Paraventricular-subparaventricular hypothalamic lesions selectively affect circadian function

The circadian timing system has three principal components: (i) entrainment pathways, (ii) pacemakers, and (iii) efferent pathways from the pacemakers that convey the circadian signal to effector systems. The suprachiasmatic nucleus (SCN) of the hypothalamus is the principal mammalian circadian pacemaker and, although we understand the organization of entrainment pathways to the SCN and the pacemaker itself, we know much less about the functional organization of SCN projections mediating control of effector systems. It is unclear, for example, whether specific subsets of SCN projections control specific effector systems. In this study, we analyzed the effects of lesions ablating the paraventricular hypothalamic nucleus (PVH), with variable extension into the subparaventricular zone (SPVZ) and adjacent structures, on nocturnal pineal melatonin production and rhythms in core body temperature (Tb) and rest-activity (R-A). In accordance with prior work, ablation of the PVH abolishes the nocturnal rise in pineal melatonin. Lesions restricted to the PVH do not affect rhythms in Tb and R-A but lesions extending caudally and ventrally into the SPVZ disrupt the R-A rhythm proportionate to the interruption of caudal SCN projections without affecting the rhythm in Tb. We conclude that pacemaker regulation of the circadian rhythms analyzed in this study is mediated by discrete sets of SCN projections: (i) dorsal projections to the PVH control pineal melatonin production; (ii) rostral projections to the anterior hypothalamic/preoptic areas mediate the Tb rhythm; and (iii) caudal projections to the SPVZ and hypothalamic arousal systems located in the posterior and lateral hypothalamic areas control the rhythm in R-A.

The effects of exposure to intense, 24 h light on the development of scoliosis in young chickens

The aetiology of adolescent 5 coliosis remains unknown and hindering research is the absence of an appropriate animal model. It is now well-established that pinealectomy in young chickens results in the development of scoliosis that has many of the characteristics seen in patients with adolescent idiopathic scoliosis but the mechanism underlying this phenomenon remains elusive. The principle product of the pineal gland is melatonin and so many studies have focused on studying the effects of reduced levels of this hormone. The results have been mixed and the role of melatonin remains unclear. As melatonin production is inhibited by light, it was hypothesised that providing the chickens with an environment consisting of intense, continuous light would reduce serum melatonin levels and avoid any of the potential artifacts involved with the pinealectomy surgery. Consequently, pinealectomised and normal chickens were exposed to very intense light for complete 24 h in each day. At the end of 22 days in this environment serum melatonin levels had been reduced to very low levels in all chickens. Most importantly, 15% of the normal chickens had developed scoliosis and the number of pinealectomised chickens that developed scoliosis increased from 50% to 80%. The results showed that a method for reducing serum melatonin without pinealectomy has been established and which can be used in further experiments. Furthermore, the results also showed that reduced levels of serum melatonin has significant effects on the development of scoliosis. The indication is that there is a threshold level of serum melatonin below which scoliosis may develop probably in conjunction with some other factor which has yet to be identified.

Optimisation of methods for selecting candidate genes from cDNA array screens: application to rat brain punches and pineal

DNA arrays are potentially powerful experimental tools within neuroscience but application of this technology to in vivo paradigms may, in practice, be limited by the sensitivity of transcript detection and inter-screen variation. Here we describe the use of brain punch micro-sampling, used in combination with commercially available cDNA arrays, for profiling brain gene expression in a mutant strain of rat (GAERS model of absence epilepsy). Furthermore, we describe a multi-step optimisation of analysis methods which provides for improved sensitivity and absence of bias in the selection of candidate genes which may be differentially expressed in the mutant. Our method has been validated through application to a second paradigm, rhythmic gene expression in the rat pineal gland. Our experimental design, and analysis method should therefore be generally applicable to subtle discriminations of transcript abundance within discrete brain areas.

Capturing the circadian rhythms of free-running blind people with 0.5 mg melatonin

We have recently shown that six of seven totally blind people (who had free-running circadian rhythms with periods longer than 24 h) could be entrained (synchronized) to a nightly dose of 10 mg melatonin. After treatment discontinuation and re-entrainment to the 10 mg dose, we further found in three of these subjects that the dose could be gradually reduced to 0.5 mg without loss of effect. The question then arose: can a de novo (starting) dose of 0.5 mg initially capture free-running rhythms? Following withdrawal of the stepped-down 0.5 mg dose and consequent release into a free-run, the same three individuals were given 0.5 mg of melatonin de novo. All entrained within a few weeks.

