bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ontogeny of apomorphine‐induced stereotypy and its D1 and D2 receptor mediation in rats depleted of dopamine as neonates
Authors: Abrams Dalia R. , Bruno John P. 
Published: January 2005

AbstractThe ontogeny of apomorphine‐induced stereotypy in rats treated with 6‐OHDA (100 μg) or its vehicle on postnatal Day 3 was determined on Days 6, 21, or 60–90. Stereotypic sniffing and mouthing behavior were produced by apomorphine in control and DA‐depleted animals as early as Day 6. Animals depleted of DA as neonates exhibited supersensitivity to these behavioral effects from Day 6 into adulthood. The relative contributions of D1 and D2 receptor activation to apomorphine‐induced behaviors were determined by measuring the ability of specific D1 or D2 antagonists to block these effects in adults. Blockade of D1 receptors with SCH 23390 or D2 receptors with clebopride suppressed apomorphine‐induced stereotypy in both vehicle‐ and 6‐OHDA‐treated rats. However, adults depleted of DA as neonates were less sensitive to the DA antagonists than were control rats. These results demonstrate that apomorphine‐induced stereotypy is present as early as postnatal Day 6. Rats depleted of DA as neonates continue to exhibit these behaviors, even at lower doses of apomorphine than were necessary in control animals. Finally, coactivation of D1 and D2 receptors appears necessary for apomorphine‐induced stereotypy in both groups of rats. © 1992 Wiley & sons. Inc.
Thermogenesis during ultrasonic vocalization by rat pups isolated in a warm environment: A thermographic analysis
Authors: Blumberg Mark S. , Efimova Inna V. , Alberts Jeffrey R. 
Published: January 2005

AbstractUltrasonic vocalizations, emitted by rat pups when separated from their mother, littermates, and home cage, have been used as a measure of isolation distress. Recently, we demonstrated that cold exposure is the primary component of isolation that induces the vocalization. We were unable, however, to suppress all ultrasound production when transferring pups to a thermoneutral (35°C) environment.Using an infrared thermography system that allows us to estimate noninvasively heat production by brown adipose tissue, we found that pups transferred from the home nest to a 35°C test chamber exhibited sizable levels of heat production while they were vocalizing. Moreover, both heat production and ultrasound emission decreased over the 15‐min test. Next, we used extreme care to minimize thermal, and therefore respiratory, stimulation of pups before, during, and after the transfer procedure. We found that such precautions prevented both heat production and ultrasound emission following transfer. These results idicate that infant rats' thermal sensitivities are far greater than previously suspected. © 1992 Wiley & sons. Inc.
Response of bonnet macaque dyads to an acute foraging task under different motivational conditions
Authors: Andrews Michael W. , Rosenblum Leonard A. 
Published: January 2005

AbstractTo explore behavioral patterns in bonnet macaque mother‐infant dyads under environmental challenge, the motivation of infants to contact their mothers during a 1‐hr foraging period was manipulated in two ways. First, sessions were given in which the infants were separated from their mothers for 3 hr prior to the foraging period. Second, sessions were given in which the infants were allowed access to food prior to the foraging period, thereby presumably reducing their motivation to separate from mother to seek food for themselves during the foraging period. Neither manipulation resulted in heightened conflict within the dyads. Separation of the infants prior to the foraging period did result, in general, in mothers forfeiting foraging task engagement to attend to their infants. The extent to which a mother exhibited this pattern correlated with her level of foraging effectiveness. © 1992 Wiley & sons. Inc.
Body scale and infant grip configurations
Authors: Newell K. M. , McDonald P. V. , Baillargeon Renee 
Published: January 2005

AbstractThis study examined whether hand/object size ratios define common boundaries to the grip configuration patterns of infants and adults. A group of 5‐ to 8‐month‐old infants and a group of adults engaged in a displacement grasping task with inverted cups that varied in size. The findings showed that infant and adult grip configurations varied systematically with object size: More digits were brought into the contact grip configurations with increasing object size. Furthermore, when object size was scaled to hand size, common dimensionless ratios defined the grasping patterns and transitions between grasping patterns in a similar manner for both adults and infants. Consistent with a dynamical view of the development of coordination, the strong role of body scale on the developmental prehensile coordination pattern was observed for a given set of task constraints. © 1993 John Wiley & Sons, Inc.
Development of manipulation in capuchin monkeys during the first 6 months
Authors: Adams‐Curtis L. E. , Fragaszy D. M. 
Published: January 2005

