bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elevation of intracellular Ca2+ in the physiologically relevant range does not inhibit voltage‐gated K+ channels in human T lymphocytes
Authors: Verheugen Jos A. H. 
Published: September 2010

Human T lymphocytes express both voltage‐gated (K(V)) and Ca2+‐activated (K(Ca)) potassium channels. The K(Ca) channel is activated by elevations of intracellular Ca2+ ([Ca2+]i) at concentrations attained during physiological Ca2+ signalling. Whether or not the K(V) channel is affected by [Ca2+]i is a matter of controversy. Here, the interaction between the K+ channels of lymphocytes and [Ca2+]i was studied using cell‐attached and whole‐cell patch‐clamp recordings, while [Ca2+]i of the same cell was monitored simultaneously by fura‐2 imaging or from the activity of the K(Ca) channels.
The K+ channels in cell‐attached patches were measured using a high K+ pipette solution. The K(V) conductance was quantified as the integral of the inward current during voltage ramp stimulation, yielding a measure independent of the cell membrane potential. Whereas the open probability of the K(Ca) channel showed an absolute dependence on [Ca2+]i, the K(V) channel was little affected by [Ca2+]i. The K(V) conductance is not reduced by elevations of [Ca2+]i in the range 0‐8 μM. On the contrary, a modest but consistent increase in the K(V) current component in cell‐attached currents was observed when [Ca2+]i was elevated.
The absence of inhibition of the K(V) current by [Ca2+]i was also apparent from whole‐cell measurements with pipette solutions buffered to 1 μM free Ca2+: following break‐in to whole‐cell configuration, depolarizing voltage ramps were applied at regular intervals to activate the K(V) current while the K(Ca) current was measured from the slope of the ramp current below the activation of the voltage‐gated current. During the gradual activation of the K(Ca) current, as the cell interior was perfused with the pipette solution, the K(V) current remained constant in amplitude.
In the initial period following break‐in to whole‐cell configuration, a gradual increase in the rate of K(V) current inactivation was generally observed. However, the time course of this change in kinetics was much slower than the perfusion of the cell interior, as judged from the activation of the K(Ca) conductance, ruling out a direct effect of Ca2+, within the physiological range, on K(V) channel kinetics.
Regulation of arterial diameter and wall [Ca2+] in cerebral arteries of rat by membrane potential and intravascular pressure
Authors: Knot Harm J. , Nelson Mark T. 
Published: September 2010

The regulation of intracellular [Ca2+] in the smooth muscle cells in the wall of small pressurized cerebral arteries (100‐200 μm) of rat was studied using simultaneous digital fluorescence video imaging of arterial diameter and wall [Ca2+], combined with microelectrode measurements of arterial membrane potential.Elevation of intravascular pressure (from 10 to 100 mmHg) caused a membrane depolarization from ‐63 ± 1 to ‐36 ± 2 mV, increased arterial wall [Ca2+] from 119 ± 10 to 245 ± 9 nM, and constricted the arteries from 208 ± 10 μm (fully dilated, Ca2+free) to 116 ± 7 μm or by 45 % (‘myogenic tone’).Pressure‐induced increases in arterial wall [Ca2+] and vasoconstriction were blocked by inhibitors of voltage‐dependent Ca2+channels (diltiazem and nisoldipine) or to the same extent by removal of external Ca2+.At a steady pressure (i.e. under isobaric conditions at 60 mmHg), the membrane potential was stable at ‐45 ± 1 mV, intracellular [Ca2+] was 190 ± 10 nM, and arteries were constricted by 41 % (to 115 ± 7 μm from 196 ± 8 μm fully dilated). Under this condition of ‐45 ± 5 mV at 60 mmHg, the voltage sensitivity of wall [Ca2+] and diameter were 7.5 nM mV−1and 7.5 μm mV−1, respectively, resulting in a Ca2+sensitivity of diameter of 1 μm nM−1.Membrane potential depolarization from ‐58 to ‐23 mV caused pressurized arteries (to 60 mmHg) to constrict over their entire working range, i.e. from maximally dilated to constricted. This depolarization was associated with an elevation of arterial wall [Ca2+] from 124 ± 7 to 347 ± 12 nM. These increases in arterial wall [Ca2+] and vasoconstriction were blocked by L‐type voltage‐dependent Ca2+channel inhibitors.The relationship between arterial wall [Ca2+] and membrane potential was not significantly different under isobaric (60 mmHg) and non‐isobaric conditions (10‐100 mmHg), suggesting that intravascular pressure regulates arterial wall [Ca2+] through changes in membrane potential.The results are consistent with the idea that intravascular pressure causes membrane potential depolarization, which opens voltage‐dependent Ca2+channels, acting as ‘voltage sensors’, thus increasing Ca2+entry and arterial wall [Ca2+], which leads to vasoconstriction.
Attenuated neuroendocrine responses to emotional and physical stressors in pregnant rats involve adenohypophysial changes
Authors: Neumann I. D. , Johnstone H. A. , Hatzinger M. , Liebsch G. , Shipston M. , Russell J. A. , Landgraf R. , Douglas A. J. 
Published: September 2010

