bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of home orientation in offspring of protein‐restricted cats
Authors: Gallo Patricia Vetula , Werboff Jack , Knox Kirvin
Published: January 2005

The development of home orientation was evaluated in 2–14‐day‐old kittens nursing from mothers fed a protein‐restricted or control diet during late gestation and lactation. Although restricted kittens remained in the home when placed in it, their ability to return to the home was delayed when they were removed from it. Restricted kittens also exhibited aberrant locomotor development and an increased frequency of loss of balance (upsets) en route to the home. During postnatal Week 1, vocalization frequency, an index of kitten disturbance when outside the home, was increased in restricted kittens tested in the home, and in adjacent and diagonal corners. Restricted kittens persisted in vocalizing more frequently than controls in home and adjacent corner tests during Week 2. Taken together, these data suggest that maternal protein restriction during late gestation and lactation disrupts the development of home orientation behavior by impairing locomotor function and increasing emotional responsiveness.
Overstimulation, occipital/somesthetic cerebral cortical depth, and cortical asymmetry in mice
Authors: Lindroos Ove Fredrik Christian , Riittinen Marja‐Leena Annikki , Veilahti Jukka Veikko , Tarkkonen Lauri Juhani , Multanen Heikki Ilmari , Bergström Rudolf Matias
Published: January 2005

It was hypothesized on theoretical grounds that sensory multidimensional overstimulation (stress) during development might not yield increased cerebral cortical depth, as has been found for enriched rearing conditions. We found that such overstimuliation in growing mice resulted in a low occipital/somesthetic cortical depth ratio in comparison to EC‐stimulated mice (EC, enriched conditions). It is unclear whether this is due to small occipital or large somesthetic cortical depth. Principal‐component analytic techniques indicate a complicated interaction during development involving sex, environmental condition, and cortical asymmetry.
A specialization of taste aversion learning during suckling and its weaning‐associated transformation
Authors: Gubernick David J. , Alberts Jeffrey R.
Published: January 2005

During ontogenesis, altricial mammals advance through different ecological niches with require correspondingly different adaptive strategies. We view learning as an important feature of ontogenetic adaptations and consider the acquisition and expression of taste aversion learning during nursing with in this framework. Fifteeen‐day‐old preweanling rat pups fail to acquire conditioned taste aversions while nursing, whereas 20‐day‐old weanlings readily learn flavor aversions while suckling (Martin & Alberts, 1979). The developmental emergence of taste aversion learning while nursing coincides with reduction in maternal milk supply and the rat pup's transition to a solid food diet. We considered the ontogenetic transformation of learning while nursing as a feeding‐relaated adaptive strategy of the weanling rat and tested wot predictions derived from this view: (1) delayed weaning might postpone acquisition or expression of suckling‐related taste aversions and (2) conditions that permit weaning (e.g., acess to alternate food sources) might induce acquisition or expression of such taste aversions. Both predictions were confirmed.
Development of sound production in normal, isolated, and deafened kittens during the first postnatal months
Authors: Romand Raymond , Ehret Günter
Published: January 2005

The development of cells (quantified by a series of acoustiv parameters) of (a) normal, (b) socially isolated, and (c) deafened kittens that were released in four different situation has been studied from birth to 170 days of age. All call parameters studied except noise components show developmental changes that can be related to the development of (a) the vocal tract (fundamental frequency, harmonic with maximum intensity, uper‐frequency limit and frequency range, occurrence of frequency, and intensity modulations), (b) feedback control through the auditory system sound‐pressure level, harmonic with maximum intensity, call‐variability, and (c) motivational valuation of the releasing situations (duration). Isolated and deafened kittens displayed quantitative differences in certain call parameters compared with normal animals. Calls of deafened animals are, on the average, louder, more tonal and uniform, and differentially pitched compared with those of normal, hearing animals.
Developmental origins of motor coordination: Leg movements in human infants
Authors: Thelen Esther
Published: January 2005

The development of coordination of leg movements of human infants is discussed from the perspective of dynamic motor theory. Even in the newborn period, leg movements have topographical and temporal organization, but it is global and inflexible. During the first year, limb segments become both disassociated from these global synergies and reintegrated into more complex coalitions. Growthrelated changes in the biodynamic properties of the body segments may be as important as neurological maturation in determining the movement outcomes and may help explain the spurts, regressions, and asymmetries seen in early infancy.
Habitat selection in larval anurans: Early experience and substrate pattern selection in Rana pipiens
Authors: Dunlap Donald G. , Satterfield Cynthia K.
Published: January 2005

