bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Noun and Verb Learning in Chinese‐, English‐, and Japanese‐Speaking Children
Authors: Imai Mutsumi , Li Lianjing , Haryu Etsuko , Okada Hiroyuki , Hirsh‐Pasek Kathy , Golinkoff Roberta Michnick , Shigematsu Jun
Published: July 2008

When can children speaking Japanese, English, or Chinese map and extend novel nouns and verbs? Across 6 studies, 3‐ and 5‐year‐old children in all 3 languages map and extend novel nouns more readily than novel verbs. This finding prevails even in languages like Chinese and Japanese that are assumed to be verb‐friendly languages (e.g.,T. Tardif, 1996). The results also suggest that the input language uniquely shapes verb learning such that English‐speaking children require grammatical support to learn verbs, whereas Chinese children require pragmatic as well as grammatical support. This research bears on how universally shared cognitive factors and language‐specific linguistic factors interact in lexical development.
Does Chronic Classroom Peer Rejection Predict the Development of Children’s Classroom Participation During the Grade School Years?
Authors: Ladd Gary W. , Herald‐Brown Sarah L. , Reiser Mark
Published: July 2008

A sample of 398 children was followed up from ages 5 to 12 to investigate the relation between peer group rejection and classroom participation. The participation trajectories of individuals and groups of children who were rejected for differing periods of time were examined both during and after rejection using piecewise growth curve analyses. The results showed that whereas during periods of rejection, children exhibited negative or negligible growth in participation, when nonrejected, they manifested positive growth. These findings corroborated the hypothesis that (a) peer rejection creates constraints that inhibit children’s classroom participation and (b) the cessation of rejection enables children to become more active and cooperative participants in classroom activities.
Numerical Magnitude Representations Influence Arithmetic Learning
Authors: Booth Julie L. , Siegler Robert S.
Published: July 2008

This study examined whether the quality of first graders’ (mean age = 7.2 years) numerical magnitude representations is correlated with, predictive of, and causally related to their arithmetic learning. The children’s pretest numerical magnitude representations were found to be correlated with their pretest arithmetic knowledge and to be predictive of their learning of answers to unfamiliar arithmetic problems. The relation to learning of unfamiliar problems remained after controlling for prior arithmetic knowledge, short‐term memory for numbers, and math achievement test scores. Moreover, presenting randomly chosen children with accurate visual representations of the magnitudes of addends and sums improved their learning of the answers to the problems. Thus, representations of numerical magnitude are both correlationally and causally related to arithmetic learning.
Intergenerational Transmission of Social Anxiety: The Role of Social Referencing Processes in Infancy
Authors: Murray Lynne , De Rosnay Marc , Pearson Joanna , Bergeron Caroline , Schofield Elizabeth , Royal‐Lawson Melanie , Cooper Peter J.
Published: July 2008

Responses to an unfamiliar adult were examined in infants of mothers with social phobia (N= 79) and infants of nonanxious comparison mothers (N= 77) at 10 and 14 months in a social referencing paradigm. On each occasion, a female stranger first interacted with the mother and then approached and interacted with the infant. Over time, infants of mothers with social phobia showed increasing avoidance of the stranger, particularly when they were behaviorally inhibited. In boys, maternal social phobia was associated with increasing fearful responses. Infant avoidance was predicted by expressed maternal anxiety and low levels of encouragement to interact with the stranger. The findings are discussed in relation to theories concerning the intergenerational transmission of social anxiety.
Family Resources and Parenting Quality: Links to Children’s Cognitive Development Across the First 3 Years
Authors: Lugo‐Gil Julieta , Tamis‐LeMonda Catherine S.
Published: July 2008

Reciprocal associations among measures of family resources, parenting quality, and child cognitive performance were investigated in an ethnically diverse, low‐income sample of 2,089 children and families. Family resources and parenting quality uniquely contributed to children’s cognitive performance at 14, 24, and 36 months, and parenting quality mediated the effects of family resources on children’s performance at all ages. Parenting quality continued to relate to children’s cognitive performance at 24 and 36 months after controlling for earlier measures of parenting quality, family resources, and child performance. Similarly, children’s early cognitive performance related to later parenting quality above other measures in the model. Findings merge economic and developmental theories by highlighting reciprocal influences among children’s performance, parenting, and family resources over time.
Phonological and Semantic Priming in Children With Reading Disability
Authors: Betjemann Rebecca S. , Keenan Janice M.
Published: July 2008

Lexical priming was assessed in children with reading disability (RD) and in age‐matched controls (M= 11.5 years), in visual and auditory lexical decision tasks. In the visual task, children with RD were found to have deficits in semantic (SHIP–BOAT), phonological/graphemic (GOAT–BOAT), and combined (FLOAT–BOAT) priming. The same pattern of semantic priming deficits also occurred in auditory lexical decisions, suggesting that the semantic deficits are not confined to reading. Children with RD also showed less priming than reading‐age matched controls, suggesting that their priming deficits are not simply due to lower reading level but are due to the reading disability in particular. These semantic deficits may contribute to both the word reading and the comprehension problems seen in children with RD.
Individual Differences in Adolescents’ Beliefs About the Legitimacy of Parental Authority and Their Own Obligation to Obey: A Longitudinal Investigation
Authors: Darling Nancy , Cumsille Patricio , Martínez M. Loreto
Published: July 2008

