bluuebunny/crossref_metadata_2025_split huggingface dataset:
Status and Reproduction in Humans: New Evidence for the Validity of Evolutionary Explanations on Basis of a University Sample
Authors: Fieder Martin , Huber Susanne , Bookstein Fred L. , Iber Karoline , Schäfer Katrin , Winckler Georg , Wallner Bernard 
Published: September 2005

AbstractA strong positive relationship between reproductive success (offspring count) and status (position in the institutional hierarchy) is demonstrated in a contemporary sample of male university employees (n = 2693). Male academics in leading positions have more children than do other male employees. In female university employees (n = 2073), a negative relationship between status and reproductive success was found, but only if childless women were included in the analysis. Although a positive relationship between male status and offspring count has been predicted by evolutionary theory and was found in animal species and ‘traditional’ human societies, in modern societies most of the studies found no or even a negative relationship between status and reproductive success in males. We suggest that status may be a more important dimension for particular subsamples of modern society than for samples representing entire societies, so that associations might actually differ among subsamples. We suggest that analyses on a small and rather uniform level using modern large‐scale hierarchical organizations (such as universities) are candidates for the investigation of appropriate ‘society subsets’. Our results may stress the importance of evolutionary predictions and may be of relevance for theoretical and empirical considerations at the levels of economics and administration.
Up‐regulation of lysosomal cathepsin L and autophagy during neuronal death induced by reduced serum and potassium
Authors: Kaasik Allen , Rikk Tiina , Piirsoo Andres , Zharkovsky Tamara , Zharkovsky Alexander 
Published: September 2005

AbstractSerum and potassium deprivation‐induced neuronal death on the primary culture of rat cerebellar granule neurons is being widely used as an in vitro model of neurodegeneration and neuronal apoptosis. In our experiments, serum and potassium deprivation for 12 h induced neuronal death in ≈ 20% of cerebellar granule neurons as demonstrated by Trypan Blue assay. Neuronal death was accompanied by a transient increase in the intralysosomal cathepsin L activity, which preceded neuronal death. During this time, the lysosomal membrane integrity remained preserved and no leakage of cathepsin L into the cytosol was seen. Ultrastructural analysis revealed the appearance of multiple vacuoles and autophagosomes in the cytoplasmatic compartment of serum‐ and potassium‐deprived granule neurons. Addition of selective cathepsin L inhibitors or of the autophagy inhibitor 3‐methyladenine provided partial protection against serum and potassium deprivation‐induced death. Our data also show that combining cathepsin L inhibitors and caspase‐3 inhibitors leads to a synergistic neuroprotective effect against serum and potassium deprivation. The results of the current study suggest that activation of the autophagosomal–lysosomal compartment plays an important role in neuronal death induced by serum and potassium deprivation in cultured cerebellar granule cells.
Temperature cycles drive Drosophila circadian oscillation in constant light that otherwise induces behavioural arrhythmicity
Authors: Yoshii Taishi , Heshiki Yoshihiro , Ibuki‐Ishibashi Tadashi , Matsumoto Akira , Tanimura Teiichi , Tomioka Kenji 
Published: September 2005

AbstractThe fruit fly, Drosophila melanogaster, shows a clear circadian locomotor rhythm in light cycles and constant darkness. Although the rhythm disappears in constant light, we found that temperature cycles drive the circadian rhythm both in locomotor activity and molecular abundance of PERIOD (PER) and TIMELESS (TIM). The thermoperiodically induced locomotor rhythm entailed an anticipatory activity at the late thermophase, which required several transient cycles to establish a steady‐state entrainment, suggesting that the rhythm is endogenous and driven by a circadian clock. Western blot analysis revealed that PER and TIM increased during the cryophase, peaking at the middle to late cryophase. PER was also cyclically expressed under the temperature cycle in the known per‐expressing neurons, i.e. so‐called lateral (LNs) and dorsal neurons (DNs), and two pairs of cells (LPNs) that were located in the lateral posterior protocerebrum. It is thus suggested that the temperature cycle induces the cycling of PER and TIM either by blocking somewhere in the photic entrainment pathway during the cryophase or temporally activating their translation to sufficient protein levels to drive a circadian oscillation. In flies lacking pigment‐dispersing factor (PDF) or PDF‐expressing cells, the anticipatory activity was relatively dispersed. disco2 mutant flies lacking the lateral neurons still showed an anticipatory activity, but with dispersed activity. These behavioural results suggest that not only LNs but also DNs and LPNs can, at least, partially participate in regulating the thermoperiodically induced rhythm.
Expression of the mu‐opioid receptor is induced in dentate gyrus granule cells after focal cerebrocortical ischaemia and stimulation of entorhinal afferents
Authors: Stumm Ralf , Rüthrich Heinz , Schulz Stefan , Zhou Chun , Hollt Volker 
Published: September 2005