Melatonin: a significant contributor to the pathogenesis of migraine

It is generally accepted that migraine is caused by a primary biochemical disorder of the central nervous system involving neurotransmitters, specifically serotonin. The pathogenetic mechanism triggered by external and internal stimuli is not well explained or understood. This article points to the possibility that the pineal gland, a primary source of central serotonin and melatonin, contributes significantly to migraine attacks.

[Possible role of the pineal gland in the pathogenesis of idiopathic scoliosis. Experimental and clinical studies]

The unexpected finding in 1959 by Marie-Jeanne Thillard that pinealectomy in young chickens gives way to spinal deformities was confirmed by the authors. In another experiment they found that injected melatonine to the chick at adequate dose and at the same time as surgery, lessen or even totally prevents the occurrence of deformities. On the other hand, at too low dose or delayed after pinealectomy melatonine injection, may not prevent the deformity which will be persisting or even increasing. In a subsequent series of experiments on the rat, pinealectomy results in decreasing the plasmatic amount of melatonine as well as giving way to spinal deformities. The nature of these deformities observed here is dependent on the stature between of the animal. The normal quadrupede rat develops after pinealectomy a standard scoliosis. Inversely the scoliotic deformity occurs when the animal has been forced to a bipede condition, which may be achieved by removing its forelimbs when baby, then forcing it to stand and remain in erect posture by high enough feeding. Melatonine depressing and erect position are in two conditions, when associated, likely to give way to experimental scoliosis. In human, a low nycthemeral level of plasmatic melatonine is correlated with progressive scoliosis. The level of platelets calmoduline, when is normally modulated by melatonine, has been proved by Kindsfater to be increased in progressive scoliosis. Then raises the hypothesis that human idiopathic scoliosis may be due to an inherited disorder of neuro-transmitters from neuro-hormonal origin, associated with bipedal condition, where an horizontal localized neuro-muscular imbalance starts and produces the scoliotic deformity of the fibro-elastic and bony structures axial spinal pilar.

[Shifts in the level of plasma melatonin and changes in circadian locomotion changes after lesioning of the dorsal hippocampus in intact and stressed rats]

Local lesion of the dorsal hippocampus and swimming stress increase the level of plasma melatonin in rats. After hippocampectomy, the disorganization of the circadian locomotion rhythm and inversion of melatonin response to stress were observed.

The therapeutic potential of melatonin in migraines and other headache types

A large number of individuals suffer from migraine headaches. Several theories attempt to explain migraine etiology. One such theory holds that since environmental stimuli are well known to trigger migraine headaches, the pineal gland may be involved in migraine etiology. Specifically, a pineal gland irregularity may be the physical origin of migraine headaches, with subsequent physiological changes being secondary. Research has found the pineal hormone melatonin is low in migraine patients. Additionally, several studies found administering melatonin to migraine sufferers relieved pain and decreased headache recurrence in some cases. It has been suggested melatonin may play an important therapeutic role in the treatment of migraines and other types of headaches, particularly those related to delayed sleep phase syndrome. Current research supports the hypothesis that migraines are a response to a pineal circadian irregularity in which the administration of melatonin normalizes this circadian cycle; i.e., melatonin may play a role in resynchronizing biological rhythms to lifestyle and subsequently relieve migraines and other forms of headaches. In addition, research testing the administration of melatonin found it safe in migraine sufferers, with few or no side effects. However, a larger, randomized control trial is needed to definitively determine if administration of melatonin to migraine patients is effective.