Adolescents’ beliefs about the legitimacy of parental authority and obligation to obey were examined in 568 Chilean adolescents (11–14 years old at Wave 1), followed once a year for 4 years. Adolescents’ beliefs about parental legitimacy and obligation to obey declined with age. The steepest decline occurred during early adolescence, particularly in the personal domain. Adolescents who were uninvolved in problem behavior and perceived their parents to be supportive or high in monitoring at Wave 1 were more likely to endorse parental legitimacy and obligation to obey over time. There was little evidence that parenting or problem behavior moderated the normative decline in adolescents’ beliefs about parental authority. Findings concerning individual differences in adolescents’ endorsement of parental authority are highlighted in this study.
The Breadth of Peer Relationships Among Preschoolers: An Application of the Q‐Connectivity Method to Externalizing Behavior
Authors: Hanish Laura D. , Martin Carol Lynn , Fabes Richard A. , Barcelo Hélène
Published: July 2008

Preschoolers’ (Mage = 48.7 months) social breadth (the number of peer children interact with and the frequency of these interactions) and the relations between breadth and externalizing behaviors were examined using the Q‐connectivity method. After considering age, sex, and classroom effects on social breadth, children’s externalizing behaviors were studied in relation to levels of social breadth across variations in frequency of exposure to peers and to patterns of decline in social breadth. Externalizing preschoolers occasionally interacted with most of their classmates. However, their individual peer networks moderately to rapidly became selective, and they engaged in repeated interactions with a relatively small number of peers. Although there were no sex effects, significant age and classroom effects were obtained.
The Effects of Background Television on the Toy Play Behavior of Very Young Children
Authors: Schmidt Marie Evans , Pempek Tiffany A. , Kirkorian Heather L. , Lund Anne Frankenfield , Anderson Daniel R.
Published: July 2008

This experiment tests the hypothesis that background, adult television is a disruptive influence on very young children’s behavior. Fifty 12‐, 24‐, and 36‐month‐olds played with a variety of toys for 1 hr. For half of the hour, a game show played in the background on a monaural TV set. During the other half hour, the TV was off. The children looked at the TV for only a few seconds at a time and less than once per minute. Nevertheless, background TV significantly reduced toy play episode length as well as focused attention during play. Thus, background television disrupts very young children’s play behavior even when they pay little overt attention to it. These findings have implications for subsequent cognitive development.
German Children’s Comprehension of Word Order and Case Marking in Causative Sentences
Authors: Dittmar Miriam , Abbot‐Smith Kirsten , Lieven Elena , Tomasello Michael
Published: July 2008

Two comprehension experiments were conducted to investigate whether German children are able to use the grammatical cues of word order and word endings (case markers) to identify agents and patients in a causative sentence and whether they weigh these two cues differently across development. Two‐year‐olds correctly understood only sentences with both cues supporting each other—the prototypical form. Five‐year‐olds were able to use word order by itself but not case markers. Only 7‐year‐olds behaved like adults by relying on case markers over word order when the two cues conflicted. These findings suggest that prototypical instances of linguistic constructions with redundant grammatical marking play a special role in early acquisition, and only later do children isolate and weigh individual grammatical cues appropriately.
The Dynamics of Life Stressors and Depressive Symptoms in Early Adolescence: A Test of Six Theoretical Models
Authors: Clements Margaret , Aber J. Lawrence , Seidman Edward
Published: July 2008

Structural equation modeling was used to compare 6 competing theoretically based psychosocial models of the longitudinal association between life stressors and depressive symptoms in a sample of early adolescents (N= 907; 40% Hispanic, 32% Black, and 19% White; mean age at Time 1 = 11.4 years). Only two models fit the data, both of which included paths modeling the effect of depressive symptoms on stressors recall: The mood‐congruent cognitive bias model included only depressive symptoms to life stressors paths (DS→S), whereas the fully transactional model included paths representing both the DS→S and stressors to depressive symptoms (S→DS) effects. Social causation models and the stress generation model did not fit the data. Findings demonstrate the importance of accounting for mood‐congruent cognitive bias in stressors–depressive symptoms investigations.
Predicting Social Wariness in Middle Childhood: The Moderating Roles of Childcare History, Maternal Personality and Maternal Behavior
Authors: Degnan Kathryn Amey , Henderson Heather A. , Fox Nathan A. , Rubin Kenneth H.
Published: July 2008

Children with behavioral inhibition, a temperamental style characterized by infant distress to novelty and childhood social reticence, exhibit both continuity and discontinuity of this behavioral trait over the course of development. However, few researchers have identified factors that might be responsible for these different patterns. In the current study, childcare history, maternal personality, and maternal behavior were examined as moderators of the relations between infant temperament, preschool social reticence, and childhood social wariness. Seventy‐seven children participated in this longitudinal study that began in infancy and continued into middle childhood. Maternal negative personality moderated the relation between infant temperament and childhood social wariness. In addition, maternal behavior moderated the relation between preschool social reticence and childhood social wariness. The findings suggest that a complex interplay of within‐child and maternal factors affect the development of internalizing behavior in the early school years.
Booms and Busts: Consumption, House Prices and Expectations
Authors: ATTANASIO ORAZIO P. , BLOW LAURA , HAMILTON ROBERT , LEICESTER ANDREW
Published: July 2008

Over much of the past 25 years, house price and consumption growth have been closely synchronized. Three main hypotheses for this have been proposed: increases in house prices raise household wealth and so their consumption; house price growth reduces credit constraints by increasing the collateral available to homeowners; and house prices and consumption are together influenced by common factors. Using microeconomic data, we find that the relationship between house prices and consumption is stronger for younger than older households, contradicting the wealth channel. We suggest that common causality has been the most important factor linking house prices and consumption.
Economics of Food Energy Density and Adolescent Body Weight
Authors: AULD M. CHRISTOPHER , POWELL LISA M.
Published: July 2008

