bluuebunny/crossref_metadata_2025 huggingface dataset:
Warm ischemic preconditioning improves mitochondrial redox balance during and after mild hypothermic ischemia in guinea pig isolated hearts
Authors: An Jianzhong , Camara Amadou K. S. , Rhodes Samhita S. , Riess Matthias L. , Stowe David F.
Published: January 2005

Ischemic preconditioning (IPC) induces distinctive changes in mitochondrial bioenergetics during warm (37°C) ischemia and improves function and tissue viability on reperfusion. We examined whether IPC before 2 h of hypothermic (27°C) ischemia affords additive cardioprotection and improves mitochondrial redox balance assessed by mitochondrial NADH and flavin adenine dinucleotide (FAD) autofluorescence in intact hearts. A mediating role of ATP-sensitive K+(KATP) channel opening was investigated. NADH and FAD fluorescence was measured in the left ventricular wall of guinea pig isolated hearts assigned to five groups of eight animals each: hypothermia alone, hypothermia with ischemia, IPC with cold ischemia, 5-hydroxydecanoic acid (5-HD) alone, and 5-HD with IPC and cold ischemia. IPC consisted of two 5-min periods of warm global ischemia spaced 5 min apart and 15 min of reperfusion before 2 h of ischemia at 27°C and 2 h of warm reperfusion. The KATPchannel inhibitor 5-HD was perfused from 5 min before until 5 min after IPC. IPC before 2 h of ischemia at 27°C led to better recovery of function and less tissue damage on reperfusion than did 27°C ischemia alone. These improvements were preceded by attenuated increases in NADH and decreases in FAD during cold ischemia and the reverse changes during warm reperfusion. 5-HD blocked each of these changes induced by IPC. This study indicates that IPC induces additive cardioprotection with mild hypothermic ischemia by improving mitochondrial bioenergetics during and after ischemia. Because effects of IPC on subsequent changes in NADH and FAD were inhibited by 5-HD, this suggests that mitochondrial KATPchannel opening plays a substantial role in improving mitochondrial bioenergetics throughout mild hypothermic ischemia and reperfusion.
Serine 68 of phospholemman is critical in modulation of contractility, [Ca2+]itransients, and Na+/Ca2+exchange in adult rat cardiac myocytes
Authors: Song Jianliang , Zhang Xue-Qian , Ahlers Belinda A. , Carl Lois L. , Wang JuFang , Rothblum Lawrence I. , Stahl Richard C. , Mounsey J. Paul , Tucker Amy L. , Moorman J. Randall , Cheung Joseph Y.
Published: January 2005

Overexpression of phospholemman (PLM) in normal adult rat cardiac myocytes altered contractile function and cytosolic Ca2+concentration ([Ca2+]i) homeostasis and inhibited Na+/Ca2+exchanger (NCX1). In addition, PLM coimmunoprecipitated and colocalized with NCX1 in cardiac myocyte lysates. In this study, we evaluated whether the cytoplasmic domain of PLM is crucial in mediating its effects on contractility, [Ca2+]itransients, and NCX1 activity. Canine PLM or its derived mutants were overexpressed in adult rat myocytes by adenovirus-mediated gene transfer. Confocal immunofluorescence images using canine-specific PLM antibodies demonstrated that the exogenous PLM or its mutants were correctly targeted to sarcolemma, t-tubules, and intercalated discs, with little to none detected in intracellular compartments. Overexpression of canine PLM or its mutants did not affect expression of NCX1, sarco(endo)plasmic reticulum Ca2+-ATPase, Na+-K+-ATPase, and calsequestrin in adult rat myocytes. A COOH-terminal deletion mutant in which all four potential phosphorylation sites (Ser62, Ser63, Ser68, and Thr69) were deleted, a partial COOH-terminal deletion mutant in which Ser68and Thr69were deleted, and a mutant in which all four potential phosphorylation sites were changed to alanine all lost wild-type PLM's ability to modulate cardiac myocyte contractility. These observations suggest the importance of Ser68or Thr69in mediating PLM's effect on cardiac contractility. Focusing on Ser68, the Ser68to Glu mutant was fully effective, the Ser63to Ala (leaving Ser68intact) mutant was partially effective, and the Ser68to Ala mutant was completely ineffective in modulating cardiac contractility, [Ca2+]itransients, and NCX1 currents. Both the Ser63to Ala and Ser68to Ala mutants, as well as PLM, were able to coimmunoprecipitate NCX1. It is known that Ser68in PLM is phosphorylated by both protein kinases A and C. We conclude that regulation of cardiac contractility, [Ca2+]itransients, and NCX1 activity by PLM is critically dependent on Ser68. We suggest that PLM phosphorylation at Ser68may be involved in cAMP- and/or protein kinase C-dependent regulation of cardiac contractility.
Studies on rabbit natural and recombinant tissue factors: intracellular retention and regulation of surface expression in cultured cells
Authors: Fortin Jean-Philippe , Rivard Georges E. , Adam Albert , Marceau François
Published: January 2005