AbstractFocal ischaemia in the cerebral cortex affects the inducibility of long‐term potentiation (LTP) in the hippocampus. This impairment of hippocampal function may result from excessive activation of cortico‐hippocampal afferents and subsequent perturbation of hippocampal LTP‐relevant transmitter systems, which include opioids. Here, we tested if permanent focal ischaemia and electrical afferent stimulation influence the expression of the mu‐opioid receptor (MOR) in the rat hippocampus. In the applied ischaemia model, the entire ipsilateral cortical hemisphere and hippocampus experienced sustained excitation as indicated by a long‐lasting increase in the expression of arg 3.1/arc (ARG) mRNA, a marker for neuronal activity. Expression of MOR mRNA and protein was strongly increased in granule cells, which contain very low MOR levels under normal conditions, but not in γ‐aminobutyric acid (GABA)ergic neurons, which express the MOR constitutively. In the molecular layer, which contains the dendrites of granule cells, focal ischaemia caused a redistribution of MOR‐like immunoreactivity. In contrast to the dentate gyrus, MOR expression was unaltered in the hippocampus proper and in non‐infarcted cortical areas. Repetitive high‐frequency stimulation of cortico‐hippocampal perforant path afferents induced strong MOR mRNA expression throughout the granular layer. However, weak tetanization sufficient to induce LTP and ARG expression did not influence MOR mRNA levels. Taken together, we provide direct evidence for the induction of MOR expression in granule cells experiencing sustained excitation by cortical afferents. In activated, MOR‐expressing granule cells, inhibitory opioids may counter‐regulate glutamatergic excitation by the perforant path.
Apoptotic cell death progression after photothrombotic focal cerebral ischaemia: effects of the lipophilic iron chelator 2,2′‐dipyridyl
Authors: Van Hoecke Michaël , Prigent‐Tessier Anne , Bertrand Nathalie , Prevotat Laurent , Marie Christine , Beley Alain 
Published: September 2005

AbstractTwo different forms of cell death have been distinguished morphologically following cerebral ischaemia: necrotic and apoptotic cell death. The aim of this study was to investigate the contribution of apoptosis to ischaemic damage by carefully depicting the temporal and spatial neuronal death following focal ischaemia. For this purpose, rats were subjected to chemical photothrombosis, and histological and biochemical analyses were performed over a period of 24 h after the onset of ischaemia. In addition, the effects of the lipophilic antioxidant iron chelator 2,2′‐dipyridyl (DP) were evaluated 24 h after photothrombosis when the lesion volume was maximal. Our results showed two separate waves of neuronal death. In the first wave, shrunken dark neurons were massively present as early as 2 h after photothrombosis in the infarct core. From this initial neuronal abnormal population, progressive and time‐dependent changes of both necrotic and apoptotic cell death were observed, leading to ghost neurons and apoptotic bodies after 24 h. The extension of the lesion coincided with a second wave of cell death. Massive and rapid neuronal loss occurred at the infarct border, which appeared as a sharply demarcated pale region. Procaspase and poly(ADP‐ribose) polymerase‐1 (PARP‐1) cleavages were also detected in the infarct core and surrounding damaged tissue. DP treatment markedly blocked the enlargement of the lesion, the infarct border being rescued from infarction. Furthermore, a large decrease of apoptotic bodies was associated with a significant drop of caspase and PARP‐1 cleavages, suggesting that the protective effect of DP closely correlates with limitation of apoptosis expansion.
Early changes in synaptic connectivity following progressive photoreceptor degeneration in RCS rats
Authors: Cuenca Nicolás , Pinilla Isabel , Sauvé Yves , Lund Raymond 
Published: September 2005

