bluuebunny/crossref_metadata_2025 huggingface dataset:
When coagulation fails in the oldest: Acquired hemophilia caused by chronic lymphocytic leukemia in a 92‐years‐old woman
Authors: Masotti Luca , Vecce Roberto , Gianchecchi Daniele , Cantini Roberto , Cannistraro Daniela , Matteucci Angela , Cecconi Nadia
Published: May 2005

Acquired hemophilia is a severe, potentially life‐threatening condition usually involving elderly patients, caused by an auto‐antibody against factor VIII of coagulation. We describe the case of a 92‐years‐old woman who came to our attention for severe acute anemia associated with many spontaneous diffuse skin bleedings secondary to a prolonged aPTT 110 sec, factor VIII < 1% with a titer of factor VIII inhibitor of 5.5 Bethesda Units. A diagnosis of chronic lymphocytic leukemia was determined. We treated the patient with a blood transfusion and intravenous corticosteroids with prompt reduction of aPTT and inhibitor factor VIII titer. The present case report involving a very old patient could represent an example of acquired hemophilia as a first manifestation of a lymphoproliferative syndrome.
Glutamatergic innervation of neuropeptide Y and pro‐opiomelanocortin‐containing neurons in the hypothalamic arcuate nucleus of the rat
Authors: Kiss József , Csaba Zsolt , Csáki Ágnes , Halász Béla
Published: May 2005

The hypothalamic arcuate nucleus contains a number of neurochemically different cell populations, among others neuropeptide Y (NPY)‐ and pro‐opiomelanocortin (POMC)‐derived peptide‐expressing neurons; both are involved in the regulation of feeding and energy homeostasis, NPY neurons also in the release of hypophysiotropic hormones, sexual behaviour and thermogenesis. Recent observations indicate that there is a dense plexus of glutamatergic fibres in the arcuate nucleus. The aim of the present studies was to examine the relationship of these fibres to the NPY and POMC neurons in the arcuate nucleus. Double‐label immunoelectron microscopy was used. Glutamatergic elements were identified by the presence of vesicular glutamate transporter 1 (VGluT1) or 2 (VGluT2) (selective markers of glutamatergic elements) immunoreactivity. A significant number of VGluT2‐immunoreactive terminals was observed to make asymmetric type of synapses with NPY and with β‐endorphin (a marker of POMC neurons)‐immunostained nerve cells of the arcuate nucleus. About 15% of VGluT2 synapsing terminals established asymmetric synapses with NPY‐positive cells and more than 40% of VGlut2‐positive terminals formed synapse on β‐endorphin‐positive neurons. VGluT2‐positive perikarya were also observed, part of them also contained β‐endorphin. Nerve terminals containing both VGluT2 and β‐endorphin were demonstrated in the cell group. Only very few VGluT1 fibres were detected. Our observations provide the first direct neuromorphological evidence for the existence of glutamatergic innervation of NPY and POMC neurons of the arcuate nucleus.
Attraction to sexual pheromones and associated odorants in female mice involves activation of the reward system and basolateral amygdala
Authors: Moncho‐Bogani Jose , Martinez‐Garcia Fernando , Novejarque Amparo , Lanuza Enrique
Published: May 2005

Adult female mice are innately attracted to non‐volatile pheromones contained in male‐soiled bedding. In contrast, male‐derived volatiles become attractive if associated with non‐volatile attractive pheromones, which act as unconditioned stimulus in a case of Pavlovian associative learning. In this work, we study the chemoinvestigatory behaviour of female mice towards volatile and non‐volatile chemicals contained in male‐soiled bedding, in combination with the analysis of c‐fos expression induced by such a behaviour to clarify: (i) which chemosensory systems are involved in the detection of the primary attractive non‐volatile pheromone and of the secondarily attractive volatiles; (ii) where in the brain male‐derived non‐volatile and volatile stimuli are associated to induce conditioned attraction for the latter; and (iii) whether investigation of these stimuli activates the cerebral reward system (mesocorticolimbic system including the prefrontal cortex and amygdala), which would support the view that sexual pheromones are reinforcing. The results indicate that non‐volatile pheromones stimulate the vomeronasal system, whereas air‐borne volatiles activate only the olfactory system. Thus, the acquired preference for male‐derived volatiles reveals an olfactory‐vomeronasal associative learning. Moreover, the reward system is differentially activated by the primary pheromones and secondarily attractive odorants. Exploring the primary attractive pheromone activates the basolateral amygdala and the shell of nucleus accumbens but neither the ventral tegmental area nor the orbitofrontal cortex. In contrast, exploring the secondarily attractive male‐derived odorants involves activation of a circuit that includes the basolateral amygdala, prefrontal cortex and ventral tegmental area. Therefore, the basolateral amygdala stands out as the key centre for vomeronasal‐olfactory associative learning.
G‐protein coupled activation of potassium channels by endogenous neuropeptides in snail neurons
Authors: Kiss Tibor
Published: May 2005

