Pineal Melatonin Rhythms And The Timing Of Puberty In Mammals

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The Effects of Altered Prenatal Melatonin Signaling on Adult

Melatonin, the hormone that encodes information about daily rhythms in mammals, has been implicated in various psychopathologies in humans. Changes in melatonin secretion have been found in depression (for a review see Srinivasan et al. 2006), Alzheimer s disease and Parkinson s disease (for a review see Srinivasan et al.

Photoperiodism in Pigs

Short days stimulate puberty and long days delay sexual maturation and reduce boar taint. However, the pre-weaning photoperiod can influence the response to the subsequent photoperiod. In mammals, seasonal changes in photoperiod are mediated through the pineal hormone melatonin. Melatonin secretion is typically high during the dark hours

Indian J. Psychiat. (1982), 24(4), 329 337

defining the circadian rhythms in indole metabolism within the pineal of mammals. The two major classes of pineal hormones isolation and characterisation of the pineal hormone melatonin was


Melatonin was originally thought to be produced exclusively by the pineal gland in most, if not all, vertebrate species, including mammals. It now ranks as one of the most phylogenetically old and fundamental biological signaling molecules present in organisms ranging through bacteria, unicellular organisms, plants, and animals. In

Anatomy and Physiology - Home

clear, but circumstantial evidence suggests that melatonin may play a role in the timing of human sexual matura- tion. Melatonin levels in the blood decline at puberty, and pineal tumors that eliminate melatonin production cause premature puberty in young children. Antioxidant activity. Melatonin is a very effective antioxi-

Author Deputy Editor - Wurtman Lab @ MIT

melatonin rhythms. The most compelling evidence now available supports two roles for melatonin in humans: the involvement of nocturnal melatonin secretion in initiating and maintaining sleep, and control by the day/night melatonin rhythm of the timing of other 24-hour rhythms. (See 'Circadian rhythm' below.)

MIT - Massachusetts Institute of Technology

and control by the day/night melatonin rhythm Of the timing Of other 24 hr rhythms. It is melatonin's effect on sleep that underlies most of its current use as a dietary supplement. Some additional possible benefits or melatonin supplementation have been proposed (e.g., as an antioxidant, or to glow aging.


predominant cue for the timing of seasonal breeding. The environmental signal for changes in reproductive competency is the change in the time of sunrise and sunset, which together with an endogenous timing system, controls the daily secretion of the pineal hormone melatonin (Reiter 1980). The daily rhythm of

Wurtman Lab @ MIT

and control by the day/night melatonin rhythm Of the timing Of other 24 hr rhythms. It is melatonin's effect on sleep that underlies most of its current use as a dietary supplement. Some additional possible benefits or melatonin supplementation have been proposed (e.g., as an antioxidant, or to glow aging.

Melatonin and the pineal gland: influence on mammalian

The pineal gland appears to serve the same function in all mammals studied to date. The pattern of secretion of its major hormone, melatonin, conveys information concerning light dark cycles to the body physiology for the organization of seasonal and circadian rhythms (Arendt, 1995). Recently, much progress

Light and Immunomodulation - Fordham University

such as the pituitary, hypothalamus, and the pineal glands are stimulated to produce neurochemicals 7 that could direct changes in immune function. 8 11 Either or both pathways may be involved. Skin-Mediated Response The wavelengths of light transmitted through different layers of skin do not vary dramatically from lower mammals to primates.

Pattern of Melatonin Secretion Mediates Transfer of

In adult mammals, the circadian rhythm of pineal melatonin secretion is an important component of the photoperiodic mech-anism. Blood concentrations of melatonin are increased during a part, though not necessarily all, of the dark period, but mela-tonin concentrations are always low during the daylight hours.

Endocrinological basis of seasonal infertility in pigs

mammals, the seasonal effects on reproduction are mediated by the pineal hormone melatonin. In the domestic pig, there has been considerable controversy about the existence and role of a circadian melatonin pattern. The aims of the study were to investigate the melatonin secretion of the wild boar and compare it with that of the domestic pig.

Melatonin: Countering Chaotic Time Cues

circulating concentrations represent endogenous pineal production. It will concentrate mainly on the most researched, and accepted area of therapeutic use and potential use of melatonin its undoubted ability to realign circadian rhythms and sleep since this is the author s bias.


timing signals and local effects. Melatonin is one of the most potent antioxidants known. Each melatonin molecule may scavenge up to 10 free radicals in a cascade extending to its secondary, tertiary and quaternary metabolites.40 Serum melatonin levels contribute significantly to total plasma anti-oxidant capacity.41 Melatonin has numerous

Melatonin And The Mammalian Pineal Gland 1st Edition

Its 9 chapters cover (1) an introduction to melatonin and the mammalian pineal gland, (2) structure of the pineal gland, (3) biochemistry of the pineal, (4) light=dark control of melatonin synthesis, (5) role of the pineal in photoperiodic seasonal functions, (6) role of the pineal and melatonin in circadian rhythms, (7) human physiology and

thalamus - University of Wisconsin Madison

The pineal is a small midline mass of glandular tissue that secretes the hormone melatonin. In lower mammals, melatonin plays a central role in control of diurnal rhythms (cycles in body states and hormone levels that follow the day-night cycle). In humans, at least a portion of the control of diurnal rhythms has been taken over by the

could long-term administration of melatonin to prepubertal

due to its ability to shift the timing of sleep and circadian rhythms.3,18 the photoneuroendocrine system In mammals, photoperiodic (or relative length of light and dark periods) information is received at the level of the retina and is transmitted through a multi-synaptic neural pathway to the pineal gland to modulate melatonin secre-