We present a simple microeconomic behavioral model showing that decreases in the price of energy‐dense foods increase body weight if the price of obtaining a calorie from dense food is lower than that of less dense food. Estimates of the determinants of adolescent BMI suggest that the price of high‐density food is negatively related to BMI whereas the price of low density food is positively related. Restaurant availability is not associated with weight, but increases in supermarket density predict lower weight. Quantile regressions show that most of the changes in body weight occur in the top quintile of the conditional distribution of BMI.
The Balance Sheet Channel of Monetary Policy Transmission: Evidence from the United Kingdom
Authors: ANGELOPOULOU ELENI , GIBSON HEATHER D.
Published: July 2008

This paper examines the cash flow sensitivity of investment using a panel of UK manufacturing firms to investigate the existence of a balance sheet channel. In addition to examining the impact of cash flow in different subsamples based on company size or financial policy, we investigate the extent to which investment becomes more sensitive to cash flow in periods of monetary tightness by employing a narrative indicator constructed for the United Kingdom. The results indicate that cash flow sensitivity in financially constrained firms is higher during periods of tight monetary policy and that financial constraints weaken with financial market sophistication.
TENS and optokinetic stimulation in neglect therapy after cerebrovascular accident: a randomized controlled study
Authors: Schröder A. , Wist E. R. , Hömberg V.
Published: July 2008

Background:  In a randomized controlled type Ib study, the effectiveness of three different forms of therapy for the treatment of visual neglect was assessed by comparing therapy outcomes in three groups of patients after cerebrovascular accidents.

Methods:  A control group received only standard exploration training, whilst the second and third group received exploration training combined with either contralateral transcutaneous electrical nerve stimulation (TENS) or optokinetic stimulation (OKS) respectively.

Results:  It was found that exploration training alone resulted in no improvement on both standard neglect tests (NTs) and everyday‐relevant measures of reading and writing performance. In contrast, the groups receiving TENS or OKS showed significant improvements in both sets of measures with the difference that for the TENS group the improvement in NT scores at the end of therapy had disappeared 1‐week later. However, both treatments resulted in significant improvements in reading and writing which were still present upon retesting 1‐week after the end of therapy.

Conclusion:  Both methods can be recommended for neglect therapy and are superior to exploration therapy alone.
A novel presenilin 1 mutation (V261L) associated with presenile Alzheimer’s disease and spastic paraparesis
Authors: Jiménez Caballero P. E. , De Diego Boguna C. , Martin Correa E. , Serviá Candela M. , Marsal Alonso C.
Published: July 2008

Background and purpose:  We report a novel mutation in exon 8 of the presenilin 1 (PSEN1) gene (V261L) associated with early‐onset autosomal dominant Alzheimer’s disease and spastic paraparesis.

Methods and results:  The proband was a woman who developed insidious cognitive decline with predominant memory loss and gait disorder secondary to spasticity at the age of 40. Her brother and her mother had a similar disease in the fifth decade of life. The feature of amnestic presentation with spastic paraparesis is consistent with the majority of mutations in the exon 8 of the PSEN1 1 gene.

Conclusions:  Screening for PSEN1 mutations is especially likely to be productive when directed toward persons with positive family history and with age at onset of under 60.
Natural history of multiple sclerosis in a population‐based cohort
Authors: Debouverie M. , Pittion‐Vouyovitch S. , Louis S. , Guillemin F. ,   for the LORSEP Group
Published: July 2008

Background and purpose:  We sought to identify predictive clinical factors of disability during initial course in multiple sclerosis (MS) patients.

Methods:  A total of 2871 MS patients from the LORSEP (Lorraine Multiple Sclerosis) population‐based cohort were analyzed. The relationships between baseline demographic, clinical predictors and time to assignment of Expanded Disability Status Scale (EDSS) scores of 3, 4 and 6 were assessed using a Cox regression model.

Results:  Multivariate analysis showed that, for relapsing–remitting patients, a shorter time to assignment of an EDSS score of 4 was associated with an older age of onset of MS and incomplete recovery from the first relapse. Median times were not influenced by gender or the time between the first two relapses. The results also demonstrated that MS progression is independent of the initial clinical data once an EDSS score of 4 is reached rather than a score of 3 because the time from EDSS 3 to assignment of EDSS 4 were correlated with predicting variables. The data were very different for the time between assignment of scores of 4 and 6 because the median times were not influenced by any of the predicting variables.
Transient global amnesia and brain lesions: new hints into clinical criteria
Authors: Agosti C. , Borroni B. , Akkawi N. M. , De Maria G. , Padovani A.
Published: July 2008

Background and purpose:  Transient global amnesia (TGA) is the abrupt onset of anterograde amnesia with repetitive queries. Different hypotheses have been considered for its aetiology, but it still remains obscure. In 1990, Hodges and Warlow proposed clinical criteria for TGA. Applying these criteria, clinical studies looked for an unifying theory, considering TGA almost a primary and benign disorder. However, spare descriptions of TGA in patients with brain structural lesions have been reported. The aim of this study was to evaluate the prevalence of brain structural lesions among TGA patients.

Methods:  One hundred and thirty clinically defined TGA were consecutively recruited. Among them, 13 patients (10%) showed brain structural lesions (TGA‐b).

