bluuebunny/crossref_metadata_2025 huggingface dataset:
Party actors and party change: Does factional dominance matter?
Authors: HARMEL ROBERT , C.TAN ALEXANDER
Published: December 2004

Abstract. Other works have asked whether parties matter; this article asks whether parties’ dominant factions matter. Special focus is placed on whether change in dominant faction or coalition within the party tends to produce other significant party change, and under what circumstances. Three specific hypotheses are developed and tested, one involving motivation for change and the other two involving ‘resources’ which are necessary to make dramatic change possible. Empirical analysis rests upon original data covering seven changes in dominant faction and several dimensions of party change within five parties in the United Kingdom and Germany for the period 1950 to 1990. The authors conclude that not all of the hypothesized factors have equal impact on degree of party change, with ability of the newly dominant faction to control its coalition being primary.
Reordering the French election calendar: Forecasting the consequences for 2002
Authors: JÉRÔME BRUNO , JÉRÔME‐SPEZIARI ÉRONIQUE , S. LEWIS‐BECK MICHAEL
Published: December 2004

Abstract. French politicians sometimes change election rules for political advantage. In the Spring of 2001, the ruling Socialists pushed through the inversion of the 2002 election calendar despite stiff opposition. What were the consequences of scheduling the presidential election before the legislature elections? Employing new techniques for French election forecasting, we show that the inversion brought great vote gains to the Socialist‐led coalition in both the legislative and presidential arenas. One advantage of this forecasting methodology is that it allows counterfactual comparisons in advance of the actual election contest. Comparing the scenarios ‘inversion’ versus ‘no inversion’, the Socialist leadership appeared highly strategic and successful.
A Community of Law? ‘European’ Law and Judicial Politics: The Court of Justice and Beyond
Authors: Wincott Daniel
Published: December 2004

OVER THE LAST DECADE AND A HALF THE PART PLAYED BY THE European Court of Justice (ECJ) in the construction and operation of the European Union has become controversial. Relatively unnoticed beyond specialist legal circles in the 1960s, 1970s and early 1980s, the role of the Court featured prominently in the debates occasioned by the Treaty of Maastricht. In this article I consider the use of heroic and villainous imagery to describe the Court. After arguing that such imagery now conceals more than it reveals, I suggest that if its role is to be understood properly, the Court needs to be placed in strategic context. For convenience, the discussion of strategic context, which makes up the largest part of this article, is divided into five sections. In turn these sections consider member state executives, other European Union institutions, ‘European’ law(s), European Community law and actors in civil society (particularly litigants).
Is the State a Corporation?
Authors: Runciman David
Published: December 2004

THE PURPOSE OF THIS ARTICLE IS TO ESTABLISH THE RELEVANCE OF the question that forms its title for contemporary political theory. It is not an obvious question, both because it is not obvious what the answer is, but also because it is not obvious what it means in contemporary terms. In order to establish its significance, it is necessary first of all to establish what the question does mean, and what the term ‘corporation’ means within it. It is, ultimately, a philosophical question, and the idea of the ‘corporation’ has therefore to be understood in a more abstract sense than is usual in contemporary political discourse. Because of this, the question has a tendency to sound archaic, if not obscure, when set out in philosophical terms. Nevertheless, I hope to demonstrate its continuing relevance by looking at one particular attempt to answer it, undertaken by a political thinker who was self-professedly not a philosopher, writing in a setting that was recognizably modern. The thinker was the legal historian F.W. Maitland, who produced in the early years of this century a series of essays in which he set out the contemporary significance of a problem which he believed went to the heart of the identity of the modern state. Of course, the question of the state's corporate identity is a perennial theme of European, and more particularly German, political philosophy, but Maitland wanted to demonstrate that it was also a question of practical significance, even for those who are traditionally unmoved by grand philosophical themes. That it is still of practical significance I hope to illustrate by applying some of Maitland's conclusions to one of the fundamental questions of contemporary politics: the question of the nature of the welfare state.
Defining Fellow Compatriots as ‘Others’ ‐ National Identity in Hong Kong
Authors: Chan Elaine
Published: December 2004

Recent theoretical discussion and Empirical Evidence have shown that national identity is important at both collective and individual levels. The issue of national identity is particularly relevant to the community of Hong Kong, which was reunited with the People's Republic of China (PRC) on 1 July 1997. The fact that 97 per cent of Hong Kong's population is Chinese does not guarantee the automatic development of a sense of national identity. Mutual understanding between the people of the two places is not as easy and natural as one might expect, for objective differences, such as those found in the political, legal and economic systems, make the ‘other’ more stranger than kin. Such difficulties were compounded by the phenomenon that, unlike in many former colonies, the people of Hong Kong did not abhor their outgoing British rulers; in fact many were quite nostalgic about the colonial period.
Democratization or Oligarchic Restructuring? The Politics of Reform in Malaysia
Authors: Singh Hari
Published: December 2004