Photoperiod, melatonin and its importance in fish reproduction

physiological rhythms. In this article we have reviewed about the photoperiod and its importance in fish reproduction, pineal gland structure and function, sites of melatonin production in fish, role of AANAT enzyme in melatonin production, endocrine regulation of melatonin production and its role in

Melatonin utility in neonates and children

the pineal gland, providing circadian and seasonal timing cues. Melatonin is locally found in various cells, tissues, and organs, including lymphocytes, bone marrow, the thymus, the gastrointestinal tract, the skin, the Harderian gland, and the retina.1,2,4 The production of melatonin also occurs in invertebrates, bacteria, and plants.12

Normal Sleep: Neurobiological Mechanisms

Unresolved issues: Sleep in birds and mammals may have evolved independently. Developmentally sleep and REM sleep in particular are often expressed at a high level before the emergence of NREM and adult patterns of wake/sleep transition. Sleep is embedded in a circadian rhythm.

Human pineal physiology and functional signiWcance of melatonin

tion of the day night cycle. Melatonin production is controlled by an endogenous circadian timing system and is also suppressed by light. In lower vertebrates, the pineal gland is photosensitive, and is the site of a self-sustaining circadian clock. In mammals, including

Photoperiod effects on circadian rhythms and puberty onset in

regulation of pineal melatonin synthesis in teleosts. 72 4. paper ii clock controllled endogenous melatonin rhythms in nil tilapia (oreochromis niloticus) and african catfish (clarias gariepinus). 97 5. paper iii circadian rhythms of locomotor activity in the african catfish, clarias gariepinus. 125 6.


In mammals, a circadian oscillator present in the suprachiasmatic nucleus of the hypothalamus receives photic stimuli via the retinohypothalmic tract. The circadian system regulates the rhythmic secretion of the melatonin i.e., pineal hormone. Melatonin is secreted at night and duration of secretion varies inversely with day length.

Physiology - MIT

the day/night melatonin rhythm of the timing of other 24-hour rhythms (see below). Melatonin's effect on sleep underlies most of its current use as a drug and the development of melatonin analogs as new drugs [19].Some additional possible benefits of melatonin supplementation have been proposed (eg, as an antioxidant, or to slow aging, or to


In seasonal mammals, robust annual cycles of adiposity, food intake, and energy metabolism are driven by daylength, which generates a diurnal melatonin profile and acts on neuroendocrine pathways (Rousseau et al., 2003). Salmonids also exhibit behavioral and physiologi-cal rhythms, of which the generation of the biological timing system is

946 Experientia 45 (1989), Birkh/iuser Verlag, CH-4010 Basel

946 Experientia 45 (1989), Birkh/iuser Verlag, CH-4010 Basel/Switzerland Pineal melatonin rhythms and the timing of puberty in mammals

TiHo Hannover

Supervisor: Prof Stephan Steinlechner Advisory Committee: Prof. Dr. Stephan Steinlechner Prof. Dr. Elke Zimmermann Prof. Dr. Fritz Trillmich 1st Evaluation: Prof

Functional Interdependency between Intestinal Microbiota and

The pineal is a master regulator, produces melatonin in the absence of light. Serotonin is converted to melatonin in the pineal gland in the absence of light; this master regulator of the clock is light dependent. There is a close relationship between the pineal cycle and biological rhythms. The biological clock controls the timing of

Melatonin And The Mammalian Pineal Gland 1st Edition

Read Book Melatonin And The Mammalian Pineal Gland 1st Edition Melatonin And The Mammalian Pineal Gland 1st Edition This is likewise one of the factors by obtaining the soft documents of this melatonin and the mammalian pineal gland 1st edition by online. You might not require more era to spend to go to the book

Elimination of Short-Day Melatonin Signaling Accelerates

elimination of pineal melatonin secretion by constant light or pinealectomy initi-ates a cycle of gonadal involution and recrudescence outwardly similar to that induced by short days. The present study assessed whether short days and con-stant light induce the seasonal reproductive cycle via common or different inter-val timing mechanisms.

Ethanol Impairs Spatial Cognitive Processing: New Behavioral

The effects of melatonin on the timing of sleep in patients with delayed sleep phase syndrome. In Y. Touitou, J. Arendt, & P. Pe vet (Eds.), Melatonin and the pineal gland: From basic science to clinical application (pp. 351-354). Amsterdam: Excerpta Medica. I Tzischinsky, O., & Lavie, P. (1994). Melatonin I possesses a time-dependent hypnotic

Hormones and Hair Growth: Variations in Androgen Recet&or

and reproductive cycles in many mammals, e.g., red deer [7]. Changes in the environment are interpreted for the hair follicle by the endocrine system. In many species this has been shown to involve melatonin from the pineal plus the hormones of the hy- P

Effect of Melatonin on Human Skin Color

2. Axelrod J: The pineal gland: a neurochemical transducer. Science 184:1341-1348, 1974 3. Ebling FJP, Foster DL: Pineal melatonin rhythms and the timing of puberty in mammals. Experientia 45:946 -954, 1989 4. Tamarkin L, Baird CJ, Almeida OFX: Melatonin: a coordinating signal for mam­ malian reproduction. Science 227:714 -720, 1985 5.