Tissue factor (TF) is the most important trigger of blood coagulation in vascular pathology. Rabbit TF, with or without (ΔC) its COOH-terminal intracellular tail, has been conjugated to green fluorescent protein (GFP) to study subcellular localization and other functions of TF. TF-GFP and TFΔC-GFP are associated with Na2CO3-resistant buoyant fractions in HEK-293 cells (lipid rafts); there is no morphological difference in the surface distribution of these or other GFP-labeled membrane proteins present in or excluded from rafts (confocal microscopy, HEK-293 cells). Endogenous TF expressed by rabbit aortic smooth muscle cells (SMCs) is also raft associated. Membranes from HEK-293 cells expressing recombinant TF-GFP or wild-type TF were equipotent to clot human plasma; however, TFΔC-GFP was ∼20-fold more active (per membrane weight). Immunoblot confirmed that the deletion mutant is more abundantly expressed, and confocal microscopy showed that it has preferential membrane localization, whereas TF-GFP is mainly intracellular (nuclear lining and multiple granules). With a similar half-life (<4 h), the two constructions differ by their intracellular retention, lower for TFΔC-GFP. In serum-starved SMCs, the expression of endogenous TF was upregulated by interleukin-1β and/or FBS treatment (immunoblot, immunofluorescence, clotting assay). However, TF secretion or surface expression was not regulated by stimuli of physiological intensity (such as stimulation of the coexpressed kinin B1receptors), although a calcium ionophore was highly active in this respect. TF is a raft-associated molecule whose surface expression (secretion) is apparently retarded or impaired by structural determinant(s) located in its COOH-terminal tail.
Defective calcium handling in cardiomyocytes isolated from hearts subjected to ischemia-reperfusion
Authors: Saini Harjot K. , Dhalla Naranjan S.
Published: January 2005

Although ischemia-reperfusion (I/R) has been shown to affect subcellular organelles that regulate the intracellular Ca2+concentration ([Ca2+]i), very little information regarding the Ca2+handling ability of cardiomyocytes obtained from I/R hearts is available. To investigate changes in [Ca2+]idue to I/R, rat hearts in vitro were subjected to 10–30 min of ischemia followed by 5–30 min of reperfusion. Cardiomyocytes from these hearts were isolated and purified; [Ca2+]iwas measured by employing fura-2 microfluorometry. Reperfusion for 30 min of the 20-min ischemic hearts showed attenuated cardiac performance, whereas basal [Ca2+]ias well as the KCl-induced increase in [Ca2+]iand isoproterenol (Iso)-induced increase in [Ca2+]iin cardiomyocytes remained unaltered. On the other hand, reperfusion of the 30-min ischemic hearts for different periods revealed marked changes in cardiac function, basal [Ca2+]i, and Iso-induced increase in [Ca2+]iwithout any alterations in the KCl-induced increase in [Ca2+]ior S(−)-BAY K 8644-induced increase in [Ca2+]i. The I/R-induced alterations in cardiac function, basal [Ca2+]i, and Iso-induced increase in [Ca2+]iin cardiomyocytes were attenuated by an antioxidant mixture containing superoxide dismutase and catalase as well as by ischemic preconditioning. The observed changes due to I/R were simulated in hearts perfused with H2O2for 30 min. These results suggest that abnormalities in basal [Ca2+]ias well as mobilization of [Ca2+]iupon β-adrenoceptor stimulation in cardiomyocytes are dependent on the duration of ischemic injury to the myocardium. Furthermore, Ca2+handling defects in cardiomyocytes appear to be mediated through oxidative stress in I/R hearts.
Ephedrine plus caffeine causes age-dependent cardiovascular responses in Fischer 344 rats
Authors: Howden Reuben , Hanlon Paul R. , Petranka John G. , Kleeberger Steven , Bucher John , Dunnick June , Nyska Abraham , Murphy Elizabeth
Published: January 2005

Human consumption of ephedrine and caffeine in dietary supplements has been associated with a number of adverse effects including changes in the ECG, myocardial infarction, hyperthermia, and, in rare instances, death. The purpose of this study was to investigate the potential mechanisms associated with the cardiotoxicity of combined ephedrine and caffeine ingestion. Seven- and fourteen-week-old Fischer 344 rats treated with ephedrine in combination with caffeine exhibited increases in heart rate (HR), temperature, and corrected QT interval. Of the 14-wk-old rats treated with 25 mg/kg ephedrine plus 30 mg/kg caffeine, 57% died within 3–5 h of treatment, whereas none of the similarly treated 7-wk-old rats nor any of the rats treated with vehicle died. One hour after treatment with this dose of ephedrine plus caffeine, 14-wk-old rats exhibited a larger increase in HR (as % increase over baseline) than 7-wk-old rats. Furthermore, the 14-wk-old rats that died had a higher HR and temperature than the 14-wk-old rats that lived. Histopathological studies suggested interstitial hemorrhage and myofiber necrosis in the 14-wk-old rats treated with the highest concentration of ephedrine and caffeine. This study showed enhanced susceptibility to ephedrine plus caffeine in 14-wk-old rats compared with 7-wk-old rats. The greater mortality in the 14-wk-old rats was associated with increases in body temperature, HR, and myocardial necrosis.
Ethanol stimulates the expression of fibronectin in lung fibroblasts via kinase-dependent signals that activate CREB
Authors: Roman Jesse , Ritzenthaler Jeffrey D. , Bechara Rabih , Brown Lou Ann , Guidot David
Published: January 2005

