The pineal region can be affected by different types of lesions, ranging from benign masses (e.g. pineal cysts) to highly malignant tumors. These neoplasms are typical of the pediatric age, while they are rarer in adults. Due to the extreme heterogeneity of the cell types of the pineal gland and its surrounding structures, these tumors include several entities, namely germ cell tumors (GCTs), w...

1. In pineal glands of adult spontaneously hypertensive rats (Okamoto strain), dopamine levels increased 34%, adrenaline concentrations increased 152% and noradrenaline levels decreased by 26%, when compared with WistarKyoto normotensive controls. 2. These results are consistent with the hypothesis of an increased uptake of peripheral adrenaline resulting in increased release of noradrenaline f...

The pineal organ has a unique feature in its evolutionary aspects. In the lower vertebrates like fish and amphibian, the organ contains neurons and photoreceptors, and plays a role in photoreceptive function to perceive light information in animals’ circumstances;, while in the mammal, it functions exclusively as an endocrinal organ. These functional alterations are accompanied with morphologic...

The generally accepted view as to the nature of the mammalian pineal is that this organ has secretory activity, but the evidence available, especially the morphological one, is far from sufficient. Recently the pineal of various animal species has been examined repeatedly by electron microscopy (MILOFSKY 1957, GUSEK and SANTORO 1961, DE ROBERTIS and PELLEGRINO DE IRALDI 1961, ANDERSON 1965, GUS...

The adult pineal gland is composed of pinealocytes, astrocytes, microglia, and other interstitial cells that have been described in detail. However, factors that contribute to pineal development have not been fully elucidated, nor have pineal cell lineages been well characterized. We applied systematic double, triple and quadruple labeling of cell-specific markers on prenatal, postnatal and mat...

The mammalian pineal gland is rich in serotonin content and this amine is present in high concentration within the sympathetic nerve endings of this organ (Quay and Halevy, 1962; Bertler et al., 1963). Sympathetic denervation of the pineal gland results in a 50% decrease in its serotonin content (Bertler et al., 1963; Pellegrino de Iraldi et al., 1963). Recently it has been demonstrated that th...

The effect of bovine pineal extract and light duration on lactation in mice was examined in two experiments. In Exp. I, groups of lactating mice were injected intraperitoneally with 0, .5, 1.0, 2.0 and 4.0 mg extractable protein from a bovine pineal crude extract. The highest dose level was equal to .14 g of pineal tissue. Neither lit ter (eight pups per litter) weight gains, which were used as...

Pineal cysts occur in all ages, predominantly in adults in the fourth decade of life. In series of magnetic resonance imaging (MRI) studies, the prevalence of pineal cysts ranged between 1.3% and 4.3% of patients examined for various neurologic reasons and up to 10.8% of asymptomatic healthy volunteers. The diagnosis of pineal cyst is usually established by MRI with defined radiological criteri...

Lower vertebrates can detect UV light with the pineal complex independently of eyes. Electrophysiological studies, together with chromophore extraction analysis, have suggested that the underlying pigment in the lamprey pineal exhibits a bistable nature, that is, reversible photoreaction by UV and visible light, which is never achieved by known UV pigments. Here we addressed the molecular ident...

Lindane, a chlorinated hydrocarbon pesticide, was previously shown to enhance the nighttime rise in pineal N-acetyltransferase (NAT) activity and melatonin as well as serum melatonin levels. The purpose of the present study was to test whether lindane acts on the pineal gland by means of a beta-adrenergic receptor mechanism. Whereas lindane (total dose 17.8 mg/kg b.wt. over 6 days) by itself si...