The presence of pigment has been demonstrated in different nervous structures such as those of retina, substantia nigra, and locus coeruleus. These pigments have also been described in the pineal gland of different mammal species. Histochemical and ultrastructural studies of the pineal gland of female viscacha (Lagostomus maximus maximus) were performed to analyze the presence of pigmented cell...

Melatonin, the major hormone produced by the pineal gland, displays characteristic daily and seasonal patterns of secretion. These robust and predictable rhythms in circulating melatonin are strong synchronizers for the expression of numerous physiological processes in photoperiodic species. In mammals, the nighttime production of melatonin is mainly driven by the circadian clock, situated in t...

The pineal gland is very important human endocrine gland and its location and size is very important for the neurologist and neurosurgeons and for the radiologist because in certain radiological investigations it is the guide of midline and its right or left shifting is highly suggestive of space occupying lesion in the brain. The aim of study was to find out the morphometric parameters of pine...

Norepinephrine (NE) released from the sympathetic nerve endings is the main neurotransmitter controlling melatonin synthesis in the mammalian pineal gland. Although neuropeptide Y (NPY) co-exists with NE in the pineal sympathetic nerve fibers it also occurs in a population of non-adrenergic nerve fibers located in this gland. The role of NPY in pineal physiology is still enigmatic. The present ...

The pineal glands of donkey were light beige to dark brown, fusiform structure. It lies at the pineal recess caudal to the splenium of the corpus callosum and caudodorsal to the third ventricle, just in front of the rostral colliculi and in between the para hippocampal gyrus. The pineal gland was supplied from the caudal choroidal artery and branches from artery of corpus callosum. The venous d...

In mammals, hypocretin/orexin (HCRT) neuropeptides are important sleep-wake regulators and HCRT deficiency causes narcolepsy. In addition to fragmented wakefulness, narcoleptic mammals also display sleep fragmentation, a less understood phenotype recapitulated in the zebrafish HCRT receptor mutant (hcrtr-/-). We therefore used zebrafish to study the potential mediators of HCRT-mediated sleep co...

The immunohistochemical detection of bromodeoxyuridine (BrdU) was used to study the time of origin of the cells in the pineal gland of the rat. A study was made involving 17 groups of 4 rats each, administered with a single dose of bromodeoxyuridine (BrdU, 25 mg/kg) in 7 phases of the embryonic period (E15 to E21) and in 10 postnatal phases (between P0 and P30), followed by determination in eac...

Research over the past 10 years into the pineal gland and its possible connection with a psiconducive state of consciousness (Roney Dougal, 1986 & 1989), has recently become linked with research on the connection between the earth's magnetic field (EMF) and psi awareness (Persinger, 1988a; Roney Dougal, 1988). This connection is explored with particular reference to neurochemical research into ...

It has been demonstrated that type II iodothyronine deiodinase is present in rat pineal gland, and the deiodinase activity markedly increases during the hours of darkness, primarily through beta-adrenergic mechanism. We have studied the relationship between pineal type II iodothyronine deiodinase messenger RNA (mRNA) and the deiodinase activity to elucidate the mechanisms involved in the noctur...

Relatively little is known about the effects of melatonin on the aging of the pineal, the organ which is the main place for synthesis of this hormone. Using simple morphometric methods, some parameters of the pineal gland, such as total volume, number of pinealocytes and pinealocyte volume were estimated in two mice strains: normal CBA and melatonin-deficient C57BL/6J. Two age groups, 6 weeks a...