Results:  No significant difference in clinical features, duration of TGA episode, age of onset, gender between primary TGA (TGA‐p) and TGA‐b were found. Triggering factors were comparable, suggesting that TGA‐b should be considered in the spectrum of TGA, being clinically indistinguishable.

Conclusions:  Transient global amnesia deserves a careful neuroimaging study and clinical follow‐up considering the high prevalence of brain lesions among these patients and the impossibility to exclude TGA‐b by clinical features. The follow‐up of these patients and the evaluation of involved brain areas might help to further elucidate the pathogenetic mechanisms of the disease.
A SACRAMENTAL JOURNEY TO THE BEATIFIC VISION: THE INTELLECTUALISM OF PIERRE ROUSSELOT1
Authors: BOERSMA HANS
Published: July 2008

This essay traces the intellectualist position of Pierre Rousselot (1878–1915) as he developed it in reaction to neo‐Thomist scholasticism, and argues that at the heart of Rousselot's approach lay a sacramental ontology. Rousselot's 1908 dissertations on St. Thomas's intellectualism and on love in the Middle Ages are best understood in the context of the 1907 condemnations of Modernism. Rousselot questioned the firmly entrenched rationalist approach of the neo‐Thomist revival. While continuing in the Thomist intellectualist tradition, he argued for a chastened epistemology in which the intellect aimed beyond discursive knowledge at union with God. The implication, for Rousselot, was that in its current condition, the human intellect could arrive at knowledge only in an indirect fashion. Accepting Thomas's view of the unity between love of desire and love of friendship, Rousselot emphasized the continuity between nature and the supernatural. Furthermore, his insistence that rational judgements of credibility were powerless without corresponding ‘eyes of faith’ implied a sacramental view of the natural order as pointing to the supernatural end of the beatific vision. His moderated intellectualism, with its implied sacramental ontology, would prove an attractive paradigm for the later movement of nouvelle théologie.
‘NOLI ME TANGERE’: WHY JOHN MEIER WON'T TOUCH THE RISEN LORD
Authors: CRAIG WILLIAM LANE
Published: July 2008

John Meier distinguishes ‘the real Jesus’ from ‘the historical Jesus’. Meier claims that whatever happened to the real Jesus after his death, his resurrection cannot belong to the historical Jesus because that event is in principle not open to the observation of any observer. But why think that the resurrection is not observable in this way? Meier finds justification in Gerald O'Collins' view that although the resurrection of Jesus is a real event, it is not an event in space and time and hence should not be called historical, since a necessary condition of historical occurrences is that they are known to have happened in our space‐time continuum. Is this a good argument for the resurrection's being in principle excludable from the historical Jesus? A close examination of the argument reveals that it is not and that Meier's adoption of such a procedure contradicts Meier's own historical methodology.
Post‐disturbance effects of even‐aged timber harvest on stream salamanders in southern Appalachian forests
Authors: Crawford J. A. , Semlitsch R. D.
Published: July 2008

Habitat degradation and fragmentation has received increased attention in the past 15 years as a primary factor responsible for the decline of many species of wildlife including amphibians. In the eastern USA many of the studies have focused on fully terrestrial plethodontid salamanders, while information on stream‐breeding plethodontids remains relatively lacking. Using two different survey methods (area‐constrained daytime searches and night‐time visual encounter searches), we estimated terrestrial habitat use and abundance for stream‐breeding salamanders in three different tree stand age‐classes in southern Appalachian streams from May to August 2005. We found that overall stream salamander abundance and terrestrial habitat use was reduced in stands <40 years of age compared with stands 41–80 years old, and >81 years old. The decreased abundance and terrestrial habitat use was accompanied by a decrease in leaf litter depth, soil moisture and canopy cover. The Blue Ridge two‐lined salamanderEurycea wilderaewas the most affected salamander in the assemblage and we conservatively estimate at least a 40‐year recovery period for the assemblage to return to pre‐disturbance levels. To protect stream amphibians, alternative silvicultural practices such as uneven‐aged timber harvest (e.g. selective harvesting) must be considered.
Relationship between field metabolic rate and body weight in mammals: effect of the study
Authors: Riek A.
Published: July 2008

Field metabolic rate (FMR) is a measure of daily energy expenditure under field conditions. Results of various studies on FMR have been used to calculate allometric equations that can predict FMR from body weight. One of the problems in calculating these regression equations lies in the treatment of the available FMR and body weight data. However, with the tool of mixed model analysis, it is possible to account for the effect of the study as a random effect in this kind of meta‐analysis. The present study is the first that has included the study as a random effect in an FMR meta‐analysis. Prediction equations were derived, allowing the estimation of FMR based on body weight. Including all available single animal data on FMR and body mass in a mixed model analysis with the study as a random effect yielded the equation: FMR in kJ day−1=6.68 ± 1.21 (body weight in g)0.67 ± 0.03(P<0.001) that had a mean error rate of 21.5% (sd29.0%, minimum 0, maximum 236%) and a coefficient of variation of 98%. This wasc. 2.7 times more precise than not including the study effect (mean error rate 58.4%). Thus, the present investigation showed that including the effect of the study in FMR meta‐analysis changes not only the predictive values of the equation but also the exponent (slope).
Analogous effects of arbuscular mycorrhizal fungi in the laboratory and a North Carolina field
Authors: Pringle Anne , Bever James D.
Published: July 2008