Members of the mytilus inhibitory peptide (MIP) family play an important role in the modulation of many physiological processes in molluscs. The signal transduction pathways affected by the MIP effect have not, however, been elucidated. Application of guanosine 5′‐[γ‐thio]triphosphate tetralithium salt (GTPγS), guanosine 5′‐[β‐thio]diphosphate trilithium salt (GDPβS), the G‐protein inhibitor suramin and pertussis toxin (PTX) demonstrated the involvement of the PTX‐insensitive G‐protein in the signal transduction pathway mediating MIP effects. Both G‐protein αi and βγ subunits were identified in D‐neurons of Helix pomatia by immunoblotting. Their role in signal transduction was shown in electrophysiological experiments, which supported the notion that, in addition to the Gα subunit, the βγ dimer also participates in the neuropeptide‐induced activation of K‐channels in snail neurons. Finally, neuropeptide‐activated responses were inhibited by the activation of adenylyl cyclase and by blockers of the phospholipase pathway. We suggest that bifurcation of the signal transduction takes place at the level of G‐protein subunits. The α subunit may have a direct effect on adenylyl cyclase, while the βγ subunit may have a direct effect on phospholipase enzymes.
Olfactory learning‐induced morphological modifications in single dendritic spines of young rats
Authors: Knafo Shira , Libersat Frederic , Barkai Edi
Published: May 2005

Learning‐related morphological modifications in single dendritic spines were studied quantitatively in the brains of young Sprague–Dawley rats. We have previously shown that olfactory discrimination rule‐learning results in transient physiological and morphological modifications in piriform cortex pyramidal neurons. In particular, spine density along the apical dendrites of neurons from trained rats is increased after learning. The aim of the present study was to identify and describe olfactory learning‐induced modifications in the morphology of single spines along apical dendrites of the same type of neurons. By using laser‐scanning confocal microscopy, we show that 3 days after training completion spines on neurons from olfactory discrimination trained rats are shorter as compared to spines on neurons from control rats. Further analysis revealed that spine shortening attributed to olfactory discrimination learning derives from shortening of spine head and not from shortening of spine neck. In addition, detailed analysis of spine head volume suggests that spines with large heads are absent after learning. As spine head size may be related to the efficacy of the synapse it bears, we suggest that modifications in spine head dimensions following olfactory rule‐learning enhance the cortical network ability to enter into a ‘learning mode’, in which memories of new odours can be acquired rapidly and efficiently.
Preferential localization of the hyperpolarization‐activated cyclic nucleotide‐gated cation channel subunit HCN1 in basket cell terminals of the rat cerebellum
Authors: Luján Rafael , Albasanz José Luis , Shigemoto Ryuichi , Juiz José Manuel
Published: May 2005

Hyperpolarization‐activated and cyclic nucleotide‐gated (HCN) channels are involved in the control of neuronal excitability and plasticity. In this study, we used immunoblotting and immunohistochemical techniques to reveal the developmental expression and subcellular distribution of the HCN1 subunit in the cerebellar cortex. During postnatal development, the spatio‐temporal expression of HCN1 correlated well with the morphological events occurring during the ontogenesis of cerebellar interneurons. Using immunoblotting techniques, HCN1 was weakly detected during the first postnatal week and continued to increase throughout postnatal development, peaking at postnatal day (P)15. At the light‐microscopic level, HCN1 immunoreactivity was very weak until P7 whereas from P10–12 to adulthood it was strongly detected in the lower third of the molecular layer and in the Purkinje cell layer. HCN1 was present in axons running through the molecular layer and in the pericellular basket around Purkinje cells at P12, but in the periaxonal plexus (the pinceau) surrounding their initial segment only after P15. Using immunofluorescence, HCN1 colocalized with GAD65 and synaptophysin, demonstrating that the subunit was present in inhibitory axons and axon terminals. At the electron‐microscopic level, in adulthood, HCN1 immunoparticles were detected at postsynaptic sites in basket and Purkinje cells but most immunoparticles were found at presynaptic sites in basket cell axons and in terminals. In the axon terminals, the distribution of HCN1 was relatively uniform along the extrasynaptic plasma membrane; this was confirmed using quantitative techniques. The present findings suggest that HCN1 channels may provide a significant route for modulating co‐ordinated cerebellar synaptic transmission through basket cells.
Unilateral optic nerve crush induces bilateral retinal glial cell proliferation
Authors: Panagis L. , Thanos S. , Fischer D. , Dermon C. R.
Published: May 2005

The post‐injury responses of retinal ganglion cells elicit a number of glial reactions which have not been completely understood. The bilateral pattern of non‐neuronal retinal cell proliferation was examined in association with the differential fates of unilaterally injured adult retinal ganglion cells by means of bromodeoxyuridine (BrdU) immunocytochemistry. Lateralization of the glioproliferative events was studied by analysing both the experimental and the uninjured contralateral as well as matched retinas of sham‐operated animals. Control adult rat retina included very few BrdU‐positive cells within the nerve fibre and ganglion cell layers; however, experimental retinas of degenerating groups exhibited statistically significantly higher densities of newborn cells in most layers. Clusters of labelled cells were found in the inner plexiform layer related to OX‐42 staining, indicating their microglial nature. Indeed, double‐labelling experiments, after short‐term unilateral optic nerve crushing, identified proliferating retinal glial cells in vivo. Both types of glia, astroglial and microglial cells, exhibited BrdU‐positive labelling in injured as well as uninjured experimental rat retinas. Moreover, microglial proliferating cells were also identified in explanted retinal pieces after 2 days in culture. Affected and contralateral retinas responded similarly to the unilateral experimental manipulations applied with respect to BrdU labelling. The acute glial responses observed suggest that bilateral glial proliferation might represent a common response related to degeneration events in both retinas, i.e. ipsi‐ and contralateral to the experimental injury.
Rapid non‐genomic effect of glucocorticoid metabolites and neurosteroids on the γ‐aminobutyric acid‐A receptor
Authors: Strömberg J. , Bäckström T. , Lundgren P.
Published: May 2005