The tadpoles of Rana pipiens, unlike those of other frogs that have been reported on, do not develop clear‐cut perceptual preferences for familiar background patterns composed of either squares or stripes. When larvae reared on white and/or patterned backgrounds are tested for preference between these backgrounds, they all exhibited a preference for white backgrounds. When the larvae were tested for preference among uniform backgrounds of varying brightness, those reared on the two brighter backgrounds showed no preference, and those reared on the two darker backgrounds preferred the brightest of the available backgrounds. The larvae of R. pipiens behave as if they possess an experientially modifiable defense reaction such that, when frightened, they move preferentially onto brighter backgrounds and avoid boldly patterned backgrounds. A pattern may be less aversive if it is familiar than if it is unfamiliar. Larvae from South Dakota tended to habituate more effectively to striped backgrounds, and those from Wisconsin to backgrounds composed of squares.
Social preferences in stump‐tailed macaques (Macaca arctoides): Effects of companionship, kinship, and rearing
Authors: MacKenzie Muriel M. , McGrew W. C. , Chamove Arnold S.
Published: January 2005

Social preferences in the directionality of social behavioral patterns in a heterogeneous group of 26 stump‐tailed macaques (Macaca arctoides) were examined to see if kin recognition occurred. Four behavioral measures were analyzed: proximity, contact, grooming, and play. Three independent variables were examined: early companionship, condition of early rearing, and kinship. The latter was divided into partrilineal, matrilineal, and shared kinship. Partial correlational analysis showed that social preferences correlated most strongly with companionship, followed by kinship and rearing conditions. Within kinship, patrilineal and matrilineal effects differed markedly, suggesting that natural selection has operated differentially in a species in which normal child‐rearing is done by matrilineal kin.
Ontogenesis of learning: V. Variation in associative and nonassociative control of an operant forelimb response in infant rats
Authors: Camp Laurel L. , Rudy Jerry W.
Published: January 2005

To study ontogenetic variation in the mechanisms that control operant responding, infant rats 4–16 days old were trained to lift a forelimb in order to receive an infusion of a sucrose–milk solution (reinforcer). Although the learning processes that contribute to this behavior were to some extent functional in pups 5–6 days old (Experiment V), there were major age‐related constraints on the performance of this response. We were unable to observe selective responding with the reinforced forelimb until pups were 9 days old (Experiment I). This was in part because pups tested when 7, but not 9 days old, were highly activated (as measured by responding with both forelimbs) by both the reinforcer (Experiment II) and cues associated with the reinforcer during training (Experiment IV). Implications of these findings are discussed.
Effects of early experience on the development of filial preferences in the domestic chick
Authors: Bolhuis J. J. , Johnson M. H. , Horn G.
Published: January 2005

Factors affecting the development of filial preferences in chicks were investigated. Four groups of chicks were hatched and maintained in darkness. When the chicks were 20‐hr old, three of these groups were exposed to an overhead light (“primed”) for .5 h. When 24‐hr old, all groups were placed in running wheels for 2 hr. While in the wheels one group was exposed to a visually complex pattern, one group to diffuse overhead light, and the remaining two groups (one primed and one not primed) were in darkness. All chicks were then returned to a dark incubator until their preference for a red box or a stuffed jungle fowl was measured in a simultaneous choice test either 2 hr (Test I) or 24 hr (Test II) later. At Test I the chicks which had been exposed to the complex visual pattern showed a significant preference for the fowl. Chicks in the other groups showed no preference. At Test II all groups showed a significant preference for the fowl. The results of a second experiment suggested that the later emerging preference was related to the chicks experience in the running wheel. It was concluded that the preference for the fowl will develop in entirely dark‐reared chicks that are allowed a period of time in a running wheel, but that this preference will appear earlier in chicks which have had experience of a complex visual pattern.
Cyclic motor activity in the human fetus after midgestation
Authors: Robertson Steven S.
Published: January 2005

