The Role of the Melatoninergic System in Circadian and Seasonal Rhythms-Insights From Different Mouse Strains.

The melatoninergic system comprises the neurohormone melatonin and its molecular targets. The major source of melatonin is the pineal organ where melatonin is rhythmically produced during darkness. In mammals, melatonin biosynthesis is controlled by the central circadian rhythm generator in the suprachiasmatic nucleus (SCN) and photoreceptors in the retina.

Body procurement in the Dr. Senckenbergische Anatomie in Frankfurt/Main after the Second World War - From unclaimed corpses to body bequests.

The present paper provides a detailed historical and numerical analysis of the processes regarding body procurement in a particular German anatomical institute, namely, the Dr. Senckenbergische Anatomie (DSA) in Frankfurt am Main. It covers the period from 1946 to 1980; i.

Seasonal Variations of Locomotor Activity Rhythms in Melatonin-Proficient and -Deficient Mice under Seminatural Outdoor Conditions.

Locomotor activity patterns of laboratory mice are widely used to analyze circadian mechanisms, but most investigations have been performed under standardized laboratory conditions. Outdoors, animals are exposed to daily changes in photoperiod and other abiotic cues that might influence their circadian system. To investigate how the locomotor activity patterns under outdoor conditions compare to controlled laboratory conditions, we placed 2 laboratory mouse strains (melatonin-deficient C57Bl and melatonin-proficient C3H) in the garden of the Dr.

Dynamics of core body temperature cycles in long-term measurements under real life conditions in women.

Studies under real life conditions become more and more relevant in chronobiological and chronomedical research. The present study aims to analyze one of the most prominent biological rhythms: the core body temperature (CBT) rhythm in the real world outside the laboratory. CBT was recorded continuously in 37 healthy women (age between 21 and 44 years, median 29 years) with a newly developed intravaginal temperature sensor for up to 102 days.

Synchronizing effects of melatonin on diurnal and circadian rhythms.

In mammals, the rhythmic secretion of melatonin from the pineal gland is driven by the circadian clock in the suprachiasmatic nucleus (SCN) of the hypothalamus. The robust nightly peak of melatonin secretion is an output signal of the circadian clock and is supposed to deliver the circadian message to the whole of the organism. Since the circadian system regulates many behavioral and physiological processes, its disruption by external (shift-work, jet-lag) or internal desynchronization (blindness, aging) causes many different health problems.

The Role of the Melatoninergic System in Light-Entrained Behavior of Mice.

The role of endogenous melatonin for the control of the circadian system under entrained conditions and for the determination of the chronotype is still poorly understood. Mice with deletions in the melatoninergic system (melatonin deficiency or the lack of melatonin receptors, respectively) do not display any obvious defects in either their spontaneous (circadian) or entrained (diurnal) rhythmic behavior. However, there are effects that can be detected by analyzing the periodicity of the locomotor behaviors in some detail.

Impact of Ataxin-2 knock out on circadian locomotor behavior and PER immunoreaction in the SCN of mice.

In Drosophila melanogaster, Ataxin-2 is a crucial activator of Period and is involved in the control of circadian rhythms. However, in mammals the function of Ataxin-2 is unknown despite its involvement in the inherited neurogenerative disease Spinocerebellar Ataxia type 2 in humans. Therefore, we analyzed locomotor behavior of Atxn2-deficient mice and their WT littermates under entrained- and free-running conditions as well as after experimental jet lag.

Melatonin Receptor 1 Deficiency Affects Feeding Dynamics and Pro-Opiomelanocortin Expression in the Arcuate Nucleus and Pituitary of Mice.

Background/methods: Melatonin, the neurohormone for darkness, mediates photoperiod-dependent changes in physiology and behavior by targeting specific membrane-bound receptors (MT1 and MT2). In the present study, we investigated the impact of MT1 receptor deficiency on feeding behavior, locomotor activity and mRNA expression levels encoding for the polypeptide pro-opiomelanocortin (Pomc) and neuropeptide Y (Npy) in the hypothalamic arcuate nucleus (ARC) and the adenohypophysis [pars distalis (PD) and pars intermedia (PI)] in a comparison between wild-type (WT) and MT1-deficient (MT1-/-) mice.