Glucocorticoids and neurosteroids, such as allopregnanolone and tetrahydrodeoxycorticosterone, are released during stress. A non‐genomic effect of glucocorticoids has been established but is not yet fully understood. We have studied the effect of glucocorticoid metabolites on the γ‐aminobutyric acid (GABA) system. In these experiments we studied the effects of the glucocorticoid metabolites allotetrahydrocortisol, tetrahydrocortisol, allotetrahydrocortisone and tetrahydrocortisone in rat cortical microsacs. Our results showed that both these cortisol and cortisone metabolites reduce GABA‐mediated chloride ion uptake. This reduction was not observed in the presence of allopregnanolone but allotetrahydrocortisol interacts with allopregnanolone, enhancing the allopregnanolone‐stimulated potentiation of GABA‐mediated chloride ion uptake. This enhanced effect was completely blocked by the addition of 30 µm of the 3β‐isomer of allopregnanolone, isoallopregnanolone. Our findings show that steroids released during stress interact with each other and GABA in the GABA system.
Short‐term synaptic plasticity during development of rat mossy fibre to granule cell synapses
Authors: Wall Mark J.
Published: May 2005

Changes occur during the postnatal development of the rat glutamatergic mossy fibre to granule cell synapse: to the morphology of synapses, glutamate transporter expression, AMPA receptor expression and the kinetics of AMPA receptor‐mediated synaptic transmission. For example, both the rise and decay times of AMPA receptor‐mediated excitatory postsynaptic currents significantly shorten. To further define the development of mossy fibre to granule cell synaptic transmission, the properties and mechanisms of short‐term plasticity have been described. The characterization of short‐term plasticity will aid our understanding of the mechanisms that define the parameters of synaptic transmission during development and furthermore short‐term plasticity may play an important role in determining information transfer between mossy fibres and granule cells. In response to pairs of stimuli (2–100‐ms interval), depression (second excitatory postsynaptic current amplitude smaller than the first) was observed at both mature (older than 40 postnatal days) and immature (between 8 and 12 postnatal days) synapses. The degree of depression was similar at both stages of development, although recovery from depression was slower at mature synapses (τ 22 vs 12.5 ms). Several experimental approaches (coefficient of variation, low‐affinity antagonists and cyclothiazide) suggest that depression at immature synapses results from multiple mechanisms. At mature synapses, postsynaptic receptor desensitization appears to be the major cause of depression.
Nitric oxide release is induced by dopamine during illumination of the carp retina: serial neurochemical control of light adaptation
Authors: Sekaran S. , Cunningham J. , Neal M. J. , Hartell N. A. , Djamgoz M. B. A.
Published: May 2005

Several lines of indirect evidence have suggested that nitric oxide may play an important role during light adaptation of the vertebrate retina. We aimed to verify directly the effect of light on nitric oxide release in the isolated carp retina and to investigate the relationship between nitric oxide and dopamine, an established neuromodulator of retinal light adaptation. Using a biochemical nitric oxide assay, we found that steady or flicker light stimulation enhanced retinal nitric oxide production from a basal level. The metabotropic glutamate receptor agonist l‐amino‐4‐phosphonobutyric acid, inhibited the light adaptation‐induced nitric oxide production suggesting that the underlying cellular pathway involved centre‐depolarizing bipolar cell activity. Application of exogenous dopamine to retinas in the dark significantly enhanced the basal production of nitric oxide and importantly, inhibition of endogenous dopaminergic activity completely suppressed the light‐evoked nitric oxide release. The effect of dopamine was mediated through the D1 receptor subtype. Imaging of the nitric oxide‐sensitive fluorescent indicator 4,5‐diaminofluorescein di‐acetate in retinal slices revealed that activation of D1 receptors resulted in nitric oxide production from two main spatial sources corresponding to the photoreceptor inner segment region and the inner nuclear layer. The results taken together would suggest that during the progression of retinal light adaptation there is a switch from dopaminergic to nitrergic control, probably to induce further neuromodulatory effects at higher levels of illumination and to enable more efficient spreading of the light adaptive signal.
Daily number and lengths of activity bursts in rabbit jaw muscles
Authors: Van Wessel Tim , Langenbach Geerling E. J. , Van Ruijven Leo J. , Brugman Peter , Van Eijden Theo M. G. J.
Published: May 2005