DOI: 10.1111/j.1469-8137.2008.02608.xCommentary p 1
Regional alterations in the endocannabinoid system in an animal model of depression: effects of concurrent antidepressant treatment
Authors: Hill Matthew N. , Carrier Erica J. , McLaughlin Ryan J. , Morrish Anna C. , Meier Sarah E. , Hillard Cecilia J. , Gorzalka Boris B.
Published: July 2008

It has been suggested that disturbances in endocannabinoid signaling contribute to the development of depressive illness; however, at present there is insufficient evidence to allow for a full understanding of this role. To further this understanding, we performed an analysis of the endocannabinoid system in an animal model of depression. Male rats exposed to chronic, unpredictable stress (CUS) for 21 days exhibited a reduction in sexual motivation, consistent with the hypothesis that CUS in rats induces depression‐like symptoms. We determined the effects of CUS, with or without concurrent treatment with the antidepressant imipramine (10 mg/kg), on CP55940 binding to the cannabinoid CB1receptor; whole tissue endocannabinoid content; and fatty acid amide hydrolase (FAAH) activity in the prefrontal cortex, hippocampus, hypothalamus, amygdala, midbrain and ventral striatum. Exposure to CUS resulted in a significant increase in CB1receptor binding site density in the prefrontal cortex and a decrease in CB1receptor binding site density in the hippocampus, hypothalamus and ventral striatum. Except in the hippocampus, these CUS‐induced alterations in CB1receptor binding site density were attenuated by concurrent antidepressant treatment. CUS alone produced a significant reduction in N‐arachidonylethanolamine (anandamide) content in every brain region examined, which was not reversed by antidepressant treatment. These data suggest that the endocannabinoid system in cortical and subcortical structures is differentially altered in an animal model of depression and that the effects of CUS on CB1receptor binding site density are attenuated by antidepressant treatment while those on endocannabinoid content are not.
Reduced vesicular storage of dopamine exacerbates methamphetamine‐induced neurodegeneration and astrogliosis
Authors: Guillot Thomas S. , Shepherd Kennie R. , Richardson Jason R. , Wang Min Z. , Li Yingjie , Emson Piers C. , Miller Gary W.
Published: July 2008

The vesicular monoamine transporter 2 (VMAT2) controls the loading of dopamine (DA) into vesicles and therefore determines synaptic properties such as quantal size, receptor sensitivity, and vesicular and cytosolic DA concentration. Impairment of proper DA compartmentalization is postulated to underlie the sensitivity of DA neurons to oxidative damage and degeneration. It is known that DA can auto‐oxidize in the cytosol to form quinones and other oxidative species and that this production of oxidative stress is thought to be a critical factor in DA terminal loss after methamphetamine (METH) exposure. Using a mutant strain of mice (VMAT2 LO), which have only 5–10% of the VMAT2 expressed by wild‐type animals, we show that VMAT2 is a major determinant of METH toxicity in the striatum. Subsequent to METH exposure, the VMAT2 LO mice show an exacerbated loss of dopamine transporter and tyrosine hydroxylase (TH), as well as enhanced astrogliosis and protein carbonyl formation. More importantly, VMAT2 LO mice show massive argyrophilic deposits in the striatum after METH, indicating that VMAT2 is a regulator of METH‐induced neurodegeneration. The increased METH neurotoxicity in VMAT2 LO occurs in the absence of any significant difference in basal temperature or METH‐induced hyperthermia. Furthermore, primary midbrain cultures from VMAT2 LO mice show more oxidative stress generation and a greater loss of TH positive processes than wild‐type cultures after METH exposure. Elevated markers of neurotoxicity in VMAT2 LO mice and cultures suggest that the capacity to store DA determines the amount of oxidative stress and neurodegeneration after METH administration.
Gender differences and estrogen effects in parkin null mice
Authors: Rodríguez‐Navarro José A. , Solano Rosa M. , Casarejos María J. , Gomez Ana , Perucho Juan , García de Yébenes Justo , Mena María A.
Published: July 2008

Estrogens are considered neurotrophic for dopamine neurons. Parkinson’s disease is more frequent in males than in females, and more prevalent in females with short reproductive life. Estrogens are neuroprotective against neurotoxic agents for dopamine neurons in vivo and in vitro. Here, we have investigated the role of estrogens in wild‐type (WT) and parkin null mice (PK−/−). WT mice present sexual dimorphisms in neuroprotective mechanisms (Bcl‐2/Bax, chaperones, and GSH), but some of these inter‐sex differences disappear in PK−/−. Tyrosine hydroxylase (TH) protein and TH+ cells decreased earlier and more severely in female than in male PK−/− mice. Neuronal cultures from midbrain of WT and PK−/− mice were treated with estradiol from 10 min to 48 h. Short‐term treatments activated the mitogen‐activated protein kinase pathway of WT and PK−/− neurons and the phosphatidylinositol 3′‐kinase/AKT/glycogen synthase kinase‐3 pathway of WT but not of PK−/− cultures. Long‐term treatments with estradiol increased the number of TH+ neurons, the TH expression, and the extension of neurites, and decreased the level of apoptosis, the expression of glial fibrillary acidic protein, and the number of microglial cells in WT but not in PK−/− cultures. The levels of estrogen receptor‐α were elevated in midbrain cultures and in the striatum of adult PK−/− male mice, suggesting that suppression of parkin changes the estrogen receptor‐α turnover. From our data, it appears that parkin participates in the cellular estrogen response which could be of interest in the management of parkin‐related Parkinson’s disease patients.
The life, death, and replacement of oligodendrocytes in the adult CNS
Authors: McTigue Dana M. , Tripathi Richa B.
Published: July 2008