Results: The MT1-/- mice spent significantly more time feeding than the WT mice, while the general locomotor behavior, body weight and the total amount of food consumed did not differ between both genotypes.

Notes on the history of the Dr. Senckenbergische Anatomie in Frankfurt/Main. Part I. Development of student numbers, body procurement, and gross anatomy courses from 1914 to 2013.

Until recently, it was believed that all internal documentation regarding student affairs and body procurement of the Dr. Senckenbergische Anatomie concerning the time before March 1944 - when the building was destroyed during an Allied air raid - was lost. A few years ago, however, we discovered stacks of old documents in the current anatomy building.

Notes on the history of the Dr. Senckenbergische Anatomie in Frankfurt/Main. Part II. The Dr. Senckenbergische Anatomie during the Third Reich and its body supply.

In order to be able to understand how body supply was maintained at the Dr. Senckenbergische Anatomie from 1933 to 1945 - with special emphasis on victims of the National Socialist regime - we have collected information from various and often fragmentary sources. The documents reveal that during this period at least 474 bodies were brought to the anatomical institute.

Owls and larks in mice.

Humans come in different chronotypes and, particularly, the late chronotype (the so-called owl) has been shown to be associated with several health risks. A number of studies show that laboratory mice also display various chronotypes. In mice as well as in humans, the chronotype shows correlations with the period length and rhythm stability.

The brainstem pathologies of Parkinson's disease and dementia with Lewy bodies.

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are among the human synucleinopathies, which show alpha-synuclein immunoreactive neuronal and/or glial aggregations and progressive neuronal loss in selected brain regions (eg, substantia nigra, ventral tegmental area, pedunculopontine nucleus). Despite several studies about brainstem pathologies in PD and DLB, there is currently no detailed information available regarding the presence of alpha-synuclein immunoreactive inclusions (i) in the cranial nerve, precerebellar, vestibular and oculomotor brainstem nuclei and (ii) in brainstem fiber tracts and oligodendroctyes. Therefore, we analyzed the inclusion pathologies in the brainstem nuclei (Lewy bodies, LB; Lewy neurites, LN; coiled bodies, CB) and fiber tracts (LN, CB) of PD and DLB patients.

Chronotypes and rhythm stability in mice.

Humans come in different chronotypes: The phase of their sleep-wake cycle with respect to the phase of the external, sidereal cycle of night and day differs. Colloquially, the early chronotypes are addressed as "larks," the late ones as "owls." The human chronotype can be quantified in hours and minutes of local time by determining the median of the sleep phase.

Spatial and temporal expression patterns of Bmal delineate a circadian clock in the nervous system of Branchiostoma lanceolatum.

We cloned the homologue of the clock gene Bmal from a cephalochordate, Branchiostoma lanceolatum (syn. amphioxus). Amphioxus possesses a single copy of this gene (amphiBmal) that encodes for a protein of 649 amino acids, which is quite similar to BMALs of other chordates.

Nocturnal behavior and rhythmic period gene expression in a lancelet, Branchiostoma lanceolatum.

The authors here present the first anatomical, molecular biological, and ethological data on the organization of the circadian system of a lancelet, Branchiostoma lanceolatum, a close invertebrate relative of vertebrates. B. lanceolatum was found to be a nocturnal animal and, since its rhythmic activity persisted under constant darkness, it also appears to possess an endogenous, circadian oscillator.

The dissection course - necessary and indispensable for teaching anatomy to medical students.

Anatomy is a major basic subject in medicine and related biomedical sciences. A central tool most universities use for teaching anatomy is the "dissection course", in which medical students learn the basic constructional principles of the human body by dissecting a cadaver. In recent years, the relevance and value of the dissection laboratory have been under discussion at different universities due to high costs and problems of shortness in time in some medical curricula.

Distribution of transcription factor inducible cyclicAMP early repressor (ICER) in rodent brain and pituitary.

In morphogenetic dynamics of neurons, and in adaptive physiology of brain function, transcription factors of the cyclicAMP signaling pathway, such as activator cyclicAMP responsive element binding protein (CREB) and inhibitor inducible cyclicAMP early repressor (ICER), play an important role. In particular, the presence of the transcription factor ICER in neurons or neuroendocrine cells suggests the need for the gating of an up-regulated gene expression. Little is known, however, about the natural distribution of the inhibitory transcription factor ICER.