Muscle activity has predominantly been studied for specific motor tasks not necessarily representative of normal daily behaviour. The few studies that have examined daily muscle use have quantified this by duty time, merging all levels of muscle activity. Muscle activity can also be characterized by the number, duration and level of bursts. The purpose of this study was to characterize, for various levels of muscle activity, the daily masseter and digastric actions in the rabbit. Characterization was realized by quantification of duty time (summed length of all bursts as a percentage of total time), number of bursts and distribution of burst lengths. A telemetric device was implanted in the two muscles of six rabbits, ensuring the recording of their jaw muscle activities while they moved freely. The continuously transmitted signals over 1 day were analysed. The results showed that (i) more than 100 000 bursts per day exceeded the 2% level of the maximum muscle activity in both muscles, whereas fewer than 100 bursts per day exceeded the 90% level; and (ii) the digastric muscle exhibited a significantly higher duty time than the masseter (respectively, 23% and 14% for activities exceeding the 2% level), which was mainly caused by the on average longer burst lengths at the lowest levels. The characterization of muscle activity in daily burst number and distribution of burst lengths exceeding various activity levels provides valuable information on motor control and enables further investigation of the adaptive capacity of muscles.
Removal of cholinergic input to perirhinal cortex disrupts object recognition but not spatial working memory in the rat
Authors: Winters Boyer D. , Bussey Timothy J.
Published: May 2005

The perirhinal cortex of the temporal lobe has a crucial role in object recognition memory. Cholinergic transmission within perirhinal cortex also seems to be important for this function, as the muscarinic receptor antagonist scopolamine disrupts object recognition performance when administered systemically or directly into perirhinal cortex. In the present study, we directly assessed the contribution of cholinergic basal forebrain input to perirhinal cortex in object recognition. Selective bilateral removal of the cholinergic basal forebrain inputs to perirhinal cortex was accomplished by injecting the immunotoxin 192 IgG‐saporin directly into perirhinal cortex in rats. These animals were significantly impaired relative to vehicle‐injected controls in a spontaneous object recognition task despite intact spatial alternation performance. These results are consistent with recent reports of object recognition impairment following acute cholinergic receptor blockade and extend these findings by demonstrating that chronic removal of cholinergic basal forebrain input to an otherwise intact perirhinal cortex causes a severe object recognition deficit similar to that associated with more extensive cell body lesions of perirhinal cortex.
Cannabinoid CB1 receptor antagonism reduces conditioned reinstatement of ethanol‐seeking behavior in rats
Authors: Cippitelli Andrea , Bilbao Ainhoa , Hansson Anita C. , Del Arco Ignacio , Sommer Wolfgang , Heilig Markus , Massi Mauricio , Bermúdez‐Silva Francisco Javier , Navarro Miguel , Ciccocioppo Roberto , De Fonseca Fernando Rodríguez
Published: May 2005

The endocannabinoid system is involved in a variety of effects of drugs of misuse, and blockade of the cannabinoid CB1 receptor by selective antagonists elicits marked reductions in opioid and alcohol self‐administration. The present study was designed to extend our knowledge of the role of the cannabinoid CB1 receptor in the modulation of alcohol misuse vulnerability in rats. Accordingly, using nonselected Wistar rats and genetically selected Marchigian Sardinian alcohol‐preferring (msP) rats, we investigated the effect of the CB1 antagonist SR141716A on operant alcohol self‐administration and on reinstatement of alcohol‐seeking behavior by environmental conditioning factors. In addition, in situ hybridization studies in both strains were performed to measure cannabinoid CB1 receptor mRNA in different brain areas of these animals. Results showed that intraperitoneal administration of SR141716A (0.03, 1.0 and 3.0 mg/kg) markedly inhibits ethanol self‐administration and conditioned reinstatement of ethanol‐seeking behavior in both strains of rats. ED50 analysis showed significantly higher sensitivity (P < 0.05) to the effect of SR141716A in msP rats than in heterogeneous Wistar rats. In situ hybridization studies revealed that, compared with Wistar rats, msP animals have consistently greater cannabinoid CB1 receptor mRNA expression in a number of brain areas, including the frontoparietal cortex, caudate‐putamen and hippocampus (CA1 and dentate gyrus areas). In conclusion, we provide clear evidence that blockade of CB1 receptors reduces both ethanol self‐administration and conditioned reinstatement of alcohol‐seeking behavior in rats. In addition, current pharmacological and neuroanatomical data suggest that an altered function of the CB1 receptor system exists between genetically selected alcohol‐preferring msP rats and a heterogeneous animal population.
Candidate pheromone receptors of the silkmoth Bombyx mori
Authors: Krieger Jürgen , Große‐Wilde Ewald , Gohl Thomas , Breer Heinz
Published: May 2005