AbstractThe Royal College of Surgeons (RCS) rat has a retinal pigment epithelial cell defect that causes progressive loss of photoreceptors. Although it is extensively used in retinal degeneration and repair studies, how photoreceptor degeneration affects retinal circuitry has not been fully explored. This study examined the changes in synaptic connectivity between photoreceptors and their target cells using immunocytochemistry and correlated these changes with retinal function using the electroretinogram (ERG). Immunostaining with bassoon and synaptophysin (as presynaptic markers) and metabotropic glutamate receptor (mGluR6, a postsynaptic marker for ON‐bipolar dendrites) was already impaired at postnatal day (P) 21 and progressively lost with infrequent pairing of presynaptic and postsynaptic elements at P60. By P90 to P120, staining became increasingly patchy and was eventually restricted to sparsely and irregularly distributed foci in which the normal pairing of presynaptic and postsynaptic markers was lost. ERG results showed that mixed scotopic a‐waves and b‐waves were already reduced by P21 but not oscillatory potentials. While cone‐driven responses (photopic b‐wave) reached normal levels at P30, they were impaired by P60 but could still be recorded at P120, although with reduced amplitude; rod responses never reached normal amplitudes. Thus, only cone‐driven activity attained normal levels, but declined rapidly thereafter. In conclusion, the synaptic markers associated with photoreceptors and processes of bipolar and horizontal cells show abnormalities prior to significant photoreceptor loss. These changes are paralleled with the deterioration of specific aspects of ERG responsiveness with age. Besides providing information on the effects of photoreceptor dysfunction and loss on connection patterns in the retina, the work addresses the more general issue of how disorder of input neurons affects downstream circuitry.
Functional and molecular development of striatal fast‐spiking GABAergic interneurons and their cortical inputs
Authors: Plotkin Joshua L. , Wu Nanping , Chesselet Marie‐Françoise , Levine Michael S. 
Published: September 2005

AbstractDespite their small number, fast‐spiking (FS) GABAergic interneurons play a critical role in controlling striatal output by mediating cortical feed‐forward inhibition of striatal medium‐sized spiny (MS) projection neurons. We have examined the functional development of FS interneurons and their cortical inputs, and the expression of three of their molecular markers, in the dorsolateral rat striatum between postnatal days (P)12–14 and 19–23, the time of major corticostriatal synaptogenesis. FS interneurons were visualized with infrared differential interference contrast (IR‐DIC) optics and examined with current‐clamp recording in the presence of the GABAA receptor antagonist bicuculline methiodide. FS interneurons displayed action potentials at relatively high frequencies in response to depolarizing current pulses by P12, but developmental changes occurred in action potential and afterhyperpolarization duration and amplitude and input resistance between P12–14 and P19–23, as well as an increase in maximum firing frequency in response to depolarizing current pulses. Maturation in electrophysiological properties was paralleled by increases in Kv3.1 and parvalbumin mRNA expression, while GAD‐67 mRNA levels remained constant. Furthermore, FS interneurons in the younger age group responded to stimulation of cortical afferents with excitatory postsynaptic potentials (EPSPs) of higher amplitudes and received significantly more spontaneous depolarizing inputs than did MS neurons. Thus, FS interneurons are under frequent and continuous cortical influence by the end of the 2nd postnatal week, a time when corticostriatal synapses are sparse, suggesting that they may provide a major inhibitory influence in the striatum during the period of intense developmental maturation.
Synapse independence breaks down during highly synchronous network activity in the rat hippocampus
Authors: Biró Ágota A. , Nusser Zoltan 
Published: September 2005

