bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic association of the Ca2+ channel α1A subunit and SNAP‐25 in round or neurite‐emitting chromaffin cells
Authors: Andrés‐Mateos Eva , Renart Jaime , Cruces Jesús , Solís‐Garrido Luisa M. , Serantes Rocío , de Lucas‐Cerrillo Ana M. , Aldea Marcos , García Antonio G. , Montiel Carmen 
Published: November 2005

AbstractAlthough the specific interaction between synaptic protein SNAP‐25 and the α1A subunit of the Cav2.1 channels, which conduct P/Q‐type Ca2+ currents, has been confirmed in in vitro‐translated proteins and brain membrane studies, the question of how native proteins can establish this association in situ in developing neurons remains to be elucidated. Here we report data regarding this interaction in bovine chromaffin cells natively expressing both proteins. The two carboxyl‐terminal splice variants of the α1A subunit identified in these cells share a synaptic protein interaction (‘synprint’) site within the II/III loop segment and are immunodetected by a specific antibody against bovine α1A protein. Moreover, both α1A isoforms form part of the P/Q‐channels–SNARE complexes in situ because they are coimmunoprecipitated from solubilized chromaffin cell membranes by a monoclonal SNAP‐25 antibody. The distribution of α1A and SNAP‐25 was studied in round or transdifferentiated chromaffin cells using confocal microscopy and specific antibodies: the two proteins are colocalized at the cell body membrane in both natural cell types. However, during the first stages of the cell transdifferentiation process, SNAP‐25 migrates alone out to the developing growth cone and what will become the nerve endings and varicosities of the mature neurites; α1A follows and colocalizes to SNAP‐25 in the now mature processes. These observations lead us to propose that the association between SNAP‐25 and α1A during neuritogenesis might promote not only the efficient coupling of the exocytotic machinery but also the correct insertion of P/Q‐type channels at specialized active zones in presynaptic neuronal terminals.
Activity of individual reticulospinal neurons during different forms of locomotion in the lamprey
Authors: Zelenin Pavel V. 
Published: November 2005

AbstractLamprey (a lower vertebrate) can employ different modes of locomotion, i.e. swimming in open water and crawling in tight places. Swimming is due to the periodic waves of lateral undulations with reciprocal activity of right and left muscles. In contrast, crawling (forward and backward) is based on single waves with coactivation of muscles on two sides. Basic mechanisms of swimming and, most likely, crawling reside in the spinal cord, and are activated by supraspinal commands. The main source of these commands is the reticulospinal (RS) system. The goal of the present experiments was to characterize the activity of individual RS neurons during swimming and during crawling in a U‐shaped tunnel. The activity was recorded by means of chronically implanted electrodes in freely behaving animals. All recorded RS neurons were active during swimming but silent in quiescent animals. Many of them (61%) showed phasic modulation of their firing rate approximately in phase with the activity of ipsilateral rostral muscles. The majority of the neurons (80%) were also active during crawling. Many of them either increased or decreased their activity during crawling as compared to the background activity. These changes were better correlated with the direction of progression (forward or backward) than with the direction of turning in the tunnel (right or left). No correlation of the activity of RS neurons during locomotion and their sensory inputs was found. The results of this study suggest that different modes of locomotion in lampreys can be caused by considerably overlapping groups of RS neurons.
Melatonin inhibits hippocampal long‐term potentiation
Authors: Wang Louisa M. , Suthana Nanthia A. , Chaudhury Dipesh , Weaver David R. , Colwell Christopher S. 
Published: November 2005

