bluuebunny/crossref_metadata_2025 huggingface dataset:
Criminal Attempts and the Subjectivism/Objectivism Debate
Authors: Mathis Stephen
Published: August 2004

Abstract.  This essay offers a particular view of the distinction between criminal attempts and actions that could constitute “mere preparation” for the later commission of a crime, that prioritizes a proper balancing of public safety and the protection of individual liberty. Modeled after Hart's distinction between the general justifying aims and the principles of distribution of a system of punishment, this view allows a coherent way of distinguishing between attempts and mere preparation that avoids many difficulties associated with subjectivist and objectivist approaches.**
Divine Foreknowledge and Freedom of the Will: Contemporary Work Revisits Calvinism
Authors: Anderson Owen
Published: August 2004

Books reviewed:

Linda Trinkaus Zagzebski, ‘Recent Work on Divine Foreknowledge and Free Will’ in Robert Kane (ed.), The Oxford Handbook of Free Will

Millard J. Erickson, What Does God Know and When Does He Know It?
Government Performance and Political Accountability at Subnational Level: The Electoral Fate of Local Incumbents in Norway
Authors: Martinussen Pål E.
Published: August 2004

Under which circumstances do voters turn against governing parties for their performance in office? This question forms the basis of the considerable research field often referred to as the ‘VP‐literature’, which seeks to explain support for governments as a function of economic and political outcomes. After thirty years and more than 200 studies the economic part of the VP‐function still remains much better explored than the political part. In addition, focus has almost solely been on the national level so far. The present study therefore sets out to bridge the gap between the VP‐literature and the field of coalition studies to examine the relevance of the VP‐function for local elections. The ambition is to arrive at a more satisfactory understanding of the political part of the model. Results from the two most recent Norwegian local elections, in 1995 and 1999, reveal that the electoral liability associated with office is almost three percentage points. The multivariate analysis then tests systematically under which economic and political conditions local incumbents suffer the most electorally. The rate of unemployment plays an important role in how the voters evaluate the incumbents, since each extra percentage point of unemployment translates into additional loss for the incumbents. The levels of local fees and charges and service coverage are also significant. Political characteristics are furthermore highly relevant, since the numerical status of the government is in fact one of the most important predictors of electoral success, the advantage enjoyed by minority cabinets over majority coalitions amounting to more than three percentage points of the popular vote. Other important political determinants of local electoral performance are one‐party status, national support and ideological closeness.
Deliberative Democracy and the Deliberative Poll on the Euro
Authors: Hansen Kasper M. , Andersen Vibeke Normann
Published: August 2004

Focus on the concept of deliberative democracy has increased rapidly within recent decades. However, the concept is weakly defined, if at all. ‘Deliberation’ is defined as an unconstrained exchange of arguments that involves practical reasoning and potentially leads to a transformation of preferences. Throughout the 1990s several innovative democratic experiments have flourished focusing on citizens’ involvement and deliberation. The Deliberative Poll in focus here is, according to many parameters, the most ambitious one. The article presents the results from the Danish National Deliberative Poll on the single currency. In August 2000, 364 repres‐entative Danish citizens assembled to deliberate on Denmark's participation in the single currency. The Deliberative Poll is described as a quasi‐experiment set out to explore the empirical potentials of deliberative democracy. The focus is whether the claimed potential of deliberative democracy is present in the experimental setting. The participants’ answers reflect a deliberative process dominated by considerable changes in opinion, an increase in knowledge and an improved ability to form a reasoned opinion. Mutual understanding among the participants prevailed. At the same time, self‐interest and domination were also part of the deliberative process. Thus, this article encourages the development of deliberative democratic theory in order to incorporate these features of politics.
Silencer or Amplifier? The European Union Presidency and the Nordic Countries
Authors: Bengtsson Rikard , Elgström Ole , Tallberg Jonas
Published: August 2004

How did the three Nordic European Union member states approach their periods as holders of the European Union (EU) Council Presidency? Two radically different predictions about the impact of the Presidency on member state behaviour can be found in the literature. Some maintain that the position functions as an amplifier, strengthening the already existing tendency to propagate national concerns. Others argue that the Presidency functions as a silencer, subordinating national material interests to the benefit of common European concerns. In this article we analyse the ways in which Finland, Sweden and Denmark actually performed the Presidency role. Which of the competing interpretations is most appropriate? Was the Presidency role performed differently by the three countries? Our main finding is that the Presidency generally functioned as an amplifier during the Nordic presidencies. There are, however, interesting differences between the three states, Denmark being the least constrained in using the Presidency to further national interests whereas Finland was most anxious not to violate norms of impartiality and neutrality, even in cases where such behaviour ran contrary to national interests.
Representation and Democracy: Uneasy Alliance
Authors: Pitkin Hanna Fenichel
Published: August 2004

The concept of ‘representation’ is puzzling not because it lacks a central definition, but because that definition implies a paradox (being present and yet not present) and is too general to help reconcile the word's many senses with their sometimes conflicting implications.

Representation has a problematic relationship with democracy, with which it is often thoughtlessly equated. The two ideas have different, even conflicting, origins. Democracy came from ancient Greece and was won through struggle, from below. Greek democracy was participatory and bore no relationship to representation. Representation dates – at least as a political concept and practice – from the late medieval period, when it was imposed as a duty by the monarch. Only in the English Civil War and then in the eighteenth‐century democratic revolutions did the two concepts become linked.