Ethanol renders the lung susceptible to acute lung injury in the setting of insults such as sepsis. The mechanisms mediating this effect are unknown, but activation of tissue remodeling is considered key to this process. We found that chronic ethanol ingestion in rats increased the expression of fibronectin, a matrix glycoprotein implicated in acute lung injury. In cultured NIH/3T3 cells and in primary rat and mouse lung fibroblasts, ethanol induced fibronectin mRNA and protein expression in a dose- and time-dependent fashion. The effect of ethanol was prevented by inhibitors of protein kinase C and mitogen-activated protein kinases and was associated with the phosphorylation and increased DNA binding of the transcription factor cAMP response element binding protein, followed by increased transcription of the fibronectin gene. Fibroblasts were found to express α7nicotinic acetylcholine receptor (nAChR), and ethanol induction of fibronectin was abolished by α-bungarotoxin and methyllcaconitine, inhibitors of α7nAChRs. However, ethanol was able to induce fibronectin mRNA and protein in primary lung fibroblasts isolated from α7nAChR knockout mice. The ethanol-induced fibronectin response was dependent on ethanol metabolism since 4-methylpyrazole, an inhibitor of alcohol dehydrogenase, abolished the effect and acetaldehyde induced it. These observations suggest that ethanol or ethanol metabolites stimulate lung fibroblasts to produce fibronectin by inducing specific signals transmitted via nAChRs independent of the α7-subunit, and this might represent a mechanism by which ethanol renders the lung susceptible to acute lung injury.
Loss of Gadd45a does not modify the pulmonary response to oxidative stress
Authors: Roper Jason M. , Gehen Sean C. , Staversky Rhonda J. , Hollander M. Christine , Fornace Albert J. , O'Reilly Michael A.
Published: January 2005

It is well established that exposure to high levels of oxygen (hyperoxia) injures and kills microvascular endothelial and alveolar type I epithelial cells. In contrast, significant death of airway and type II epithelial cells is not observed at mortality, suggesting that these cell types may express genes that protect against oxidative stress and damage. During a search for genes induced by hyperoxia, we previously reported that airway and alveolar type II epithelial cells uniquely express the growth arrest and DNA damage ( Gadd) 45a gene. Because Gadd45a has been implicated in protection against genotoxic stress, adult Gadd45a (+/+) and Gadd45a (−/−) mice were exposed to hyperoxia to investigate whether it protected epithelial cells against oxidative stress. During hyperoxia, Gadd45a deficiency did not affect loss of airway epithelial expression of Clara cell secretory protein or type II epithelial cell expression of pro-surfactant protein C. Likewise, Gadd45a deficiency did not alter recruitment of inflammatory cells, edema, or overall mortality. Consistent with Gadd45a not affecting the oxidative stress response, p21Cip1/WAF1and heme oxygenase-1 were comparably induced in Gadd45a (+/+) and Gadd45a (−/−) mice. Additionally, Gadd45a deficiency did not affect oxidative DNA damage or apoptosis as assessed by oxidized guanine and terminal deoxyneucleotidyl transferase-mediated dUTP nick-end labeling staining. Overexpression of Gadd45a in human lung adenocarcinoma cells did not affect viability or survival during exposure, whereas it was protective against UV-radiation. We conclude that increased tolerance of airway and type II epithelial cells to hyperoxia is not attributed solely to expression of Gadd45a.
3-Nitrotyrosine attenuates respiratory syncytial virus infection in human bronchial epithelial cell line
Authors: Huang Yuh-Chin T. , Li Zhuowei , Brighton Luisa E. , Carson Johnny L. , Becker Susanne , Soukup Joleen M.
Published: January 2005

3-Nitrotyrosine (NO2Tyr), an l-tyrosine derivative during nitrative stress, can substitute the COOH-terminal tyrosine of α-tubulin, posttranslationally altering microtubular functions. Because infection of the cells by respiratory syncytial virus (RSV) may require intact microtubules, we tested the hypothesis that NO2Tyr would inhibit RSV infection and intracellular signaling via nitrotyrosination of α-tubulin. A human bronchial epithelial cell line (BEAS-2B) was incubated with RSV with or without NO2Tyr. The release of chemokines and viral particles and activation of interferon regulatory factor-3 (IRF-3) were measured. Incubation with NO2Tyr increased nitrotyrosinated α-tubulin, and NO2Tyr colocalized with microtubules. RSV-infected cells released viral particles, RANTES, and IL-8 in a time- and dose-dependent manner, and intracellular RSV proteins coprecipitated with α-tubulin. NO2Tyr attenuated the RSV-induced release of RANTES, IL-8, and viral particles by 50–90% and decreased α-tubulin-associated RSV proteins. 3-Chlorotyrosine, another l-tyrosine derivative, had no effects. NO2Tyr also inhibited the RSV-induced shift of the unphosphorylated form I of IRF-3 to the phosphorylated form II. Pre-exposure of the cells to NO2(0.15 ppm, 4 h), which produced diffuse protein tyrosine nitration, did not affect RSV-induced release of RANTES, IL-8, or viral particles. NO2Tyr did not affect the potential of viral spreading to the neighboring cells since the RSV titers were not decreased when the uninfected cells were cocultured with the preinfected cells in NO2Tyr-containing medium. These results indicate that NO2Tyr, by replacing the COOH-terminal tyrosine of α-tubulin, attenuated RSV infection, and the inhibition appeared to occur at the early stages of RSV infection.
2-Aminoethoxydiphenyl borate stimulates pulmonary C neurons via the activation of TRPV channels
Authors: Gu Qihai , Lin Ruei-Lung , Hu Hong-Zhen , Zhu Michael X. , Lee Lu-Yuan
Published: January 2005

