bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmental and post‐injury cortical gliogenesis: A Genetic fate‐mapping study with Nestin‐CreER mice
Authors: Burns Kevin A. , Murphy Brian , Danzer Steve C. , Kuan Chia‐Yi 
Published: December 2008

AbstractThe primary sources of cortical gliogenesis, either during development or after adult brain injury, remain uncertain. We previously generated Nestin‐CreER mice to fate‐map the progeny of radial glial cells (RG), a source of astrocytes and oligodendrocytes in the nervous system. Here, we show that Nestin‐CreER mice label another population of glial progenitors, namely the perinatal subventricular zone (SVZ) glioblasts, if they are crossed with stop‐floxed EGFP mice and receive tamoxifen in late embryogenesis (E16–E18). Quantification showed E18 tamoxifen‐induction labeled more perinatal SVZ glioblasts than RG and transitional RG combined in the newborn brain (54% vs. 22%). Time‐lapse microscopy showed SVZ‐glioblasts underwent complex metamorphosis and often‐reciprocal transformation into transitional RG. Surprisingly, the E10‐dosed RG progenitors produced astrocytes, but no oligodendrocytes, whereas E18‐induction fate‐mapped both astrocytes and NG2+ oligodendrocyte precursors in the postnatal brain. These results suggest that cortical oligodendrocytes mostly derive from perinatal SVZ glioblast progenitors. Further, by combining genetic fate‐mapping and BrdU‐labeling, we showed that cortical astrocytes cease proliferation soon after birth (<P10) and only undergo nonproliferative gliosis (i.e., increased GFAP expression without cell‐division) after stab‐wound injury in adult brains. By contrast, 9.7% of cortical NG2+ progenitors remained mitotic at P29, and the ratio rose to 13.8% after stab‐wound injury. Together, these results suggest NG2+ progenitors, rather than GFAP+ astrocytes, are the primary source of proliferative gliosis after adult brain injury. © 2008 Wiley‐Liss, Inc.
Live imaging of amyotrophic lateral sclerosis pathogenesis: Disease onset is characterized by marked induction of GFAP in Schwann cells
Authors: Keller A. Florence , Gravel Mathieu , Kriz Jasna 
Published: December 2008

AbstractAmyotrophic lateral sclerosis (ALS) is a late‐onset neurological disease characterized by progressive loss of motor neurons. At present, the pathological events precipitating disease onset and the exact pattern of disease progression are not fully understood. Recent studies suggest that glial cells, in particular activated astrocytes, can release factors that can directly kill motor neurons. To further investigate the involvement of glial cells (astrocytes and Schwann cells) in the pathogenesis of ALS, we generated ALS‐(GFAP‐luciferase/SODG93A) reporter mouse in which upregulation of glial fibrillary acidic protein (GFAP) can be visualized from live animals throughout the different stages of disease. Our results suggest that the disease in mice is initiated simultaneously in the spinal cord and in the peripheral nerves and is characterized by several cycles of GFAP upregulation. Immunohistochemical analysis confirmed that the induction GFAP bioluminescence signals were associated with the significant increases in GFAP immunoreactivity. The first pathological GFAP signals occurring at 25–30 days were asymptomatic and detectable at the level of lumbar spinal cord projections and at the periphery. These early events were then followed by GFAP promoter inductions that were associated with the distinct clinical symptoms. As expected, the onset of paralysis (112 days) was associated with the gradual and marked GFAP upregulation in the spinal cord. Interestingly, however, the disease onset (90 days) was characterized by sharp and synchronized induction of GFAP in peripheral nerve Schwann cells suggesting that peripheral nerves pathology/denervation and associated Schwann cell stress may play an important role in the ALS pathogenesis. © 2008 Wiley‐Liss, Inc.
Cannabinoid CB2receptor agonists protect the striatum against malonate toxicity: Relevance for Huntington's disease
Authors: Sagredo Onintza , González Sara , Aroyo Ilia , Pazos María Ruth , Benito Cristina , Lastres‐Becker Isabel , Romero Juan P. , Tolón Rosa M. , Mechoulam Raphael , Brouillet Emmanuel , Romero Julián , Fernández‐Ruiz Javier 
Published: December 2008