Malaysia's impact on World Politics Exceeds the usual level of inf luence expected of a small state in an international system. It has exercised a leadership role in the Commonwealth, the Association of Southeast Asian Nations, the Non-aligned Movement and South-South Cooperation, and has tried to modify the agenda of Asia-Pacific Economic Cooperation through the East Asian Economic Caucus. In addition, Malaysia has championed selfdetermination, articulated an ‘Asian’ approach to the issues of human rights and democratization, and has contributed to international peace-keeping operations under the aegis of the United Nations, where it has also served as a non-permanent member of its Security Council and chaired its General Assembly. These achievements in themselves are sufficient to draw scholarly attention to Malaysia although, it must be admitted, that the arena of foreign policy itself is part of domestic politics. In this domain too, Malaysia has long been of interest to political scientists. For an ethnically divided society, Malaysia has maintained a remarkable record of political stability. This in turn had contributed to sustained development, and up till the advent in 1997 of the Asian financial crisis, Malaysia was poised to be the next newly-industrialized country in the Asia-Pacific.
The Return of Populism ‐ The 2000 Romanian Elections
Authors: Mungiu‐Pippidi Alina
Published: December 2004

During The Years Immediately Following The Fall Of The Ceausescu regime in 1989, Romania fulfilled the requirements of an ‘electoral democracy’. Free and reasonably fair elections regularly produced parliaments (1990, 1992) and governments dominated by the communist successor parties run by Ion Iliescu, a member of the old nomenklatura. Once elected, these institutions operated in principle within the framework of procedural democracy, but in practice often broke the rules and norms accepted in the West as characteristic of liberal democracy. When this occurred public opinion was either too weak, or divided, or simply too indifferent to demand more accountability. Further impoverishment of the poorest citizens due to mismanagement of the economy and rampant corruption contributed to the demise of the post-communist regime in 1996, which in turn led to the hope that with electoral democracy established, the development of democratic institutions and government accountability would follow.
Who Knows Best? The Creation of the Citizen‐initiated Referendum in New Zealand
Authors: Parkinson John
Published: December 2004

Among Arguments Advanced In Favour Of Direct Democracy, legitimacy pleas loom large. If the rules governing people can only be legitimate when those rules arise from and represent the will of all, then it is commonly argued that people should have the right to vote not just for representatives but on substantive issues of public policy as well. To claim otherwise is regarded as anti-democratic: for example, Bogdanor writes that ‘in the final analysis, the arguments against referendums are arguments against democracy’, while Saward asks, ‘What better way to maximize responsiveness of rulers to the ruled than by fostering a system in which the ruled themselves make the decisions?’
Speaking of Books: Christian Marriage
Authors: Martin Dennis D.
Published: December 2004

Book reviewed in this article:

Glenn W. Olsen (ed.), Christian Marriage: A Historical Study
The Relationship among Biases, Misperceptions, and the Introduction of Pioneering Products: Examining Differences in Venture Decision Contexts
Authors: Simon Mark , Houghton Susan M.
Published: December 2004

Although biases influence the decision to take entrepreneurial actions, studies have not differentiated among entrepreneurial decision environments. These environments vary greatly and affect which biases arise and their context–specific consequences. Focusing on the role of firm size, age, and type of product introduction, we propose that entrepreneurs in smaller, younger, firms, who are considering pioneering, are more likely to exhibit illusion of control, law of small numbers, and reasoning by analogy. These biases contribute to underestimating competition, overestimating demand, and overlooking requisite assets. We hope to spur researchers to examine information processing across different types of entrepreneurial firms and actions.
Two‐dimensional gel analysis of haemolymph proteins from Plasmodium‐melanizing and ‐non‐melanizing strains of Anopheles gambiae
Authors: Chun J. , McMaster J. , Han Y.‐S. , Schwartz A. , Paskewitz S. M.
Published: December 2004

Haemolymph polypeptides from Plasmodium‐refractory and ‐susceptible mosquitoes were compared by one‐ and two‐dimensional gel electrophoresis. The refractory strain of Anopheles gambiae kills malaria parasites by a humoral melanization mechanism whereas the parasites develop normally in susceptible mosquitoes. The two strains respond in a similar manner to carboxy‐methyl‐Sephadex beads that have been injected into the thoracic haemocoel, i.e. beads are strongly melanized in refractory but not susceptible mosquitoes. Protein profiles were compared between strains following cold shock (naïve control), saline injection and Sephadex bead injection. Using the susceptible naïve control as the standard, eight constitutively expressed polypeptides were specific to naïve susceptible mosquitoes while twelve other spots were reduced, enhanced or specific to refractory mosquitoes. Several of the strain‐specific spots probably comprise related pairs (one in each strain) which vary only in isoelectric focusing point. Nine spots were induced by sham injection or by an injection of beads or saline, but none was reproducibly different between the strains. Amino acid sequence analysis of one of the refractory strain‐specific spots identified it as AgSp14D1, an A. gambiae infection‐responsive serine protease that is most similar to the Drosophila gene easter and Manduca prophenoloxidase activating enzyme. This gene maps to polytene chromosome division 14, which has been implicated in the melanization phenotype by quantitative trait loci mapping.
Cystic fibrosis mutation screening before assisted reproduction
Authors: Gazvani R. , Lewis‐Jones D. I.
Published: December 2004

Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians, with a reported incidence of one in 2500. In 97–98% of men with CF, a congenital bilateral absence of the vas deferens (CBAVD) blocks the transport of spermatozoa from testicular or epididymal structures to the outer genital tract, resulting in azoospermia. Abnormalities in semen parameters have also been identified in males with CF. Around 10% of obstructive azoospermia is congenital and is due to mutations the CF gene. It is therefore suggested that men who have CBAVD should be considered for CF screening prior to intracytoplasmic sperm injection (ICSI) treatment. Men with azoospermia of unknown origin should also be considered for screening. Couples requesting surgical sperm retrieval/ICSI should therefore be advised and counselled to bear an elevated risk for CF in their offspring. Counselling of these couples is vitally important in order to help them understand and cope with the diagnosis.
Coexistence in Mediterranean warblers: ecological differences or interspecific territoriality?
Authors: Martin Jean‐Louis , Thibault Jean‐Claude
Published: December 2004

We studied the coexistence of four species of Sylvia warblers living in Mediterranean matorral in order to identify the respective role of ecological segregation and of interspecific territoriality in explaining the local distribution of these four species. Data on habitat use, foraging behaviour and interspecific spacial segregation were collected on Corsica and on Spargi (Sardinia) islands. Despite large overlap in patch selection and in foraging behaviour the four species did segregate ecologically and behaviourally while foraging (differences in the choice of plant species used for foraging, in the height of the plant selected, in the selection of the portion of the plant volume used and in the selection of the plant structure explored). Complementarity in foraging behaviour was observed in the morphologically and ecologically closest species: the Dartford (Sylvia undata) and the Marmora's (Sylvia sarda) warblers. We did not observe any evidence of direct interspecific interactions in song, alarm, or aggressive behaviour. Nor did we observe patterns of spatial distribution that would support the idea of coexistence by interspecific territorial exclusion. These results contrast with the results of Cody & Walter (1976) suggesting interspecific territoriality in Mediterranean Sylvia warblers. They are consistent with other published results emphasizing ecological differences as explanation for species coexistence.
Biogeography of lemurs in the humid forests of Madagascar: the role of elevational distribution and rivers
Authors: Goodman Steven M. , Ganzhorn Jörg U.
Published: December 2004

Aim  Elucidation of the influence of river systems on the distribution of lemurs.

Location  Humid forests of Madagascar.

Methods  We review the elevational distribution of Malagasy lemurs to address hypotheses of the role of rivers as physical barriers.

Main conclusions  Rivers are barriers for some species. However, several lemurs have altitudinal ranges that are higher than the headwaters of a given river, and in such cases these species are able to disperse across the source.
Associations of smoking, alcohol and physical activity with risk factors for coronary heart disease and diabetes risk in the first follow‐up cohort of the Heart Disease and Diabetes Risk Indicators in a Screened Cohort study (HDDRISC‐1)
Authors: Godsland I. F. , Leyva F. , Walton C. , Worthington M. , Stevenson J. C.
Published: December 2004

Godsland IF, Levya F, Walton C, Worthington M, Stevenson JC (Imperial College School of Medicine, London, UK). Associations of smoking, alcohol and physical activity with risk factors for coronary heart disease and diabetes in the first follow‐up cohort of the Heart Disease and Diabetes Risk Indicators in a Screened Cohort study. J Intern Med 1998; 244: 33–41.

Objectives

To investigate the associations between risk factors for cardiovascular disease and cigarette smoking, alcohol intake, and physical activity in a group of predominantly healthy men.

Design

Cohort study with baseline characterisation, clinical follow‐up, and identification of predictors of coronary artery disease and diabetes.

Setting

University hospital metabolic day ward.

Subjects

Participants in a company health programme (n= 742).

Main outcome measures

Routine haematology and biochemistry, cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol (on a subset of 522 subjects), and glucose and insulin levels during a 3 h oral glucose tolerance test (OGTT).

Results

Independent associations with previous cigarette smoking included high uric acid and low HDL cholesterol, and with current cigarette smoking, high haemoglobin and white cell count and low OGTT insulin. Increasing alcohol intake was associated with increasing blood pressure, uric acid, HDL cholesterol and fasting glucose. The moderate range of exercise intensity in this cohort was associated with decreasing systolic blood pressure, fasting insulin and OGTT glucose and insulin. Factor analysis distinguished principal factors comprising features of the metabolic syndrome with low physical activity, and high white cell count, high haemoglobin concentration and low HDL cholesterol with increasing previous and current cigarette smoking and alcohol intake.