Communication via specific chemical signals is vitally important for the reproductive behaviour of many species. The first identified sex‐attractant pheromone was bombykol from the silkmoth Bombyx mori. This female‐released signalling compound is perceived by the male moth with extreme sensitivity and specificity. Antennal sensory cells supposedly respond to individual bombykol molecules and can efficiently distinguish bombykol from highly related structural analogues like bombykal, a second female‐released pheromone component. In the four decades since the discovery of bombykol, the Bombyx mori system has continued to serve as an invaluable model system for unraveling the intricacies of chemical communication. The molecular basis for this extraordinary specific recognition of an extraneous compound is still elusive but probably based on specific receptors of the pheromone‐responsive cells. In this study, molecular and bioinformatic approaches were employed to search for candidate pheromone receptors of Bombyx mori. A few receptor types were identified that are related to Heliothis candidate pheromone receptors. They were found to be almost exclusively expressed in male antennae, and double in situ hybridization experiments disclosed a characteristic topographic expression pattern that was reminiscent of pheromone‐responsive cells. Furthermore, the receptor‐expressing cells were closely associated with cells expressing the pheromone‐binding protein. Together, the data support the view that the identified receptor types of Bombyx mori are candidate receptors for pheromone components.
Over‐expression of the human EAAT2 glutamate transporter within neurons of mouse organotypic hippocampal slice cultures leads to increased vulnerability of CA1 pyramidal cells
Authors: Selkirk Julie V. , Stiefel Theodore H. , Stone Ida M. , Naeve Greg S. , Foster Alan C. , Poulsen David J.
Published: May 2005

Excitatory amino acid transporters (EAATs) maintain the balance between pathological and physiological conditions by limiting the extracellular concentration of glutamate within the CNS and thus preventing excitotoxic injury. The loss of EAAT2 has been associated with the development of neurological diseases such as amyotrophic lateral sclerosis. It has therefore been suggested that the over‐expression of specific EAATs may provide some degree of neuroprotection. However, the inability to isolate and study the function of the different EAAT isoforms in a cell type‐specific manner has made it difficult to determine the exact contribution of individual EAATs toward neuroprotection or neurodegeneration in the context of excitotoxic injury. To address this question, we transduced hippocampal slice cultures from 1‐week‐old C57B/6 mice with recombinant adeno‐associated virus carrying an EAAT2 gene expression cassette. EAAT2 gene expression was driven in neurons with the neuron‐specific enolase promoter. Using this model system, we were able to induce a significant increase in the expression of functional EAAT2. Consequently, a significant increase in CA1 neuronal damage was observed in slices over‐expressing EAAT2 in neurons following an acute exposure to exogenous glutamate. These data suggest that the increased expression of EAAT2 within neurons may contribute to neurodegeneration.
Pathological implications of iNOS expression in central white matter: an ex vivo study of optic nerves from rats with experimental allergic encephalomyelitis
Authors: Garthwaite G. , Batchelor A. M. , Goodwin D. A. , Hewson A. K. , Leeming K. , Ahmed Z. , Cuzner M. L. , Garthwaite J.
Published: May 2005

Excessive nitric oxide (NO) production from the inducible isoform of nitric oxide synthase (iNOS) has been invoked as a causative factor in many neurodegenerative disorders, including multiple sclerosis. This hypothesis has been supported by in vitro studies showing that glial iNOS expression results in toxic NO concentrations (near 1 µm). To investigate the relevance of such findings, experiments were carried out ex vivo on optic nerves from rats with exacerbated experimental allergic encephalomyelitis, a model of multiple sclerosis. The nerves displayed characteristic immunopathology and expression of iNOS in macrophages and/or microglia and there was overt axonal damage in localized regions of the optic chiasm. The resulting NO levels in the optic nerve were sufficient to cause activation of guanylyl cyclase‐coupled NO receptors, resulting in marked cGMP accumulation in axons throughout the nerve. Nevertheless, calibration of cGMP levels against those evoked by exogenous NO indicated that the nerves were not compromised metabolically and that their ambient NO concentration was only ≈ 1 nm. Consistent with this observation, electrophysiological tests indicated that there was no ongoing malfunctioning of the type that can be elicited by high exogenous NO concentrations. It is concluded that, with iNOS expressed in physiological locations and levels, the tissue levels of NO remain at concentrations far lower than those shown to have toxic effects, despite continuous NO synthesis. The fact that NO can rise to much higher levels in dispersed cultures in vitro may be attributable to a deficiency in NO inactivation in such preparations.
Lasting accelerative effects of 1 Hz and 20 Hz electrical stimulation on cortical spreading depression: relevance for clinical applications of brain stimulation
Authors: Fregni Felipe , Monte‐Silva Katia K. , Oliveira Manuella B. , Freedman Steven D. , Pascual‐Leone Alvaro , Guedes Rubem C. A.
Published: May 2005

Clinical applications of brain stimulation have been increasing during the last decade; however, the mechanisms of action remain unknown. One proposed mechanism of action is that repetitive stimulation modulates cortical excitability. Herein, we explore the question of whether repetitive electric stimulation increases cortical excitability as indexed by the cortical spreading depression. Twenty‐four Wistar rats were divided into three groups according to the treatment: sham, 1‐Hz and 20‐Hz stimulation. Stimulation was applied to the left frontal cortex through a pair of epidurally implanted silver‐wire electrodes. The cortical spreading depression‐features were analysed at three time points (one day before, one day after and 2 weeks after treatment) in both the stimulated and unstimulated hemisphere. A 3 × 2 × 3 factorial anova with repeated measures showed significant differences in the main effect of time (P < 0.0001), hemisphere (P = 0.0002) and stimulation group (P = 0.008). The interaction between time vs. hemisphere vs. stimulation group was also significant (P < 0.0001). Posthoc analysis demonstrated that 1‐Hz and 20‐Hz repetitive electrical stimulation significantly increased the velocity of cortical spreading depression in the stimulated hemisphere. Furthermore, 20‐Hz stimulation showed a greater effect on cortical spreading depression compared to 1‐Hz stimulation. The results show that 1‐Hz and 20‐Hz repetitive electrical stimulation results in an increase in cortical spreading depression velocity that is associated with the frequency and the hemisphere of stimulation. Furthermore, the effects are found to be long lasting. We believe that these findings have strong relevance to support the clinical application of therapies involving electrical stimulation for diseases of reduced cortical excitability.
Real Options Effects on Employment: Does Exchange Rate Uncertainty Matter for Aggregation?
Authors: Belke Ansgar , Göcke Matthias
Published: May 2005