AbstractCannabinoid agonists might serve as neuroprotective agents in neurodegenerative disorders. Here, we examined this hypothesis in a rat model of Huntington's disease (HD) generated by intrastriatal injection of the mitochondrial complex II inhibitor malonate. Our results showed that only compounds able to activate CB2receptors were capable of protecting striatal projection neurons from malonate‐induced death. That CB2receptor agonists are neuroprotective was confirmed by using the selective CB2receptor antagonist, SR144528, and by the observation that mice deficient in CB2receptor were more sensitive to malonate than wild‐type animals. CB2receptors are scarce in the striatum in healthy conditions, but they are markedly upregulated after the lesion with malonate. Studies of double immunostaining revealed a significant presence of CB2receptors in cells labeled with the marker of reactive microglia OX‐42, and also in cells labeled with GFAP (a marker of astrocytes). We further showed that the activation of CB2receptors significantly reduced the levels of tumor necrosis factor‐α (TNF‐α) that had been increased by the lesion with malonate. In summary, our results demonstrate that stimulation of CB2receptors protect the striatum against malonate toxicity, likely through a mechanism involving glial cells, in particular reactive microglial cells in which CB2receptors would be upregulated in response to the lesion. Activation of these receptors would reduce the generation of proinflammatory molecules like TNF‐α. Altogether, our results support the hypothesis that CB2receptors could constitute a therapeutic target to slowdown neurodegeneration in HD. © 2008 Wiley‐Liss, Inc.
A behavioral analysis of the impact of voluntary physical activity on hippocampus‐dependent contextual conditioning
Authors: Greenwood Benjamin N. , Strong Paul V. , Foley Teresa E. , Fleshner Monika 
Published: December 2008

AbstractVoluntary physical activity induces molecular changes in the hippocampus consistent with improved hippocampal function, but few studies have explored the effects of wheel running on specific hippocampal‐dependent learning and memory processes. The current studies investigated the impact of voluntary wheel running on learning and memory for context and extinction using contextual fear conditioning which is known to be dependent on the hippocampus. When conditioning occurred prior to the start of 6 weeks of wheel running, wheel running had no effect on memory for context or extinction (assessed with freezing). In contrast, when wheel running occurred for 6 weeks prior to conditioning, physical activity improved contextual memory during a retention test 24 h later, but did not affect extinction learning or memory. Wheel running had no effect on freezing immediately after foot shock presentation during conditioning, suggesting that physical activity does not affect the acquisition of the context—shock association or alter the expression of freezing, per se. Instead, it is argued that physical activity improves the consolidation of contextual memories in the hippocampus. Consistent with improved hippocampus‐dependent context learning and memory, 6 weeks of wheel running also improved context discrimination and reduced the context pre‐exposure time required to form a strong contextual memory. The effect of wheel running on brain‐derived neurotrophic factor (BDNF) messenger ribonucleic acid (mRNA) in hippocampal and amygdala subregions was also investigated. Wheel running increased BDNF mRNA in the dentate gyrus, CA1, and the basolateral amygdala. Results are consistent with improved hippocampal function following physical activity. © 2008 Wiley‐Liss, Inc.
Early maternal deprivation induces gender‐dependent changes on the expression of hippocampal CB1 and CB2 cannabinoid receptors of neonatal rats
Authors: Suárez Juan , Llorente Ricardo , Romero‐Zerbo Silvana Y. , Mateos Beatriz , Bermúdez‐Silva Francisco J. , de Fonseca Fernando Rodríguez , Viveros María‐Paz 
Published: December 2008

AbstractEarly maternal deprivation (MD) in rats (24 h, postnatal day 9–10) is a model for neurodevelopmental stress. There are some data proving that MD affects the endocannabinoid system (ECS) in a gender‐dependent manner, and that these changes may account for the proposed schizophrenia‐like phenotype of MD rats. The impact of MD on cannabinoid receptor distribution in the hippocampus is unknown. The aim of this study is to evaluate the expression of CB1 and CB2 receptors in diverse relevant subregions (DG, CA1, and CA3) of the hippocampus in 13‐day‐old rats by immunohistochemistry and densitometry. MD induced a significant decrease in CB1 immunoreactivity (more marked in males than in females), which was mainly associated with fibers in the strata pyramidale and radiatum of CA1 and in the strata oriens, pyramidale, and radiatum of CA3. In contrast, MD males and females showed a significant increase in CB2 immunoreactivity in the three hippocampal areas analyzed that was detected in neuropil and puncta in the stratum oriens of CA1 and CA3, and in the polymorphic cell layer of the dentate gyrus. A marked sex dimorphism was observed in CA3, with females exhibiting higher CB1 immunoreactivity than males, and in dentate gyrus, with females exhibiting lower CB2 immunoreactivity than males. These results point to a clear association between developmental stress and dysregulation of the ECS. The present MD procedure may provide an interesting experimental model to further address the role of the ECS in neurodevelopmental mental illnesses such as schizophrenia. © 2008 Wiley‐Liss, Inc.
Excitability changes within transverse lamellae of dentate granule cells and their longitudinal spread following orthodromic or antidromic activation
Authors: Lømo Terje 
Published: December 2008