This study was carried out to determine the effect of 2-aminoethoxydiphenyl borate (2-APB), a common activator of transient receptor potential vanilloid (TRPV) type 1, 2, and 3 channels, on cardiorespiratory reflexes, pulmonary C fiber afferents, and isolated pulmonary capsaicin-sensitive neurons. In anesthetized, spontaneously breathing rats, intravenous bolus injection of 2-APB elicited the pulmonary chemoreflex responses, characterized by apnea, bradycardia, and hypotension. After perineural treatment of both cervical vagi with capsaicin to block the conduction of C fibers, 2-APB no longer evoked any of these reflex responses. In open-chest and artificially ventilated rats, 2-APB evoked an abrupt and intense discharge in vagal pulmonary C fibers in a dose-dependent manner. The stimulation of C fibers by 2-APB was attenuated but not abolished by capsazepine, a selective antagonist of the TRPV1, which completely blocked the response to capsaicin in these C fiber afferents. In isolated pulmonary capsaicin-sensitive neurons, 2-APB concentration dependently evoked an inward current that was partially inhibited by capsazepine but almost completely abolished by ruthenium red, an effective blocker of all TRPV channels. In conclusion, 2-APB evokes a consistent and distinct stimulatory effect on pulmonary C fibers in vivo and on isolated pulmonary capsaicin-sensitive neurons in vitro. These results establish the functional evidence demonstrating that TRPV1, V2, and V3 channels are expressed on these sensory neurons and their terminals.
Learning Places from Views: Variation in Scene Processing as a Function of Experience and Navigational Ability
Authors: Epstein Russell A. , Higgins J. Stephen , Thompson-Schill Sharon L.
Published: January 2005

Humans and animals use information obtained from different viewpoints to form representations of the spatial structure of the world. We used functional magnetic resonance imaging (fMRI) adaptation to investigate the neural basis of this learning process and to show how the concomitant representations vary across individuals as a function of navigational ability. In particular, we examined the effect of repeating viewpoint and/ or place information over both short (within-trial) and long (across-scan) intervals on the neural response in scene processing regions. Short-term fMRI adaptation effects in the parahippocampal cortex were initially highly viewpoint-specific but became less so over time. Long-term fMRI repetition effects included a significant viewpoint-invariant component. When individual differences in navigational ability were considered, a significant correlation between the strength of these effects and self-reported navigational competence was observed. In particular, good navigators encoded representations that differed between new and old views and new and old places, whereas bad navigators did not. These results suggest that cortical scene representations evolve over time to become more viewpoint-invariant and that the quality of these representations directly impacts navigational ability.
Real and Imaginary Rotary Motion Processing: Functional Parcellation of the Human Parietal Lobe Revealed by fMRI
Authors: Podzebenko Katherine , Egan Gary F. , Watson John D. G.
Published: January 2005

Functional magnetic resonance imaging was performed in 16 healthy subjects while they undertook orientation discrimination tasks of real rotating and mentally rotating alphanumeric characters. Perception of rotating and stationary abstract characters was also performed. Mental rotation and the perception of alphanumeric characters undergoing real rotation activated equivalent cortical areas, in keeping with the analogue hypothesis of mental rotation. In addition, areas along the dorsal stream, including the V5/middle temporal complex and the intraparietal sulcus (IPS), were activated during both the real and imaginary rotary conditions.

Within the parietal lobe there were areas of convergence (i.e., recruited by all three motion conditions) and areas of divergence (i.e., selectively activated by a particular condition). Tasks requiring canonical-mirror orientation discrimination revealed involvement of neural substrates localized to the ventrolateral bank of the IPS. Tasks in which this judgment was not performed and during which the subject viewed rotary motion of abstract stimuli recruited activity in the medial bank of the IPS. These results indicate subspecialization of the human posterior parietal lobe according to function.
Attention and Interhemispheric Transfer: A Behavioral and fMRI Study
Authors: Weber B. , Treyer V. , Oberholzer N. , Jaermann T. , Boesiger P. , Brugger P. , Regard M. , Buck A. , Savazzi S. , Marzi C. A.
Published: January 2005