AbstractThis study describes the orderly changes in manipulation over the first 6 months in capuchin monkeys (Cebus apella). By 6 months of age, all the basic forms of manipulation seen in adults have appeared. Actions that occur frequently in the first 8 weeks are gentle and involve sustained visual orientation and aimed reaching. Later actions are more vigorous, and involve grasping. Large increases in the rate of activity are evident over the period of development studied. The increase from the first 8 weeks to the second may be due to (a) an increase in the amount of time spent alert and active, (b) a decrease in the amount of time spent in a ventral position, (c) improvements in postural control and stamina and (d) the onset of independent locomotion. Changes in form can be attributed primarily to postural factors and to neuromuscular development (precisely aimed and controlled movements appearing in the 5th and 6th months).© 1994 John Wiley & Sons, Inc.
Cardiorespiratory functioning of preterm infants: Stability and risk associations for measures of heart rate variability and oxygen saturation
Authors: Dipietro Janet A. , Caughy Margaret O'brien , Cusson Regina , Fox Nathan A. 
Published: January 2005

AbstractCardiorespiratory measures are used with increasing frequency to assess individual differences in development in full‐term and preterm infants, yet little information exists concerning the stability of these measures or their relations to each other. This study assessed three common cardiac measures (heart period, heart period variability, and vagal tone) and two measures of arterial oxygenation based on pulse oximetry (mean pulse oxygen saturation and variability) in a sample of 35 preterm infants. Data were collected on five occasions: on 3 consecutive days in the early neonatal period, at 34 weeks postconceptional age, and at discharge. Results indicate both short‐term and longer term stability for all cardiac measures. Oxygen saturation demonstrated only short‐term stability prior to 34 weeks. Mean heart period was positively associated with both measures of heart period variability at each assessment point, while mean oxygen saturation level was inversely related to oxygen saturation variability. In addition, significant associations between cardiorespiratory patterns and perinatal risk measures were found. It is concluded that these measures reflect stable characteristics of neuroregulatory function in preterm infants.© 1994 John Wiley & Sons, Inc.
Federal evaluation in a legislative environment: Producing on a faster track
Authors: Chelimsky Eleanor 
Published: January 2005

AbstractEvaluations must respond rapidly to legislative information needs. In certain cases, this implies the development of methods that can provide answers even more quickly than usual. Currently, GAO is testing three such methods: the evaluation synthesis, the use of extant data, and the evaluation planning review. All three methods rely heavily on past research, all place heavy time pressures on evaluators, and all are highly promising in terms of user satisfaction.
AIDS prevention: A public health psychology perspective
Authors: Rugg Deborah L. 
Published: January 2005

AbstractTo prevent HIV infection we must influence risky sexual and drug‐using practices, some of the most basic yet complex of human behaviors. No single discipline or one‐shot intervention is going to solve this problem; rather, a sustained, multidimensional, interdisciplinary effort with repeat exposures to a variety of well‐planned and targeted strategies is essential.
Centralized versus decentralized coordination in the adult day health care evaluation study
Authors: Hedrick Susan C. , Sullivan Jean H. , Ehreth Jenifer L. , Rothman Margaret L. , Connis Richard T. , Erdly William W. 
Published: January 2005

AbstractDecisions about the appropriate balance between centralized and decentralized staffing and responsibilities in multisite evaluations should be based on scientific, administrative, and political considerations.
Nervenkitt: Notes on the history of the concept of neuroglia
Authors: Somjen George G. 
Published: January 2005

AbstractThe evolution of concepts concerning the identity and the functions of neuroglia is traced. Some of the main ideas in the works of Virchow, Deiters, Golgi, Lenhossék, Lugaro, Ramón y Cajal, del Río‐Hortega, Achúcarro, Penfield, and others are highlighted.
Effect of benzodiazepines and pentobarbital on the GABA‐induced depolarization in cultured astrocytes
Authors: Backus Kurt Harald , Kettenmann Helmut , Schachner Melitta 
Published: January 2005