Democrats saw representation – with an extended suffrage – as making possible large‐scale democracy. Conservatives instead saw it as a tool for staving off democracy. Rousseau also contrasted the two concepts, but favoured democratic self‐government.

He was prescient in seeing representation as a threat to democracy. Representative government has become a new form of oligarchy, with ordinary people excluded from public life. This is not inevitable. Representation does make large‐scale democracy possible, where it is based in participatory democratic politics at the local level.

Three obstacles block access to this possibility today: the scope of public problems and private power; money, or rather wealth; and ideas and their shaping, in an age of electronic media.
Synaptic efficacy and reliability of excitatory connections between the principal neurones of the input (layer 4) and output layer (layer 5) of the neocortex
Authors: Feldmeyer Dirk , Sakmann Bert
Published: August 2004

A prerequisite for the understanding of how a cortical column functions is a description of small and defined neuronal circuits consisting of only a few identified neurones. Here we summarise, with particular reference to the barrel cortex, the morphological and physiological properties of two synaptic connections, namely those between pairs of spiny neurones in layer 4 and pairs of pyramidal cells in layer 5. While layer 4 spiny neurones are the cortical input neurones that amplify and relay incoming excitation from the periphery, layer 5 pyramidal cells integrate neuronal activity both within and across cortical columns and subsequently distribute it to both cortical and subcortical brain regions.
Ion channel sequestration in central nervous system axons
Authors: Rasband Matthew N. , Shrager Peter
Published: August 2004

Na+ and K+ channel localization and clustering are essential for proper electrical signal generation and transmission in CNS myelinated nerve fibres. In particular, Na+ channels are clustered at high density at nodes of Ranvier, and Shaker‐type K+ channels are sequestered in juxtaparanodal zones, just beyond the paranodal axoglial junctions. The mechanisms of channel localization at nodes of Ranvier in the CNS during development in both normal and hypomyelinating mutant animals are discussed and reviewed. As myelination proceeds, Na+ channels are initially found in broad zones within gaps between neighbouring oligodendroglial processes, and then are condensed into focal clusters. This process appears to depend on the formation of axoglial junctions. K+ channels are first detected in juxtaparanodal zones, and in mutant mice lacking normal axoglial junctions, these channels fail to cluster. In these mice, despite the presence of numerous oligodendrocytes, Na+ channel clusters are rare, and when present, are highly irregular. A number of molecules have recently been described that are candidates for a role in the neuron‐glial interactions driving ion channel clustering. This paper reviews the cellular and molecular events responsible for formation of the mature node of Ranvier in the CNS.
Effect of hypothermia on the volume of rat glial cells
Authors: Plesnila Nikolaus , Müller Edith , Guretzki Susanne , Ringel Florian , Staub Frank , Baethmann Alexander
Published: August 2004

The cell volume of suspended C6 glioma cells and primary cultured rat astrocytes was measured at normothermia (37 °C), and at mild (32 °C) and moderate (27 °C) hypothermia by flow cytometry with electrical cell sizing.

Under control conditions (37 °C), C6 glioma cells had a volume of 809 ± 29 μm3. Moderate hypothermia (27 °C) led to rapid cell swelling, with a maximum volume of 113.1 ± 1.3 % of control being achieved after 50 min. After rewarming to 37 °C, cell volume recovered very slowly and incompletely (to 107.2 ± 0.4 % of control). Less severe hypothermia (32 °C) led to a smaller increase in cell volume (108.7 ± 0.5 % of control).

The maximal cell swelling response and the kinetics of swelling were similar in C6 glioma cells and primary cultured astrocytes.

Hypothermia‐induced cell swelling was dependent on the presence of extracellular Na+ and was reduced by the Na+−H+ antiporter inhibitor EIPA.

The underlying mechanisms of hypothermia‐induced cell swelling are an intracellular accumulation of Na+ by (1) differential effects of hypothermia on the membrane permeabilities of Na+ and K+ and (2) activation of the Na+−H+ antiporter by a shift of its activation curve to a more alkaline value.
Solvent effects on squid sodium channels are attributable to movements of a flexible protein structure in gating currents and to hydration in a pore
Authors: Kukita Fumio
Published: August 2004

Solvent effects on the time course of gating and sodium currents were analysed in squid sodium channels using four non‐electrolytes of different size, glycerol, erythritol, glucose and sucrose, to separate effects of viscosity from those of osmolarity and to obtain viscosity and osmolarity parameters that were independent of molecular size.

The gating and sodium currents were reversibly slowed in a voltage‐independent manner as the non‐electrolyte concentration increased.

Solvent effects were analysed using a model in which the percentage change in time constant was expressed by an equation involving the viscosity parameter α and the osmolarity parameter δ: t/t0=α((η/η0) – 1 + 100α−1)exp(δΔΠ), where η/η0 is solution viscosity and ΔΠ is increase in osmolarity. Since the solution viscosity was found experimentally to be a function of the solution osmolarity, solvent effects are described by an equation with one independent variable η/η0 or ΔΠ.

Voltage sensor movement, reflected in gating currents, was primarily sensitive to viscosity, as its decay time constant was a function of η/η0, with only a minor sensitivity to osmolarity (δ was 2–3 water molecules).

For sodium currents, α was equal to that of gating currents but δ was 2–3 times greater, suggesting that the final channel opening was primarily sensitive to osmolarity (Δδ was 5 water molecules). The relative ineffectiveness of the largest non‐electrolyte, sucrose, suggested that this osmolarity‐sensitive step in channel opening occurred in the narrow pore region.