The spontaneous movements of human fetuses were studied longitudinally between 21 and 41 weeks of gestation. At each age, spectral analysis of the fluctuations in fetal movement revealed strong cyclic patterns. The frequency of the dominant motor rhythms ranged from .13 to 1.91 cycles per minute. The strength of oscillations between .18 and 1.02 cycles per minute increased slightly with gestation, but the frequency of the dominant motility cycle, the width of the corresponding spectral peak, and the incidence of weaker (usually faster) rhythms did not change. Neuromuscular activity is known to serve important developmental functions in the embryo and fetus. The ubiquity and relative consistency of cyclic motility in the last half of human gestation, and the existence of similar periodicity in other species, suggest that the cyclic activation of developing motor circuits may possess particular adaptive value.
Conditioning of an odor aversion in preweanlings with isolation from home nest as the unconditioned stimulus
Authors: Smith Gregory J. , Kucharski David , Spear Norman E.
Published: January 2005

Four experiments assessed the acquisition of aversions by preweanling rats to odors experienced during isolation from their home‐nest environment. Conditioned aversion occurred for animals given a second novel odor paired with the home‐nest environment, depending upon the duration of the odor‐isolation pairing. With a brief duration of pairing (two pairings of 3 min each) novel odors became more preffered when paired with isolation or, to a lesser extent, when paired with home. With longer durations of pairing (two pairings of 4 hr each) the odor paired with isolation became absolutely aversive, although the odor paired with home did not become absolutely preferred. With intermediate durations neither aversion nor preference for the odors was substantial. Animals conditioned at ages 9, 16 or 23 days postnatal acquired aversions to odors paired with isolation, but 30‐day‐old rats did not.
Cardiac orienting and habituation to auditory and vibrotactile stimuli in the infant decerebrate rat
Authors: Ronca April E. , Berntson Gary G. , Tuber David S.
Published: January 2005

Phasic changes in heart rate were used to evaluate sensory reactivity and habituation in 5‐ and 12‐day‐old normal and decerebrate rats. Twenty‐four and forty‐eight hours after thalamic transection, temporally paired auditory or vibrotactile stimuli were repeatedly presented in a sensory disparity paradigm. While tone stimuli failed to evoke consistent cardiac change, vibrotactile stimuli produced cardiac decelerations, characteristic of the orienting response, in all subject groups. The magnitude of this response was comparable in both normal and decerebrate subjects at 5 days of age, but demonstrated a more notable increase with age in the normal subjects. Habituation of the cardiac response was apparent in all groups, and was not significantly different in the normal and decerebrate subjects. No consistent responses were apparent in any group to the unexpected omission of the second stimulus of the pair. Results indicate that orienting and habituation processes can persist in the absence of the cerebral hemispheres and support the view that lower levels of the neuraxis are capable of mediating a range of adaptive functions.
Incidental learning is impaired during early‐life undernutrition
Authors: Rogers Peter J. , Tonkiss John , Smart James L.
Published: January 2005

Rats were either well‐nourished (control) or undernourished (PU) during the suckling and early postweaning periods (birth to 45 days), after which all animals were fed ad libitum. From 25 to 45 days half of the rats in each group were exposed continuously in their home cases to shape stimuli (triangle and circles). Half of each of these 4 groups were given “reminders” of the stimuli through exposure for 2 h every 10–12 days from 55 to 131 days. Beginning on day 132, ability to discriminate these same visual stimuli was tested using a nonappetitively motivated version of the Lashley jumping stand technique. Discrimination learning per se was unimpaired by previous undernutrition (control and PU rats not viewing the stimuli prior to training performed equally well). However, early‐life exposure led to improved learning performance only in control rats; it had no effect on the performance of PU rats (significant exposure X nutrition interaction). These findings indicate that undernutrition interfered with early “incidental learning”, that is, learning about features of the environment which are not, at the time, biologically relevant. Finally, retention of the discrimination was assessed 9 weeks after the rats had attained criterion performance. There were no effects of nutrition or prior exposure on long‐term memory.
Behavioral displays to gustatory stimuli in newborn rat pups
Authors: Ganchrow Judith R. , Steiner Jacob E. , Canetto Silvia
Published: January 2005