When both detections and responses to visual stimuli are performed within one and the same hemisphere, manual reaction times (RTs) are faster than when the two operations are carried out in different hemispheres. A widely accepted explanation for this difference is that it reflects the time lost in callosal transmission. Interhemispheric transfer time can be estimated by subtracting RTs for uncrossed from RTs for crossed responses (crossed – uncrossed difference, or CUD). In the present study, we wanted to ascertain the role of spatial attention in affecting the CUD and to chart the brain areas whose activity is related to these attentional effects on interhemispheric transfer. To accomplish this, we varied the proportion of crossed and uncrossed trials in different blocks. With this paradigm subjects are likely to focus attention either on the hemifield contralateral to the responding hand (blocks with 80% crossed trials) or on the ipsilateral hemifield (blocks with 80% uncrossed trials). We found an inverse correlation between the proportion of crossed trials in a block and the CUD and this effect can be attributed to spatial attention. As to the imaging results, we found that in the crossed minus uncrossed subtraction, an operation that highlights the neural processes underlying interhemispheric transfer, there was an activation of the genu of the corpus callosum as well as of a series of cortical areas. In a further commonality analysis, we assessed those areas which were activated specifically during focusing of attention onto one hemifield either contra- or ipsilateral to the responding hand. We found an activation of a number of cortical and subcortical areas, notably, parietal area BA 7 and the superior colliculi. We believe that the main thrust of the present study is to have teased apart areas important in interhemispheric transmission from those involved in spatial attention.
ERP Nonword Rhyming Effects in Children and Adults
Authors: Coch Donna , Grossi Giordana , Skendzel Wendy , Neville Helen
Published: January 2005

In a simple prime–target auditory rhyming event-related potential (ERP) paradigm with adults and 6-, 7-, and 8-year-old children, nonword stimuli (e.g., nin–rin, ked–voo) were used to investigate neurocognitive systems involved in rhyming and their development across the early school years. Even absent semantic content, the typical CNV to primes and late rhyming effect (RE) to targets were evident in all age groups. The RE consisted of a more negative response to nonrhyming targets as compared to rhyming targets over posterior sites, with a reversal of this pattern at lateral anterior sites. The hypothesis that the CNV indexes phonological memory processes was not well supported by correlation analyses conducted with the ERP measures and scores on standardized behavioral tests. However, the onset of the rhyming effect was later in those scoring lower on phonological awareness measures.
Neural Topography and Content of Movement Representations
Authors: Lange Floris P. de , Hagoort Peter , Toni Ivan
Published: January 2005

We have used implicit motor imagery to investigate the neural correlates of motor planning independently from actual movements. Subjects were presented with drawings of left or right hands and asked to judge the hand laterality, regardless of the stimulus rotation from its upright orientation. We paired this task with a visual imagery control task, in which subjects were presented with typographical characters and asked to report whether they saw a canonical letter or its mirror image, regardless of its rotation. We measured neurovascular activity with fast event-related fMRI, distinguishing responses parametrically related to motor imagery from responses evoked by visual imagery and other task-related phenomena. By quantifying behavioral and neurovascular correlates of imagery on a trial-by-trial basis, we could discriminate between stimulus-related, mental rotation-related, and response-related neural activity. We found that specific portions of the posterior parietal and precentral cortex increased their activity as a function of mental rotation only during the motor imagery task. Within these regions, the parietal cortex was visually responsive, whereas the dorsal precentral cortex was not. Response- but not rotation-related activity was found around the left central sulcus (putative primary motor cortex) during both imagery tasks. Our study provides novel evidence on the topography and content of movement representations in the human brain. During intended action, the posterior parietal cortex combines somatosensory and visuomotor information, whereas the dorsal premotor cortex generates the actual motor plan, and the primary motor cortex deals with movement execution. We discuss the relevance of these results in the context of current models of action planning.
Aging and the Neural Correlates of Successful Picture Encoding: Frontal Activations Compensate for Decreased Medial-Temporal Activity
Authors: Gutchess Angela H. , Welsh Robert C. , Hedden Trey , Bangert Ashley , Minear Meredith , Liu Linda L. , Park Denise C.
Published: January 2005

We investigated the hypothesis that increased prefrontal activations in older adults are compensatory for decreases in medial-temporal activations that occur with age. Because scene encoding engages both hippocampal and prefrontal sites, we examined incidental encoding of scenes by 14 young and 13 older adults in a subsequent memory paradigm using functional magnetic resonance imaging (fMRI). Behavioral results indicated that there were equivalent numbers of remembered and forgotten items, which did not vary as a function of age. In an fMRI analysis subtracting forgotten items from remembered items, younger and older adults both activated inferior frontal and lateral occipital regions bilaterally; however, older adults showed less activation than young adults in the left and right parahippocampus and more activation than young adults in the middle frontal cortex. Moreover, correlations between inferior frontal and parahippocampal activity were significantly negative for old but not young, suggesting that those older adults who showed the least engagement of the parahippocampus activated inferior frontal areas the most. Because the analyses included only the unique activations associated with remembered items, these data suggest that prefrontal regions could serve a compensatory role for declines in medial-temporal activations with age.
Brain Responses to Segmentally and Tonally Induced Semantic Violations in Cantonese
Authors: Schirmer Annett , Tang Siu-Lam , Penney Trevor B. , Gunter Thomas C. , Chen Hsuan-Chih
Published: January 2005

The present event-related potential (ERP) study examined the role of tone and segmental information in Cantonese word processing. To this end, participants listened to sentences that were either semantically correct or contained a semantically incorrect word. Semantically incorrect words differed from the most expected sentence completion at the tone level, at the segmental level, or at both levels. All semantically incorrect words elicited an increased frontal negativity that was maximal 300 msec following word onset and an increased centroparietal positivity that was maximal 650 msec following word onset. There were differences between completely incongruous words and the other two violation conditions with respect to the latency and amplitude of the ERP effects. These differences may be due to differences in the onset of acoustic deviation of the presented from the expected word and different mechanisms involved in the processing of complete as compared to partial acoustic deviations. Most importantly, however, tonally and segmentally induced semantic violations were comparable. This suggests that listeners access tone and segmental information at a similar point in time and that both types of information play comparable roles during word processing in Cantonese.
Parietal rTMS Disrupts the Initiation but not the Execution of On-line Adjustments to a Perturbation of Object Size
Authors: Glover Scott , Miall R. Chris , Rushworth Matthew F. S.
Published: January 2005