Seasonal rhythms of 6-sulphatoxymelatonin (aMT6s) excretion in female rats are abolished by growth of malignant tumors

The effect of development and growth of malignant tumors on pineal melatonin production was studied in two different hormone-dependent tumor systems in female rats. Urinary excretion of 6-sulphatoxymelatonin (aMT6s), the metabolic end product of melatonin, which parallels its production, was determined by radioimmunoassay at fortnightly or monthly intervals over the period of 1 year in female F344 Fischer rats bearing chemically-induced mammary carcinomas and in BDII/Han rats with spontaneous endometrial carcinomas. Untreated Fischer rats and BDII/Han rats in which tumor growth was suppressed by treatment with a progestin served as controls. Based on the cosinor analysis, animals without tumors showed significant seasonal rhythms of aMT6s excretion, with peaks in August (Fischer rats) and in May (BDII/Han rats). In contrast, such rhythms were absent in animals with developing and manifest tumors. It is concluded that animals kept under constant environmental conditions still show seasonal rhythms of pineal activity. Tumor development and growth affect pineal activity leading to disturbance of these rhythms.

The lack of vasoconstrictor effect of the pineal hormone melatonin in an animal model predictive of antimigraine activity

The pineal hormone, melatonin, has been implicated in the pathophysiology of migraine and several studies have demonstrated its vasoconstrictor properties. In the present study, systemic and carotid haemodynamic effects of melatonin, administered directly into the carotid artery, were investigated in anaesthetized pigs. Ten-minute intracarotid infusions of melatonin (1, 10 and 100 microg kg(-1) min(-1)) produced slight decreases in blood pressure and total carotid and arteriovenous anastomotic blood flows, but nutrient blood flow was not affected. The decrease in carotid blood flow was entirely caused by the hypotension, since no changes in vascular conductance values were observed. It is concluded that melatonin itself is not capable of producing vasoconstriction in the cranial circulation of anaesthetized pigs. Thus, it appears that melatonin has no anti-migraine potential via a vasoconstrictor mechanism.

Increased pineal Fdopa uptake is related to severity of Parkinson's disease--a PET study

We investigated regional L-3,4-dihydroxy-6-[18F]fluoro-phenyl-alanine (Fdopa) uptake within the pineal gland using co-registration of Fdopa PET and MRI images. Data from 12 early Parkinson's disease (PD) and 9 advanced PD patients were compared with those from 13 age-matched healthy controls. We found a significant increase of Fdopa influx constants (Ki) and relative Fdopa tracer activity in the pineal gland of PD patients. Additionally, significant correlations were found between Ki and the Hoehn and Yahr (H&Y) scores, and between the relative Fdopa activity and the parameters disease duration, H&Y disease score and Unified Parkinson's Disease Rating Scale (UPDRS). Our studies in patients with PD indicate a participation of extrastriatal dopaminergic structures within the scope of pathophysiological processes in PD. The result may be explained as a compensatory upregulation of monoaminergic transmitter systems outside the basal ganglia. Increased Fdopa uptake in the pineal gland may reflect pineal dysfunction in PD patients.

Longitudinal neuropsychological evaluation of a case of pineal tumor occurring in an adolescent girl

There has been a relative absence of studies that have longitudinally examined the neuropsychological profiles of patients suffering from pineal tumors. A case is reported of an adolescent girl with a pineoblastoma and spinal metastases who received extensive chemotherapy and cranio-spinal irradiation. Neuropsychological assessments conducted approximately 5 months and 2.5 years posttumor diagnosis revealed a diversity of impairments indicative of mild to moderate neuropsychological dysfunction. By the 2nd evaluation (2 years postbaseline) there was evidence of increased neurocognitive impairment suggestive of greater dysfunction of the patient's right, versus left, cerebral hemisphere. Overall, the patient's neuropsychological profile coincided with the Syndrome of Nonverbal Learning Disabilities as proposed by Rourke and his colleagues (Rourke, 1987, 1988, 1995; Rourke & Tsatsanis, 1996). These findings are discussed in light of the Syndrome of Nonverbal Learning Disabilities (and the related white matter model) and the possible negative impact of the patient's pineal tumor and subsequent chemotherapy and cranio-spinal irradiation on her neuropsychological functioning.

