bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proximal control of fetal rat behavior
Authors: Ronca April E. , Kamm Kathi , Thelen Esther , Alberts Jeffrey R. 
Published: January 2005

AbstractWe examined the influence of the amniotic sac on spontaneous movement in late gestation fetal rats. Using techniques for in vivo observation of fetal behavior, Day 21 rat fetuses were exteriorized from the uterus, with umbilical connections to the dam intact, and videotaped for 15 min either: (a) through the intact amniotic membranes, or (b) following removal of the membranes. Analysis of fetal behavior categories replicated the findings of previous investigators: Movements of the head, forelimbs, and rearlimbs were significantly increased by sac removal, as was the total frequency of behavior categories and the simultaneous occurrence of different behavior categories. Frame‐by‐frame analysis of videotaped behavior revealed that amniotic sac removal increased the frequency of movement bouts without altering the overall amount of time that fetuses spent moving. Movement bout durations ranged from 50 msec to 70 s. The average duration of movement bouts was significantly reduced for fetuses lacking the amniotic sac as compared to fetuses within the sac, as was the overall distribution of movement bout durations. Frequency distributions of movement bout durations and interbout interval (IBIs) revealed that sac removal significantly increased the occurrence of short (1–2 s) movement bouts and reduced the frequency of protracted movement bouts and interbout intervals ( > 10‐s duration). Taken together, these findings indicate that the quantitative dimensions of fetal rat movements are influenced by proximal features of the uterine environment. During prenatal life, the amniotic sac appears to sustain movement, possibly by providing proprioceptive feedback or physical support to the fetus, or by regulating the chemical milieu.© 1994 John Wiley & Sons, Inc.
Metabolic activation of the brain of young rats after exposure to environmental complexity
Authors: Gonzalez‐Lima F. , Ferchmin P. A. , Eterovic V. A. , Gonzalez‐Lima E. M. 
Published: January 2005

AbstractAutoradiography with 14C‐2‐deoxyglucose was used to determine brain metabolic activity during the quiet period that follows after daily exploratory experiences in new complex environments. Eight 1‐month‐old, male Tryon rats were selected from two litters. Pairs of littermates matched by body weight were assigned to one of two conditions: rats housed individually in small home cages as the “impoverished condition,” or rats exposed twice daily to changing and complex environments of two large cages with inanimate objects and conspecifics as the “enriched condition.” After 4 days, rats were injected with 2‐deoxyglucose, placed individually in a home cage and left undisturbed for 90 min until sacrificed. The brains of “enriched” rats were heavier than their “impoverished” littermates, and showed a global trend for metabolic enhancement. They also showed significantly greater amounts of 2‐deoxyglucose in occipital cortex (27%), hippocampal subiculum (36%), and nucleus accumbens (40%).©1994 John Wiley & Sons, Inc.
Phrasing in prelinguistic vocalizations
Authors: Lynch Michael P. , Oller D. Kimbrough , Steffens Michele L. , Buder Eugene H. 
Published: January 2005

AbstractPhrasing is a universal characteristic of human communication, and the present investigation explored its developmental roots in nonvegetative, prelinguistic vocalizations. Adult judges identified a hierarchical arrangement of syllables embedded within utterances and utterances embedded within prelinguistic phrases in the vocalizations of infants. Prelinguistic phrases were characterized by systematic lengthening of phrase final syllables, temporal patterning, and stable durations across development that were similar to those of some cross‐culturally optimal rhythmic units from other domains. Analyses of vocalizations of infants with Down syndrome indicated similar internal structure of prelinguistic phrases to those of typically developing infants, but with longer durations. These findings suggest that relative durational characteristics of prelinguistic phrasing are stable features of early vocal behavior, although the absolute durational characteristics of prelinguistic phrases can be impacted by a complex and severe disorder such as Down syndrome. © 1995 John Wiley & Sons, Inc.
Methodological issues in coding sleep states in immature infants
Authors: Sahni Rakesh , Schulze Karl F. , Stefanski Mark , Myers Michael M. , Fifer William P. 
Published: January 2005