Previous studies have implicated the human parietal lobes in the on-line guidance of action. However, no study to date has examined at what stage in the on-line adjustment process do the parietal lobes play their most critical role. Repetitive transcranial magnetic stimulation (rTMS) was applied over the left intraparietal sulcus as participants reached to grasp a small or large illuminated cylinder. On some trials, the illumination could suddenly switch from the small to large cylinder, or vice-versa. Small–Large switches were associated with relatively early grip aperture adjustments, whereas Large–Small switches were associated with relatively late grip aperture adjustments.

When rTMS was applied early in the movement, it disrupted on-line adjustments to Small–Large target switches, but not to Large–Small switches. Conversely, when rTMS was applied late in the movement, it disrupted adjustments to Large–Small target switches but not to Small–Large switches. The timing of the disruption by rTMS appeared linked to the initiation of the adjustment. It was concluded that the left parietal lobe plays a critical role in initiating an on-line adjustment to a change in target size, but not in executing that adjustment. The implications of these results for current views of on-line control are discussed.
Influence of Prosodic Information on the Processing of Split Particles: ERP Evidence from Spoken German
Authors: Isel Frédéric , Alter Kai , Friederici Angela D.
Published: January 2005

Spoken language comprehension involves the use of different sources of linguistic information such as prosodic, syntactic, lexical, and semantic information. The question, however, of “when” and “how” these sources of information are exploited by the language processing system still remains unanswered. In the present study, we used event-related brain potentials (ERPs) to investigate the interaction between prosodic, syntactic, and lexical information during the processing of spoken German sentences. The sentence structure was manipulated by positioning a split particle at the end of the sentences after the occurrence of inflected verb whose lexical entry does not contain a split particle (e.g., *Sie alarmierte den Detektiv an [*She alerted at the detective]) [According to linguistic convention, incorrect sentences are marked by an asterisk.]. The prosodic contour of the verb stems was manipulated such that it marked either the presence of a split particle at a later position in the sentence or not. Participants performed an off-line probe-detection task. ERP data indicate that prosodic information of German-inflected verb stems is consulted on-line by the language processing system (“parser”) in order to “predict” the presence of a split particle at a later position in the sentence. An N400 effect was observed for the processing of split particles following verb stems which do not take a particle. However, this effect was only observed when the prosody of the verb stem did signal the presence of a split particle. We argue that the N400 component reflects the high costs associated with the lexical search that the language processing system has to perform when confronted with nonexisting words such as these resulting from the combination of the split particle and the verb stem in the present study. Furthermore, as a general reflection of prosodic processes, a Closure Positive Shift (CPS) was found at intonational phrase boundaries. In sum, the present findings provide strong evidence that prosodic information is a good “predictor” of upcoming information during the auditory processing of German sentences.
Effects of Aging on Arithmetic Problem-Solving: An Event-related Brain Potential Study
Authors: Yagoubi Radouane El , Lemaire Patrick , Besson Mireille
Published: January 2005

Younger and older participants were asked to indicate if 240 complex two-digit addition problems were smaller than 100 or not. Half of the problems were small-split problems (i.e., the proposed sums were 2% or 5% away from 100; e.g., 53 + 49) and half were large-split problems (i.e., proposed sums were 10% or 15% away from 100; 46 + 39). Behavioral and event-related potential (ERP) data revealed that (a) both groups showed a split effect on both reaction times and percent errors, (b) split effects were smaller for older than for younger adults in ERPs, and (c) the hemispheric asymmetry (left hemisphere advantage) reported for younger adults was reduced in older adults (age-related hemispheric asymmetry reduction). These results suggest that older adults tend to use only one strategy to solve all problems, whereas younger adults flexibly and adaptively use different strategies for small- and large-split problems. Implications of these findings for our understanding of age-related similarities and differences in arithmetic problem-solving are discussed.
Dynamic Dopamine Modulation in the Basal Ganglia: A Neurocomputational Account of Cognitive Deficits in Medicated and Nonmedicated Parkinsonism
Authors: Frank Michael J.
Published: January 2005

Dopamine (DA) depletion in the basal ganglia (BG) of Parkinson's patients gives rise to both frontal-like and implicit learning impairments. Dopaminergic medication alleviates some cognitive deficits but impairs those that depend on intact areas of the BG, apparently due to DA “overdose.” These findings are difficult to accommodate with verbal theories of BG/DA function, owing to complexity of system dynamics: DA dynamically modulates function in the BG, which is itself a modulatory system. This article presents a neural network model that instantiates key biological properties and provides insight into the underlying role of DA in the BG during learning and execution of cognitive tasks. Specifically, the BG modulates the execution of “actions” (e.g., motor responses and working memory updating) being considered in different parts of the frontal cortex. Phasic changes in DA, which occur during error feedback, dynamically modulate the BG threshold for facilitating/suppressing a cortical command in response to particular stimuli. Reduced dynamic range of DA explains Parkinson and DA overdose deficits with a single underlying dysfunction, despite overall differences in raw DA levels. Simulated Parkinsonism and medication effects provide a theoretical basis for behavioral data in probabilistic classification and reversal tasks. The model also provides novel testable predictions for neuropsychological and pharmacological studies, and motivates further investigation of BG/DA interactions with the prefrontal cortex in working memory.
Grammatical Gender and Number Agreement in Spanish: An ERP Comparison
Authors: Barber Horacio , Carreiras Manuel
Published: January 2005