The responsiveness of the rat hypothalamo‐pituitary‐adrenal (HPA) axis and hypothalamo‐neurohypophysial system (HNS) to emotional (elevated plus‐maze) and physical (forced swimming) stressors and to administration of synthetic corticotrophin‐releasing hormone (CRH) was investigated during pregnancy and lactation. In addition to pregnancy‐related adaptations at the adenohypophysial level, behavioural responses accompanying the neuroendocrine changes were studied.
Whereas basal (a.m.) plasma corticosterone, but not corticotrophin (adrenocorticotrophic hormone; ACTH), levels were increased on the last day (i.e. on day 22) of pregnancy, the stress‐induced rise in both plasma hormone concentrations was increasingly attenuated with the progression of pregnancy beginning on day 15 and reaching a minimum on day 21 compared with virgin control rats. A similar attenuation of responses to both emotional and physical stressors was found in lactating rats.
Although the basal plasma oxytocin concentration was elevated in late pregnancy, the stress‐induced rise in oxytocin secretion was slightly lower in day 21 pregnant rats. In contrast to vasopressin, oxytocin secretion was increased by forced swimming in virgin and early pregnant rats indicating a differential stress response of these neurohypophysial hormones.
The blunted HPA response to stressful stimuli is partly due to alterations at the level of corticotrophs in the adenohypophysis, as ACTH secretion in response to CRH in vivo (40 ng kg−1, i.v.) was reduced with the progression of pregnancy and during lactation. In vitro measurement of cAMP levels in pituitary segments demonstrated reduced basal levels of cAMP and a lower increase after CRH stimulation (10 nM, 10 min) in day 21 pregnant compared with virgin rats, further indicating reduced corticotroph responsiveness to CRH in pregnancy.
The reduced pituitary response to CRH in late pregnancy is likely to be a consequence of a reduction in CRH receptor binding as revealed by receptor autoradiography. [125I] CRH binding in the anterior pituitary was significantly reduced in day 11, 17 and 22 pregnant rats compared with virgin controls.
Anxiety‐related behaviour of the animals as revealed by the time on and entries into the open arms of the elevated plus‐maze was different between virgin and pregnant rats with decreased number of entries indicating increased anxiety with the progression of pregnancy (except on pregnancy day 18). The emotional behaviour, however, was not correlated with the neuroendocrine responses.
The results indicate that the reduced response of the HPA axis to stressors described previously during lactation is already manifested around day 15 of pregnancy in the rat and involves physiological adaptations at the adenohypophysial level. However, alterations in stressor perception at higher brain levels with the progression of pregnancy may also be involved.
ERRATUM
Authors: Gross E. , Hawkins K. , Pushkin A. , Sassani P. , Dukkipati R. , Abuladze N. , Hopfer U. , Kurtz I. 
Published: September 2010

Journal of Physiology
537, 659–665 (2001)On page 660, eqn (1) should have appeared as:
urn:x-wiley:00223751:media:TJP1003:tjp1003-math-0001u
Faculty Positions in Institute of ZoologyAcademia Sinica, Taipei, TaiwanTwo tenure‐track positions in the ranks of assistant, or associate research fellows, which are equivalent to assistant, or associate professors positions are available in Physiology and Organismic Group of the Institute. Individuals with at least two years of postdoctoral training who are interested and/or have prior knowledge and experience in the following two areas ‐ (i) integrative and comparative physiology and (ii) ecological and evolutionary physiology, are encouraged to send a CV, a description of past research accomplishment and a proposal of the future research, and three letters of recommendation to, Institute of Zoology, Academia Sinica, Taipei 11529, Taiwan.Academia Sinica website: http://www.sinica.edu.twDeadline for application is March 15, 2002
What is stress? Concepts, definitions and applications in seed science
Authors: Kranner Ilse , Minibayeva Farida V. , Beckett Richard P. , Seal Charlotte E. 
Published: September 2010