AbstractThe functional organization of the perforant path input to the dentate gyrus of the exposed hippocampus was studied in adult rabbits anesthetized with urethane and chloralose. Electrical stimulation of perforant path fibers caused excitation of granule cells along narrow, nearly transverse strips (lamellae) of tissue. Stimulation of granule cell axons (mossy fibers) in CA3 caused antidromic activation of granule cells along similar strips. Paired‐pulse stimulation revealed marked changes in granule cell excitability both within a lamella (on‐line) and for several mm off‐line along the septo‐temporal axis of the dentate gyrus. After the first pulse, granule cells were inhibited for up to about 100 ms and then facilitated for up to hundreds of ms. Feedback activity along mossy fiber collaterals exciting local inhibitory and excitatory neurons appeared to dominate in producing on‐ and off‐line inhibition and facilitation. Neurons mediating these effects could be inhibitory basket cells and other inhibitory interneurons targeting granule cells on‐ and off‐line. In addition, excitatory mossy cells with far reaching, longitudinally running axons could affect off‐line granule cells by exciting them directly or inhibit them indirectly by exciting local inhibitory interneurons. A scheme for dentate gyrus function is proposed whereby information to the dentate gyrus becomes split into interacting transverse strips of neuronal assemblies along which temporal processing occurs. A matrix of neuronal assemblies thus arises within which fragments of events and experiences is stored through the plasticity of synapses within and between the assemblies. Similar fragments may then be recognized at later times allowing memories of the whole to be created by pattern completion at subsequent computational stages in the hippocampus. © 2008 Wiley‐Liss, Inc.
Impaired in vivo synaptic plasticity in dentate gyrus and spatial memory in juvenile rats induced by prenatal morphine exposure
Authors: Niu Lei , Cao Bing , Zhu Hong , Mei Bin , Wang Ming , Yang Yupeng , Zhou Yifeng 
Published: December 2008

AbstractPrenatal morphine exposure induces neurobiological changes, including deficits in learning and memory, in juvenile rat offspring. However the effects of this exposure on hippocampal plasticity, which is critical for learning and memory processes, are not well understood. The present study investigates the alterations of spatial memory and in vivo hippocampal synaptic plasticity in juvenile rats prenatally exposed to morphine. On gestation days 11–18, pregnant rats were randomly chosen to be injected twice daily with morphine or saline. Each juvenile offspring (postnatal day 22–31) performed one two‐trial Y‐maze task to evaluate spatial memory. Afterwards, the in vivo field excitatory postsynaptic potential (fEPSP) and population spike (PS) were recorded in the perforant path dentate gyrus (DG) pathway in the hippocampus. Prenatal morphine exposure reduced depotentiation (DP), but not long‐term potentiation (LTP), of the EPSP slope. However, both LTP and DP of the EPSP slope were depressed in prenatal morphine‐exposed juvenile offspring. The morphine group also showed poorer performance for the Y‐maze task than the control group. Depressed PS LTP, but not EPSP LTP, in the morphine group suggested that prenatal morphine exposure changed GABAergic inhibition, which mediates EPSP‐spike potentiation. Then a loss of GABA‐containing neurons in the DG area of the morphine group was observed using immunohistochemistry. Taken together, our results suggest that prenatal morphine exposure impairs the juvenile offspring's dentate synaptic plasticity and spatial memory, and that decreased GABAergic inhibition may play a role in these effects. These findings might contribute to an explanation for the cognitive deficits in children whose mothers abuse opiates during pregnancy. © 2008 Wiley‐Liss, Inc.
Two‐dimensional physically based finite element runoff model for small agricultural watersheds: I. Model development
Authors: Bhardwaj Anil , Kaushal M. P. 
Published: December 2008