Bone-implant interface around titanium implants under different loading conditions: a histomorphometrical analysis in the Macaca fascicularis monkey.

Background: Bone healing around endosseous dental implants is associated with peri-implant loading conditions. Therefore, the aim of this study was to evaluate histomorphometrically the bone response around unloaded, delayed, and immediately loaded implants with a progressive thread design that were placed in the posterior regions of the lower jaw in monkeys.

Methods: Nine adult monkeys (Macaca fascicularis) were used in this study.

Cytoarchitecture, topography, and descending supraspinal projections in the anterior central nervous system of Branchiostoma lanceolatum.

The central nervous system (CNS) of the chordate amphioxus (Branchiostoma lanceolatum) is divisible into a spinal cord and an anterior portion in some ways equivalent to the brain of craniates. The present study reports on this anterior portion, with respect to general topography, cytoarchitecture, and cells that give rise to descending supraspinal projections. The anterior portion of the CNS is located adjacent to the first four myomeres and rostral to the first giant cell of Rohde-it can be divided into several regions that differ with respect to their cytoarchitecture.

Signal transduction in the rodent pineal organ. From the membrane to the nucleus.

The rodent pineal organ transduces a photoneural input into a hormonal output. This photoneuroendocrine transduction leads to highly elevated levels of the hormone melatonin at night-time which serves as a message for darkness. The melatonin rhythm depends on transcriptional, translational and posttranslational regulation of the arylalkylamine-N-acetyltransferase, the key enzyme of melatonin biosynthesis.

Bone morphogenetic proteins are required in vivo for the generation of sympathetic neurons.

Bone morphogenetic proteins (BMPs) induce autonomic neurogenesis in neural crest cultures and stimulate sympathetic neuron development when overexpressed in vivo. We demonstrate that inhibition of BMPs in the chick embryo bythe BMP antagonist Noggin prevents sympathetic neuron generation. In Noggin-treated embryos, the noradrenergic marker genes tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH), panneuronal neurofilament 160 (NF160) and SCG10 genes, and the transcriptional regulators Phox2b and Phox2a are not expressed in sympathetic ganglia.

CREB phosphorylation and melatonin biosynthesis in the rat pineal gland: involvement of cyclic AMP dependent protein kinase type II.

Phosphorylation of cyclic AMP response element binding protein (CREB) at amino acid serine 133 appears as an important link between the norepinephrine (NE)-induced activation of second messenger systems and the stimulation of melatonin biosynthesis. Here we investigated in the rat pineal gland: 1) the type of protein kinase that mediates CREB phosphorylation: and 2) its impact on melatonin biosynthesis. Immunochemical or immunocytochemical demonstration of serine133-phosphorylated cyclic AMP regulated element binding protein (pCREB) and radioimmunological detection of melatonin revealed that only cyclic AMP-dependent protein kinase (PKA) inhibitors suppressed NE-induced CREB phosphorylation and stimulation of melatonin biosynthesis, whereas inhibitors of cyclic GMP-dependent protein kinase (PKG), mitogen-activated protein kinase kinase, protein kinase C, or calcium-calmodulin-dependent protein kinase (CaMK) were ineffective.

Early postembryonic neural development in the zebrafish: a 3-D reconstruction of forebrain proliferation zones shows their relation to prosomeres.

Based on a section-by-section analysis of the morphology (combined silver/Nissl stain) and of the distribution of proliferation zones (immunohistochemical detection of the proliferating cell nuclear antigen) in the zebrafish (Danio rerio) forebrain at 5 days postfertilization, we created a three-dimensional reconstruction of proliferation zones of that developmental stage. The resulting model visualizes the size, number, location and morphology of forebrain proliferation zones. The latter foreshadow closely adult neuroanatomical forebrain entities.

A semiquantitative image-analytical method for the recording of dose-response curves in immunocytochemical preparations.

Knowledge about intracellular signal transduction cascades is largely based on investigations of cultured cells whose responses to different stimuli are typically quantified via RIA, ELISA, or immunoblots. These techniques, which require relatively large amounts of biological material, are performed with homogenized cells and therefore do not allow localization of the molecules under investigation. We describe a protocol for recording dose-response curves directly from immunocytochemical preparations using rat pinealocytes as a model system.