AbstractThe discharge pattern of hippocampal pyramidal cells (PC) varies depending on the behaviour of the animal and on the accompanying network states. During theta activity, PCs fire asynchronously at low rates whereas during sharp waves PCs increase their firing frequency and many cells fire synchronously. In the present study, we addressed how the presynaptic activity of CA1 PCs influences the precise operation of their output synapses. Asynchronous presynaptic discharge was mimicked by activating only a single PC during paired recordings, whereas the highly synchronous presynaptic firing was emulated by extracellularly stimulating the axons of ≈ 70 PCs in acute hippocampal slices. By using low‐ and high‐affinity glutamate receptor competitive antagonists to monitor the synaptic glutamate concentration transient, we show that the synaptic transmitter concentration varies depending on the release probability (Pr) when many fibres are synchronously activated. Our kinetic analysis revealed that an ≈ 5‐fold increase in Pr from the beginning to the end of an action potential train resulted in a slowing down of the decay of evoked EPSCs, suggesting neurotransmitter spillover between neighbouring synapses. In agreement with this prediction, the slowing of the decay was reversed by the application of the low‐affinity antagonist γ‐D‐glutamyl‐glycine. In contrast, altering Pr had no effect on the kinetics of unitary EPSCs. Our data demonstrate that synapse independence breaks down during synchronous presynaptic activity, but the point‐to‐point communication is preserved when PCs fire asynchronously.
Ryanodine receptors and BK channels act as a presynaptic depressor of neurotransmission in cochlear inner hair cells
Authors: Beurg Maryline , Hafidi Aziz , Skinner Liam J. , Ruel Jérome , Nouvian Régis , Henaff Morgana , Puel Jean‐Luc , Aran Jean‐Marie , Dulon Didier 
Published: September 2005

AbstractRyanodine receptors (RyRs) are known to contribute to the regulation of free cytosolic calcium concentration. This family of intracellular calcium channels plays a significant role in calcium‐induced‐calcium‐release (CICR), and have been implicated in calcium‐dependent processes requiring exquisite spatio‐temporal regulation. In order to characterize the importance of these intracellular calcium channels in cochlear physiology, we perfused the guinea pig cochlea with antagonistic concentrations of ryanodine. The distortion products of the cochlear microphonic and the compound action potential of the auditory nerve were reversibly inhibited by ryanodine (IC50 = 27.3 µm, Hill coefficient = 1.9), indicating an action at the cochlear amplifier. Single auditory nerve fibre recordings showed that ryanodine slightly increased spontaneous firing rates by 22%, suggesting an excitatory effect of ryanodine. This paradoxical effect could be explained by an inhibitory action of ryanodine on presynaptic BK channels of inner hair cells (IHC). Indeed, perfusing iberiotoxin also increased the spontaneous firing activity of the auditory nerve fibres. Furthermore, whole‐cell patch‐clamp recordings demonstrated that ryanodine inhibits BK currents at the IHC level. Conversely, immunohistochemistry demonstrated a strong expression of RyR in IHCs and, more particularly, below the cuticular plate where membranous BK channels are highly expressed. Overall, the study demonstrated a key role for RyR and CICR in signal transduction at the IHCs. We therefore propose that coupled RyR–BK channels act to suppress the fast neurotransmission in IHCs.
Photoperiodic regulation of annual testicular events in the Indian major carp Catla catla
Authors: Bhattacharyya S. , Dey R. , Maitra S. K. 
Published: September 2005

AbstractThe importance of photoperiods in the regulation of annual testicular events in the carp Catla catla was evaluated by subjecting them to either long (16 h light : 8 h dark) or short (8 h light : 16 h dark) photoperiods for 30 days during the preparatory, prespawning, spawning and postspawning phases of an annual gonadal cycle. In each reproductive phase, testicular responsiveness to subjected photoperiods was determined by comparing the gonadal status in corresponding groups of control or natural photoperiodic fish. The values of testicular weight, gametogenic index, as well as testicular activity of two steroidogenic enzymes (Δ53β‐, and 17β‐hydroxysteroid dehydrogenase), and the serum titre of testosterone were considered as the indices of functional status of the testis in the fish concerned. During the prespawning phase, exposure of fish to a daily long photoperiod schedule resulted in precocious maturation of testis, while retardation of testicular growth was noted under the influences of short photoperiod. However, none of the employed photo‐schedules could influence the gametogenic and steroidogenic functions of the testis in the remaining part of the gonadal cycle. Collectively, the present study provides evidence for the first time that in the case of a commercially important carp, Catla catla, artificial, long photoperiods may be used for advanced testicular maturation, while reductions in maturation‐associated growth and deterioration in flesh quality may be avoided by submitting the fish to shorter day lengths during the prespawning phase of the reproductive cycle.
Pretarsal structures in Reduviidae (Heteroptera, Ins ecta)
Authors: Weirauch Christiane 
Published: September 2005