Immunomodulatory effects of IL-12 in relation to the pineal endocrine function in metastatic cancer patients

In addition to IL-2, IL-12 would constitute one of the most promising cytokines in the treatment of human neoplasms. IL-2 has been proven to induce in vitro and in vivo several evident changes in the secretion of cytokines and various other immunoinflammatory substances. In contrast, very little data are available about the immune effects of IL-12 in humans. The present study was carried out to investigate the in vivo immunoinflammatory effects of IL-12 by analyzing the secretions of neopterin, soluble IL-2 receptor (SIL-2R), tumor necrosis factor alpha (TNF), IL-2 and IL-6 in relation to the neuroendocrine function of the pineal gland, which is one of the most important organs involved in neuroimmunomodulation. Pineal endocrine function was investigated by evaluating the whole daily urinary excretion of the main catabolite of its hormone melatonin, 6-sulfatoxymelatonin (6-MTS). The study was performed on metastatic renal cell cancer patients. Each course of IL-12 consisted of 1.25 microg/ kg b.w. subcutaneously in the morning once a week for 3 consecutive weeks. The study evaluated 10 IL-12 courses. Mean serum levels of neopterin, SIL-2R and TNF significantly increased in response to IL-12, whereas no significant change occurred in IL-6 and IL-2 mean concentrations. Finally, 6-MTS urinary excretion was significantly reduced by IL-12 injection, particularly during the dark phase of the day. This preliminary study would suggest that IL-12 may induce important changes in the in vivo immunoinflammatory response. Moreover, IL-12 administration would suppress pineal endocrine activity, thus confirming its previously suggested involvement in the neuroimmunomodulatory processes. Because of the fundamental role of the pineal gland in neuroimmunomodulation, IL-12-induced immune variations could depend at least in part on its action at central neuroendocrine sites.

Interaction between the adrenal and the pineal gland in chronic experimental inflammation induced by BCG in mice

OBJECTIVE

To investigate the adrenal gland influence on diurnal rhythm of chronic inflammation induced by BCG in mice and its interaction with the pineal gland.

METHODS

C57Bl/6 mice were injected with BCG in the footpad and maintained in a 12/12 h light-dark cycle. All the experimental manipulations were done after 20-45 days. Paw swelling was measured every 4 h for 48 or 72 h and decomposed by Fourier transformation. Vascular permeability was evaluated by Evans Blue overflow, in mice killed at midday or midnight. 6-Sulphatoxymelatonin urine concentration was determined by radioimmunoassay in samples taken during the dark or light phase.

RESULTS

Adrenalectomy or metyrapone treatment abolished the paw swelling diurnal rhythm, the nocturnal reduction in vascular permeability, and the nocturnal increase in 6-sulphatoximelatonin in the urine. Nocturnal administration of melatonin to adrenalectomized mice restored the paw swelling diurnal variation and the reduction of vascular permeability of the inflamed paw.

CONCLUSION

Adrenal cortical hormones are important for the maintenance of the diurnal rhythm of chronic inflammation (paw swelling and vascular permeability), probably by promoting a nocturnal surge of melatonin, which is the hormone that modulates the diurnal variation of chronic inflammation.

Pineal and pituitary-adrenocortical function in physiological aging and in senile dementia

The simultaneous evaluation of the circadian rhythm of plasma melatonin and ACTH and of serum cortisol and DHEAS represents a clinically reliable tool to appreciate the neuroendocrine changes occurring in physiological and pathological brain aging.A selective impairment of the nocturnal melatonin secretion has been observed in elderly subjects, being significantly related either to the age or to the severity of dementia. A significant increase of serum cortisol levels during evening- and night-times was found in elderly subjects, particularly if demented, when compared to young controls. Besides, both the circadian amplitude of cortisol rhythm and the nocturnal cortisol increase were significantly reduced in relation either to age or to cognitive impairment. By comparison to vascular dementia, patients with Alzheimer's disease exhibited the highest cortisol concentrations throughout the 24h. The sensitivity of the hypothalamic-pituitary-adrenal axis to the steroid feedback was significantly impaired in old subjects and particularly in the demented ones. The serum DHEAS levels were significantly lower in elderly subjects and even more in demented patients than in young controls. Consequently, a significant increase of the cortisol/DHEAS molar ratio was evident when going from young controls to healthy elderly subjects and to demented patients. In conclusion, the aging process affects many neuroendocrine functions resulting in subtle but clinically relevant consequences; the occurrence of senile dementia seems to play an additive role.