Sodium channel inactivation was primarily sensitive to osmolarity (Δδ was 8–12 water molecules).

The observed viscosity dependence of the sodium current activation and inactivation processes was attributable to the viscosity‐dependent process accompanying the gating current.

This model explains why non‐electrolytes slow sodium currents while electrolytes do not.

Viscosity effects on gating currents can be explained by a process in which non‐electrolytes interact with the flexible hydrophilic parts of sodium channel proteins, but osmolarity effects on the final step need to be explained by a local interaction of several water molecules with fluctuating protein segments in the pore.
Spontaneous photo‐relaxation of urethral smooth muscle from sheep, pig and rat and its relationship with nitrergic neurotransmission
Authors: Triguero D. , Costa G. , Labadía A. , Jiménez E. , García‐Pascual A.
Published: August 2004

In the present work we have characterized the relaxant response induced by light stimulation (LS) in the lower urinary tract from sheep, pig and rat, establishing its relationship with nitrergic neurotransmission.

Urethral, but not detrusor, preparations showed pronounced photo‐relaxation (PR) which declined progressively following repetitive LS. Sheep urethral PR was again restored either spontaneously or (to a greater extent) by exogenous nitric oxide (NO) addition and by electrical field stimulation (EFS) of intrinsic nitrergic nerves.

Greater NO generation was detected from sheep urethral than from detrusor homogenates following illumination.

Sheep urethral PR was inhibited by oxyhaemoglobin, but not by methaemoglobin, carboxy‐PTIO, extracellular superoxide anion generators or superoxide dismutase. Guanylyl cyclase but not adenylyl cyclase activation mediates urethral relaxation to LS.

Urethral PR was more resistant to inhibition by L‐thiocitrulline than EFS‐induced responses, although this agent prevented PR restoration by high‐frequency EFS.

Urethral PR was TTX insensitive and partially modified in high‐K+ solutions. Cold storage for 24 h greatly impaired urethral PR, although it was restored by high‐frequency EFS.

Repetitive exposure to LS, EFS or exogenous NO induced changes in the shape of the EFS‐induced nitrergic relaxation, possibly by pre‐synaptic mechanisms.

In conclusion, we suggest the presence of an endogenous, photo‐labile, nitro‐compound store in the urethra, which seems to be replenished by neural nitric oxide synthase activity, indicating a close functional relationship with the nitrergic neurotransmitter.
Heterodimeric amino acid transporters: expression of heavy but not light chains of CD98 correlates with induction of amino acid transport systems in human placental trophoblast
Authors: Kudo Yoshiki , Boyd C. A. R.
Published: August 2004

Activity of amino acid transport and relative abundance of mRNAs encoding related transporters have been studied in parallel either before or following in vitro culture of explants of human placental chorionic villi.

Amino acid transport activities through systems L (1.9‐fold), y+L (2.6‐fold) and y+ (3.2‐fold) were markedly enhanced following culture for 48 h.

Relative mRNA abundance (determined by reverse transcription‐polymerase chain reaction) for the heavy chain of CD98 surface antigen and for the cationic amino acid transporter‐1 were similarly stimulated (2.8‐fold and 2.6‐fold, respectively). In contrast, none of the mRNA levels for light chains of CD98 (system L‐amino acid transporter‐1, system L‐amino acid transporter‐2, system y+L‐amino acid transporter‐1 and system y+L‐amino acid transporter‐2) studied nor for the cationic amino acid transporter‐2B were altered.
Reversible Ca2+‐induced fast‐to‐slow transition in primary skeletal muscle culture cells at the mRNA level
Authors: Meißner Joachim D. , Kubis Hans‐Peter , Scheibe Renate J. , Gros Gerolf
Published: August 2004

The adult fast character and a Ca2+‐inducible reversible transition from a fast to a slow type of rabbit myotube in a primary culture were demonstrated at the mRNA level by Northern blot analysis with probes specific for different myosin heavy chain (MyHC) isoforms and enzymes of energy metabolism.

No non‐adult MyHC isoform mRNA was detected after 22 days of culture. After 4 weeks of culture the fast MyHCIId mRNA was strongly expressed while MyHCI mRNA was virtually absent, indicating the fast adult character of the myotubes in the primary skeletal muscle culture.

The data show that a fast‐to‐slow transition occurred in the myotubes at the level of MyHC isoform gene expression after treatment with the Ca2+ ionophore A23187. The effects of ionophore treatment were decreased levels of fast MyHCII mRNA and an augmented expression of the slow MyHCI gene. Changes in gene expression started very rapidly 1 day after the onset of ionophore treatment.

Levels of citrate synthase mRNA increased and levels of glyceraldehyde 3‐phosphate dehydrogenase mRNA decreased during ionophore treatment. This points to a shift from anaerobic to oxidative energy metabolism in the primary skeletal muscle culture cells at the level of gene expression.

Withdrawal of the Ca2+ ionophore led to a return to increased levels of MyHCII mRNA and decreased levels of MyHCI mRNA, indicating a slow‐to‐fast transition in the myotubes and the reversibility of the effect of ionophore on MyHC isoform gene expression.
Cell volume regulation: the role of taurine loss in maintaining membrane potential and cell pH
Authors: Guizouarn H. , Motais R. , Garcia‐Romeu F. , Borgese F.
Published: August 2004

In response to a hyposmotic stress cells undergo a regulatory volume decrease (RVD) by losing osmotically active solutes and obliged water. During RVD, trout red cells lost taurine, K+ and Cl− but gained Na+ and Cl−. Over the full time course of RVD the chloride concentration in the cell water remained remarkably constant. Thus membrane potential and cell pH, which depends on the ratio of internal to external chloride concentration ([Cl−]i:[Cl−]o), remained fixed.