AbstractA survey of pretarsal structures in Reduviidae of 22 higher‐level taxa and several outgroup representatives is conducted using scanning electron microscopy (SEM) and light microscopy. Based on histology and SEM, pretarsal structures are described in detail forRhodnius prolixus. Structures of the distal tarsomer, which appear to be functionally correlated with the pretarsus, are documented for the first time in Heteroptera. These comprise lateral oval sclerites, two campaniform sensilla and two marginal setae, observed in Reduviidae and other heteropteran taxa. The presence of a peg‐like dorsomedian sensillum medially between the claws in Reduviidae and Nabidae is demonstrated. As a result of its structure and position, homology of this sensillum with the ‘dorsal arolium’ in other heteropteran groups is proposed. Within Reduviidae, the transformation of the peg‐like dorsomedian sensillum to a campaniform sensillum, as seen in most representatives of the harpactoroid complex, is hypothesized. The first record of parempodia other than setiform within Reduviidae is noted in nymphs of Harpactorinae, which may possess lamellate parempodia. Several characters that are possibly useful for clarifying relationships among the harpactoroid groups are described and discussed. The pretarsal structures, including the unguitractor plate and the tarsal marginal setae among reduviid groups are discussed in a phylogenetic context.
Comparative morphology of the first instar of three species of Metopia Meigen (Diptera: Sarcophagidae, Miltogramminae)
Authors: Szpila K. , Pape T. 
Published: September 2005

AbstractThe first instar larva is described for three species of the kleptoparasitic miltogrammine genus Metopia Meigen: M. campestris (Fallén), M. argentata Macquart and M. argyrocephala (Meigen). Using a combination of light microscopy and scanning electron microscopy, the morphology of the cephaloskeleton as well as the general external morphology are extensively documented, and the phylogenetic implications are discussed. Like other species of Miltogramminae, the first instar of species of Metopia possesses a strong labrum and well‐developed mouth‐hooks. Some other features found in Metopia spp. are rare in the Miltogramminae, such as a serrated ventral surface of the tip of the mouth‐hook and the lack of a posterior spiracular cavity. A few larval features apparently unique for species of Metopia have so far been documented: base of mouth‐hook with a lateral arm‐like extension and abdominal segments with transverse furrow ventrally. The body is equipped with longitudinal cuticular ridges on all segments, which may be a subfamily ground‐plan autapomorphy. Marked morphological and behavioural differences are documented between the first instar of M. argentata and that of M. argyrocephala, the adult females of which are otherwise difficult to separate.
Ontogenetic variations in characters of Euchone analis (Krøyer, 1856) (Polychaeta, Sabellidae, Sabellinae) from Spitsbergen, and new assignments of Oriopsis ingelorae Plate, 1995 and O. liefdefjordensis Plate, 1995
Authors: Bick Andreas , Randel Nadine 
Published: September 2005

Abstract Euchone analis, the type species of its genus, was collected in high densities and in different size classes from Kongsfjorden, west Spitsbergen. This material has provided the basis for an investigation of the size dependence of characters. Almost all characters used in diagnoses were highly variable, especially the number of abdominal chaetigers forming the anal depression and the shape of the depression. The only relatively constant features are the number of chaetigers anterior to the anal depression and the branchial crown‐to‐body length ratio. A branchial skeleton extension of the radiolar appendages of the dorsal lips was found for the first time within Euchone, and this character has been added to the diagnosis of Euchone. Oriopsis liefdefjordensis and small specimens of E. analis agree in all characters, and O. liefdefjordensis is proposed to be a junior synonym of E. analis. Characters found in O. ingelorae are in accordance with those described for Chone, and we propose assigning O. ingelorae to this genus. The significance of ontogenetic character variations in the Sabellidae is discussed.