Conclusions

Some characteristics of the metabolic syndrome were seen with previous but not current smoking habit. Regular alcohol consumption was associated with mainly unfavourable metabolic characteristics, although there was an independent beneficial association with HDL cholesterol. The improved metabolic syndrome profile seen with increasing exercise is consistent with even moderate degrees of physical activity having beneficial effects on metabolism.
Bank Safety and Soundness and the Structure of Bank Supervision: A Cross‐Country Analysis
Authors: Barth James R. , Dopico Luis G. , Nolle Daniel E. , Wilcox James A.
Published: December 2004

Two central questions about the structure of bank supervision are whether central banks should supervise banks and whether to have multiple supervisors. We use data for 70 countries across developed, emerging and transition economies to estimate statistical connections between banking performance, the structure of bank supervision, permissible banking activities, legal environments, banking market structure and macroeconomic conditions. We find that where central banks supervise banks, banks tend to have more non‐performing loans. Countries with multiple supervisors have lower capital ratios and higher liquidity risk. We also find that conclusions from non‐transition economies may not necessarily apply to transition economies.
Impact of International Cross‐listing on Local Exchanges: Evidence from Chile
Authors: Jayakumar Vivekanand
Published: December 2004

This article examines the impact of international cross‐listings on local stock exchanges by focusing on the experience of Chile. First, we analyse the consequences to the domestically traded shares of a sample of Chilean companies that undertook ADR listings. Our findings show that there is no indication of order‐flow migration from the domestic market following cross‐listings. There is, however, evidence that in the aftermath of cross‐listings trading becomes concentrated in the ADR market. There is also some indication of an increase in the base‐level price volatility of the underlying stock series following cross‐listings. Second, we study the changes in Chile's local stock market vis‐à‐vis the ADR market. We observe that the increase in the size and liquidity of the domestic stock exchange is overshadowed by the rapid growth of the ADR market. From a policy perspective, the continued rise in the number of companies undertaking international cross‐listings can cause the local stock markets to become secondary role players relative to the major foreign exchanges, thus affecting domestic financial development.
Feeding Performance in Heterochronic Alpine Newts is Consistent with Trophic Niche and Maintenance of Polymorphism
Authors: Denoël Mathieu
Published: December 2004

The feeding performances of two heterochronic morphs of the Alpine newt Triturus alpestris were investigated in laboratory experiments. Although both morphs are able to feed in the aquatic habitat, the hydrodynamics of prey capture differ between morphs. In paedomorphs water sucked with prey is expelled behind the mouth through gill bars. In metamorphs, water is expelled by the mouth as gill slits are closed. Feeding performance was better in paedomorphs than in metamorphs when foraging on aquatic crustaceans, but paedomorphs were less successful when foraging on terrestrial invertebrates caught at the water surface. These differences in prey capture success related to prey type allow the two morphs to use specific resources in their aquatic habitat. These results are consistent with previous studies that showed diet differentiation between morphs in natural populations. Such resource partitioning is a factor favouring the maintenance of facultative paedomorphosis in natural populations.
Male Mate Choice in the Guppy (Poecilia reticulata): Do Males Prefer Larger Females as Mates?
Authors: Herdman Emily J. E. , Kelly Clint D. , Godin Jean‐Guy J.
Published: December 2004

Although females are the choosier sex in most species, male mate choice is expected to occur under certain conditions. Theoretically, males should prefer larger females as mates in species where female fecundity increases with body size. However, any fecundity‐related benefits accruing to a male that has mated with a large female may be offset by an associated fitness cost of shared paternity if large females are more likely to be multiply mated than smaller females in nature. We tested the above hypothesis and assumption using the Trinidadian guppy (Poecilia reticulata) by behaviourally testing for male mate choice in the laboratory and by ascertaining (with the use of microsatellite DNA genotyping) patterns of male paternity in wild‐caught females. We observed significant positive relationships between female body length and fecundity (brood size) and between body length and level of multiple paternity in the broods of females collected in the Quaré River, Trinidad. In laboratory tests, a preference for the larger of two simultaneously‐presented virgin females was clearly expressed only when males were exposed to the full range of natural stimuli from the females, but not when they were limited to visual stimuli alone. However, as suggested by our multiple paternity data, males that choose to mate with large females may incur a larger potential cost of sperm competition and shared paternity compared with males that mate with smaller females on average. Our results thus suggest that male guppies originating from the Quaré River possess mating preferences for relatively large females, but that such preferences are expressed only when males can accurately assess the mating status of encountered females that differ in body size.
Neuronal coding of interaural transient envelope disparities
Authors: Heil Peter
Published: December 2004

Onsets are salient and important transient (i.e. dynamic) features of acoustic signals, and evoke vigorous responses from most auditory neurons, but paradoxically these onset responses have most often been analysed with respect to steady‐state stimulus features, e.g. the sound pressure level (SPL). In nearly all studies concerned with the coding of differences in SPL at the two ears (interaural level differences; ILDs), which provide a major cue for the azimuthal location of high frequency sound sources, interaural onset disparities were covaried with ILD, but the possibly confounding effects of this covariation on neuronal responses have been entirely neglected. Therefore, dichotic stimulus paradigms were designed here in which onset and steady‐state features were varied independently. Responses were recorded from single neurons in the inferior colliculus of rats, anaesthetized with pentobarbital and xylazine. It is demonstrated that onset responses, or the onset response components of neurons with more complex temporal response patterns, are dependent on the binaural combination of dynamic envelope features associated with conventional ILD stimulus paradigms, but not on the binaural combination of steady‐state SPLs reached after the onset. In contrast, late or sustained response components appear more sensitive to the binaural combination of steady‐state SPLs. These data stress the general necessity for a separate analysis of onset and late response components, with respect to different stimulus features, and suggest a need for re‐evaluation of existing studies on ILD coding. The sensitivity of onset responses to the binaural combination of envelope transients, rather than to steady‐state ILD, is in line with their sensitivity to other interaural envelope disparities, created by stationary or moving sounds.
Co‐localized neuropeptide Y and GABA have complementary presynaptic effects on sensory synaptic transmission
Authors: Parker David , Söderberg Charlotte , Zotova Elena , Shupliakov Oleg , Langel Ülo , Bartfai Tamas , Larhammar Dan , Brodin Lennart , Grillner Sten
Published: December 2004