AbstractThirty‐five healthy, premature infants, ranging from 30–39 weeks postconceptional age, were observed continuously for 6 to 24 hr. Behavioral state and electroencephalographic patterns were coded for each minute. Using these data, three questions regarding coding of states of sleep were addressed: What is the concordance between behavioral codes and specific EEG patterns? Does the concordance between behavioral codes and EEG patterns change with postconceptional age? What range of error can be expected when observation periods shorter than 24‐hr are used to estimate the daily distribution of quiet sleep (QS) and active sleep (AS)?With behavioral codes as the standard, concordances of EEG patterns for QS and AS were 72.5 and 92.1% respectively. With EEG patterns as the standard, behavioral codes for QS and AS agreed 83.0 and 88.9%. Agreement between behavioral codes and EEG patterns for QS increased with age. Finally, variation in estimates of the daily distribution of QS and AS decreased dramatically as the length of observation increased from 3 to 24 hr. © 1995 John Wiley & Sons, Inc.
Delayed development of conditioned heart rate responses to auditory stimuli in the rat
Authors: Richardson Rick , Wang Peiyin , Campbell Byron A. 
Published: January 2005

AbstractThis study examined heart rate responses to an auditory conditioned stimulus during development in the rat. The unconditioned stimulus (US) in all experiments was an acoustic startle stimulus. The conditioned stimulus elicited a monophasic bradycardia in animals 21 days of age and older, but no response in younger animals. These results are strikingly similar to an earlier study that used shock as the US (Campbell & Ampuero, 1985). Further, the conditioned cardiac responses in adults was found to be mediated entirely through activation of the parasympathetic division of the autonomic nervous system (ANS) even though the US unconditionally activates the sympathetic system at that age. The delayed development of several different forms of conditioned fear is discussed. © 1995 John Wiley & Sons, Inc.
A New Strategy for the Preparation of Metallaboranes − Solvothermal Synthesis and Structural Characterisation of Two Nido 11‐vertex Diplatinaundecaborane Clusters
Authors: Dou Jianmin , Wu Libin , Guo Qingliang , Li Dacheng , Wang Daqi 
Published: December 2004

AbstractTwo novel nido 11‐vertex diplatinaundecaborane clusters [(μ‐PPh2)(PPh3)2Pt2B9H6Cl(OiPr)2] (1) and [(μ‐PPh2)(PPh3)2Pt2B9H6(OiPr)3] (2) have been solvothermally synthesised and characterised by elemental analysis, IR, Raman, 1H and 13C NMR spectroscopy and single‐crystal X‐ray diffraction. The latter analysis revealed that two Pt atoms remain in neighbouring positions of the open Pt2B3 face in both clusters which were markedly different from the products obtained from the identical starting mixture under refluxing conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
The design and construction of implicit LES models
Authors: Margolin L. G. , Rider W. J. 
Published: December 2004

AbstractWe offer preliminary thoughts on the design of a modified equation and the construction of a corresponding numerical algorithm, which may be intended for use in an implicit large eddy simulation. The principle of design here is based on ensuring a form for the energy dissipation that is not significantly dissipative on the resolved scales of the numerical mesh, but is strongly dissipative when the solution is unresolved and so provides strong nonlinear stability in the simulation. The construction process is modelled on the composition (hybridization) of two flux approximations by means of a nonlinear, flow‐dependent switch. Published in 2004 by John Wiley & Sons, Ltd.
Serotonin promotes region‐specific glial influences on cultured serotonin and dopamine neurons
Authors: Liu Jiangping , Lauder Jean M. 
Published: December 2004