AbstractThe goal of this study is to investigate the effect of the hormone melatonin on long‐term potentiation and excitability measured by stimulating the Schaffer collaterals and recording the field excitatory postsynaptic potential from the CA1 dendritic layer in hippocampal brain slices from mice. Application of melatonin produced a concentration‐dependent inhibition of the induction of long‐term potentiation, with a concentration of 100 nm producing an ≈ 50% inhibition of long‐term potentiation magnitude. Long‐duration melatonin treatments of 6 h were also effective at reducing the magnitude of long‐term potentiation. Melatonin (100 nm) did not alter baseline evoked responses or paired‐pulse facilitation recorded at this synapse. The inhibitory actions of melatonin were prevented by application of the melatonin (MT) receptor antagonist luzindole as well as the MT2 receptor subtype antagonist 4‐phenyl‐2‐propionamidotetraline. These inhibitory actions of melatonin were lost in mice deficient in MT2 receptors but not those deficient in MT1 receptors. In addition, application of the protein kinase A inhibitor H‐89 both mimicked the effects of melatonin and precluded further inhibition by melatonin. Finally, the application an activator of adenylyl cyclase, forskolin, overcame the inhibitory effects of melatonin on LTP without affecting the induction of long‐term potentiation on its own. These results suggest that hippocampal synaptic plasticity may be constrained by melatonin through a mechanism involving MT2‐receptor‐mediated regulation of the adenylyl cyclase–protein kinase A pathway.
Movement‐related changes in oscillatory activity in the human subthalamic nucleus: ipsilateral vs. contralateral movements
Authors: Alegre M. , Alonso‐Frech F. , Rodríguez‐Oroz M. C. , Guridi J. , Zamarbide I. , Valencia M. , Manrique M. , Obeso J. A. , Artieda J. 
Published: November 2005

AbstractA voluntary movement is accompanied by a series of changes in neuronal oscillatory activity in the subthalamic nucleus (STN). These changes can be recorded through electrodes implanted for deep brain stimulation to treat Parkinson's disease in the time interval between the surgery and the internalization of the connections to the batteries. Both baseline activity and movement‐related changes are different in the ‘on’ and ‘off’ medication motor states. In the ‘off’ state a low frequency activity in the alpha–beta range (8–25 Hz) that dominates the spectrum is interrupted during the movement, while in the ‘on’ state baseline frequencies are higher and a peri‐movement gamma increase (70–80 Hz) is usually observed. Similar changes have been described with electrocorticographic recordings over the primary motor cortex but the gamma increase was only present during contralateral movements. We compared ipsi‐ and contralateral movement‐related changes in STN activity, using a time–frequency analysis of the recordings obtained simultaneously in both STN and the scalp (electroencephalography) during right and left hand movements. The movement‐related changes observed in the STN in the ‘on’ and the ‘off’ states were similar to those described previously in terms of predominant frequency bands, but we found bilateral changes in the STN during movements of either hand. A contralateral earlier start of the beta STN changes was mostly observed when the moving hand corresponded to the less‐affected side, irrespective of hand dominance. These results suggest that movement‐related activity in the STN has, by and large, a bilateral representation and probably reflects cortical input.
Home bases formed to visual cues but not to self‐movement (dead reckoning) cues in exploring hippocampectomized rats
Authors: Hines Dustin J. , Whishaw Ian Q. 
Published: November 2005

AbstractSpatial theory proposes that the hippocampus contributes to exploratory behavior allowing animals to acquire information about their environment. In the present study, the exploratory movements of control rats, bulbectomized (anosmic) rats and hippocampectomized rats using the neurotoxin N‐methyl‐d‐aspartate (NMDA) were monitored on a large circular table without walls and around which visual cues were manipulated. The rats displayed organized spatial behavior in that they developed home bases, one or more places operationally defined as those in which they spent a preponderance of time, in which they moved slowly, and to which they returned after excursions. Control rats and hippocampectomized rats were similar in that they established home bases: (i) adjacent to a proximal stable or moving visual landmark; (ii) in relation to more distant visual room cues; and (iii) in relation to contextually conditioned visual cues. Nevertheless, in exploratory tests given under infrared light, a wavelength to which rats are insensitive, control rats and bulbectomized rats established one or more home bases that were not dependent upon surface (e.g. olfactory) cues, whereas home base behavior was absent/fragmented in hippocampectomized rats. Thus, exploratory behavior, as exemplified by home base behavior, is organized in control and hippocampectomized rats in relation to visual cues, but is not organized in hippocampectomized rats when visual cues are absent. This result is discussed in relation to the idea that the hippocampus contributes to spatial behavior that is dependent upon guidance (dead reckoning) derived from self‐movement cues.
Hypotension and short‐term anaesthesia induce ERK1/2 phosphorylation in autonomic nuclei of the brainstem
Authors: Springell Deborah A. , Costin Natalie S. , Pilowsky Paul M. , Goodchild Ann K. 
Published: November 2005