AbstractWe have previously shown that cultured astrocytes from neonatal rat cerebral cortex are depolarized by GABA. The underlying ionic mechanism, activation of a Cl−− conductance and responses to an agonist and antagonists were found to be similar to those of the neuronal GABAA receptor (Kettenmann et al.: Brain Research 404:1–9, 1987; Kettenmann and Schachner: Journal of Neuroscience 5:3295–3301, 1985). To characterize further the pharmacological properties of the GABA receptor we have tested the influence of pentobarbital and benzodiazepines on the GABA response. Pentobarbital potentiated and prolonged the GABA‐induced depolarization and enhanced the velocity of the depolarization. Agonists of the neuronal benzodiazepine receptor, flunitrazepam, diazepam, and midazolam, increased the GABA‐induced depolarization. As in neurons, an antagonist of the benzodiazepine receptor, Ro 15‐1788, blocked the flunitrazepam‐induced enhancement of the GABA response. In contrast to their effects on neurons, the inverse agonists Ro 22‐7497 and DMCM increased the GABA‐induced depolarization. The ligand of the putative peripheral benzodiazepine binding site, Ro 5‐4864, did not show consistent effects on the GABA response.These studies confirm that cultured astrocytes express GABAA receptors. This receptor is similar to the neuronal GABAA receptor with regard to Cl−− conductance and its pharmacological responses to muscimol, bicuculline, picrotoxin, pentobarbital, and benzodiazepine agonists and an antagonist, but it is different in its responses to inverse agonists of the benzodiazepine site. The physiological role of the glial GABAA receptor is at present unknown.
Plasma membrane of cultured oligodendrocytes: III. Relatedness to myelin
Authors: Szuchet Sara , Polak Paul E. , Yim Sung Hye , Arvanitis Dimitrios 
Published: January 2005

AbstractWe have compared highly purified fractions of oligodendrocyte plasma membrane to myelin by one‐ and two dimensional gel electrophoresis and found them to be distinct. The major myelin proteins—proteolipid protein (PLP), DM‐20, and myelin basic protein (MBP), which dominate the sodium dodecyl sulfate polyacrylamide gel electrophoresis pattern of myelin–were minor components of the plasmalemma. However, 2′,3′, cyclic nucleotide phosphodiesterase (CNPase) and myelin‐associated glycoprotein (MAG) were represented equally in both membranes. Labeling the cells with various precursors followed by isolation of plasmalemma revealed that newly synthesized PLP, DM‐20, CNPase, and MAG were incorporated into the plasma membrane of “floating” oligodendrocytes (i.e., nonattached to substratum). This was not so with MBP. Nevertheless, scattered patches of MBP were localized on the plasma membrane of intact cells using the immunogold method at the electron microscopic level. The data are consistent with the notion that MBP is not a constituent of the plasma membrane of mature oligodendrocytes (the MBP patches on intact cells are likely remnants from past association with myelin) but is rapidly associated with the plasmalemma of myelinating oligodendrocytes (i.e., attached cells). It is suggested that phosphorylation of MBP provides the triggering signal for plasma membrane association. In order to analyze the minor proteins in myelin and compare them to the plasma membrane by two‐dimensional gel electrophoresis, myelin was extracted with chloroform:methanol to remove PLP, DM‐20, and MBP. Even in the absence of PLP, DM‐20, and MBP the pattern of extracted myelin still differed from that of plasmalemma indicating that their minor protein compositions were not the same. Myelin was characterized by a group of proteins that clustered at pI 5.5–6.5 and Mr 40,000–60,000 of which α‐tubulins, β‐tubulins, and actin are part: the plasmalemma had tubulins and actin but in different proportions. Our findings indicate that in addition to PLP, DM‐20, and MPB, myelin is also enriched relative to the plasmalemma in another group of proteins.
Astrocytes as eicosanoid‐producing cells
Authors: Murphy Sean , Pearce Brian , Jeremy James , Dandona Paresh 
Published: January 2005