AbstractTo test the hypothesis that glia mediate interactions between embryonic serotonergic (5‐HT) neurons and dopamine neurons, we studied the effects of 5‐HT in co‐cultures of E14 raphe neurons of mesencephalic dopamine neurons and radial glia/astrocytes derived from the same (homotypic) or opposite (heterotypic) brain region using a dose (10−5 M) that would produce 5‐HT uptake into glial cells as well as activate 5‐HT receptors. Morphometric analysis of 5‐HT and tyrosine hydroxylase (TH) immunoreactive neurons revealed regilonal differences in the effects of 5‐HT (and nialamide) on survival, cell soma size, and dendrite‐like neurite outgrowth in neuronal‐glial co‐cultures. In general, 5‐HT had more significant effects on both types of monoamine neuron when they were cultured with mesencephalic glia (GSN). Stimulatory effects of 5‐HT on growth of TH neurons in GSN cultures suggest that developing raphe axons, which reach the mesencephalon during the early differentiation of these neurons, may enhance the influence of local glial‐derived trophic factors. Likewise, the promotion of 5‐HT neuronal survival in these cultures suggests that glial factors in the mesencephalon may contribute to the support of 5‐HT neurons in addition to the influences of raphe glia. The inhibitory effects of 5‐HT on neurite outgrowth by raphe neurons in GSN co‐cultures indicates enhanced sensitivity of these neurons to the inhibitory effects of 5‐HT in the presence of mesencephalic glia. The region‐specific effects of 5‐HT and nialamide in glial co‐cultures suggest that raphe and mesencephalic glia may express different capacities for 5‐HT uptake, receptors, and/or monoamine oxidase (MAO) activities. These characteristics could be important for the specificity of growth‐regulatory influences of glial cells on the development of brain monoamine neurons. © 1992 Wiley‐Liss, Inc.
A monoclonal anti‐idiotypic antibody to opioid receptors labels desipramine‐induced opioid binding sites on rat C6 glioma cells and attenuates thymidine incorporation into DNA
Authors: Barg Jacob , Belcheva Mariana M. , Levy Rivka , McHale Robert J. , McLachlan Julie A. , Johnson Frank E. , Coscia Carmine J. , Vogel Zvi 
Published: December 2004

AbstractTreatment of rat C6 glioma cells with the tricyclic antidepressant desipramine induces opioid binding. Here the distribution of these opioid‐binding sites on C6 cell membranes and a functional property were investigated. Immunohistochemical examination of C6 cells was performed using a monoclonal anti‐idiotypic antibody to opioid receptors (Ab2AOR). Ab2AOR uniformly labeled >97% of the cells exposed to desipramine over their entire surface. The opioid‐receptor antagonist naltrexone completely blocked Ab2AOR binding. Ab2AOR, which has opioid agonist properties, also inhibited DNA synthesis in desipramine‐treated but not in naive C6 cells. Similarly, morphine blocked C6 cell proliferation only after desipramine treatment. The antineurotrophic action of Ab2AOR was reversed by naltrexone and was insensitive to pertussis toxin. These findings demonstrate that Ab2AOR suppresses the proliferation of C6 glioma cells by binding to desipramine‐induced opioid receptors. © 1994 Wiley‐Liss, Inc.
Cold storage of peripheral nerves: An in vitro assay of cell viability and function
Authors: Levi Allan D. O. , Evans Peter J. , Mackinnon Susan E. , Bunge Richard P. 
Published: December 2004

AbstractThe development of a nerve bank as a source of donor material to repair large defects in peripheral nerve injuries requires an understanding of the influence of cold storage on cell viability and function in these potential nerve grafts. Segments of peripheral nerves from both human and rat were stored in University of Wisconsin Cold Storage Solution (UW) at 4°C for < 12 h, 3 days, and 1, 2, or 3 weeks. Cellular viability was initially assessed by the degree of cellular outgrowth from explants of the stored nerves placed in culture, and then further quantitated by dissociating the cultured nerve explants and calculating the type and number of cells per milligram of peripheral nerve. Rat Schwann cells (SCs) obtained from the stored (control and 1 and 2 weeks) nerves were tested for their functional ability to myelinate dorsal root ganglion (DRG) neurons in culture. Our findings indicate that human and rat peripheral nerves contain few viable SCs and fibroblasts after 3 weeks of cold storage with the quantity of viable cells within the human cold stored peripheral nerves decreasing significantly after 1 week of cold storage. Despite their reduced number, some SCs from rat nerves stored up to 2 weeks are capable of myelinating DRG axons in culture. These results suggest that short intervals (< 1 week) of cold storage will result in potential peripheral nerve grafts containing large populations of functional cells, while long‐term (≥ 3 weeks) cold stored peripheral nerves will contain few viable cells. © 1994 Wiley‐Liss, Inc.
Sodium channel in isolated human brain macrophages (microglia)
Authors: Nöurenberg Wolfgang , Illes Peter , Gebicke‐Haerter Peter J. 
Published: December 2004