These experiments examine behavioral responses to taste stimuli in newborn rat pups during the first 4 postnatal days. Motor displays in the face and head regions of 90 neonate rats were recorded during 60‐sec observation periods in a double‐blind setting. Stimuli, presented as single droplets to the lips, included 2 concentrations each of sucrose, sodium saccharin, citric acid, quinine, and distilled water. Results from 5 different judges making “blind” and independent observations on different animals were compared for concordance. It was agreed that certain features were consistently associated with one stimulus more than another. Licking and rhythmic mouth movements were found to be the most salient features elicited by sweet stimuli, while head movements and gaping most accurately identified quinine. The sour reaction often contained components characterizing both sweet and bitter. Salient features differed not only by their association with certain stimuli, but by their repetitive frequencies as well as by their likelihood to initiate a behavioral sequence. Intensity and hedonic values assigned to taste‐induced behaviors were usually different from water and accurately related to stimulus type. Results suggest that the gustatory system becomes functionally mature during the first postnatal days, and that this functionality occurs before the structural development of all taste buds is complete.
Conditioning of aversion to alcohol orosensory cues in 5‐ and 10‐day rats: Subsequent reduction in alcohol ingestion
Authors: Molina Juan C. , Hoffmann Heather , Spear Norman E.
Published: January 2005

Two experiments examined in 5‐ and 10‐day‐old rat pups the impact of alcohol olfactory aversions upon subsequent alcohol intake. In Experiment 1 it was observed that at both ages, animals given a single pairing of alcohol odor and LiCl subsequently consumed less alcohol than those in any of 4 control conditions (alcohol odor unpaired with LiCl, alcohol odor exposure, lemon odor paired with LiCl, and untreated animals). In Experiment 2, pups of both age groups were given LiCl following exposure to alcohol odor, the infusion of an alcohol solution or both stimuli simultaneously. Rats given explicitly unpaired presentations of the different conditioned stimuli and internal malaise served as controls. It was observed that equivalent aversions to alcohol ingestion were expressed whether the infants had experienced the alcohol odor, the alcohol infusion, or both, paired with toxicosis. These experiments extend the ontogenetic spectrum of circumstances in which olfactory experiences affect subsequent ethanol ingestion and also may indicate an early nondifferentiated processing of odorant and gustatory cues arising from an ethanol stimulus.
Development of the surgically produced singleton mouse fetus
Authors: Gandelman Ronald , Graham Scott
Published: January 2005

All but one mouse embryo were removed from uteri on Day 8 of gestation and delivered via cesarean section on Day 18. Singletons were compared on various developmental indices to similarly delivered controls permitted to reside in uteri containing the normal complement of fetuses. The former were heavier at birth and weaning, had smaller ano‐genital distance ratios (ano‐genital distance/delivery weight), and displayed walking, gripping, eye‐opening, and vaginal‐opening earlier than controls. Singletons also exhibited greater durations and frequencies of various prenatal activities relative to controls when observed on Day 17 of gestation. Singleton status did not advance the onset of prenatal activity.
The development of defensive behavior against predation by army ants
Authors: McDonald Philip , Topoff Howard
Published: January 2005

The development of defensive reaction in the ant Novomessor albisetosus against predation by army ants is studied in the laboratory and field. Two clusters of behavior emerge: escape with or without the brood, and aggressive defense. Escape develops specifically as a reaction against army ants and not in the presence of other ant species. Other behaviors develop with varying degrees of specificity toward army ants. All behaviors develop with age in workers isolated from experience with army ants. However, evidence is presented suggesting that experience with army ants alters the course of this development.
Proximal control of fetal rat behavior
Authors: Ronca April E. , Kamm Kathi , Thelen Esther , Alberts Jeffrey R.
Published: January 2005

We 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

Autoradiography 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

Phrasing 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

Thirty‐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

This 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

Two 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

We 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

To 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

Treatment 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

The 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

Human 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

We 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

Young 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

We 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

The 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

Activated 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

Attachment 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.
Change of phosphotyrosine immunoreactivity on microglia in the rat substantia nigra following striatal ischemic injury
Authors: Korematsu Kojiro , Goto Satoshi , Nagahiro Shinji , Inoue Nobuhiro , Oyama Taro , Yamada Kazumichi , Ushio Yukitaka
Published: December 2004

Using immunohistochemistry, we investigated changes in phosphotyrosine (P‐Tyr) immunoreactivity on the microglia of the rat substantia nigra (SN) following striatal ischemic injury produced by transient middle cerebral artery (MCA) occlusion. Anterograde axonal degeneration in the SN due to striatal ischemic injury was detected by depletion of calcineurin immunoreactivity in that region from 1 day after operation. From 3 days to 1 month (the longest period examined in this study) after MCA occlusion, there was a significant increase in P‐Tyr immunoreactivity in the SN ipsilateral to the MCA occlusion. Also, light microscopic observation showed that the microglia exhibited an increased immunoreactivity for P‐Tyr and characteristic morphological changes in the ipsilateral SN. The present results indicate that a signal transducing cascade(s) associated with tyrosine phosphorylation may be involved in the activation of the microglia in the SN responding to anterograde degeneration of the striatonigral pathway. © 1995 Wiley‐Liss, Inc.
Effects of enhanced extracellular ammonia concentration on cultured mammalian retinal glial (müller) cells
Authors: Reichenbach A. , Stolzenburg J.‐U. , Wolburg H. , Härtig W. , El‐Hifnawi E. , Martin H.
Published: December 2004