Summary‘Stresses’ that impact upon seeds can affect plant reproduction and productivity, and, hence, agriculture and biodiversity. In the absence of a clear definition of plant stress, we relate concepts from physics, medicine and psychology to stresses that are specific to seeds. Potential ‘eustresses’ that enhance function and ‘distresses’ that have harmful effects are considered in relation to the seed life cycle. Taking a triphasic biomedical stress concept published in 1936, the ‘General Adaptation Syndrome’, to the molecular level, the ‘alarm’ response is defined by post‐translational modifications and stress signalling through cross‐talk between reactive oxygen and nitrogen species, and seed hormones, that result in modifications to the transcriptome. Protection, repair, acclimation and adaptation are viewed as the ‘building blocks’ of the ‘resistance’ response, which, in seeds, are the basis for their longevity over centuries. When protection and repair mechanisms eventually fail, depending on dose and time of exposure to stress, cell death and, ultimately, seed death are the result, corresponding to ‘exhaustion’. This proposed seed stress concept may have wider applicability to plants in general.

Contents

Summary
655

I.

Definitions of stress
656

II.
The seed life cycle revisited in view of the eustress–distress concept
657

III.
Common denominators of many stresses: reactive oxygen and nitrogen species
660

IV.
Alarm
662

V.
Resistance
664

VI.
Exhaustion
666

VII.
Conclusions
667

Acknowledgements
669

References
669
NOCTURNAL EEG PROFILES AND PERFORMANCE
Authors: Williams Harold L. , Williams Cindy L. 
Published: September 2010

ABSTRACTStatistical analysis of baseline nocturnal EEG profiles identified two groups of Ss (a restless and quiet set) who differed in their performance efficiency under acute sleep deprivation. The restless group with less slow‐wave sleep, more body movements, more awakenings, more transitions from stage to stage, and longer sleep latencies showed greatest sleep‐loss decrement. On the first night of recovery sleep, the sleep profiles of the two groups were virtually identical, but by the third recovery night, the restless group was again showing signs of disturbed sleep. Within each group, all Ss had highly systematic stage‐of‐sleep cycles, forming Markov chains of at least order one.
AVOIDANCE CONDITIONING OF HEART RATE IN HUMANS
Authors: Frazier Thomas W. 
Published: September 2010

ABSTRACTAn avoidance conditioning technique was employed to obtain external control over heart rate. A contingency was set up between heart‐rate maintenance and punishment avoidance. During periods of time signified by a visual stimulus, punishments were dispensed when the total number of beats per minute decreased from the previous minute's total.Subjects (Ss) performed an instrument‐panel‐monitoring task without awareness of the biological avoidance contingency, but they were correctly informed that shocks were available only when the visual stimulus was present. After punishments had been dispensed on the basis of the contingency for several periods, punishment was discontinued and the visual stimulus was used alone as a conditioned aversive stimulus, in order to shape predetermined response patterns.Results included: clear evidence of heart‐rate control over all Ss after training periods; maintenance of heart‐rate control over continuous 40‐min periods through continuous presentation of the visual stimulus; and shaping and replication of three prespecified response patterns.These findings demonstrate that punishment avoidance contingencies can be used to impose effective control over cardiovascular functioning.
A CARDIOTACHOGRAPH WITH LOGARITHMIC RESPONSE FOR USE WITH RATS1
Authors: Mundl Wm. J. 
Published: September 2010

ABSTRACTA cardiotachograph (ECTG) for recording short term changes in heart rate of rats after electric brain stimulation is described. This instrument provides instantaneous graphical display of the electrocardiotachogram, showing the ratio of increase or decrease in heart rate regardless of the basal rate. The output voltage is proportional to the logarithm of the frequency of the electrocardiographic (EKG) signal. Stimulation artifacts are minimized by means of a filter network.
THE APPLICATION OF REGRESSION ANALYSIS TO QUANTITATIVE ELECTROENCEPHALOGRAPHY IN MAN
Authors: Burdick J. Alan , Sugerman A. Arthur , Goldstein Leonide 
Published: September 2010