Oligodendrocytes (OLs) are mature glial cells that myelinate axons in the brain and spinal cord. As such, they are integral to functional and efficient neuronal signaling. The embryonic lineage and postnatal development of OLs have been well‐studied and many features of the process have been described, including the origin, migration, proliferation, and differentiation of precursor cells. Less clear is the extent to which OLs and damaged/dysfunctional myelin are replaced following injury to the adult CNS. OLs and their precursors are very vulnerable to conditions common to CNS injury and disease sites, such as inflammation, oxidative stress, and elevated glutamate levels leading to excitotoxicity. Thus, these cells become dysfunctional or die in multiple pathologies, including Alzheimer’s disease, spinal cord injury, Parkinson’s disease, ischemia, and hypoxia. However, studies of certain conditions to date have detected spontaneous OL replacement. This review will summarize current information on adult OL progenitors, mechanisms that contribute to OL death, the consequences of their loss and the pathological conditions in which spontaneous oligodendrogenesis from endogenous precursors has been observed in the adult CNS.
Redox‐based endoplasmic reticulum dysfunction in neurological diseases
Authors: Bánhegyi Gábor , Mandl József , Csala Miklós
Published: July 2008

The redox homeostasis of the endoplasmic reticulum lumen is characteristically different from that of the other subcellular compartments. The concerted action of membrane transport processes and oxidoreductase enzymes maintain the oxidized state of the thiol‐disulfide and the reducing state of the pyridine nucleotide redox systems, which are prerequisites for the normal functions of the organelle. The powerful thiol‐oxidizing machinery allows oxidative protein folding but continuously challenges the local antioxidant defense. Alterations of the cellular redox environment either in oxidizing or reducing direction affect protein processing and may induce endoplasmic reticulum stress and unfolded protein response. The activated signaling pathways attempt to restore the balance between protein loading and processing and induce apoptosis if the attempt fails. Recent findings strongly support the involvement of this mechanism in brain ischemia, neuronal degenerative diseases and traumatic injury. The redox changes in the endoplasmic reticulum are integral parts of the pathomechanism of neurological diseases, either as causative agents, or as complications.
Dopamine is necessary to endogenous morphine formation in mammalian brain in vivo
Authors: Neri Carla , Ghelardini Carla , Sotak Bethany , Palmiter Richard D. , Guarna Massimo , Stefano George , Bianchi Enrica
Published: July 2008

Morphine, the most used compound among narcotic analgesics, has been shown to be endogenously present in different mammalian/invertebrate normal tissues. In this study, we used mice that cannot make dopamine due to a genetic deletion of tyrosine hydroxylase specifically in dopaminergic neurons, to test the hypothesis that endogenous dopamine is necessary to endogenous morphine formation in vivo in mammalian brain. When dopamine was lacking in brain neurons, endogenous morphine was missing in brain mouse whereas it could be detected in brain from wild type rodent at a picogram range. Our data prove for the first time that endogenous dopamine is necessary to endogenous morphine formation in normal mammalian brain. Morphine synthesis appears to be originated from dopamine through L‐tyrosine in normal brain tissue. Morphine synthesis is not considered to occur inside the same neuron in normal tissue; released dopamine might be transported into morphinergic neuron and further transformed into morphine. A physiological role for endogenous morphine is suggested considering that dopamine could modulate thermal threshold through endogenous morphine formation in vivo. Thus, dopamine and endogenous opiates/opioid peptides may be interconnected in the physiological processes; yet, endogenous morphine may represent a basic link of this chain.
Edaravone protects against MPP+‐induced cytotoxicity in rat primary cultured astrocytes via inhibition of mitochondrial apoptotic pathway
Authors: Chen Hui , Wang Sen , Ding Jian‐Hua , Hu Gang
Published: July 2008

Edaravone (Eda) is a potent scavenger of hydroxyl radicals and has been demonstrated to be beneficial for patients with acute ischemic stroke. This study was set out to investigate whether Eda protect against MPP+‐induced cytotoxicity in rat primary cultured astrocytes. The results showed that pre‐treatment with Eda inhibited astrocytic apoptosis and lactate dehydrogenase release induced by MPP+ (200 μM). Further study revealed that Eda prevented GSH depletion, down‐regulated mRNA expressions of NADPH oxidase membrane subunit gp91 and membrane‐translocated subunit p47, and prevented the decreases of state 3 respiration respiration and respiratory control ratio induced by MPP+, and thereby inhibited reactive oxygen species production evoked by MPP+. Moreover, Eda could ameliorate mitochondrial respiratory function, restrain, and prevent mitochondrial membrane potential loss induced by MPP+. Consequently, Eda inhibited releases of cytochrome c and apoptosis‐inducing factor induced by MPP+. Taken together, these findings reveal for the first time that Eda protects against MPP+‐induced astrocytic apoptosis via decreasing intracellular reactive oxygen species level and subsequently inhibiting mitochondrial apoptotic pathway. The antiapoptosis effects of Eda on astrocytes may provide a new perspective on neuroprotective therapy.
Covalent modification of GABAAreceptor isoforms by a diazepam analogue provides evidence for a novel benzodiazepine binding site that prevents modulation by these drugs
Authors: Baur Roland , Tan Kelly R. , Lüscher Benjamin P. , Gonthier Anne , Goeldner Maurice , Sigel Erwin
Published: July 2008