AbstractThe aims of this study were: first, to investigate the effects of anaesthesia on phosphorylated extracellular signal‐regulated kinase (p‐ERK)1/2‐immunoreactivity (‐ir) in the brainstem; second, to choose the best anaesthetic for p‐ERK1/2 studies; and third, to determine the effect of short‐term hypotension on p‐ERK1/2‐ir in the brainstem. Rats were anaesthetized with halothane, sodium pentobarbital or 100% CO2 narcosis, or were cervically dislocated and within 5 min perfused and the brains processed immunohistochemically for pERK1/2‐ir. p‐ERK1/2‐ir was primarily observed in regions associated with cardiovascular and/or respiratory control. Several regions consistently showed dense p‐ERK1/2 labelling, including a restricted region of the ventrolateral medulla (VLM). In contrast, other regions showed differential labelling depending on the mode of death. Cervical dislocation showed the least VLM labelling, limited to a discrete area approximately 0.6–1.4 mm caudal to the facial nucleus. Anaesthetics induced labelling throughout the VLM, with halothane inducing the most. Many p‐ERK1/2‐ir VLM neurons were catecholaminergic following halothane or sodium pentobarbital anaesthesia, but no double labelling was seen following cervical dislocation. Of the anaesthetics, sodium pentobarbital induced the least labelling and was used subsequently. Intravenous hydralazine was used to induce a 20‐min period of hypotension, whereas arterial pressure did not change in vehicle‐treated animals. Hydralazine evoked more pERK‐ir neurons in specific regions, including the VLM, nucleus tractus solitarius (NTS), parabrachial nuclei, Kolliker‐Fuse nucleus and locus coeruleus. Approximately twice as many p‐ERK1/2‐positive neurons were seen in the intermediate NTS and rostral VLM following hydralazine compared with the vehicle. In conclusion, p‐ERK1/2‐ir identifies neurons in central autonomic regions, and their number and distribution are markedly affected by anaesthetics, and are increased in some regions by short‐term hypotension.
Memantine prolongs survival in an amyotrophic lateral sclerosis mouse model
Authors: Wang Rengang , Zhang Dongxian 
Published: November 2005

AbstractAmyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease which results from selective loss of upper and lower motor neurons. Mouse models of ALS, such as one carrying the G93A mutant of the human Cu‐Zn superoxide dismutase gene[SOD1(G93A)], develop motor neuron pathology and clinical symptoms similar to those observed in ALS patients. There is compelling evidence that both direct and indirect glutamate toxicity contribute to the pathogenesis of motor neuron degeneration. However, the therapeutic effect of various glutamate receptor antagonists has not been clearly demonstrated. Memantine is a noncompetitive N‐methyl‐d‐aspartate (NMDA) receptor antagonist. It has been shown to protect neurons against NMDA‐ or glutamate‐induced toxicity in vitro and in animal models of neurodegenerative diseases. In the current study, we have examined the therapeutic efficacy of memantine in an ALS mouse model carrying a high copy number of SOD1(G93A). Memantine treatment significantly delayed the disease progression and increased the life span of SOD1(G93A) mice, from 121.4 ± 5.5 to 129.7 ± 4.5 days (P = 0.032). Furthermore, NMDA receptor subunits were reliably detected in the spinal cord of SOD1(G93A) mice and their expression levels were similar to those in the wild‐type littermate control. Therefore, the neuroprotective effect of memantine in SOD1(G93A) mice is most probably due to the inhibition of spinal cord NMDA receptors. In view of the long‐term usage of memantine for dementia patients, with excellent tolerance and safety, these data suggest that memantine may be used in ALS patients alone or in combination with other therapies to prolong survival.
Trichomes of Lycopersicon species and their hybrids: effects on pests and natural enemies
Authors: Simmons Aaron T. , Gurr Geoff M. 
Published: November 2005