In a baseline micro model a band of inaction due to hiring and firing costs is widened by option value effects of exchange rate uncertainty. Based on this micro foundation, an aggregation approach is presented. Under uncertainty, intervals of weak response to exchange rate reversals (called ‘play’ areas) are introduced on the macro level. ‘Spurts’ in new employment or firing may occur after an initially weak response. Since these mechanisms may apply to other ‘investment’ cases where the aggregation of microeconomic real options effects under uncertainty are relevant, they may even be of a more general interest.
The Promise and Pitfalls of Restructuring Network Industries
Authors: Buehler Stefan
Published: May 2005

This paper examines the competitive effects of reorganizing a network industry’s vertical structure. In this industry, an upstream monopolist operates a network used as an input to produce horizontally differentiated final products that are imperfect substitutes. Three potential pitfalls of restructuring integrated network industries are analyzed: (i) double marginalization, (ii) underinvestment and (iii) vertical foreclosure. The paper studies the net effect of restructuring on retail prices and cost-reducing investment and discusses policy implications.
Design of the 3G Spectrum Auctions in the UK and Germany: An Experimental Investigation
Authors: Seifert Stefan , Ehrhart Karl-Martin
Published: May 2005

This paper analyses the auction designs chosen for awarding 3G licences in the UK and Germany and compares them with respect to revenues and bidders’ surplus using a laboratory experiment. In our study with a given number of bidders, the German design leads to higher revenues. However, bidder surplus in the German design is lower and bidders face a severe exposure problem. Because this might discourage participation, it will probably lead to less competitive bidding in real applications.
Money Illusion and the Double Dividend in the Short Run
Authors: Schleiniger Reto
Published: May 2005

In their seminal paper, Bovenberg and de Mooij (1994) elucidate why an ecological tax reform will not yield a double dividend, i.e. fails to increase the efficiency of the tax system. The present paper slightly modifies the Bovenberg and de Mooij model by introducing money illusion. With this modification, an environmental tax reform that raises the price level may generate a double dividend, since the additional tax on the dirty good does not reduce labor supply. A prerequisite for the double dividend to occur is a sufficiently small elasticity of substitution between clean and dirty consumption. Moreover, accounting for money illusion always reduces the intertemporal gross cost of the tax reform.
When Induction Meets Memory: Evidence for Gradual Transition From Similarity‐Based to Category‐Based Induction
Authors: Fisher Anna V. , Sloutsky Vladimir M.
Published: May 2005

The ability to perform induction appears early; however, underlying mechanisms remain unclear. Some argue that early induction is category based, whereas others suggest that early induction is similarity based. Category‐ and similarity‐based induction should result in different memory traces and thus in different memory accuracy. Performing induction resulted in low memory accuracy in adults and 11‐year‐olds, whereas 5‐, and 7‐year‐olds were highly accurate (Experiment 1). After training to perform category‐based induction, 5‐ and 7‐year‐olds exhibited patterns of accuracy similar to those of adults (Experiment 2). Furthermore, 7‐year‐olds, but not 5‐year‐olds, retained this training over time (Experiment 3). With novel categories, even adults performed similarity‐based induction, exhibiting high memory accuracy (Experiment 4). These results suggest a gradual transition from similarity‐ to category‐based induction with familiar categories.
Infants' Use of Synchronized Visual Information to Separate Streams of Speech
Authors: Hollich George , Newman Rochelle S. , Jusczyk Peter W.
Published: May 2005

In 4 studies, 7.5‐month‐olds used synchronized visual–auditory correlations to separate a target speech stream when a distractor passage was presented at equal loudness. Infants succeeded in a segmentation task (using the head‐turn preference procedure with video familiarization) when a video of the talker's face was synchronized with the target passage (Experiment 1, N=30). Infants did not succeed in this task when an unsynchronized (Experiment 2, N=30) or static (Experiment 3, N=30) face was presented during familiarization. Infants also succeeded when viewing a synchronized oscilloscope pattern (Experiment 4, N=26), suggesting that their ability to use visual information is related to domain‐general sensitivities to any synchronized auditory–visual correspondence.
Genetic Influences in Different Aspects of Language Development: The Etiology of Language Skills in 4.5‐Year‐Old Twins
Authors: Kovas Yulia , Hayiou‐Thomas Marianna E. , Oliver Bonamy , Dale Philip S. , Bishop Dorothy V. M. , Plomin Robert
Published: May 2005