When cell volume decreases it is only possible to keep the chloride concentration in the cell water constant if an equal percentage of the cell chloride pool and of the cell water pool are lost simultaneously. Quantitative analysis of our data showed that this requirement was fulfilled because, over the full time course of RVD, cells lost osmotically active solutes with a constant stoichiometry: 1 Cl−:1 positive charge:2.35 taurine. Any change in taurine permeability, by modifying the stoichiometric relationship, would affect the amount of water lost and consequently cell chloride concentration.

Experiments carried out with different cations as substitutes for external Na+ suggest that the constancy of the chloride concentration is not finely tuned by some mechanism able to modulate the channel transport capacity, but results in part from the fact that the swelling‐dependent channel constitutively possesses an adequately fixed relative permeability for cations and taurine. However, as a significant fraction of K+ and Cl− loss occurs via a KCl cotransporter, the contribution of the cotransport to the stochiometric relationship remains to be defined.

The large amount of taurine released during RVD (50 % of all solutes) was shown to be transported as an electroneutral zwitterion and not as an anion. How the channel can accommodate the zwitterionic form of taurine, which possesses a high electrical dipole, is considered.
Weak common parallel fibre synapses explain the loose synchrony observed between rat cerebellar Golgi cells
Authors: Maex Reinoud , Vos Bart P. , De Schutter Erik
Published: August 2004

In anaesthetized rats, pairs of cerebellar Golgi cells fired synchronously at rest, provided they were aligned along the parallel fibre axis. The observed synchrony was much less precise, however, than that which would be expected to result from common, monosynaptic parallel fibre excitation.

To explain this discrepancy, the precision and frequency of spike synchronization (i.e. the width and area of the central peak on the spike train cross‐correlogram) were computed in a generic model for varying input, synaptic and neuronal parameters.

Correlation peaks between model neurons became broader, and peak area smaller, when the number of afferents increased and each single synapse decreased proportionally in strength. Peak width was inversely proportional to firing rate, but independent of the percentage of shared afferents. Peak area, in contrast, scaled with the percentage of shared afferents but was almost firing rate independent.

Broad correlation peaks between pairs of model neurons resulted from the loose spike timing between single model neurons and their afferents. This loose timing reflected a need for long‐term synaptic integration to fire the neurons. Model neurons could accomplish this through firing rate adaptation mediated by a Ca2+‐activated K+ channel.

We conclude that loose synchrony may be entirely explained by shared input from monosynaptic, non‐synchronized afferents. The inverse relationship between peak width and firing rate allowed us to distinguish common parallel fibre input from firing rate covariance as a primary cause of loose synchrony between cerebellar Golgi cells in anaesthetized rats.
Voltage‐gated currents distinguish parvocellular from magnocellular neurones in the rat hypothalamic paraventricular nucleus
Authors: Luther Jason A. , Tasker Jeffrey G.
Published: August 2004

Magnocellular and parvocellular neurones of the hypothalamic paraventricular nucleus (PVN) differentially regulate pituitary hormone secretion and autonomic output. Previous experiments have suggested that magnocellular, or type I neurones, and parvocellular, or type II neurones, of the PVN express different electrophysiological properties. Whole‐cell patch‐clamp recordings were performed in hypothalamic slices to identify the voltage‐gated currents responsible for the electrophysiological differences between type I and type II PVN neurones.

Type I neurones, which display transient outward rectification and lack a low‐threshold spike (LTS), generated a large A‐type K+ current (IA) (mean ± s.e.m.: 1127.5 ± 126.4 pA; range: 250–3600 pA; voltage steps to −25 mV) but expressed little or no T‐type Ca2+ current (IT). Type II neurones, which lack transient outward rectification but often display an LTS, expressed a smaller IA (360.1 ± 56.3 pA; range: 40–1100 pA; voltage steps to −25 mV), and 75 % of the type II neurones generated an IT (‐402.5 ± 166.9 pA; range: −90 to −2200 pA; at peak).

The voltage dependence of IA was shifted to more negative values in type I neurones compared to type II neurones. Thus, the activation threshold (‐53.5 ± 0.9 and −46.1 ± 2.6 mV), the half‐activation potential (‐25 ± 1.9 and −17.9 ± 2.0 mV), the half‐inactivation potential (‐80.4 ± 9.3 and −67.2 ± 3.0 mV), and the potential at which the current became fully inactivated (‐57.4 ± 2.1 and −49.8 ± 1.5 mV) were more negative in type I neurones than in type II neurones, respectively.

I
T in type II neurones activated at a threshold of −59.2 ± 1.2 mV, peaked at −32.6 ± 1.7 mV, was half‐inactivated at −66.9 ± 2.2 mV, and was fully inactivated at −52.2 ± 2.2 mV.

Both cell types expressed a delayed rectifier current with similar voltage dependence, although it was smaller in type I neurones (389.7 ± 39.3 pA) than in type II neurones (586.4 ± 76.0 pA).