We have examined the morphological relationship of neuropeptide Y (NPY) and GABAergic neurons in the lamprey spinal cord, and the physiological effects of NPY and GABAB receptor agonists on afferent synaptic transmission.

 NPY‐containing fibres and cell bodies were identified in the dorsal root entry zone. NPY immunoreactive (–ir) fibres made close appositions with primary afferent axons. Co‐localization of NPY and GABA‐ir was found in the dorsal horn and dorsal column. Fifty‐two per cent of NPY‐ir profiles showed immunoreactivity to GABA at the ultrastructural level. Electron microscopic analysis showed that NPY‐immunoreactivity was present throughout the axoplasm, including over dense core vesicles, whereas GABA‐immunoreactivity was mainly found over small synaptic vesicles.

 Synthetic lamprey NPY, and the related peptide, peptide YY, reduced the amplitude of monosynaptic afferent EPSPs in spinobulbar neurons. NPY had no significant effect on the postsynaptic input resistance or membrane potential, the electrical component of the synaptic potential, or the response to glutamate, but it could reduce the duration of presynaptic action potentials, suggesting that it was acting presynaptically. NPY also reduced the excitability of the spinobulbar neurons, suggesting at least one postsynaptic effect. Because NPY and GABA colocalize, we compared the effects of NPY and the GABAB agonist baclofen. Both presynaptically reduced EPSP amplitudes, baclofen having a larger effect and a faster onset and recovery than NPY. The GABAB antagonist phaclofen reduced the effect of baclofen, but not that of NPY. We conclude that NPY and GABA are colocalized in terminals in the dorsal spinal cord of the lamprey, and that they have complementary actions in modulating sensory inputs.
Odour coding is bilaterally symmetrical in the antennal lobes of honeybees (Apis mellifera)
Authors: Galizia C. Giovanni , Nägler Karl , Hölldobler Bert , Menzel Randolf
Published: December 2004

The primary olfactory neuropil, the antennal lobe (AL) in insects, is organized in glomeruli. Glomerular activity patterns are believed to represent the across‐fibre pattern of the olfactory code. These patterns depend on an organized innervation from the afferent receptor cells, and interconnections of local interneurons. It is unclear how the complex organization of the AL is achieved ontogenetically. In this study, we measured the functional activity patterns elicited by stimulation with odours in the right and the left AL of the same honeybee (Apis mellifera) using optical imaging of the calcium‐sensitive dye calcium green. We show here that these patterns are bilaterally symmetrical (n = 25 bees). This symmetry holds true for all odours tested, irrespective of their role as pheromones or as environmental odours, or whether they were pure substances or complex blends (n = 13 odours). Therefore, we exclude that activity dependent mechanisms local to one AL determine the functional glomerular activity. This identity is genetically predetermined. Alternatively, if activity dependent processes are involved, bilateral connections would have to shape symmetry, or, temporal constraints could lead to identical patterns on both sides due to their common history of odour exposure.
Truncation of the Shaker‐like voltage‐gated potassium channel, Kv1.1, causes megencephaly
Authors: Petersson Susanna , Persson Ann‐Sophie , Johansen Jeanette E. , Ingvar Martin , Nilsson Johanna , Klement Göran , Århem Peter , Schalling Martin , Lavebratt Catharina
Published: December 2004

The megencephaly mouse, mceph/mceph, displays dramatically increased brain volume and hypertrophic brain cells. Despite overall enlargement, the mceph/mceph brain appears structurally normal, without oedema, hydrocephaly or leukodystrophy, and with only minor astrocytosis. Furthermore, it presents striking disturbances in expression of trophic and neuromodulating factors within the hippocampus and cortex. Using a positional cloning approach we have identified the mceph mutation. We show that mceph/mceph mice carry an 11‐base‐pair deletion in the gene encoding the Shaker‐like voltage‐gated potassium channel subtype 1, Kcna1. The mutation leads to a frame shift and the predicted MCEPH protein is truncated at amino acid 230 (out of 495), terminating with six aberrant amino acids. The expression of Kcna1 mRNA is increased in the mceph/mceph brain. However, the C‐terminal domains of the corresponding Kv1.1 protein are absent. The putative MCEPH protein retains only the N‐terminal domains for channel assembly and may congregate nonfunctional complexes of multiple Shaker‐like subunits. Indeed, whereas Kcna2 and Kcna3 mRNA expression is normal, the mceph/mceph hippocampus displays decreased amounts of Kv1.2 and Kv1.3 proteins, suggesting interactions at the protein level. We show that mceph/mceph mice have disturbed brain electrophysiology and experience recurrent behavioural seizures, in agreement with the abnormal electrical brain activity found in Shaker mutants. However, in contrast to the commonly demonstrated epilepsy‐induced neurodegeneration, we find that the mceph mutation leads to seizures with a concomitant increase in brain size, without overt neural atrophy.
Post‐lesion transcommissural growth of olivary climbing fibres creates functional synaptic microzones
Authors: Sugihara Izumi , Lohof Ann M. , Letellier Mathieu , Mariani Jean , Sherrard Rachel M.
Published: December 2004