The genetic and environmental etiologies of diverse aspects of language ability and disability, including articulation, phonology, grammar, vocabulary, and verbal memory, were investigated in a U.K. sample of 787 pairs of 4.5‐year‐old same‐sex and opposite‐sex twins. Moderate genetic influence was found for all aspects of language in the normal range. A similar pattern was found at the low end of the distribution with the exception of two receptive measures. Environmental influence was mainly due to nonshared factors, unique to the individual, with little influence from shared environment for most measures. Genetic and environmental influences on language ability and disability are quantitatively and qualitatively similar for males and females.
Representations of Attachment Relationships in Children of Incarcerated Mothers
Authors: Poehlmann Julie
Published: May 2005

Representations of attachment relationships were assessed in 54 children ages 2.5 to 7.5 years whose mothers were currently incarcerated. Consistent with their high‐risk status, most (63%) children were classified as having insecure relationships with mothers and caregivers. Secure relationships were more likely when children lived in a stable caregiving situation, when children reacted to separation from the mother with sadness rather than anger, and when children were older. Common reactions to initial separation included sadness, worry, confusion, anger, loneliness, sleep problems, and developmental regressions. Results highlight need for support in families affected by maternal imprisonment, especially efforts to promote stable, continuous placements for children, in addition to underscoring the importance of longitudinal research with this growing but understudied group.
The Development of Nonverbal Working Memory and Executive Control Processes in Adolescents
Authors: Luciana Monica , Conklin Heather M. , Hooper Catalina J. , Yarger Rebecca S.
Published: May 2005

The prefrontal cortex modulates executive control processes and structurally matures throughout adolescence. Consistent with these events, prefrontal functions that demand high levels of executive control may mature later than those that require working memory but decreased control. To test this hypothesis, adolescents (9 to 20 years old) completed nonverbal working memory tasks with varying levels of executive demands. Findings suggest that recall‐guided action for single units of spatial information develops until 11 to 12 years. The ability to maintain and manipulate multiple spatial units develops until 13 to 15 years. Strategic self‐organization develops until ages 16 to 17 years. Recognition memory did not appear to develop over this age range. Implications for prefrontal cortex organization by level of processing are discussed.
When You Shouldn't Do What You Want to Do: Young Children's Understanding of Desires, Rules, and Emotions
Authors: Lagattuta Kristin Hansen
Published: May 2005

This research investigated 4‐ through 7‐year‐olds' and adults' (n=64) concepts about the emotional consequences of desire fulfillment versus desire inhibition in situations where people's desires conflict with prohibitive rules. Results revealed developmental increases in attributing positive or mixed emotions to story characters that make willpower decisions and negative or mixed emotions to characters that transgress. These developmental changes in emotion predictions were accompanied by age‐related differences in emotion explanations. Whereas 4‐ and 5‐year‐olds largely explained emotions in relation to the characters' goals, 7‐year‐olds and adults further explained how rules and future consequences influence emotions. Results are discussed in relation to connections among children's psychological, deontic, and future‐oriented reasoning about emotions as well as the development of self‐control.
Ego Development and Ethnic Identity Formation in Rural American Indian Adolescents
Authors: Newman Denise L.
Published: May 2005

Ethnic identity development was assessed in the context of ego development in 12‐ to 15‐year‐old students from a Southeastern American Indian community. Self‐protective was the modal level and was characterized by awareness of ethnic group membership but little exploration or self‐reflection. Impulsive adolescents had the least developed ethnic identities and highest levels of interpersonal vulnerability. Conformist adolescents expressed positive feelings about ethnic group affiliation, described relationships as harmonious, but demonstrated moderate social anxiety. Postconformist adolescents had the highest levels of agency, social competence, and identity achievement, but also had high levels of psychological distress and family conflict. Adolescent identity strivings may be understood in context with the level and timing of psychosocial maturity, for which ego development appears a useful marker.
The Two Faces of Adolescents' Success With Peers: Adolescent Popularity, Social Adaptation, and Deviant Behavior
Authors: Allen Joseph P. , Porter Maryfrances R. , McFarland F. Christy , Marsh Penny , McElhaney Kathleen Boykin
Published: May 2005

This study assessed the hypothesis that popularity in adolescence takes on a twofold role, marking high levels of concurrent adaptation but predicting increases over time in both positive and negative behaviors sanctioned by peer norms. Multimethod, longitudinal data, on a diverse community sample of 185 adolescents (13 to 14 years), addressed these hypotheses. As hypothesized, popular adolescents displayed higher concurrent levels of ego development, secure attachment, and more adaptive interactions with mothers and best friends. Longitudinal analyses supported a popularity‐socialization hypothesis, however, in which popular adolescents were more likely to increase behaviors that receive approval in the peer group (e.g., minor levels of drug use and delinquency) and decrease behaviors unlikely to be well received by peers (e.g., hostile behavior with peers).
A Note on Political Science and the Metaphorical Imagination
Authors: Lunt Neil
Published: May 2005

This article discusses the role of metaphor in political science, highlighting the centrality of the metaphor historically for understanding human societies. It notes how the contemporary emphasis on global interconnectedness has generated an influx of new metaphors influenced by technological developments, such as networks and the Internet. The article highlights questions that are of enduring interest for political scientists: how to make sense of metaphor itself, and the place of metaphor in political analysis.
Social Inclusion: A Philosophical Anthropology
Authors: O'Reilly Dermot
Published: May 2005