In type I neurones IA was reduced by 41.1 ± 7.0 % and the action potential delay caused by the transient outward rectification was reduced by 46.2 ± 10.3 % in 5 mm 4‐aminopyridine. In type II neurones IT was reduced by 66.8 ± 10.9 % and the LTS was reduced by 76.7 ± 7.8 % in 100 μM nickel chloride, but neither IT nor LTS was sensitive to 50 μM cadmium chloride.

Thus, differences in the electrophysiological properties between type I, putative magnocellular neurones and type II, putative parvocellular neurones of the PVN can be attributed to the differential expression of voltage‐gated K+ and Ca2+ currents. This diversity of ion channel expression is likely to have profound effects on the response properties of these neurosecretory and non‐neurosecretory neurones.
Responses of neurones of the rat suprachiasmatic nucleus to retinal illumination under photopic and scotopic conditions
Authors: Aggelopoulos Nicholas C. , Meissl Hilmar
Published: August 2004

We have examined the responses of neurones in the suprachiasmatic nuclei (SCN) of the rat to retinal illumination under photopic and scotopic conditions to identify the types of photoreceptor input to these nuclei.

The majority of visually responsive SCN neurones studied under dark adaptation received rod input (48 of 52, 92 %). The action spectrum conformed to the sensitivity of rhodopsin, with maximal sensitivity at around 505 nm.

When also studied under light adaptation, most visually responsive SCN neurones (20 out of 26, 77 %) responded to input from cones. The action spectra conformed to the spectrum of green cone opsin, with a main sensitivity peak at 510 nm and a significant secondary peak in the near‐ultraviolet region of the spectrum.

The frequency of spontaneous activity was typically low under scotopic conditions (range 0.2‐17.2 Hz) and higher under photopic conditions (range 0.6‐40 Hz) for any given neurone. The most common response under scotopic conditions was an ‘on‐excitation’ (32 of 48, 62.5 %), which changed under photopic conditions to an on‐excitation followed by a more prominent off‐inhibition.

Responses also changed due to endogenous ultradian cycles. Depending on the phase, responses could be altogether absent and even reverted from excitation to inhibition on opposite phases of a cycle. Ultradian cycles had a circadian dependence and were most common at around the light phase:dark phase (L:D) and D:L transition points of the circadian cycle.

Under photopic conditions, SCN neurones showed rhythmic electrical activity, with a preferred firing interval that had a value between 18 and 39 ms. This rhythmic activity was probably the result of endogenous subthreshold membrane potential oscillations.

In conclusion, light acting either via rod or cone pathways could have powerful, opposing actions on SCN neurones. These actions were state dependent. The presence of these neuronal responses suggests a role for rod and cone photoreceptors in SCN function.
Cerebral correlates of autonomic cardiovascular arousal: a functional neuroimaging investigation in humans
Authors: Critchley H. D. , Corfield D. R. , Chandler M. P. , Mathias C. J. , Dolan R. J.
Published: August 2004

States of peripheral autonomic arousal accompany emotional behaviour, physical exercise and cognitive effort, and their central representation may influence decision making and the regulation of social and emotional behaviours. However, the cerebral functional neuroanatomy representing and mediating peripheral autonomic responses in humans is poorly understood.

Six healthy volunteer subjects underwent H215O positron emission tomography (PET) scanning while performing isometric exercise and mental arithmetic stressor tasks, and during corresponding control tasks. Mean arterial blood pressure (MAP) and heart rate (HR) were monitored during scanning.

Data were analysed using statistical parametric mapping (SPM99). Conjunction analyses were used to determine significant changes in regional cerebral blood flow (rCBF) during states of cardiovascular arousal common to both exercise and mental stressor tasks.

Exercise and mental stressor tasks, relative to their control tasks, were associated with significantly (P< 0.001) increased MAP and HR. Significant common activations (increased rCBF) were observed in cerebellar vermis, brainstem and right anterior cingulate. In both exercise and mental stress tasks, increased rCBF in cerebellar vermis, right anterior cingulate and right insula covaried with MAP; rCBF in pons, cerebellum and right insula covaried with HR. Cardiovascular arousal in both categorical and covariance analyses was associated withdecreasedrCBF in prefrontal and medial temporal regions.

Neural responses in discrete brain regions accompany peripheral cardiovascular arousal. We provide evidence for the involvement of areas previously implicated in cognitive and emotional behaviours in the representation of peripheral autonomic states, consistent with a functional organization that produces integrated cardiovascular response patterns in the service of volitional and emotional behaviours.
Regulation of neuronal function by protein trafficking: a role for the endosomal pathway
Authors: Buckley Kathleen M. , Melikian Haley E. , Provoda Chester J. , Waring Michael T.
Published: August 2004

Protein trafficking plays a central role in many aspects of neuronal function, from the release of neurotransmitters by exocytosis and the recycling of synaptic vesicle proteins to the regulation of receptor signalling. Synaptic function can be significantly modified on a short time scale by alterations in the levels of receptors, ion channels and transporters both pre‐ and postsynaptically. In many cases, these alterations appear to be mediated by acute changes in the rates at which the proteins are endocytosed from and exocytosed to the cell surface from intracellular pools. While our current understanding of the signalling mechanisms and the intracellular pathways responsible for these acute changes is still in its infancy, intriguing details are beginning to emerge from a number of systems.
Presynaptic dopamine D2‐like receptors inhibit excitatory transmission onto rat ventral tegmental dopaminergic neurones
Authors: Koga Eiko , Momiyama Toshihiko
Published: August 2004

The effects of dopamine (DA) on non‐NMDA glutamatergic transmission onto dopaminergic neurones in the ventral tegmental area (VTA) were examined in rat midbrain slices using the whole‐cell patch‐clamp technique. EPSCs in dopaminergic neurones evoked by focal stimulation within the VTA were reversibly blocked by 5 μM CNQX in the presence of bicuculline (20 μM), strychnine (0.5 μM) and D‐amino‐5‐phosphonopentanoic acid (D‐AP5, 25 μM).