In the adult mammalian central nervous system, reinnervation and recovery from trauma is limited. During development, however, postlesion plasticity may generate alternate paths, providing models to investigate reinnervating axon–target interactions. After unilateral transection of the neonatal rat olivocerebellar path, axons from the ipsilateral inferior olive grow into the denervated hemicerebellum and develop climbing fibre (CF)‐like arbors on Purkinje cells (PCs). However, the synaptic function and extent of PC reinnervation remain unknown. In adult rats pedunculotomized on postnatal day 3 the morphological and electrophysiological properties of reinnervating olivocerebellar axons were studied, using axonal reconstruction and patch‐clamp PC recording of CF‐induced synaptic currents. Reinnervated PCs displayed normal CF currents, and the frequency of PC reinnervation decreased with increasing laterality. Reinnervating CF arbors were predominantly normal but 6% branched within the molecular layer forming smaller secondary arbors. CFs arose from transcommissural olivary axons, which branched extensively near their target PCs to produce on average 36 CFs, which is six times more than normal. Axons terminating in the hemisphere developed more CFs than those terminating in the vermis. However, the precise parasagittal microzone organization was preserved. Transcommissural axons also branched, although to a lesser extent, to the deep cerebellar nuclei and terminated in a distribution indicative of the olivo‐cortico‐nuclear circuit. These results show that reinnervating olivocerebellar axons are highly plastic in the cerebellum, compensating anatomically and functionally for early postnatal denervation, and that this reparation obeys precise topographic constraints although axonal plasticity is modified by target (PC or deep nuclear neurons) interactions.
A role for dendritic protein synthesis in hippocampal late LTP
Authors: Bradshaw K. D. , Emptage N. J. , Bliss T. V. P.
Published: December 2004

The late temporal component of long‐term potentiation (LTP), a putative neural mechanism for information storage in the brain, is protein synthesis‐dependent, but the site of obligatory protein synthesis is not known. Here we show that when the protein synthesis inhibitor emetine is applied locally to the apical dendritic field of CA1 pyramidal cells in the murine hippocampus, late LTP is impaired at apical but not at basal dendrites, and conversely when emetine is applied locally to basal dendrites, late LTP is impaired only at basal dendrites. Thus, local protein synthesis modulates the expression of tetanically induced late LTP at Schaffer‐commissural synapses on CA1 pyramidal cells.
Protein synthesis in the amygdala, but not the auditory thalamus, is required for consolidation of Pavlovian fear conditioning in rats
Authors: Maren Stephen , Ferrario Carrie R. , Corcoran Kevin A. , Desmond Timothy J. , Frey Kirk A.
Published: December 2004

The amygdala is an essential neural substrate for Pavlovian fear conditioning. Nevertheless, long‐term synaptic plasticity in amygdaloid afferents, such as the auditory thalamus, may contribute to the formation of fear memories. We therefore compared the influence of protein synthesis inhibition in the amygdala and the auditory thalamus on the consolidation of Pavlovian fear conditioning in Long–Evans rats. Rats received three tone‐footshock trials in a novel conditioning chamber. Immediately after fear conditioning, rats were infused intra‐cranially with the protein synthesis inhibitor, anisomycin. Conditional fear to the tone and conditioning context was assessed by measuring freezing behaviour in separate retention tests conducted at least 24 h following conditioning. Post‐training infusion of anisomycin into the amygdala impaired conditional freezing to both the auditory and contextual stimuli associated with footshock. In contrast, intra‐thalamic infusions of anisomycin or a broad‐spectrum protein kinase inhibitor [1‐(5′‐isoquinolinesulphonyl)‐2‐methylpiperazine, H7] did not affect conditional freezing during the retention tests. Pre‐training intra‐thalamic infusion of the NMDA receptor antagonist 2‐amino‐5‐phosphonopentanoic acid (APV), which blocks synaptic transmission in the auditory thalamus, produced a selective deficit in the acquisition of auditory fear conditioning. Autoradiographic assays of cerebral [14C]‐leucine incorporation revealed similar levels of protein synthesis inhibition in the amygdala and thalamus following intra‐cranial anisomycin infusions. These results reveal that the establishment of long‐term fear memories requires protein synthesis in the amygdala, but not the thalamus, after auditory fear conditioning. Forms of synaptic plasticity that depend on protein synthesis, such as long‐term potentiation, are likely candidates for the encoding and long‐term storage of fear memories in the amygdala.
Environmental enrichment during adolescence reverses the effects of prenatal stress on play behaviour and HPA axis reactivity in rats
Authors: Morley‐Fletcher Sara , Rea Monica , Maccari Stefania , Laviola Giovanni
Published: December 2004