AbstractSoil erosion by water is the root cause of ecological degradation in the Shiwalik foothills of Northern India. Simulation of runoff and its component processes is a pre‐requisite to develop the management strategies to tackle the problem, successfully. A two‐dimensional physically based distributed numerical model, ROMO2D has been developed to simulate runoff from small agricultural watersheds on an event basis. The model employs the 2‐D Richards equation with sink term to simulate infiltration and soil moisture dynamics in the vadoze zone under variable rainfall conditions, and 2‐D Saint‐Venant equations under the kinematic wave approximation along with Manning's equation as the stage‐discharge equation for runoff routing. The various flow‐governing equations have been solved numerically by employing a Galerkin finite element method for spatial discretization using quadrilateral elements and finite difference techniques for temporal solutions. The ROMO2D computer program has been developed as a class‐based program, coded in C + + in such a way that with minor modifications, the model can be used to simulate runoff on a continuous basis. The model writes output for a runoff hydrograph of each storm. Model development is described in this paper and the results of model testing and field application are to be presented in a subsequent paper. Copyright © 2008 John Wiley & Sons, Ltd.
Long term trend of snow depth at Sonnblick (Austrian Alps) and its relation to climate change
Authors: Schöner W. , Auer I. , Böhm R. 
Published: December 2008

AbstractThe extensive snow measurement network of the Sonnblick region (Hohe Tauern, Austrian Alps) is used to describe temporal trends of snow‐depth as well as its relation to climate change for a high‐elevated site of the European Alps (2400–3100 m.a.s.l.). Spatial representativeness of single snow stakes, with readings back to 1928, is derived for maximum snow‐depth in May using a spatially dense snow depth probing from glacier mass balance measurements. Long‐term trends of snow depth show a significant reduction in the contribution of snow accumulation from core‐winter (1 December to 1 March) compared to early and late‐winter periods. Largest values of snow‐depth since 1928 were measured in the 1940s and 1950s. Comparison of monthly changes in snow‐depth with precipitation measurements underlines the high influence of wind drift on snow‐depth during winter season from 1 October to 30 April. Whereas inter‐annual variability of maximum snow‐depth is better explained by low elevation precipitation measurements than by local (high elevation) precipitation measurements, the longer‐term mean of local precipitation measurements, however, fits well to the snow‐depth measurements, if a mean snow‐density of about 400 kg m−3 is assumed (which matches field observations). Both maximum snow‐depth and winter season precipitation show a clear decreasing trend for inter‐annual variability. A statistical relationship between air temperature and fraction of solid precipitation is used for estimation of temporal trends in the fraction of solid precipitation at measurement sites. For summer a decrease of about 1% of solid precipitation per decade was found for the lowest elevated sites whereas fraction of solid precipitation in winter remains stable. Relation between snow‐depth and climate is investigated by means of local climate data of Sonnblick‐Observatory (SBO) and by means of the North‐Atlantic Oscillation Index (NAOI). Whereas winter air‐temperature is significantly correlated with the NAOI, for winter precipitation and snow depth on 1 May no correlation was found with NAOI. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of lateral canal water depth on offtake and cross‐regulator discharge
Authors: Shahrokhnia Mohammad Ali , Javan Mahmood , Shahrokhnia Mohammad Hosein 
Published: December 2008

AbstractMonitoring and effective operation of control structures are of importance in a modern irrigation system. Previously developed sensitivity indicators can be useful tools for better management of irrigation systems. The influence of lateral canal water depth on the offtaking and ongoing discharges were simulated and evaluated using a simple model in the Doroodzan irrigation system in south‐western Iran. Results confirmed the influence of water level changes in the lateral irrigation canal on offtake and cross‐regulator discharge. Results obtained also led us to introduce and evaluate two other sensitivity indicators: offtake sensitivity to downstream water depth, and check sensitivity to tertiary canal water depth.Application of the sensitivity indicators in the Doroodzan irrigation system showed the usefulness of developed sensitivity indicators. The average sensitivity indicators varied from 1.10 to 0.44 (m−1) for offtakes and 0.58 to 0.03 (m−1) for cross‐regulators. Copyright © 2008 John Wiley & Sons, Ltd.
Spectral detection of micro‐metastases in lymph node histo‐pathology
Authors: Bird Benjamin , Romeo Melissa , Laver Nora , Diem Max 
Published: December 2008