Bath application of DA reduced the amplitude of EPSCs up to 65.1 ± 9.52% in a concentration‐dependent manner between 0.3‐1000 μM (IC50, 16.0 μM) without affecting the holding current at −60 mV measured using a Cs+‐filled electrode.

The effect of DA on evoked EPSCs was mimicked by the D2‐like receptor agonist quinpirole but not by the D1‐like receptor agonist SKF 81297, and was antagonized by the D2‐like receptor antagonist sulpiride (KB, 0.96 μM), but not by the D1‐like receptor antagonist SCH 23390 (KB, 228.6 μM).

Dopamine (30 μM) reduced the mean frequency of spontaneous miniature EPSCs (mEPSCs) without affecting their mean amplitude, and the DA‐induced effect on the mEPSCs was dependent on the external Ca2+ concentration.

These results suggest that afferent glutamatergic fibres which terminate on VTA dopaminergic neurones possess presynaptic D2‐like receptors, activation of which inhibits glutamate release by reducing Ca2+ influx.
The actin cytoskeleton in store‐mediated calcium entry
Authors: Rosado Juan A. , Sage Stewart O.
Published: August 2004

Store‐mediated Ca2+ entry is the main pathway for Ca2+ influx in platelets and many other cells. Several hypotheses have considered both direct and indirect coupling mechanisms between the endoplasmic reticulum and the plasma membrane. Here we pay particular attention to new insights into the regulation of store‐mediated Ca2+ entry: the role of the cytoskeleton in a secretion‐like coupling model. In this model, Ca2+ entry may be mediated by a reversible trafficking and coupling of the endoplasmic reticulum with the plasma membrane, that shows close parallels to the events mediating secretion. As with secretion, the actin cytoskeleton plays an inhibitory role in the activation of Ca2+ entry by preventing the approach and coupling of the endoplasmic reticulum with the plasma membrane, making cytoskeletal remodelling a key event in the activation of Ca2+ entry. We also review recent advances investigating the regulation of store‐mediated Ca2+ entry by small GTPases and phosphoinositides, which might be involved in the store‐mediated Ca2+ entry pathway through roles in the remodelling of the cytoskeleton.
Mitochondrial Ca2+ homeostasis during Ca2+ influx and Ca2+ release in gastric myocytes from Bufo marinus
Authors: Drummond Robert M. , Mix T. Christian H. , Tuft Richard A. , Walsh John V. , Fay Fredric S.
Published: August 2004

The Ca2+‐sensitive fluorescent indicator rhod‐2 was used to monitor mitochondrial Ca2+ concentration ([Ca2+]m) in gastric smooth muscle cells from Bufo marinus. In some studies, fura‐2 was used in combination with rhod‐2, allowing simultaneous measurement of cytoplasmic Ca2+ concentration ([Ca2+]i) and [Ca2+]m, respectively.

During a short train of depolarizations, which causes Ca2+ influx from the extracellular medium, there was an increase in both [Ca2+]i and [Ca2+]m. The half‐time (t½) to peak for the increase in [Ca2+]m was considerably longer than the t½ to peak for the increase in [Ca2+]i. [Ca2+]m remained elevated for tens of seconds after [Ca2+]i had returned to its resting value.

Stimulation with caffeine, which causes release of Ca2+ from the sarcoplasmic reticulum (SR), also produced increases in both [Ca2+]i and [Ca2+]m. The values of t½ to peak for the increase in [Ca2+] in both cytoplasm and mitochondria were similar; however, [Ca2+]i returned to baseline values much faster than [Ca2+]m.

Using a wide‐field digital imaging microscope, changes in [Ca2+]m were monitored within individual mitochondria in situ, during stimulation of Ca2+ influx or Ca2+ release from the SR.

Mitochondrial Ca2+ uptake during depolarizing stimulation caused depolarization of the mitochondrial membrane potential. The mitochondrial membrane potential recovered considerably faster than the recovery of [Ca2+]m.

This study shows that Ca2+ influx from the extracellular medium and Ca2+ release from the SR are capable of increasing [Ca2+]m in smooth muscle cells. The efflux of Ca2+ from the mitochondria is a slow process and appears to be dependent upon the amount of Ca2+ in the SR.
The capacity of mdx mouse diaphragm muscle to do oscillatory work
Authors: Stevens E. Don , Faulkner J. A.
Published: August 2004

Mdx mice were used as a model for Duchenne muscular dystrophy; both lack dystrophin. It was hypothesized that the mdx condition would have a marked effect on the ability of diaphragm muscle from mdx mice to do active net work and generate power. This hypothesis was tested using the work‐loop technique.

Specific twitch force, specific tetanic force and maximum power were all significantly less in diaphragm strips from mdx mice than those from control mice.

In all preparations muscle length at which maximum power was achieved (Lw) was about 8% less than that at which maximum tetanic force was achieved (L0), both in mdx and control muscle.

The isometric force‐length curve for mdx muscle was steeper on both sides of the plateau. Similarly, the curve relating net work per cycle to muscle length was steeper for mdx muscle on both sides of the plateau.