AbstractHuman brain macrophages (microglia) have been isolated from mixed brain cell cultures initiated from explants of neurosurgical adult human tissue in one step according to a method developed for rat microglia. Cells were characterized enzyme‐histochemically (NDPase) in mixed and immunocytochemically (anti‐CD 14) in mixed and isolated cultures. Purified cells were used to investigate in more detail membrane currents by the patch clamp technique. In 14 cells microdialyzed with a standard, K+‐containing intracellular solution there was no indication for a hyperpolarization‐induced K+‐inward current characteristic for newborn rat microglia. However, in 12 cells depo‐larizing pulses initiated a rapidly inactivating inward current which was followed by an outward current (in 4 cells). The outward current appeared to be carried by K+, since it was absent in another 18 cells, recorded by micropipettes containing Cs+ instead of K+ as the main intracellular cation. The depolarization‐induced inward current persisted un‐der these conditions. This current was inhibited by tetrodotoxin (5μM) and by substitu‐tion of Na+ by choline in the bath solution. It is suggested that this Na+‐current is specifically expressed in macrophages derived from adult brain. © 1994 Wiley‐Liss, Inc.
Isolation, identification, and culture of normal mouse colonic glia
Authors: Bernstein Charles N. , Vidrich Alda 
Published: December 2004

AbstractWe have developed a novel method of isolating and culturing murine colonic mucosal glial cells. Two morphologies are appreciated, a small flat bi or tri polar cell and a larger multipolar cell. The glial cultures have been freed of contaminating fibroblasts and epithelial cells and have been passaged by trypsinization. By intermediate filament (IF) typing, the glial cells have been further characterized as astrocyte‐like. All cells expressed glial fibrillary acid protein but not neurofilament 160 protein. The glial cultures expressed the neuropeptides, substance P and substance K. Central nervous system astrocytes synthesize neuropeptides, prostaglandins and cytokines, and can express major histocompatibility class II antigens. It is likely that enteric mucosal glia will also prove to have varied functions. These cultures can now be used to define the role of enteric mucosal glia and to further study their complex interaction with other cells of the colonic mucosa.
Maturation of the GFAP‐immunopositive glial network is delayed in the olfactory bulbs of rats subjected to early, low‐dose X‐irradiation
Authors: Hajós Ferenc , Mészáros Melinda , Halász Norbert 
Published: December 2004

AbstractYoung rats were subjected to low‐level, repeated doses of x‐irradiation from a Co60 source and examined for the presence and arrangement of their GFAP‐immunopositive system at the light and electron microscopic levels. In 2‐week‐old control rats, labelled cells were already distributed homogeneously throughout the bulb, while in the experimental animal, a (newborn‐ and early postnatal‐type) radial arrangement of immunoreactive fibres continued to persist even until the end of the fourth postnatal week. This delay in the maturation of the GFAP‐immunopositive glial system may contribute to the hindered development of the bulbar neurones, neuronal connections, and field potentials, as found in earlier studies.
Regulation of gene expression in mature oligodendrocytes by the specialized myelin‐like membrane environment: Antibody perturbation in culture with the monoclonal antibody R‐mAb
Authors: Bansal R. , Pfeiffer S. E. 
Published: December 2004

AbstractWe have previously shown that the growth of oligodendrocyte progenitors in the presence of a monoclonal antibody (R‐mAb) reacting with a cell surface component reversibly blocks their further differentiation at a specific, late progenitor stage of the lineage. This block is characterized by a nearly complete elimination of the onset of terminal differentiation at the level of RNA expression. In the present study, mature oligodendrocytes already expressing markers of terminal differentiation were exposed to R‐mAb. This resulted in a retraction of cell processes and the formation of round, swollen cells, and a dose‐dependent, antibody‐specific partial reduction (30‐50%) in the steady state levels of markers of terminal differentiation. Upon removing the perturbing antibody, all markers returned to control levels within 2 days. This inhibition was due to modulations of the levels of the specific mRNAs and proteins, not to cell loss. Total protein and levels of a marker of astrocytic differentiation were not affected by the treatment. Monoclonal antibody O1 did not cause the effects observed with R‐mAb. We conclude that the response of terminally differentiating oligodendrocytes to the effects of R‐mAb is different from that of oligodendrocyte late progenitors. Whereas the latter appears to operate through perturbation of the onset of gene expression (mRNA transcription and/or stability), the partial down‐regulation of previously activated myelinogenic gene expression appears to be due to the loss of a normal, myelin‐like, membrane environment needed for the stability of myelin mRNA and protein components.
Differentiation of the O‐2A progenitor cell line CG‐4 into oligodendrocytes and astrocytes following transplantation into glia‐deficient areas of CNS white matter
Authors: Franklin R. J. M. , Bayley S. A. , Milner R. , Ffrench‐Constant C. , Blakemore W. F. 
Published: December 2004