Abstract1 The cultivated tomato, Lycopersicon esculentum, is an economically important worldwide crop. Current pest management techniques rely heavily on pesticides but trichome‐based host‐plant resistance may reduce pesticide use.2 A review of the literature is provided on trichomes of wild Lycopersicon species and the effects of trichome‐based host‐plant resistance on arthropods. Solvents have been used to remove glandular trichome exudates and the resulting dimminution of their effects quantified. Correlational approaches to assess the relationship between the different trichome types and effects on pests have also been used.3 Most studies have focused on Lepidoptera and Hemiptera, although some work has included Coleoptera, Diptera and Acarina, and both antibiotic and antixenotic effects have been demonstrated.4 Natural enemies are a cornerstone of international pest management and this review discusses how the compatibility of this approach with trichome‐based host‐plant resistance is uncertain because of the reported negative effects of trichomes on one dipteran, one hemipteran and several Hymenoptera.5 For trichome‐based host‐plant resistance to be utilized as a pest management tool, trichomes of wild species need to be introgressed into the cultivated tomato. Hybrids between the cultivated tomato and the wild species Lycopersicon hirsutum f. glabratum, Lycopersicon pennellii and Lycopersicon cheesmanii f. minor have been produced and useful levels of resistance to Acarina, Diptera and Hemiptera pests have been exhibited, although these effects may be tempered by effects on natural enemies.6 This review proposes that studies on genetic links between fruit quality and resistance, field studies to determine the compatibility of natural enemies and trichome‐based host‐plant resistance, and a strong focus on L. cheesmanii f. minor, are all priorities for further research that will help realize the potential of this natural defence mechanism in pest management.
Influence of sulphur plant nutrition on oviposition and larval performance of the cabbage root fly
Authors: Marazzi Cristina , Städler Erich 
Published: November 2005

Abstract1 Oilseed rape plants (Brassica napus) (L.) (Brassicaceae) were grown under different levels of sulphur supply and tested for the oviposition preference and larval performance of cabbage root flies Delia radicum (L.) (Diptera: Anthomyiidae).2 Adult females laid more than three‐fold as many eggs on control Sn (normal field concentration) than on sulphur‐free S0 plants. By contrast, no significant difference was observed between control and double normal concentration (S+) plants.3 The larval performance was evaluated using three additional, intermediate sulphur levels between S0 and Sn, and the plants were infected with equal numbers of eggs. The percentage pupation at the end of larval feeding ranged from 6% (S0) to 32% (Sn or S+) and the average number of pupae, or of emerging flies, was significantly correlated with sulphur application.4 The weight of emerging males and females was correlated with plant sulphur supply.5 The duration of development from eggs to adult emergence was approximately 2 days longer in females than in males. Females originating from plants with a normal or higher sulphur supply tended to emerge 1–2 days earlier.
Effects of green tree retention, prescribed burning and soil treatment on pine weevil (Hylobius abietis and Hylobius pinastri) damage to planted Scots pine seedlings
Authors: Pitkänen A. , Törmänen K. , Kouki J. , Järvinen E. , Viiri H. 
Published: November 2005

Abstract1 Feeding damage and mortality caused to planted Scots pine seedlings by the pine weevils Hylobius abietis and Hylobius pinastri were studied on burned and unburned sites with 0, 10 and 50 m3 per hectare levels of green tree retention from the second to the fourth summer after logging and burning of the sites.2 The rate of severe feeding damage to pine seedlings caused by pine weevils was higher on burned clearcut sites than on unburned ones, whereas burning did not increase the feeding damage rate on sites with groups of retention trees. The damage rate in the fourth summer was approximately the same on burned and unburned sites.3 Pine weevil feeding was the major cause of mortality of freshly planted pine seedlings on unburned sites. On burned sites, mortality was higher than the rate of severe feeding damage, particularly in the second summer after burning, possibly owing to fungal attack and abiotic factors.4 At a retention tree level of 50 m3, feeding damage to the seedlings was lower than on clearcuts and at a 10 m3 retention tree level. Furthermore, on sites with 50 m3 of retention trees, scarification of the soil was found to decrease feeding damage more effectively than on clearcuts and 10 m3 sites. If the seedlings were situated in the centre of scarified patches, scarification alone was as effective as insecticide treatment on unscarified soil for decreasing feeding damage and mortality.5 The results suggest that when burning is applied as silvicultural treatment after clear‐cuts, retention of trees is recommended to reduce the damages caused by pine weevils on pine seedlings.
Analyse factorielle des skills du savoir‐lire en première année d'étude
Authors: Dickes Paul 
Published: November 2005