Maximum power of mdx muscle was achieved at a lower strain than for control muscle; maximum power occurred at a strain of 10.2% for mdx and 14.7% for control. Further increases in strain caused a marked decrease of power production in mdx muscle, whereas they caused a smaller decrease in control muscle.

In summary, at muscle lengths longer than Lw and at high strains, performance of mdx muscle was compromised relative to that of control muscle. Work and power were compromised more than isometric force.
Patterns of fusimotor activity during locomotion in the decerebrate cat deduced from recordings from hindlimb muscle spindles
Authors: Taylor A. , Durbaba R. , Ellaway P. H. , Rawlinson S.
Published: August 2004

Recordings have been made from multiple single muscle spindle afferents from medial gastrocnemius (MG) and tibialis anterior (TA) muscles of one hindlimb in decerebrate cats, together with ankle rotation and EMG signals, during treadmill locomotion. Whilst the other three limbs walked freely, the experimental limb was denervated except for the nerves to MG and TA and secured so that it could rotate only at the ankle joint, without any external load. Each afferent was characterised by succinylcholine testing with regard to its intrafusal fibre contacts. Active movements were recorded and then replayed through a servo mechanism to reproduce the muscle length changes passively after using a barbiturate to suppress γ‐motor firing.

The difference in secondary afferent firing obtained by subtracting the discharge during passive movements from that during active movements was taken to represent the profile of static fusimotor activity. This indicated an increase before the onset of movement followed by a strongly modulated discharge in parallel with muscle shortening during locomotion. The pattern of static firing matched the pattern of unloaded muscle shortening very closely in the case of TA and with some phase advance in the case of MG. The same effects were observed in primary afferents.

Primary afferents with bag1 (b1) contacts in addition showed higher firing frequencies during muscle lengthening in active than in passive movements. This indicated increased dynamic fusimotor firing during active locomotion. There was no evidence as to whether this fluctuated during the movement cycles.

When the mean active minus passive difference profile of firing in bag2‐chain (b2c) type primary afferents was subtracted from that for b1b2c afferents, the difference was dominated by a peak centred on the moment of maximum lengthening velocity (v).

The component of the active minus passive difference firing due to b1 fibre contacts could be modelled by f(t)=av (where a is a constant) during lengthening and by f(t)= 0.2av during shortening. The remainder of the difference signal matched the predictions of the static fusimotor signal derived from secondary afferents.

The findings are discussed in relation to the concept that the modulated static fusimotor pattern may represent a ‘temporal template’ of the expected movement, though the relationship of the results to locomotion in the intact animal will require further investigation. The analysis of the data indicates that the combined action of muscle length changes and static and dynamic fusimotor activity to determine primary afferent firing can be understood in terms of the interaction between the b1 and b2c impulse initiation sites.
Swelling‐activated, cystic fibrosis transmembrane conductance regulator‐augmented ATP release and Cl− conductances in murine C127 cells
Authors: Hazama Akihiro , Fan Hai‐Tian , Abdullaev Iskandar , Maeno Emi , Tanaka Shoko , Ando‐Akatsuka Yuhko , Okada Yasunobu
Published: August 2004

A hypotonic challenge, but not cAMP stimulation, was found to induce release of ATP measured by the luciferin‐luciferase assay from both the murine mammary carcinoma cell line C127i and C127 cells stably transfected with the cDNA for human cystic fibrosis transmembrane conductance regulator (CFTR) protein (C127/CFTR). CFTR expression augmented swelling‐induced ATP release by 10–20 times under hypotonic conditions (<= 80 % osmolality).

Glibenclamide failed to suppress swelling‐induced ATP release from C127/CFTR cells. In contrast, whole‐cell patch‐clamp recordings showed that both the cAMP‐activated ohmic Cl− currents and volume‐sensitive outwardly rectifying (VSOR) Cl− currents were prominently suppressed by glibenclamide.

Gd3+ markedly blocked swelling‐induced ATP release but failed to suppress both cAMP‐ and swelling‐activated Cl− currents in the CFTR‐expressing cells. Even after pretreatment and during treatment with Gd3+, VSOR Cl− currents were activated normally.

The continuous presence of an ATP‐hydrolysing enzyme, apyrase, in the bathing solution did not prevent activation of VSOR Cl− currents in C127/CFTR cells.

The rate of regulatory volume decrease (RVD) in C127/CFTR cells was much faster than that in C127i cells. When apyrase was added to the bathing solution, the RVD rate was retarded in C127/CFTR cells.

On balance, the following conclusions can be deduced. First, swelling‐induced ATP release is augmented by expression of CFTR but is not mediated by the CFTR Cl− channel. Second, swelling‐induced ATP release is not mediated by the VSOR Cl− channel. Third, the released ATP facilitated the RVD process but is not involved in the activation of VSOR Cl− channels in C127/CFTR cells.
Isolation of microsatellite loci from the scleractinian corals, Montastraea cavernosa and Porites astreoides
Authors: SHEARER T. L. , COFFROTH M. A.
Published: August 2004