Classical benzodiazepines, for example diazepam, interact with αxβ2γ2GABAAreceptors, x = 1, 2, 3, 5. Little is known about effects of α subunits on the structure of the binding pocket. We studied here the interaction of the covalently reacting diazepam analog 7‐Isothiocyanato‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one (NCS compound) with α1H101Cβ2γ2and with receptors containing the homologous mutation, α2H101Cβ2γ2, α3H126Cβ2γ2and α5H105Cβ2γ2. This comparison was extended to α6R100Cβ2γ2receptors as this mutation conveys to these receptors high affinity towards classical benzodiazepines. The interaction was studied at the ligand binding level and at the functional level using electrophysiological techniques. Results indicate that the geometry of α6R100Cβ2γ2enables best interaction with NCS compound, followed by α3H126Cβ2γ2, α1H101Cβ2γ2and α2H101Cβ2γ2, while α5H105Cβ2γ2receptors show little interaction. Our results allow conclusions about the relative apposition of α1H101 and homologous positions in α2, α3, α5and α6with the position occupied by –Cl in diazepam. During this study we found evidence for the presence of a novel site for benzodiazepines that prevents modulation of GABAAreceptors via the classical benzodiazepine site. The novel site potentially contributes to the high degree of safety to some of these drugs. Our results indicate that this site may be located at the α/β subunit interface pseudo‐symmetrically to the site for classical benzodiazepines located at the α/γ interface.
Chromatin immunoprecipitation scanning identifies glucocorticoid receptor binding regions in the proximal promoter of a ubiquitously expressed glucocorticoid target gene in brain
Authors: Van Der Laan Siem , Sarabdjitsingh R. Angela , Van Batenburg Marcel F. , Lachize Servane B. , Li Hualing , Dijkmans Thomas F. , Vreugdenhil Erno , De Kloet E. Ron , Meijer Onno C.
Published: July 2008

While the actions of glucocorticoids on brain functions have been comprehensively studied, the underlying genomic mechanisms are poorly understood. In this study, we show that glucocorticoid‐induced leucine zipper (GILZ) mRNA is strongly and ubiquitously induced in rat brain. To decipher the molecular mechanisms underlying these genomic effects, it is of interest to identify the regulatory sites in the promoter region. Alignment of the rat GILZ promoter with the well‐characterized human promoter resulted in poor sequence homology. Consequently, we analyzed the rat 5′ flanking sequence by Matrix REDUCE and identified two high‐affinity glucocorticoid response elements (GRE) located 2 kb upstream of the transcription start site. These findings were corroborated using the glucocorticoid receptor (GR) expressing Ns‐1 PC12 rat cell‐line. In these cells, dexamethasone treatment leads to a progressive increase of GILZ mRNA expression levels via a GR‐dependent mechanism. Subsequently, using chromatin immunoprecipitation assays we show that the two high‐affinity GREs are located within the GR‐binding regions. Lastly, we demonstrate using multiple tissue in situ hybridization a marked increase in mRNA expression levels in spleen, thymus, heart, lung, liver, muscle, testis, kidney, colon, ileum, as well as in brain and conclude that the GILZ gene can be used to study glucocorticoid effects in many additional rodent tissues.
Mechanisms of hyperthermia‐induced depression of GABAergic synaptic transmission in the immature rat hippocampus
Authors: Qu Lintao , Leung L. Stan
Published: July 2008

Clinical observations and experimental studies have shown that hyperthermia can provoke febrile seizures, which are the most common type of pathological brain activity in children. We previously demonstrated that hyperthermia produced a depression of GABAergic neurotransmission in the hippocampus of immature ratsin vitro. To investigate the possible mechanisms through which hyperthermia may modulate GABAergic neurotransmission in the hippocampus, whole‐cell voltage clamp recordings were performed on CA1 pyramidal neurons in the immature rat brain slices. We found that hyperthermia (38.4–40°C) when compared with baseline temperature of 32°C reduced the frequency of both spontaneous inhibitory post‐synaptic currents (sIPSCs) and miniature IPSCs (mIPSCs). Also, hyperthermia decreased the amplitudes of mIPSCs and reduced the mIPSC decay time constants and charge transfer. Non‐stationary noise analysis of mIPSCs suggested that the number of open post‐synaptic receptors but not single channel conductance was reduced during hyperthermia. Activation of adenylyl cyclase with forskolin prevented, whereas protein kinase A inhibitorN‐(2‐[p‐bromocinnamylamino]ethyl)‐5‐isoquinolinesulfonamide potentiated, the hyperthermia (40°C)‐induced depression of evoked IPSCs (evIPSCs). But protein kinase C activator phorbol 12, 13‐dibutyrate (PDBu) did not significantly affect this depression of evIPSCs induced by hyperthermia. Furthermore, hyperthermia‐induced depression of evIPSCs was attenuated by 4‐aminopyridine, but not by BaCl2. These results suggest that hyperthermia reduces GABA release from pre‐synaptic terminals, in part by blocking the adenylyl cyclase–protein kinase A signaling pathway and activating pre‐synaptic 4‐aminopyridine‐sensitive K+channels. Also, the changes in amplitude and decay time constant of the mIPSCs may suggest that hyperthermia also decreases post‐synaptic GABAAreceptor function.
FIRST REPORT OF THE FERTILE PLANT GENUSUMKOMASIAFROM LATE PERMIAN BEDS IN INDIA AND ITS BIOSTRATIGRAPHIC SIGNIFICANCE
Authors: CHANDRA SHAILA , SINGH KAMAL JEET , JHA NEERJA
Published: July 2008

