In the study of chronobiology, entrainment refers to the synchronization of a biological clock to an environmental cycle. An example is the interaction between circadian rhythms and environmental cues, such as light and temperature. Entrainment helps organisms adapt their bodily processes according to the timing of a changing environment. For example, entrainment is manifested during travel between time zones, hence why humans experience jet lag. Biological rhythms are endogenous; they persist even in the absence of environmental cues as they are driven by an internal mechanism, most notably the circadian clock. Of the several possible cues (known as '' zeitgebers,'' German for 'time-givers') that can contribute to entrainment of the circadian clock, light has the greatest impact. Units of circadian time (CT) are used to describe entrainment to refer to the relationship between the rhythm and the light signal/pulse. Modes of entrainment There are two general modes of entrainm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