ABSTRACTThe use of the Drohocki integrator to quantitate the area under the curve of the electroencephalogram (EEG) has provided useful information in earlier studies. However, difficulties arise in comparing data obtained with different types of EEG machines and integrators because of differences in the frequency spectra to which the machines respond. The slope of the regression line of SD on mean integrated area was studied to provide a measure of group variability which would not be unduly sensitive to these differences in equipment. It was found that the slope decreased from group to group in going from normal Ss to catatonic schizophrenics, with alcoholics and undifferentiated schizophrenics in intermediate positions in that order. It was suggested that the clockwise rotation of the regression line provides a convenient measure of the level of cerebral activation.
Interactive Effects of Difficulty and Instrumentality of Avoidant Behavior on Cardiovascular Reactivity
Authors: Wright Rex A. , Williams Barry J. , Dill Jody C. 
Published: September 2010

ABSTRACTCollege‐aged subjects performed 35 trials of an easy or difficult digit‐recognition task. Half were told that a good performance would ensure a high chance of avoiding a blast of noise, and half were told that a good performance would ensure a low chance of avoiding the noise. Results indicated that heart rate and systolic blood pressure reactivity were higher in the difficult condition than in the easy condition only when the probability of avoiding the noise (given success) was high. When the probability of avoiding the noise (given success) was low, heart rate and systolic responsivity were low regardless of task difficulty. It also was found that (1) performance quality was poorer overall among difficult subjects than among easy subjects, and (2) that the difference in performance quality between the easy and difficult groups was somewhat (not significantly) greater in the low‐probability conditions than in the high‐probability conditions. Major findings are considered in terms of Obrist's reasoning regarding the psychophysiological consequences of active coping and a motivational model by Brehm, which specifies conditions under which individuals will be more and less task engaged.
Event‐related brain potential correlates of self‐reported hunger and satiety
Authors: BALDEWEG TORSTEN , ULLSPERGER PETER , PIETROWSKY REINHARD , FEHM HORST LORENZ , BORN JAN 
Published: September 2010

AbstractPerception of hunger and satiety was examined by means of event‐related potential (ERP) recordings. On the basis of Helson's frame‐of‐reference theory, it was hypothesized that hunger is perceived with reference to an actual adaptation level. ERPs were recorded to adjectives (hungry, thirsty, tired) combined with one of five adverbs (very, almost, somewhat, hardly, not). Subjects indicated whether a particular adverb‐adjective combination accurately described their actual feeling of hunger, thirst, or fatigue. They were tested after they had fasted for 16 hr and another time when they were satiated. Area of P300 of the ERP was smallest for adverb‐adjective combinations agreeing with the subject's actual state of hunger (i.e., adaptation level), which was almost hungry in fasting subjects and hardly hungry in satiated subjects. These P300 minima were flanked by significantly enhanced (p < 0.001) P300 areas for the immediately adjacent adverbs combined with hungry. P300 areas for adverbs combined with thirsty and tired did not depend on the subject's state of hunger. The data suggest that perception of internal states, such as hunger, refers to an adaptation level that is sensitively indicated by P300 area.
On the neural generators of the P300 component of the event‐related potential
Authors: JOHNSON RAY 
Published: September 2010

AbstractThe triarchic model of P300 amplitude (Johnson, 1986, 1988a) postulated that the overall amplitude of the P300 recorded at any given electrode site represented the summation of activity from different neural generators, each related to the processing of a different type of information. However, neither of these original accounts provided an explicit description of the methods required to establish experimentally the presence of multiple neural sources. This paper reviews the triarchic amplitude model, the subsequently obtained data that support the postulated presence of multiple generators underlying the P300, and the methods used to demonstrate the presence of these multiple sources. These methods are straightforward because it is only necessary to show that the portions of P300 amplitude associated with different experimental variables have different scalp distributions. The implications of the multiple‐generator basis of P300 on such factors as component definition, neural source analyses, and the cognitive processes underlying its activity are discussed.
Are the anterior negativities to grammatical violations indexing working memory?
Authors: Martín‐Loeches Manuel , Muñoz Francisco , Casado Pilar , Melcón A. , Fernández‐Frías C. 
Published: September 2010