Effect of clonidine on plasma ACTH, cortisol and melatonin in children

An interaction between melatonin and adrenocorticotropin (ACTH) seems to occur in humans and both hormones respond to beta-adrenergic stimulation. As in lower animal species, human pineal gland also contains alpha2-adrenergic receptors as does the hypothalamus-pituitary axis. In this study the response of the pineal gland and of the hypothalamus-pituitary-adrenal axis to alpha2-adrenergic stimulation was assessed. Twenty-nine children (21 males, mean age 11.2 +/- 0.6 yr and eight females, mean age 9.1 +/- 1.1 yr) from the University of Granada Hospital were studied. The children were diagnosed as having growth problems but with a normal response of growth hormone (GH) to clonidine test. Changes in plasma levels of ACTH, cortisol and melatonin were evaluated in these children after oral administration of the alpha2-adrenoceptor agonist clonidine (100 microg/m2) or a placebo. Plasma ACTH, cortisol and melatonin were measured before (basal) and at 30, 60 and 90 min after oral clonidine or placebo administration. Hormonal determinations were carried out by commercial radioimmunoassay kits, previously standardised in our laboratory. The results show a significant decrease in plasma ACTH, cortisol and melatonin 30 min after clonidine administration (P < 0.001), reaching lowest values at 90 min after the drug was administered. The reduction in the levels of these hormones is independent of their normal circadian decay since the control group showed a significantly different pattern of behaviour. These data support the existence of an inhibitory alpha2-adrenergic influence on both the pineal gland and the hypothalamus-pituitary-adrenal in children and further support the presence of alpha2-adrenoceptors in the human pineal gland.

60 Hz magnetic field exposure and urinary 6-sulphatoxymelatonin levels in the rat

Four separate experiments were carried out to investigate the effect of extremely low frequency magnetic field (MF) exposure (60 Hz, 1 mT rms) on urinary 6-sulphatoxymelatonin (aMT6s) levels in Sprague-Dawley rats. In the first experiment, immature male rats maintained under a regular 12 h daily photoperiod (white fluorescent light) were exposed to a 20 h daily MF exposure for 6 weeks. The second experiment was similar to the first, except that the MF exposure was limited to 10 days. In the third experiment, adult male rats acclimated to a combination of continuous dim red light and regular 12 h daily photoperiod (white fluorescent) were subjected to a single 1 h exposure to intermittent MF (1 min on and 1 min off cycles), 2 h before fluorescent lights went off. The fourth experiment was similar to the third, except that the animals received 2 consecutive days of 20 h daily exposure to intermittent MF, beginning 1 h before the fluorescent lights went off each day. In all four experiments, the circadian profile of urinary aMT6s was examined before, during, and after the MF exposure. No significant effect of 1 mT MF on indoleamine metabolism was observed in any of the above experiments. However, in one of the experiments (no. 4), both the control and the MF groups showed a lower aMT6s level during the exposure days, when compared with that of pre- and post-exposure days, suggesting that the existence of possible effects with lower field strengths at the range of stray field cannot be ruled out.