In this article the theoretical conflations associated with the concept of social exclusion are disaggregated into a number of competing versions in terms of their social scientific and normative bases. The types of policy, analysis and critique that are engendered by these conceptions of exclusion are examined for their underlying social scientific methodology. The disjunction between positive, interpretative and critical approaches to social exclusion can only satisfactorily be broached by a methodology utilising a critical realist framework. This framework requires the integration of a theorised dialectical linkage between inclusion and exclusion. The necessary conceptual prerequisites are outlined for modelling inclusion and exclusion in a substantive, contextually sensitive manner that enables critical assessment.
Invisible Business: The Unregulated World of Political Party Commerce
Authors: Granik Sue
Published: May 2005

This article explores an area of British political party funding that is overlooked, under-researched and under-regulated: party commerce. A comparison of the trading activities of five large and five small political party headquarters units is presented using audited political party accounts made public by the Electoral Commission in 2003, the first year in which such data became available. The anomalies in party funding transparency arising from the lack of regulation of political party commerce are discussed. The dangers of allowing party commerce to continue unregulated, or of inappropriate regulation, are debated.
Popular Politics and the Ukrainian Presidential Election of 2004
Authors: Copsey Nathaniel
Published: May 2005

Ukraine's Orange Revolution in 2004 upset the consensus amongst political scientists about Ukrainian voter behaviour, challenging the notion of voter passivity. Careful pre-election planning that anticipated falsification of the ballot brought protesters to Kyiv rapidly. Sustained and overwhelming pressure from protesters eventually forced through constitutional and electoral reforms that led to the democratic resolution of the crisis.
Professionalism and the Millbank Tendency: A Response to Webb and Fisher
Authors: Negrine Ralph
Published: May 2005

This short response examines critically both the analysis and data provided in the Webb and Fisher article concerning the trends towards professionalisation. It calls for a more thorough understanding of the idea of professionalisation and a more careful use of the word when applied to particular organisational contexts.
Uncertainty, Trust and Pensions: The Case of the Current UK Reforms
Authors: Taylor‐Gooby Peter
Published: May 2005

Trust is valuable in facilitating social cooperation and is often thought to be helpful in the running of a complex modern welfare state. However, a number of sociologists, psychologists and political scientists have recently argued that trust in social institutions is in decline. One approach argues that the issue is compounded by a shift towards a more active and discriminating trust as part of a social transition towards a more reflexive society, and goes on to suggest that people often choose to place their active trust in non‐state provision. This paper examines recent quantitative and qualitative evidence on trust in state and non‐state pensions in the UK, as a context where current policy developments throw the general issues into sharp relief. It shows that patterns of trust in this setting can be understood in active terms, but that social divisions remain important in determining how active trust operates in practice. More vulnerable groups put their trust in the state, through lack of an alternative, while more confident and better‐off groups tend to pursue investment strategies which they believe will give them more individual control over their money. Social divisions remain important during current social transitions, and often receive less attention than they merit in theoretical writing.
To Retire or Not to Retire: Is There an Option for Older Workers in Hong Kong?
Authors: Chou Kee‐Lee , Chow Nelson W. S.
Published: May 2005

Over the next thirty years, Hong Kong will have a rapidly ageing population. One possible consequence of this will be a labour shortage, which means that it will be essential to strike a proper balance between the amount of time spent in work and the amount spent in retirement in old age. The balance is determined by the interaction between the aspiration of workers, employers’ attitudes to older workers, as well as the productivity of the labour force. In this article, we examine the issue based on life‐course theory and we argue that the compartmentalization of education, work and retirement must be broken by changes in social policy. We identify three groups of future older adults in the coming three decades: those who may be forced to retire early in their fifties, those who plan to retire in their sixties, and those who will continue to work until they can no longer work. The current situations of these groups are described, and social policies that are related to retirement pension scheme, age discrimination, life‐long education, and flexible work arrangements are suggested to weaken the age structuring of education and employment institutions. Our ultimate objective is to create a societal environment in which older workers have a real option either to work or to retire in the coming decades.
Financial Incentives and Job‐search Training: Methods to Increase Labour Market Integration in Contemporary Welfare States?
Authors: Malmberg‐Heimonen Ira , Vuori Jukka
Published: May 2005

In their efforts to increase labour market integration, contemporary welfare states emphasize the importance of financial incentives, active job‐searching and participation in labour market programmes. However, the effects of these policies have been minor and in some cases even inconsistent. The aim of this study was to examine whether and how financial incentives and job‐search training programmes increase re‐employment and the quality of re‐employment. A total of 1,015 unemployed persons participated in a Finnish follow‐up study with a randomized experimental design. Although no overall impact of job‐search training on re‐employment emerged, a positive effect was found for those groups of the unemployed who had a financial incentive to participate in the programme. Nevertheless, among unemployed workers with benefits at a minimum level there were no positive effects on the quality of re‐employment, and the impact decreased when unemployment was prolonged. Financial incentives and job‐search training appear to increase re‐employment among those of the unemployed who generally have better chances on the labour market, whereas these measures are not sufficient for the more disadvantaged groups of the unemployed.