The role of grammatical gender and number representations in syntactic processes during reading in Spanish was studied using the event-related potentials (ERPs) technique. The electroencephalogram was recorded with a dense array of 128 electrodes while Spanish speakers read word pairs (Experiment 1) or sentences (Experiment 2) in which gender or number agreement relationships were manipulated. Disagreement in word pairs formed by a noun and an adjective (e.g., faro–alto [lighthouse–high]) produced an N400-type effect, while word pairs formed by an article and a noun (e.g., el–piano [the-piano]) showed an additional left anterior negativity effect (LAN). Agreement violations with the same words inserted in sentences (e.g., El piano estaba viejo y desafinado [the m-s piano m-s was old m-s and off-key]) resulted in a pattern of LAN–P600. This effect was found both when the violation occurred in the middle of the sentence (at the adjective), as well as when this happened at the beginning of the sentence (at the noun), but the last segment of the P600 effect was greater for the middle sentence position, which could indicate differences in the complexity of reanalysis processes. Differences between grammatical gender and number disagreement were found in late measures. In the word pairs experiment, P3 peak latency varied across conditions, being later for gender than for number disagreement. Similarly, in the sentence experiment, the last segment of the P600 effect was greater for gender than for number violations. These event-related potentials (ERPs) effects lend support to the idea that reanalysis or repair processes after grammatical disagreement detection could involve more steps in the case of gender disagreement, as grammatical gender is a feature of the lexical representation in contrast to number, which is considered a morphological feature that combines with the stem of the word.
What is the Red Knot Worth?: Valuing Human/Avian Interaction
Authors: Karnicky Jeffrey
Published: January 2005

Approximately at the turn of the nineteenth century, the visual encounter between humans and birds, which has been going on since both forms of life have existed, began to solidify into a hobby, into something that a middle-class citizen of American might spend a morning doing. Certain technologies—optics (binoculars), field guides, and later, automobiles—helped to enable this pursuit. In the twentieth century, bird watching became an immense industry. At the beginning of the twenty-first century, one report claims that in America "an estimated 70.4 million people now go out-of-doors to watch birds one or more times per year" (Cordell & Herbert, 2003, p. 3). Much has been written on how and why bird watching has grown in popularity during the last 150 years or so. 2 This essay will look instead at the effects produced by the nearly infinite acts of looking inherent to a hobby that has been described as one of "Americans' most-favored [outdoor] activities" (Cordell & Herbert, p. 3)
Moral Disengagement and Attitudes about Violence toward Animals
Authors: Vollum Scott , Longmire Dennis , Buffington-Vollum Jacqueline
Published: January 2005

Despite a growing body of evidence linking nonhuman animal cruelty to violence toward humans and increasing knowledge of the pain and suffering that animals experience at the hands of humans, research on violence toward animals is relatively sparse. This study examines public attitudes about violence against animals and the criminal justice response to such acts. The study included, as part of a statewide survey, questions of Texas residents gauging the perceived severity of numerous violent acts against nonhuman animals as well as the preferred criminal justice response. The paper presents descriptive analyses and employs OLS Regression to assess the relationship between Bandura's (1990, 1999) mechanisms of moral disengagement and violence toward animals. The paper discusses implications for future research on animal cruelty and animal abuse.
The Relationship between Animal Cruelty, Delinquency, and Attitudes toward the Treatment of Animals
Authors: Henry Bill
Published: January 2005

Previous research has identified a relationship between acts of cruelty to animals other than humans and involvement in other forms of antisocial behavior. The current study sought to extend these findings by examining this relationship among a sample of college students using a self-report delinquency methodology. In addition, the current study explored the relationship between a history of observing or engaging in acts of animal cruelty and attitudes of sensitivity/concern regarding the treatment of nonhuman animals. College students (n = 169) enrolled in an Introduction to Psychology course comprised the sample. Results indicated that those participants who observed acts of animal cruelty and those who participated in acts of animal cruelty had higher scores on a self-report delinquency scale than did those who had never observed or participated in acts of animal cruelty. Observation of acts of animal cruelty interacted with sex to predict attitudes toward the treatment of animals. Observation of animal cruelty and par ticipation in animal cruelty affected delinquency scores independently. The current study discusses implications and directions for future research.
Animals, Women, and Weapons: Blurred Sexual Boundaries in the Discourse of Sport Hunting
Authors: Baralt Lori , Kalof Linda , Fitzgerald Amy
Published: January 2005