Melatonin in cancer patients and in tumor-bearing animals

A review of findings is given which relate to the levels of circulating melatonin as well as the urinary excretion of its main peripheral metabolite 6-sulphatoxymelatonin (aMT6s) in patients with different types of cancer as well as in tumor-bearing animals. Clinical results show that circulating melatonin tends to be depressed in patients with primary tumors of different histological types including both endocrine-dependent (mammary, endometrial, prostate cancer) and endocrine-independent tumors (lung, gastric, colorectal cancer). Reduction of melatonin is most pronounced in patients with advanced localized primary tumors, such as mammary and prostate cancer where a clear negative correlation with tumor-size exists. The phenomenon of a reduction of circulating melatonin appears to be a transient one since patients with recidives show a normalization of melatonin. Surgical removal of the primary tumor does, however, not lead to normalization indicating that complex systemic changes appear to be involved in the down-regulation of melatonin. It is unclear at present, whether circulating melatonin is depleted in cancer patients due to a reduced production by the pineal gland or due to certain peripheral metabolic processes, although no evidence for an enhanced hepatic degradation to aMT6s, the main peripheral metabolite of melatonin, was found. The reduction of circulating melatonin is accompanied by neuroendocrine changes affecting the circadian secretion of the adenohypophyseal hormones prolactin, somatotropin and thyroid-stimulating hormone. In contrast to the above-described types of tumors many patients with ovarian cancer show highly elevated levels of melatonin perhaps due to the production of tissue-specific growth factors that could affect pineal melatonin secretion. Experiments with tumor-bearing animals clearly demonstrate that nocturnal circulating melatonin is modulated due to malignant growth. Detailed investigations with chemically induced mammary tumors in rats and serial transplants derived thereof show that slow-growing and well-differentiated tumors containing epithelial cell elements (adenocarcinomas and carcinosarcomas) lead to an enhanced production of melatonin involving activation of the rate-limiting enzyme of pineal melatonin biosynthesis (serotonin N-acetyltransferase) probably due to elevation of the sympathetic tone in response to a stimulation of the cellular immune system by malignant growth. As opposed to that nocturnal melatonin is depleted in animals with fast-growing mammary tumor transplants when myoepithelial-mesenchymal conversion leads to pure sarcomas. The reduction of melatonin appears to be due to either a reduced availability of the precursor amino acid tryptophan because of a glucocorticoid-induced activation of the hepatic enzyme tryptophan 2,3-dioxygenase or a direct peripheral degradation of melatonin via indoleamine 2,3-dioxygenase expressed in tumor and/or other tissues. The significance of these clinical and experimental findings relating to melatonin is discussed both in terms of their practical application as a possible tumor marker and from a theoretical point of view to understand better the mechanisms involved in complex host-tumor interactions involving the neuroimmunoendocrine network.

The pineal gland

The pineal gland is located posterior to the midbrain and is the site of melatonin production. Research on pineal gland function in neonates is very limited. This article will discuss pineal gland development and the possible relationship between melatonin production and sudden infant death syndrome. Further research on pineal gland function is needed in order to establish its significance for the neonate.

Melatonin and mammary pathological growth

In this article we review the state of the art on the role of the pineal gland and melatonin in mammary cancer tumorigenesis in vivo as well as in vitro. The former hypothesis of a possible role of the pineal gland in mammary cancer development was based on the evidence that the pineal, via its main secretory product, melatonin, downregulates some of the pituitary and gonadal hormones which control mammary gland development and are also responsible for the growth of hormone-dependent mammary tumors. Furthermore, melatonin could act directly on tumoral cells, thereby influencing their proliferative rate. Other possible origins of melatonin's antitumoral actions could be found in its antioxidant or immunoenhancing properties. The working hypotheses of most experiments were that the activation of the pineal gland, or the administration of melatonin, should give rise to antitumoral behavior; conversely, suppression of the pineal gland or melatonin deficits should stimulate mammary tumorigenesis. From in vivo studies on animal models of tumorigenesis, the general conclusion is that experimental manipulations activating the pineal gland, or the administration of melatonin, enlarge the latency and reduce the incidence and growth rate of chemically induced mammary tumors, while pinealectomy usually has the opposite effects. The direct actions of melatonin on mammary tumors have been suggested because of its ability to inhibit, at physiological doses (1 nM), the in vitro proliferation and invasiveness of MCF-7 human breast cancer cells. The fact that most studies have been performed on two models, chemically induced mammary adenocarcinoma in rats (in vivo studies) and the cell tumor line MCF-7 (in vitro studies), makes the generalization of the results somewhat difficult. However, the characteristics of these actions, comprising different aspects of tumor biology such as initiation, proliferation, and metastasis, as well as the doses (physiological range) at which the effect is accomplished, give special value to these findings. On the strength of these data, the small number of clinical studies focusing on the possible therapeutic value of melatonin on breast cancer is surprising.

Melatonin and adolescent idiopathic scoliosis

Scoliosis seen in the chicken after pinealectomy resembles adolescent idiopathic scoliosis in man. It has been suggested that in both species, deficiency of the pineal hormone, melatonin, is responsible for this phenomenon. In nine patients with adolescent idiopathic scoliosis and in ten age- and gender-matched controls, the circadian levels of serum melatonin and the excretion of urinary 6-hydroxy-melatonin-sulphate, the principal metabolite of melatonin, were determined. There were no statistically significant differences in the secretion of serum melatonin or the excretion of urinary 6-hydroxy-melatonin-sulphate between the patients and the control group. The hypothesis of melatonin deficiency as a causative factor in the aetiology of adolescent idiopathic scoliosis cannot be supported by our data.