Prenatal stress (PS) can produce profound and long‐lasting perturbations of individual adaptive capacities, which in turn can result in an increased proneness to behavioural disorders. Indeed, in PS rats there is evidence of impaired social play behaviour, disturbances in a variety of circadian rhythms, enhanced anxiety and increased hypothalamic–pituitary–adrenal (HPA) axis reactivity. This study was designed to experimentally investigate the degree of reversibility of PS‐induced disturbances of social play and HPA reactivity by assessing the effect of the enrichment of the physical environment on PS rats during periadolescence. PS subjects showed a reduced expression of social play behaviour and a prolonged corticosterone secretion in response to restraint stress, but both these effects were markedly reversed following environmental enrichment. Interestingly, the enrichment procedure increased social behaviour but had no effect on corticosterone secretion in nonstressed animals, indicating a differential impact of the postnatal environment as a function of prenatal background. As a whole, results clearly indicate that rats prenatally exposed to stress can benefit during periadolescence from the modulatory effects of an enriched environment. Moreover, they confirm that PS may well represent a suitable animal model for the design and testing of new therapeutic strategies for behavioural disorders produced by early insults.
Functional segregation of plural regions representing cardinal contours in cat primary visual cortex
Authors: Wang Gang
Published: December 2004

Our previous data based on an imaging study suggested that, in cat area 17, the representations of cardinal orientations overlap less than the representation of their nearby angles. The purpose of this study was to further investigate the underlying single‐cell properties. Optical imaging was performed first to map the cortical regions corresponding to the four principal contours, the two cardinals and the two obliques. The cortical region activated by a principal orientation but not by the +10° or −10° neighbouring angles, namely the area with optically relative independent orientation selectivity (RIOS), was mapped together with the regions that overlapped with the +10° and/or −10° neighbouring angles (non‐RIOS). Electrode penetrations were targeted to the RIOS and non‐RIOS regions in each of the four orientations. A comparison between the RIOS and the non‐RIOS regions documented a significantly higher percentage of cells with the orientation preference of the cardinal orientations in the cardinal RIOS region than that seen in the other regions. Additionally, the difference in the tuning width of cells between the RIOS and non‐RIOS in the cardinal region was significantly larger than the difference between the RIOS and non‐RIOS in the oblique region. The cells in the cardinal RIOS region were tuned more sharply and the cells in cardinal non‐RIOS region more broadly than the oblique RIOS and/or the non‐RIOS region, which showed no significant difference. These data strongly suggest the existence of functional segregation in the region corresponding to the cardinal contours.
An in vitro and in vivo study of early deficits in associative learning in transgenic mice that over‐express a mutant form of human APP associated with Alzheimer's disease
Authors: Domínguez‐del‐Toro Eduardo , Rodríguez‐Moreno Antonio , Porras‐García Elena , Sánchez‐Campusano Raudel , Blanchard Véronique , Laville Michel , Böhme Georg A. , Benavides Jesús , Delgado‐García José M.
Published: December 2004

Transgenic mice over‐expressing a mutated form of the human amyloid precursor protein (APP, 695 isoform) bearing a mutation associated with Alzheimer's disease (V642I, so‐called London mutation, hereafter APPLd2) and wild‐type controls were studied at age periods (3 and 10 months) prior to the overt development of neuritic amyloid plaques. Both 3‐ and 10‐month‐old APPLd2 mice had reflex eyelid responses like those of controls, but only younger mice were able to acquire a classical conditioning of eyelid responses in a trace paradigm. In vitro studies on hippocampal slices showed that 10‐month‐old APPLd2 mice also presented deficits in paired‐pulse facilitation and long‐term potentiation, but presented a normal synaptic activation of CA1 pyramidal cells by the stimulation of Schaffer collaterals. It is proposed that definite functional changes may appear well in advance of noticeable structural alterations in this animal model of Alzheimer's disease, and that specific learning tasks could have a relevant diagnostic value.
Brain‐derived neurotrophic factor induces NMDA receptor subunit one phosphorylation via ERK and PKC in the rat spinal cord
Authors: Slack Sarah E. , Pezet Sophie , McMahon Stephen B. , Thompson Stephen W. N. , Malcangio Marzia
Published: December 2004

Brain‐derived neurotrophic factor (BDNF) is involved in the modulation of synaptic transmission in the spinal cord, and several circumstantial lines of evidence suggest that it has the ability to modulate the activity of the NMDA receptor. Here we dissect the signalling mechanisms by which BDNF exerts its neuromodulatory role on the NMDA receptor subunit 1 (NR1). Using a preparation of adult isolated dorsal horn with dorsal roots attached, we found that electrical stimulation of roots induced a concomitant release of BDNF and an increased phosphorylation of NR1, which was partly prevented by the BDNF sequestering molecule, TrkB‐IgG. Using a second approach in vitro, we confirmed that both exogenous glutamate and BDNF (but not other neurotrophins) were able to induce NR1 phosphorylation, in particular at residue Ser‐897. NR1 phosphorylation induced by BDNF was blocked by a TrkB inhibitor, an ERK inhibitor and a PKC inhibitor but not a PKA inhibitor. Activation of PKC using exogenous PMA also led to NR1 phosphorylation. Together these data suggest that BDNF modulates the activity of the receptor by phosphorylation via the kinases ERK and PKC.
Adult neural progenitor cells provide a permissive guiding substrate for corticospinal axon growth following spinal cord injury
Authors: Pfeifer Katharina , Vroemen Maurice , Blesch Armin , Weidner Norbert
Published: December 2004