AbstractThe in vitro properties of the CG4 cell line have led to its increasing use as a cell line with which to study the behaviour of the O‐2A progenitor cell. In this study we have examined the in vivo behaviour of the CG4 cell line following transplantation into areas of adult rat spinal cord white matter which have been permanently depleted of glial cells by the combination of local X‐irradiation and direct injection of 0.1% ethidium bromide. Twenty‐one days after transplantation, both myelin‐forming oligodendrocytes and glial fibrillary acidic protein‐positive astrocytes were identified within the lesion, indicating that the CG4 cell line has bipotential differentiation properties when introduced into a pathological environment consisting of demyelinated axons but devoid of oligodendrocytes or astrocytes. In this respect, the CG4 cell line resembles other glial progenitor cell lines that have been transplanted into similar lesions. In some areas of the lesion, remyelination was observed that was similar in extent to that achieved by growth factor‐expanded populations of O‐2A progenitor cells. The transplant origin of the cell types within the lesion was confirmed by retroviral incorporation of the lacZ marker gene, the expression of which allowed their identification by histochemistry. In conclusion, the in vivo properties of the CG4 cell line make it a highly suitable line with which to study the behaviour of O‐2A progenitors following transplantation into normal and damaged CNS. © 1995 Wiley‐Liss, Inc.
Cytokine modulation of murine microglial cell superoxide production
Authors: Hu Shuxian , Sheng Wen S. , Peterson Phillip K. , Chao Chun C. 
Published: December 2004

AbstractActivated microglia may contribute to two opposite effects during inflammation within the central nervous system: host defense against microorganisms and neuronal injury. Each of these processes may be mediated by the generation of reactive oxygen intermediates by activated microglia. We investigated the effects of two proinflammatory cytokines, interferon (IFN)‐β and tumor necrosis factor (TNF)‐α, and of the anti‐inflammatory cytokine, transforming growth factor (TGF)‐β, on murine microglial cell superoxide (O2) production upon stimulation with phorbol myristate acetate (PMA). Priming of microglia with IFN‐β or TNF‐α resulted in a dose‐dependent enhancement of O2 release in response to PMA. The priming effects of these two cytokines were additive, suggesting that they acted by independent mechanisms. We also found that IFN‐β and TNF‐β stimulated the release of bioactive TGF‐β and that treatment of microglial cell cultures with TGF‐β antagonized the priming effects of IFN‐β and TNF‐α on O2 production. The results of this study have implications for understanding the mechanisms by which cytokines and microglia may contribute to host defense as well as to injury of the brain. © 1995 Wiley‐Liss, Inc.
Specific attachment and migration of human astrocytoma cells on human but not murine laminin
Authors: Giese Alf , Rief Monique D. , Tran Nhan L. , Berens Michael E. 
Published: December 2004

AbstractAttachment sites and biological functions of laminin isolated from murine EHS sarcoma have been well studied. Recently several variants of laminin including human placental laminin have been shown to be distinct from EHS‐laminin. This study was undertaken to determine attachment, proliferation, and migration phenomena of human astrocytoma cell lines to human and murine sarcoma EHS‐laminin. Using short‐term attachment assays human placental laminin was shown to be the better substrate for cell adhesion. EHS‐laminin mediated approximately 30–50% of the effect observed on human laminin. The astrocytoma cells expressed β1, β3, and β4 subunit mRNA as determined by RT‐PCR. Anti‐β antibodies blocked adhesion to EHS‐laminin, but antibodies against β1, β4, and αv subunits were all ineffective in blocking adhesion to human laminin. A migration assay showed that astrocytoma cells on human laminin dispersed from a central seeding area, while cells on EHS‐laminin remained where they were seeded. The pattern of dispersion could not be accounted for by changes in growth rates of astrocytoma cells on the different proteins, since both cell lines grew equally well on the two laminins. We conclude that unique epitopes on human laminin are recognized by novel receptors on human astrocytoma cells which confer a migratory phenotype to the cells. © 1995 Wiley‐Liss, Inc.