AbstractA variety of prostaglandins and leukotrienes, together with thromboxane and prostacyclin metabolites, can be detected in central nervous tissues and in cerebrospinal fluid. Defined cultures of astrocytes have revealed these cells to be a major source of eicosanoids. In common with other eicosanoid‐producing cells, agents such as calcium ionophores and phorbol esters are potent stimuli for promoting release. While in other tissues agonists for receptors linked to calcium mobilisation prompt eicosanoid release, this does not seem to be the case in astrocytes, though a range of such receptors are present. The notable exceptions to this observation are adenosine triphosphate and adenosine diphosphate, presumably acting through P2 purinergic receptors. Many cell types in the CNS are targets for eicosanoids, possessing receptors linked to adenylate cyclase or phospholipase C. An appreciation of the functional significance of activation of these receptors in just now begining. Eicosanoids have effects in the CNS that involve not only the vascular supply but also synaptic modulation and immune regulation.
Electrogenic Na+/HCO3−cotransport in neuroglia
Authors: Astion Michael L. , Orkand Richard K. 
Published: January 2005

AbstractMembrane potential recording from glial cells in Necturus optic nerve in the presence of 2 mM Ba++, which was added to block the K+ conductance, gave the following results. (1) In HCO3−‐free, low‐Na+ solutions (11% of control; Na+ replaced with N‐methyl‐D‐glucamine), the hyperpolarizing effect of adding 10 mM HCO3− was reduced by approximately 80%.(2) 4‐acetamido‐4′‐isothiocynato‐stilbene‐2,2′‐disulfonic acid (SITS, 0.1 or 1 mM) reduced the effect of HCO3− by at least 50%.(3) In the presence of HCO3−, reduction of Na+ caused a depolarization which was much larger than that observed in nominally HCO3−‐free solutions. These observations indicate the presence in the glial membrane of an electrogenic Na+/HCO3− contransporter in which the stoichiometry of HCO3− to Na+ is greater than 1.
Pure astrocyte cultures derived from cells isolated from mature brain
Authors: Norton William T. , Farooq Muhammad , Chiu Fung‐Chow , Bottenstein Jane E. 
Published: January 2005

AbstractEnriched preparations of oligodendrocytes, isolated either from adult bovine brain or from 30‐day‐old rat brain, eventually yield cultures in MEM‐15% calf serum that contain, in addition to oligodendrocytes, proliferating astrocytes and variable numbers of fibroblast‐like cells. If these cultures are switched to a serum‐free defined medium during the 1st week, mixed cultures containing only oligodendrocytes and astrocytes are obtained. Bovine cultures can be replated and purified by selective adhesion to yield cultures that are < 99% astrocytes; similar procedures were not successful with rat cultures. Cytoskeletal preparations of the purified astrocyte cultures from mature bovine brain contain both vimentin and glial fibrillary acidic protein (GFAP), but vimentin is by far the major intermediate filament protein. Thus, the intermediate filament composition of these astrocytes is similar to that of astrocytes in primary cultures obtained from neonatal rat brain. Immunofluorescent studies of these cultures at 24 hr in vitro show that there are no GFAP+ cells in cultures of either species; the bovine cultures contain < 95% GC+ cells; and the rat cultures contain 90% GC+ cells. After a few days in vitro flat cells appear that are vimentin+/GFAP–/GC–. In serum‐free medium these cells eventually become vimentin+/GFAP+. We propose that the astrocytes that grow in these cultures arise from a population of glial precursor cells, which are present even in adult brain and are isolated together with oligodendroglia, and that they do not derive from contaminating mature astrocytes. Thus, the astrocytes in our cultures may have the same origin as astrocytes grown in culture from dissociated neonatal brain.
Size and density of glial and neuronal cells within the cerebral neocortex of various insectivorian species
Authors: Stolzenburg Jens‐Uwe , Reichenbach Andreas , Neumann Michael 
Published: January 2005