The furor and public outrage surrounding the release of a fictionalized video in which naked women are hunted down and shot with paintball guns ("Hunting for Bambi") inspired this paper. Arguing that distressing representations of hunting as a sexually charged activity are resilient popular culture images, this paper examines the theoretical framework that links hunting with sex and women with animals and the empirical evidence of such linkages in the hunting discourse of a popular newsstand periodical. Contemporary feminist theory often connects hunting with sex and women with animals. This paper details clear evidence of the juxtaposition of hunting, sex, women, and animals in the photographs, narratives, and advertisements of a random sampling of Traditional Bowhunter magazines (1992-2003). Particularly prominent in the magazines' hunting discourse is the sexualization of animals, women, and weapons, as if the three are interchangeable sexual bodies in narratives of traditional masculinity. This paper concludes that moral outrage at the degradation of women might be targeted best at widely read newsstand periodicals that serve as popular culture precursors to videos that celebrate hunting naked women.
Entrainment in a Model of the Mammalian Circadian Oscillator
Authors: Geier Florian , Becker-Weimann Sabine , Kramer Achim , Herzel Hanspeter
Published: January 2005

To adapt the timing of processes regulated by the circadian clock to seasonally varying photoperiods, the phase relation between the circadian clock and dusk or dawn (“phase of entrainment”) must be tightly adjusted. The authors use a mathematical model of the molecular mammalian circadian oscillator to investigate the influence of the free-running period (•) and the shape of the PRC on the phase of entrainment. They find that a phase-dependent sensitivity (“gating”) of light-induced period gene transcription enables a constant phase relation to dusk or dawn under different photoperiods. Depending on the freerunning period • and on the shaping of the PRC by gating, the model circadian oscillator tracks either light onset or light offset under different photoperiods. The study indicates that the phase of entrainment of oscillating cells can be systematically controlled by regulating both gating and the free-running period τ.
Ramelteon (TAK-375) Accelerates Reentrainment of Circadian Rhythm after a Phase Advance of the Light-Dark Cycle in Rats
Authors: Hirai Keisuke , Kita Muneto , Ohta Hiroyuki , Nishikawa Hisao , Fujiwara Yuu , Ohkawa Shigenori , Miyamoto Masaomi
Published: January 2005

In vivo pharmacological effects of ramelteon (TAK-375), a novel, highly MT1/MT2-selective receptor agonist, were studied in rats to determine ramelteon’s ability to reentrain the circadian rhythm after an abrupt phase advance. Experiments were also conducted to assess the potential cognitive side effects of ramelteon and its potential to become a drug of abuse. After an abrupt 8-h phase shift, ramelteon (0.1 and 1 mg/kg, p.o.) and melatonin (10 mg/kg, p.o.) accelerated reentrainment of running wheel activity rhythm to the new lightdark cycle. Ramelteon (3-30 mg/kg, p.o.) and melatonin (10-100 mg/kg, p.o.) did not affect learning or memory in rats tested by the water maze task and the delayed match to position task, although diazepam and triazolam impaired both of the tasks. Neither ramelteon (3-30 mg/kg, p.o.) nor melatonin (10-100mg/kg, p.o.) demonstrated a rewarding property in the conditioned place-preference test, implying that MT1/MT2 receptor agonists have no abuse potential. In contrast, benzodiazepines and morphine showed rewarding properties in this test. The authors’ results suggest that ramelteon may be useful for treatment of circadian rhythm sleep disorders without adverse effects typically associated with benzodiazepine use, such as learning and memory impairment, and drug dependence.
Nasal versus Temporal Illumination of the Human Retina: Effects on Core Body Temperature, Melatonin, and Circadian Phase
Authors: Rüger Melanie , Gordijn Marijke C. M. , Beersma Domien G. M. , de Vries Bonnie , Daan Serge
Published: January 2005

The mammalian retina contains both visual and circadian photoreceptors. In humans, nocturnal stimulation of the latter receptors leads to melatonin suppression, which might cause reduced nighttime sleepiness. Melatonin suppression is maximal when the nasal part of the retina is illuminated. Whether circadian phase shifting in humans is due to the same photoreceptors is not known. The authors explore whether phase shifts and melatonin suppression depend on the same retinal area. Twelve healthy subjects participated in a within-subjects design and received all of 3 light conditions—1) 10 lux of dim light on the whole retina, 2) 100 lux of ocular light on the nasal part of the retina, and 3) 100 lux of ocular light on the temporal part of the retina—on separate nights in random order. In all 3 conditions, pupils were dilated before and during light exposure. The protocol consisted of an adaptation night followed by a 23-h period of sustained wakefulness, during which a 4-h light pulse was presented at a time when maximal phase delays were expected. Nasal illumination resulted in an immediate suppression of melatonin but had no effect on subjective sleepiness or core body temperature (CBT). Nasal illumination delayed the subsequent melatonin rhythm by 78 min, which is significantly ( p= 0.016) more than the delay drift in the dim-light condition (38 min), but had no detectable phase-shifting effect on the CBT rhythm. Temporal illumination suppressed melatonin less than the nasal illumination and had no effect on subjective sleepiness and CBT. Temporal illumination delayed neither the melatonin rhythm nor the CBT rhythm. The data show that the suppression of melatonin does not necessarily result in a reduction of subjective sleepiness and an elevation ofCBT. In addition, 100 lux of bright white light is strong enough to affect the photoreceptors responsible for the suppression of melatonin but not strong enough to have a significant effect on sleepiness and CBT. This may be due to the larger variability of the latter variables.