Journal ArticleDOI
Day/night changes of pineal gland volume and pinealocyte nuclear size assessed over 10 consecutive days.
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TLDR
It was found that changes in pineal gland volume could not be correlated with the light/dark phases; instead, a rhythm with a two-day period was encountered.Abstract:
Previous studies aimed at elucidating day/night changes of pineal gland size and pinealocyte nuclear volume have yielded contradictory results The aim of the present investigation was to examine the above parameters over a period of 10 successive days, at 6-hour intervals under a lighting regimen of LD 12∶12 (7 am to 7 pm) It was found that changes in pineal gland volume could not be correlated with the light/dark phases; instead, a rhythm with a two-day period was encountered Pinealocyte nuclear volume, by contrast, showed clear circadian changes, exhibiting troughs during photophase and peaks during scotophaseread more
Citations
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Journal ArticleDOI
The ultrastructure of mammalian pinealocytes: a systematic investigation.
TL;DR: Whereas sufficient structural information now exists on cytoplasmic organelles such as synaptic ribbons and spherules, annulate lamellae, subsurface cisterns, and the several types of synaptic arrangements seen in relation to the pinealocyte soma and its processes, the functional role of these structures in pineal synthetic processes remains to be elucidated.
Journal ArticleDOI
Comparisons of sizes of pinealocyte nuclei and pinealocytes in young and adult Chinese hamsters (Cricetulus griseus) under different photoperiod conditions.
TL;DR: In the Chinese hamster, the relationships between nuclear area and area of pinealocytes with time of day vary, depending on the age of animals as well as different photoperiodic conditions, although they differ only slightly.
Journal ArticleDOI
The morpho-anatomy and histology of the pineal complex in a major Indian carp, Catla catla: identification of the pineal photoreceptor cells and their responsiveness to constant light and constant darkness during different phases of the annual reproductive cycle.
TL;DR: The apparent lack of any cellular responses either in the PS, or in the DS, following exposure to LL and DD, suggests that in C. catla the photoreceptor cells are located only within the epithelial lining of the EV and that these cells respond in a manner similar to mammalian pinealocytes when subjected to comparable photoperiod‐induced experimental conditions.
Book ChapterDOI
Evolution and Environmental Control of Secretory Processes in Pineal Transducers
TL;DR: In spite of their morphological heterogeneity, pineal organs of different vertebrate species share a common function: they are components of the circadian system and, as such, effect major physiological and behavioral adjustments to daily as well as seasonal fluctuations in the environment.
Journal ArticleDOI
Lunasensor, infradian rhythms, telomeres, and the chronomere program of aging.
TL;DR: In this paper, a presumptive role for infradian hormonal rhythms is considered and it is assumed that it is a necessity to have a lunasensor as a particular variant of sensors of gravitation in the “lunasensor” system.
References
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Journal ArticleDOI
Indole Metabolism in the Pineal Gland: A Circadian Rhythm in N-Acetyltransferase
David C. Klein,Joan L. Weller +1 more
TL;DR: Experiments in vitro indicate that norepinephrine, not serotonin, regulates the activity of N-acetyl-transferase through a highly specific receptor.
Journal ArticleDOI
Control of hydroxyindole o-methyltransferase activity in the rat pineal gland by environmental lighting.
TL;DR: This work has shown that there is a ditirnal cycle in the enzymatic synthesis of melatonin and that this cycle is re,ulated by environmental lihltin.
Journal ArticleDOI
Induction and Superinduction of Serotonin N-Acetyltransferase by Adrenergic Drugs and Denervation in Rat Pineal Organ
Takeo Deguchi,Julius Axelrod +1 more
TL;DR: When rat pineal organ is denervated by ganglionectomy, beta-(3,4-dihydroxyphenyl)-L-alanine induces much more serotonin N-acetyltransferase than in the innervated gland, which appears to be due to changes of the postsynaptic site, probably the beta-adrenergic receptor on the pineal cell.
Journal ArticleDOI
Long-term studies on immunoreactive human melatonin.
TL;DR: Intra-individual variations are seen at different times of the year at 2400 and 0800, with low values in spring and autumn and high values in summer and winter.