The ability to assess genetic variation is critical for determining genetic diversity and population structure. In corals, slow evolutionary rates in mitochondrial genomes have left allozymes as the only markers presently available to investigate patterns of intraspecific genetic variation. Characteristics of microsatellites render them more informative than allozymes for such analyses; however, few coral microsatellites are available. This study describes polymorphic microsatellite loci isolated from two scleractinian coral species. Most loci exhibit significant heterozygote deficiencies, likely due to nonrandom mating or Wahlund effects. These markers are being used to investigate gene flow among populations, providing insight into reef connectivity.
Isolation and characterization of microsatellite loci in Fragaria
Authors: CIPRIANI GUIDO , TESTOLIN RAFFAELE
Published: August 2004

This study reports the development and characterization of 20 microsatellite primer pairs in wild strawberry Fragaria vesca. One hundred primers were obtained from an AC‐enriched library developed in the cultivar ‘Ilaria’. A set of eight F. vesca genotypes was used to detect the polymorphism resulting in an average of 7.0 alleles, an average observed heterozygosity of 0.32 and an average expected heterozygosity of 0.73. Nineteen (95%) of the primers also amplified the cultivated octoploid strawberry Fragaria×ananassa.
Microsatellite markers developed from Thamnophis elegans and Thamnophis sirtalis and their utility in three species of garter snakes
Authors: GARNER TRENTON W. J. , PEARMAN PETER B. , GREGORY PATRICK T. , TOMIO GIANCARLO , WISCHNIOWSKI STEPHEN G. , HOSKEN DAVID J.
Published: August 2004

Previous studies of polyandry and population genetics in garter snakes have been hampered by the limited number of available microsatellite markers. Here we report another six dinucleotide microsatellite markers, doubling the number of previously available loci. The majority of the loci exhibit utility across a broad geographical range for the common garter snake and also cross‐amplify effectively in samples from two other Thamnophis species.
Dominant (AFLP) and co‐dominant (microsatellite) markers for the kelp Postelsia palmaeformis (Laminariales)
Authors: KUSUMO HANDOJO T. , PFISTER CATHERINE A. , WOOTTON J. TIMOTHY
Published: August 2004

To aid in understanding the structure, dispersal and genetic dynamics of their populations, we developed microsatellite and amplified fragment length polymorphism (AFLP) markers for the sea palm, Postelsia palmaeformis (Laminariales) for samples taken from nine sites in the area of Cape Flattery, Washington State, USA. We identified two AFLP primers that yielded 798 variable fragments and five microsatellite markers with three to seven alleles each. We also report patterns of allelic variation for four previously identified microsatellite markers in this species and several new alleles.
Microsatellite loci for studies of wild and hatchery Australian Murray cod Maccullochella peelii peelii (Percichthyidae)
Authors: LOUGHNAN SHANNON R. , BARANSKI MATTHEW D. , ROBINSON NICK A. , JONES PAUL L. , BURRIDGE CHRISTOPHER P.
Published: August 2004

Murray cod is a species of conservation concern that is subject both to wild harvest and to aquaculture production. Six polymorphic microsatellite loci have been developed for this species, which will facilitate studies of wild‐stock structure, will help the management of hatchery diversity, and will aid genetic improvement programmes. The markers exhibited nonindependence of genotypes between loci and deviations from Hardy–Weinberg expectations, although these most probably reflect practices at the hatchery from which the genotyped individuals were sourced.
Isolation and characterization of 13 polymorphic microsatellite loci from the clam shrimp Eulimnadia texana (Crustacea: Spinicaudata)
Authors: DUFF R. JOEL , HOEH WALTER R. , COOK DOUG , WEEKS STEPHEN C.
Published: August 2004

Thirteen polymorphic microsatellite loci were isolated and characterized from the clam shrimp Eulimnadia texana. In analyses of 20–50 individuals from two populations the number of alleles ranged from two to seven with observed heterozygosity ranging between 0.00 and 0.37. The low values for heterozygosity were not unexpected for a group characterized by its unusual androdioecious mating system, in which males compete with self‐compatible hermaphrodites for offspring production. These microsatellites are likely to be useful for further evolutionary investigations of this rare mating system in these crustaceans.
Characterization of 22 microsatellite loci developed from the genome of the Woolly Lemur (Avahi laniger)
Authors: ANDRIANTOMPOHAVANA R. , RANDRIAMANANA J. C. , SOMMER J. A. , BRENNEMAN R. A. , LOUIS E. E.
Published: August 2004

Twenty‐two polymorphic microsatellite loci were isolated and characterized from the Avahi laniger genome. All were polymorphic in both the Eastern Woolly Lemur (A. laniger) and the Western Woolly Lemur (A. occidentalis). One locus, WOOL157, harboured allele structures that were species‐specific. This marker suite will be used in future studies to establish the ranges and population structures of the two Avahi species on the island of Madagascar.
Tetranucleotide and dinucleotide microsatellite loci from the northern bobwhite (Colinus virginianus)
Authors: SCHABLE NANCY A. , FAIRCLOTH BRANT C. , PALMER WILLIAM E. , CARROLL JOHN P. , BURGER L. WES , BRENNAN LEONARD A. , HAGEN CRIS , GLENN TRAVIS C.
Published: August 2004

We describe polymerase chain reaction (PCR) primers and conditions to amplify eight dinucleotide, one trinucleotide and 14 tetranucleotide microsatellite DNA loci isolated from the northern bobwhite (Colinus virginianus). The PCR primers were tested on 16 individuals collected from a population located within the Red Hills region of south Georgia and north Florida. The 23 primer pairs developed in this study yielded an average of 6.5 alleles per locus (range 2–11), an average observed heterozygosity of 0.47 (range 0.06–0.94) and average polymorphic information content of 0.60 (range 0.06–0.85).