Adult neural progenitor cells (NPC) are an attractive source for cell transplantation and neural tissue replacement after central nervous system (CNS) injury. Following transplantation of NPC cell suspensions into the acutely injured rat spinal cord, NPC survive; however, they migrate away from the lesion site and are unable to replace the injury‐induced lesion cavity. In the present study we examined (i) whether NPC can be retained within the lesion site after co‐transplantation with primary fibroblasts, and (ii) whether NPC promote axonal regeneration following spinal cord injury. Co‐cultivation of NPC with fibroblasts demonstrated that NPC adhere to fibroblasts and the extracellular matrix produced by fibroblasts. In the presence of fibroblasts, the differentiation pattern of co‐cultivated NPC was shifted towards glial differentiation. Three weeks after transplantation of adult spinal‐cord‐derived NPC with primary fibroblasts as mixed cell suspensions into the acutely injured cervical spinal cord in adult rats, the lesion cavity was completely replaced. NPC survived throughout the graft and differentiated exclusively into glial cells. Quantification of neurofilament‐labeled axons and anterogradely labeled corticospinal axons indicated that NPC co‐grafted with fibroblasts significantly enhanced axonal regeneration. Both neurofilament‐labeled axons and corticospinal axons aligned longitudinally along GFAP‐expressing NPC‐derived cells, which displayed a bipolar morphology reminiscent of immature astroglia. Thus, grafted astroglial differentiated NPC promote axon regrowth following spinal cord injury by means of cellular guidance.
Importance of NO/cGMP signalling via cGMP‐dependent protein kinase II for controlling emotionality and neurobehavioural effects of alcohol
Authors: Werner Claudia , Raivich Gennadij , Cowen Michael , Strekalova Tatyana , Sillaber Inge , Buters Jeroen T. , Spanagel Rainer , Hofmann Franz
Published: December 2004

Cyclic GMP is a second messenger for nitric oxide (NO) that acts as a mediator for many different physiological functions. The cGMP‐dependent protein kinases (cGKs) mediate cellular signalling induced by NO and cGMP. Here, we explored the localization of cGMP‐dependent protein kinase type II (cGKII) in the mouse brain. In situ hybridization revealed high levels of cGKII mRNA in cerebral cortex, thalamic nuclei, hypothalamic nuclei, and in several basal forebrain regions including medial septum, striatum and amygdala. The close link to NO and the distribution pattern of cGKII suggested that this enzyme might be involved in emotional reactions and responses to drugs of abuse. Therefore, cGKII knockout animals (cGKII–/–) were compared with littermate controls in behavioural tests (i) for emotion‐linked and (ii) for acute and chronic ethanol responses. Deletion of cGKII did not influence aggressive behaviour but led to enhanced anxiety‐like behaviour. In terms of acute responses to ethanol, cGKII–/– mice were hyposensitive to hypnotic doses of ethanol as measured by the loss of righting reflex, without an alteration in their blood alcohol elimination. In a two‐bottle free choice test, cGKII–/– mice showed elevated alcohol consumption. No taste differences to sweet solutions were observed compared to control animals. In summary, our data show that cGKII activity modulates anxiety‐like behaviour and neurobehavioural effects of alcohol.
Coexistence of competitors in metacommunities due to spatial variation in resource growth rates; does R * predict the outcome of competition?
Authors: Abrams Peter A. , Wilson William G.
Published: December 2004

Simple mathematical models are used to investigate the coexistence of two consumers using a single limiting resource that is distributed over distinct patches, and that has unequal growth rates in the different patches. Relatively low movement rates or high demographic rates of an inefficient resource exploiter allow it to coexist at a stable equilibrium with a more efficient species whose ratio of movement to demographic rates is lower. The range of conditions allowing coexistence depends on the between‐patch heterogeneity in resource growth rates, but this range can be quite broad. The between‐patch movement of the more efficient consumer turns patches with high resource growth rates into sources, while low‐growth‐rate patches effectively become sinks. A less efficient species can coexist with or even exclude the more efficient species from the global environment if it is better able to bias its spatial distribution towards the source patches. This can be accomplished with density independent dispersal if the less efficient species has a lower ratio of per capita between‐patch movement rate to demographic rates. Conditions that maximize the range of efficiencies allowing coexistence of two species are: a relatively high level of heterogeneity in resource growth conditions; high dispersal (or low demographic rates) of the superior competitor; and low dispersal (or high demographic rates) of the inferior competitor. Global exclusion of the more efficient competitor requires that the inferior competitor have sufficient movement to also produce a source‐sink environment.