Abstract: The genusUmkomasiaThomas, a female fructification ofDicroidium, is reported from Late Permian beds exposed in the Behra Rivulet near the village of Karaonda in the Tatapani‐Ramkola Coalfield, Chhattisgarh, India. This is the first record of this genus from the Late Permian, and from Indian Gondwana. Two species have been recognized:Umkomasia polycarpaHolmes andU. uniramiaAxsmith, Taylor, Taylor and Cuneo. The find suggests that the genusDicroidiumappeared in the Late Permian before reaching its acme in the Middle–Upper Triassic.
A NEW TEREBRATULID BRACHIOPOD SPECIES FROM THE SIEGENIAN OF THE DRA VALLEY, MOROCCO, AND ITS STRATIGRAPHIC, PALAEOGEOGRAPHIC AND PHYLOGENETIC SIGNIFICANCE
Authors: SCHEMM‐GREGORY MENA
Published: July 2008

Abstract:  A new terebratulid brachiopod species, Rhenorensselaeria jansenii, has been identified in the Merzâ‐Akhsaï Formation of the Dra Valley, Morocco, and the Grauwacke de Montguyon of the Amorican Massif, France. It is compared with the other known species of Rhenorensselaeria from Europe, Rh. strigiceps and Rh. demerathia, as well as with Rh. macgerriglei from North America, from which it differs in being larger and having coarser costae. Its possible life habit in clusters and its fossil community are compared with those of Rh. strigiceps from the Rheinisches Schiefergebirge (‘Rhenish Slate Mountains’), Germany, which it most resembles. A new phylogeny of the subfamily Rhenorensselaerinae is constructed. The close phylogenetic relationship between Rh. jansenii and Rh. strigiceps confirms close palaeobiogeographical relationships between North Africa, France and the Rheinisches Schiefergebirge as well as a wider relationship between Central Europe and Gaspé, eastern Canada, during the Early Devonian. Taxa of Rhenorensselaeria are mainly restricted to the Middle and Upper Siegenian, although rare individuals have been found in the Lower Emsian of Central Europe and North America. Because of their abundance in the Dra Valley and Rheinisches Schiefergebirge and their short life span, rhenorensselaerid taxa can be regarded as important stratigraphical markers of Middle–Late Siegenian and Early Emsian sediments in North Africa and Central Europe.
A NEW SEMLIKIICHTHYS FISH (TELEOSTEI, PERCIFORMES) FROM THE UPPER MIOCENE OF CHAD: FOSSIL RECORD AND PALAEOBIOGEOGRAPHICAL IMPLICATIONS
Authors: OTERO OLGA , LIKIUS ANDOSSA , VIGNAUD PATRICK , BRUNET MICHEL
Published: July 2008

Abstract:  Semlikiichthys is a fossil genus of perciform fish from the Neogene continental deposits of Africa. Until now, it was known in Mio‐Pliocene sites of the Great Lake Region and of the River Nile by a single species, S. rhachirhinchus. Here, we describe new Semlikiichthys material recovered from Central Africa (Upper Miocene of Toros‐Menalla, western Djurab, Chad), and compare it to S. rhachirhinchus, which is the only known species of the genus, and also with Lates niloticus, which is the fish in African Neogene deposits that most closely resembles it. We attribute the Chadian material to Semlikiichthys darsao sp. nov., based on ten osteological characters of the neurocranium, the maxilla, the dentary and the first vertebra. Our comparative anatomical study also enables us to provide a revised diagnosis for the genus and to reconsider the taxonomic attribution of the fossils assigned to it. Furthermore, the fossil record of Semlikiichthys supports a connection between sub‐basins of the Nilo‐Sudanese region during the Miocene, and a disruption between the Great Lake and the Nile Basin on the one hand and the Chadian Basin on the other before 7 Ma.
THE AERODYNAMICS OF THE BRITISH LATE TRIASSIC KUEHNEOSAURIDAE
Authors: STEIN KOEN , PALMER COLIN , GILL PAMELA G. , BENTON MICHAEL J.
Published: July 2008

Abstract:  The Kuehneosauridae (Late Triassic, Britain, USA) had remarkable adaptations, most notably their elongate mid‐dorsal ribs that were presumably covered with a skin membrane in life. These lateral ‘wings’ have always been linked with some form of gliding adaptation, but quantitative studies have been limited. Here, we provide a thorough aerodynamic analysis of both genera of British kuehneosaurids based on theory and on experiments with life‐sized models in a wind tunnel. Of the two genera, Kuehneosuchus, with elongate ‘wings’, was a glider, and Kuehneosaurus, with much shorter ‘wings’, was a parachutist. Kuehneosuchus most probably had highly cambered wings and no additional skin membranes on hands or feet, nor did it have a cruropatagium. Lappets on the hyoid apparatus, as seen in Draco, were probably present to enhance pitch control. Kuehneosuchus was capable of gliding at angles (θ) between 13 and 16 degrees, at speeds between 7 and 9 m/s, and was probably very manoeuvrable when airborne. Kuehneosaurus was capable of parachuting (θ > 45 degrees) at speeds between 10 and 12 m/s. It is unclear whether the British kuehneosaurid material represents two genera, as assumed here, two species of one genus, or sexual dimorphs of a single species, where the gliding Kuehneosuchus was the male, which used its gliding and perhaps highly coloured ‘wings’ to display to the parachuting Kuehneosaurus.