AbstractAnterior negativities obtained when a grammatical rule is violated may reflect highly automatic first‐pass parsing processes, the detection of a morphosyntactic mismatch, and/or the inability to assign the incoming word to the current phrase structure. However, for some theorists these negativities rather reflect some aspect of working memory processes. Event‐related brain potentials (ERPs) obtained for word category and morphosyntactic violations were directly compared with effects obtained when working memory is particularly demanded (embedding subject‐ or object‐relative clauses), yielding a significant dissociation in terms of topography. Even though, the anterior negativities for grammatical violations vanished when relative clauses were embedded, suggesting that the processes reflected by anterior negativities related to grammatical violations and those related to working memory manipulations, even if different, are placing demands on a common pool of limited resources.
Low‐density lipoprotein receptor‐related protein‐1: a serial clearance homeostatic mechanism controlling Alzheimer’s amyloid β‐peptide elimination from the brain
Authors: Zlokovic Berislav V. , Deane Rashid , Sagare Abhay P. , Bell Robert D. , Winkler Ethan A. 
Published: September 2010

J. Neurochem.(2010)115, 1077–1089.AbstractLow‐density lipoprotein receptor‐related protein‐1 (LRP1), a member of the low‐density lipoprotein receptor family, has major roles in the cellular transport of cholesterol, endocytosis of 40 structurally diverse ligands, transcytosis of ligands across the blood–brain barrier, and transmembrane and nuclear signaling. Recent evidence indicates that LRP1 regulates brain and systemic clearance of Alzheimer’s disease (AD) amyloid β‐peptide (Aβ). According to the two‐hit vascular hypothesis for AD, vascular damage precedes cerebrovascular and brain Aβ accumulation (hit 1) which then further amplifies neurovascular dysfunction (hit 2) preceding neurodegeneration. In this study, we discuss the roles of LRP1 during thehit 1andhit 2stage of AD pathogenesis and describe a three‐level serial LRP1‐dependent homeostatic control of Aβ clearance including (i) cell‐surface LRP1 at the blood–brain barrier and cerebrovascular cells mediating brain‐to‐blood Aβ clearance (ii) circulating LRP1 providing a key endogenous peripheral ‘sink’ activity for plasma Aβ which prevents free Aβ access to the brain, and (iii) LRP1 in the liver mediating systemic Aβ clearance. Pitfalls in experimental Aβ brain clearance measurements with the concurrent use of peptides/proteins such as receptor‐associated protein and aprotinin are also discussed. We suggest that LRP1 has a critical role in AD pathogenesis and is an important therapeutic target in AD.
Conflicting perceptions between health care professionals and patients on the psychological morbidity following miscarriage
Authors: KONG Grace W. S. , LOK Ingrid H. , LAM Po M. , YIP Alexander S. K. , CHUNG Tony K. H. 
Published: September 2010

Background:  Miscarriage is common and may result in significant psychological morbidity for women. Recent research has revealed that health care professionals often tend to neglect this factor. This negligence may lead to delayed diagnosis and appropriate care.Aims:  To assess health care professionals’ and patients’ attitudes towards the psychological impact of miscarriage.Methods:  A prospective, cross‐sectional survey of nearly 3000 subjects was conducted. Of these, 1269 were health care professionals and 1519 were pregnant women or their spouses. Their perceptions of the psychological impact of miscarriage, in comparison with postnatal depression were studied.Results:  Health care professionals were less aware of the psychological impact of miscarriage compared with postnatal depression (91.9 vs 98.4%, P = 0.02). Furthermore, they believed that the psychological impact of miscarriage was less than that of postnatal depression (79.9 vs 88.9%, P < 0.001). However, more patients believed that psychological impact after miscarriage can seriously affect women (59.0 vs for health care professionals 38.3%, P < 0.001). A higher proportion of patients compared with health care professionals (85.2 vs 74.3%, P < 0.001) believed that routine psychological support should be provided after miscarriage, but few agreed that primary health professionals were the most suitable people to provide this care although most health care professionals thought this to be appropriate (9.1 vs 59.7%, P < 0.001).Conclusion:  Health care professionals should be more aware of the psychological morbidity associated with miscarriage and also be sensitive to a currently unmet need for psychological care.