AbstractMorphometric measurements were done on frontal sections through the somatosensory neocortex of various insectivorian species. All measured parameters varied with the size of animals; there was a better correlation with the ventriculartopial brain wall thickness than with the brain weight. The following rules were evaluated: with increasing brain wall thickness, (1) lamina I becomes thinner; (2) the nuclei of both neuronal and glial cells become larger; (3) the volume density of neuronal cells decreases greatly; (4) the volume density of glial cells increases slightly; and (5) as a result, the glia:neuron index increases markedly. There was no equal number of neurons under a unit surface area in the cortices of any species studied. Developmental processes that might account for the above‐mentioned rules are discussed in this report.
Activation of polyphosphoinositide metabolism as a signal‐transducing system coupled to excitatory amino acid receptors in astroglial cells
Authors: Milani Daria , Facci Laura , Guidolin Diego , Leon Alberta , Skaper Stephen D. 
Published: January 2005

AbstractExcitatory amino acids (EAA) are known to induce an increase in the breakdown of polyphosphoinositides (PI) in brain slices and in dispersed cultures of neurons. We have now used astroglia cultured from newborn rat cerebra to demonstrate that glutamate provokes, in [3H]inositol‐labeled cells, an accumulation of inositol phosphates in a time‐ and concentration‐dependent manner. The ED50 value for glutamate was 40 μM. Quisqualate, ibotenate, and kainate were also active, with their relative potencies in the order of quisqualate > ibotenate >> kainate. No effect was detected with N‐methyl‐D‐aspartate and quinolinic acid in the absence of Mg2+. The nonselective glutamate receptor antagonist γ‐D‐glutamylglycine fully inhibited glutamate agonist‐induced PI breakdown. A brief pretreatment of the astroglial cells with phorbol esters negated these effects of EAA receptor agonists, suggesting a feedback role for protein kinase C in phospholipase C action. Glutamate also elevated cytosolic free Ca2+ in Fura‐2‐loaded astroglial cells, as assessed by digital fluorescence imaging microscopy. Since a close metabolic partnership is known to exist between neurons and glia, these findings may have important functional consequences for neural cells in vivo.
Increase in glial intracellular K+ in drone retina caused by photostimulation but not mediated by an increase in extracellular K+
Authors: Coles Jonathan A. , Schneider‐Picard Gisela 
Published: January 2005

AbstractThe predominant glial cells of the drone retina (outer pigment cells) respond to an increase in extracellular [K+] (K0) by a net uptake of K+; thus, they contribute to bringing K0 back toward its baseline value. The authors report herein that there is also a different mechanism by which light stimulation of the retina causes an increase in intracellular free [K+] in the glial cells. In superfused retinal slices, after 5–10 minutes of continuous illumination at physiological intensities, extracellular [K+] often fell back to below its original level in the dark. This fall can be explained by increased activity of the Na/K pump in the photoreceptors and diffusion of K+ down their axons. Despite the absence of raised K0, K+‐selective microelectrodes in glial cells recorded a small increase in intracellular [K+] that was maintained for the duration of the illumination; i.e. A change occurred in the glia that was not mediated by an increase in K0. The increase in intracellular [K+] is not mediated by illumination of the screening pigment in the glia. Unless the increase is caused by illumination of some other, unknown, pigment in the glia, the results show that some unidentified signal (that is not K+) passes from the photoreceptors to the glia.
Inhibition of peroxisomal beta‐oxidation and brain development in rats
Authors: Van Den Branden Christiane , Dacremont Georges , Hooghe Robert , Roels Frank 
Published: January 2005

AbstractThioridazine, an inhibitor of peroxisomal beta‐oxidation, was administered orally to nursing rats during the period of maximal myelination in the pups (8–21 days postnatally). Under the experimental conditions, thioridazine causes accumulation of C24 and C26 fatty acids in pup brain lipids, an effect we consider to be a typical consequence of inhibited peroxisomal beta‐oxidation. In the corpus callosum of treated pups, the relationship between axon diameter and myelin sheath thickness is altered compared with matched controls. Thioridazine also induces undernourishment effects in 21 day‐old rats. Body and brain weight are severely reduced. Liver peroxisomes show a starvation‐type metabolism. Undernourishment is known to influence myelination in developing rat brain. However, known consequences of undernourishment, such as decreased myelin concentration in whole brain, decreased percentage of myelinated fibers, and decreased granule‐to‐Purkinje cell ratio are not present.