ABSTRAITSeize tests de lecture, administrés à 217 enfants de première année d'étude, après trois, six et neuf mois d'enseignement, ont été soumis à des analyses factorielles en composantes principales. Après trois mois on trouve trois facteurs: une aptitude générale de lecture, unc aptitude à reconnaître du matériel écrit (précodage) et l'aptitude à comprendre des texts. Après six mois, trpis facteurs sont identifiés: compréhension, précodage et déchiffrage. Après neuf mois on retrouve les mêmes facteurs.L'étude de l'évolution des structures factorielles dans le temps montre que les premières compétences en lecture, relativement générales au début de l'année scolaire, ont tendance à se diffiréncier en skills de déchiffrage et de compréhension, alors que les skills de compréhension apparaissent comme relativement spécifiques au début de l'année scolaire et tendent à se généraliser par la suite. 64% de la variance de la comprehension en fin d'année scolaire est expliquée par les facteurs du premier et du second trimestres. 68% de la variance du déchiffrage, mesuréà la fin de l'année scolaire, est expliquée par les facteurs du premier et du second trimestres.
Effects of auditory perception training on reading achievement
Authors: Bailey Terence J. 
Published: November 2005

ABSTRACTThis study investigated the effect of an auditory training programme with backward readers who were also deficient in one or more auditory perceptual subskills. Thirty subjects were randomly assigned to one of three groups. The experimental group received a nine hour taped programme devised by the experimenter and designed to teach the skills of auditory discrimination, memory, analysis and synthesis and auditory‐visual integration. The comparison group listened to stories on tape for the same duration as the experimental group, while the third group served as a control merely being tested at the beginning and at the end of the experiment. It was found that although the training programme significantly improved the performance of the experimental group over the other two groups on a total auditory perceptual test, there was no corresponding improvement in reading, on word recognition or comprehension tests. The particular auditory subskills which appeared amenable to training were auditory discrimination (rhyme) and auditory synthesis (blending and closure).
The effect of colour of tester on performance on a group reading test
Authors: Anderson Eleanor , Thomas K. C. 
Published: November 2005

ABSTRACTA study of the relationship between colour of tester and performance on a group reading test was carried out using, as testers, two student teachers of similar experience and appearance apart from colour of skin and, as subjects, 24 children of families of West Indian origin and 24 indigenous children matched for school, sex and age (8‐9 yrs). Parallel forms of the Young Group Reading Test (Young, 1969) were administered on alternative occasions by the black tester and the white tester. Differences between the mean group scores were not statistically significant. Correlations between performance on test and re‐test by ethnic group, sex, school, colour of tester for first test and form of test for first test were statistically significant, and at or beyond the .05 level. Evidence of ethnic‐group effect was not apparent. Attempts to reduce stress e.g. the use of group tests, may have inhibited the expression of ethnic‐group effect, if indeed it existed.
Cognitive skills in the reading process: a review
Authors: Underwood Geoffrey , Holt Patrik O'B 
Published: November 2005

ABSTRACTSome current problems in reading, as viewed by cognitive psychology, are discussed around a summary of a symposium on Reading and Lexical Access held ac, part of the International Conference on Practical Aspects of Memory (Gruneberg, Morris arid Sykes, 1978).The analysis of component processes in reading, and the analysis of reading dynamics provide apparently opposing approaches to the study of reading, but they often lead to similar conclusions about reading behaviour and are seen here to be complementary approaches.Prompted by the discussion of phonological mediation in a number of the papers we are led to the conclusion that whereas phonological reading can be observed to be used on some occasions, it is not necessaryfor word recognition and reading. Three hypotheses of its use by skilled readers are suggested—for sequential attention control, for the generation of a working memory code, and for the resolution of ambiguity by prosodics. The beginning reader may have a further use in gaining a spoken representation, and therefore recognition, of new words.