Müller (glial) cells of the neonatal rabbit retina were cultured as confluent monolayers and exposed to enhanced concentrations of ammonia (0.25, 0.5, 1, 3, 7, and IC mM) in medium for various periods (30 min to 10 d). This caused, in a time‐ and dose‐dependent manner, similar changes in the Müller cells as had previously been described in cultured astrocytes. The most conspicuous events were (1) an increasing size of cell nuclei, (2) an accumulation of phagocytotic vacuoles, and (3) a rearrangement of intermediate filaments. (4) A considerable number of cells died when higher ammonia concentrations were applied for more than 1 h. Simultaneous application of dibutyrylcyclic adenosine monophosphate (dBcAMP) prevented almost completely both the increase in cell nucleus size and the changes of intermediate filaments, but only partly the early cell death of a subpopulation of cells, and the accumulation of phagocytotic vacuoles. Further changes evoked by enhanced ammonia concentration were (5) an accumulation of lipofuscin‐like material (“fatty degeneration”) revealed by lipophilic stain, (6) reduced immunoreactivity for cathepsin D, and increased immunoreactivity for (7) glial fibrillary acidic protein, (8) glutamine synthetase, and (9) bcl‐2 protooncogene protein. These findings are discussed in respect to the possible underlying pathophysiological mechanisms. © 1995 Wiley‐Liss, Inc.
Estradiol promotion of changes in the morphology of astroglia growing in culture depends on the expression of polysialic acid of neural membranes
Authors: Garcia‐Segura Luis M. , Cañas Benito , Parducz Arpád , Rougon Geneviève , Theodosis Dionysia , Naftolin Frederick , Torres‐Aleman Ignacio
Published: December 2004

Gonadal steroids are known to affect astroglial morphology in developing and adult animals. Earlier studies of mixed neuronal‐glial cultures from fetal rat hypothalamus showed that glial fibrillary acidic protein (GFAP)‐immunoreactive cells with a polygonal shape were transformed into process‐bearing cells upon exposure to the ovarian hormone estradiol. This effect was dependent on a direct contact of astroglia with living hypothalamic neurons. The present study shows that somata and processes of neurons in such cultures were immunoreactive for polysialic acid (PSA); astroglia were immunonegative. PSA appears to participate in the estradiol‐induced shape changes since treatment with endoneuraminidase, an enzyme that specifically removes PSA from the cell surface, abolished PSA immunostaining and prevented the 17ß‐estradiol‐induced morphological changes of astroglia. In contrast, treatment with endoneuraminidase did not affect astroglial shape changes induced by basic fibroblast growth factor (bFGF), nor those induced by the addition of neurons to glial cultures. These results suggest that PSA on neuronal membranes, probably linked to the highly sialylated isoform of the neural cell adhesion molecule, is necessary for the expression of certain hormonally‐regulated neuro‐glial interactions. © 1995 Wiley‐Liss, Inc.
Boundaries and inhibitory molecules in developing neural tissues
Authors: Faissner Andreas , Steindler Dennis
Published: December 2004

Numerous studies of the past decade have illuminated the importance of intercellular adhesion events for neural pattern formation. It has been documented that members of the Ig and cadherin gene superfamilies, that glycoproteins and, probably to some extent, proteoglycans of the extracellular matrix play a role in this context. Recent observations suggest that, in addition to adhesive interactions, repulsive and/or inhibitory phenoma are also of importance in regulating neural pattern formation. Several molecules are under study which are cosidered possible mediators of inhibitory interactions in the nervous system. The hypothesis has been advanced that some of these might be partially responsible for restrictive, boundary‐like properties ascribed to glial cells in developing and regenerating tissues. The current review summarizes these studies and focusses on molecular aspects of boundary and compartmentation phenomena. © 1995 Wiley‐Liss, Inc.