AbstractThe first detection of breast cancer micrometastases in lymph nodes by infrared spectral imaging and methods of multivariate analysis is reported. Micrometastases are indicators of early spread of cancer from the organ originally affected by disease, and their detection is of prime importance for the staging and treatment of cancer. Infrared spectral imaging, at a spatial resolution of ca. 10–12 μm, can detect small metastases down to the level of a few cancerous cells. The results presented here add to a rapidly growing database of infrared spectral imaging results for cancer diagnostics. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Real‐time in vivo imaging of adult Zebrafish brain using optical coherence tomography
Authors: Rao K. Divakar , Alex Aneesh , Verma Yogesh , Thampi Sreeja , Gupta Pradeep K. 
Published: December 2008

AbstractWe report noninvasive imaging of the brain of adult Zebrafish (Danio rerio) using real time optical coherence tomography (OCT) capable of acquiring cross sectional 2D OCT images @ 8 frames/sec. Anatomic features such as telencephalon, tectum opticum, eminentia Granularis and cerebellum were clearly resolved in the OCT images. A 3D model of Zebrafish brain was reconstructed, for the first time to our knowledge, using these 2D OCT images. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diethyl maleate‐induced oxidative stress leads to testicular germ cell apoptosis involving Bax and Bcl‐2
Authors: Kalia Sumiti , Bansal M. P. 
Published: December 2008

AbstractTesticular germ cell apoptosis is normally a continuous process throughout life. However, massive testicular germ cell loss is known to result from a wide variety of cellular stresses including toxicant exposure. Thus, the present study was aimed to investigate the mechanisms of germ cell loss under stress conditions following diethyl maleate (DEM) exposure. Stress conditions were generated in male Balb/c mice by depleting glutathione by DEM administration. The germ cell apoptosis was found to be increased as assessed by terminal deoxynucleotidyl transferase (TdT)‐mediated deoxy‐UTP biotin nick end labeling (TUNEL) staining, evaluation of histoarchitechture of testis, and germ cell numbers. It was found that the germ cell number was significantly reduced in DEM‐treated sections. RT‐PCR was carried out to assess Bax/Bcl‐2 mRNA expression levels. Immunohistochemistry of Bax and Bcl‐2 revealed Bax activation. The prevalence and cellular localization of the above markers in testicular tissues of DEM‐treated animals suggest the possible involvement of Bax/Bcl‐2 in the male germ cell apoptosis. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:371–381, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20252
Purification and characterization of a novel high molecular weight exotoxin produced by red tide phytoplankton, Alexandrium tamarense
Authors: Yamasaki Yasuhiro , Katsuo Daisuke , Nakayasu Seiichiro , Salati Cristina , Duan JingJing , Zou Yanan , Matsuyama Yukihiko , Yamaguchi Kenichi , Oda Tatsuya 
Published: December 2008

AbstractOur recent studies have demonstrated that the aqueous extract prepared from Alexandrium tamarense, a harmful red tide phytoplankton, showed cytotoxicity on Vero cells. In this study, the toxic substance was purified from the culture supernatant of A. tamarense. Based on the gel‐filtration profile, the molecular mass of a purified toxin was estimated to be about 1,000 kDa. On sodium dodecylsulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) analysis, a main band with molecular mass of 1,000 kDa was detected with periodic acid‐Schiff (PAS) staining, but no protein bands were detected by Coomassie brilliant blue (CBB) protein staining. Sugar composition analysis of the toxin suggested that the toxin contains galactose, fucose, mannose, N‐acetylglucosamine, xylose, and other minor saccharides, whereas no significant levels of amino acids were detected by amino acid analysis. These results suggest that the toxin is a polysaccharide‐based compound. The toxin showed cytotoxic effects on various cell lines in a concentration‐dependent manner. Among the cell lines tested, U937 cells were the most susceptible to the toxin. In U937 cells treated with the toxin, a typical apoptotic nuclear morphological change and DNA fragmentation were observed. This is the first report demonstrating that a polysaccharide‐based toxin isolated from red tide phytoplankton can induce apoptotic cell death. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:405–415, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20253