Kleine-Levin syndrome and psychosis: observation from an unusual case

OBJECTIVE

This study evaluated the possible pathologic relation between Kleine-Levin syndrome (KLS) and mood disorders.

BACKGROUND

A 28-year-old man with a remote history of KLS had the sudden onset of a manic episode with psychotic features after the end of hypersomnolence.

METHOD

The patient received an extensive laboratory examination, including single photon emission computed tomography and magnetic resonance imaging.

RESULTS

Single photon emission computed tomography showed decreased tracer perfusion in the basal ganglion, hypothalamus, and right frontotemporal region. Magnetic resonance imaging revealed a cystic lesion in the pineal region.

CONCLUSIONS

Hypothalamic dysfunction has been described in KLS and mood disorders, but pineal gland dysfunction has been mentioned only rarely. The clinical and neuroimaging findings suggest the need for further study of KLS.

Paroxysmal tonic upgaze: physiopathological considerations in three additional cases

Paroxysmal tonic upgaze of childhood has been described as a benign distinctive syndrome of abnormal ocular movement, with or without concomitant ataxia. After the first observation of four children, a further 29 patients have been reported with a wide spectrum of neurologic abnormalities such as ataxia, unsteady of gait, learning disabilities and mental retardation at follow-up. Electroencephalograms were normal in all the subjects and magnetic resonance imaging showed deficient myelination in only one patient. Recently it has been suggested that paroxysmal tonic upgaze could be a heterogeneous syndrome, ranging from a simply age-dependent manifestation to a clinical appearance of a variety of disorders affecting the corticomesencephalic loop of vertical eye movement. Moreover, it also could be an early sign of more widespread neurologic dysfunction. We describe three patients who presented paroxysmal tonic upgaze; in one, ataxia was present; in the second child, ataxia and language disorder also were observed; and in the third patient paroxysmal tonic upgaze was associated with loss of muscle tone (drop-attack-like events). On magnetic resonance imaging, a pinealoma compressing the dorsal mesencephalic region was detected. On the basis of our observations, we suggest that any insult with periaqueductal mesencephalic gray-matter involvement could be considered the basic condition for this peculiar clinical manifestation.

A new concept for melatonin deficit: on pineal calcification and melatonin excretion

Even though exogenous melatonin has proven to influence sleep and circadian parameters, low endogenous melatonin is not related to sleep disturbances, nor does it predict response to melatonin replacement therapy. In this manuscript, we present a new concept towards a definition of a melatonin deficit. The purpose of the study was to introduce a marker for an intra-individual decrease in melatonin production. Therefore, we developed a method to quantify the degree of pineal calcification (DOC) using cranial computed tomography. Combining pineal DOC with the organs's size, we estimated the uncalcified pineal gland volume. This estimation was positively and significantly associated with 6-sulfatoxymelatonin (aMT6s), collected over 24 hours in urine, in 26 subjects. Data yielded evidence that the decline in aMT6s excretion with age can be sufficiently explained by an increased pineal calcification. These results suggest that DOC might be useful as an indicator of an intra-individual, decreased capability of the pineal gland to produce melatonin. DOC might prove to be a response-marker for melatonin replacement therapy and a vulnerability marker of the circadian timing system.

'Synaptic ribbon' modifications in the pineal gland of the albino rat following 24 hours of immobilization

We have studied the ultrastructure of the pinealocyte after 24 h of immobilization. Thirty male albino rats (230 +/- 10 g) were used; the animals were divided into two groups of 15 each. One group was immobilized for 24 h (10.00 h a.m. to 10.00 h a.m.), whereas the other group was used as control. All animals were sacrificed between 10.00 and 14.00 h of the following day. Ultrastructural observations showed an euchromatinic nucleus with numerous giant 'lipid droplets' as well as abundant long 'synaptic ribbons' that were significantly more abundant than in the controls (p < 0.0005). These findings all suggest an increase in pineal activity following 24-hour immobilization.