Animals that inhabit mid- to high-latitude regions exhibit various adaptive behaviors, such as migration, reproduction, molting and hibernation in response to seasonal cues. These adaptive behaviors are tightly regulated by seasonal changes in photoperiod, the relative day length vs night length. Recently, the regulatory pathway of seasonal reproduction has been elucidated using quail. In birds...

Book Reviews Russel J. Reiter Pineal Research Reviews, vol. 1 Alan R. Liss, New York 1983 XI + 276 pp.; E43.00 ISBN 0-8451-3600-3 This volume is the first one of a new series which is promised a great future. For the scientists working in the field of the pineal gland, it will be of great interest, as it contains review articles written by experts. The first volume contains 6 articles of a long...

Melatonin (N-acetyl-5-methoxytrypamine) is the vertebrate hormone of the night: circulating levels at night are markedly higher than day levels. This increase is driven by precisely regulated increases in acetylation of serotonin in the pineal gland by arylalkylamine N-acetyltransferase (AANAT), the penultimate enzyme in the synthesis of melatonin. This unique essential role of AANAT in vertebr...

Deficits in neuroendocrine-immune system functioning, including alterations in pineal and thymic glands, contribute to aging-associated diseases. This study looks at ageing-associated alterations in pineal and thymic gland functioning evaluating common signaling molecules present in both human and animal pinealocytes and thymocytes: endocrine cell markers (melatonin, serotonin, pCREB, AANAT, CG...

The pineal gland is an organ involved in regulation of homeostasis and body rhythms. It plays an important role in the growth foetuses and adaptation of newborns to new environmental conditions. The requirements of foetuses and newborns progressively change during development. The purpose of the study was to evaluate morphological changes of pineal glands in foetuses and infants with brain lesi...

Immunoperoxidase methods for the demonstration of three glial antigens, vimentin, glial fibrillary acidic protein, and S-100 protein, were applied to routine-fixed paraffin sections of rat pineal gland. A pre-embedding electron microscope immunoperoxidase method was also used to study the ultrastructural localization of S-100 protein in pineal cells. Light and electron microscopic results showe...

The circadian endocrine hormone melatonin plays a significant role in many physiological processes, such as modulating the sleep/wake cycle and oxidative stress. Melatonin is synthesized and secreted during the night by the pineal gland and released into the circulatory system. It binds to numerous membrane, cytosolic, and nuclear receptors in the brain and peripheral organs. Three G-protein-li...

Nocturnal melatonin production in the pineal gland is under the control of norepinephrine released from superior cervical ganglia afferents in a rhythmic manner, and of cyclic AMP. Cyclic AMP increases the expression of serotonin N-acetyltransferase and of inducible cAMP early repressor that undergo circadian oscillations crucial for the maintenance and regulation of the biological clock. In th...

Melatonin is the principle hormonal product of the pineal gland. It is secreted with a robust daily rhythm, peaking near the middle of the night. During the daytime, concentrations remain very low, as exposure to light robustly suppresses its secretion. The regulation of melatonin by light is well-characterized, but an interesting feature of the daily melatonin rhythm is that its peak occurs ne...

To establish a possible correlation between the rate of cellular proliferation and already documented functional and morphological characteristics of the rat pineal gland during postnatal development, the bromodeoxyuridine labelling method was used to evaluate the fraction of cells at the S phase of the cell cycle in paraffin sections from 1-, 7-, 14- and 28-day-old rats. Numerical density, tak...