bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of early social isolation on the motivation for social play in juvenile rats
Authors: Ikemoto Satoshi , Panksepp Jaak 
Published: January 2005

AbstractFifteen‐day‐old rats were subjected to one of three housing conditions: mother‐and‐peer (family), peer, and isolation conditions. At 24 days of age, all subjects were rehoused individually. In Experiment 1, play behaviors were monitored in like‐raised pairs. Despite their gross lack of social experience, isolation‐reared subjects did not exhibit a deficit in frequencies of rough‐and‐tumble play. It is concluded that the fundamental motivation for rough‐and‐tumble play is relatively independent of prior learning in rats. Indeed, their elevated dorsal contacts suggested that isolation‐raised subjects may have higher appetitive motivation for play. In Experiment 2, the levels of social motivation were compared between family‐ and isolation‐raised animals, using a T‐maze. The isolation‐raised animals made reliably more choices for social interaction reward over food reward than family‐raised animals. Although inconclusive, the results from the two experiments suggest that prolonged social isolation increases the appetitive motivation for social play. © John Wiley & Sons, Inc.
Early developmental change in bitter taste responses in human infants
Authors: Kajiura Hideaki , Cowart Beverly J. , Beauchamp Gary K. 
Published: January 2005

AbstractHuman newborns (birth–6 days) and older infants (14–180 days) were allowed to ingest both urea (0.12–0.24 M) in a mildly sweet diluent and the diluent alone, and multiple measures of responsivity were obtained (relative intake, sucking behavior, and hedonic ratings based on facial expressions and body movements). For newborns, there was no indication of rejection of urea relative to the diluent in measures of intake or sucking behavior; rather, their responses were predominantly controlled by the order of presentation of the two tastes. In contrast, older infants tended to reject all concentrations of urea according to these measures. Hedonic ratings provided an indication of limited rejection of the bitter taste by newborns, but older infants were still found to respond more consistently. These data suggest there is an early developmental change in bitter taste perception © 1992 John Wiley & Sons, Inc.
Behavioral and physiological response of juvenile sooty mangabeys to reunion with their mothers following a year's absence
Authors: Gust Deborah A. , Gordon Thomas P. , Brodie Annr R. , McClure Harold M. 
Published: January 2005

AbstractThe return of 6 juvenile manabey monkeys to their social group following an absence of a year resulted in increased basal cortisol secretion for both the offspring and the mothers and in significant decrements in the absolute number of lymphocyte subsets for the offspring. Six 9‐month‐old sooty mangabeys were removed from their socially housed mothers, subsequently peer housed, and returned to the maternal social group 1 year later. Offspring showed a significant increase in cortisol levels 24 hr following reunion (48 ± 6%) and this difference persisted through 1 month, while the mothers showed a significant increase only at the 24‐hr sample point (18 ± 3%). Moreover, the offspring, but not the mothers, showed a significant decrease in lymphocyte subsets which were evident through the 1‐month sample point. Behavioral data revealed a significant positive correlation between the percent of total scan samples offspring were with their mothers (proximity, contact, huddle) the day of return and the offspring's percent change from baseline in total T cells 24 hr later, r = 0.84. All mother‐offspring pairs with the exception of one exhibited frequent affiliative behaviors toward one another by 6 days following the return. These data demonstrate that the reunion of juvenile mangabeys with their mothers after a year's absence is an acute stressor for the mothers and a relatively longer term stressor for the offspring, and that behavioral interactions which characterize the return of individual subjects to the natal group can predict acute physiological responses. © 1992 Wiley & sons. Inc.
Ultrasonic vocalization responses of rat pups to acute separation and contact comfort do not depend on maternal thermal cues
Authors: Hofer Myron A. , Brunelli Susan A. , Shair Harry N. 
Published: January 2005

AbstractIn order to assess the importance of maternal thermal cues in controlling the acute USV responses of rat pups to contact with her body (the contact comfort response) and to separation from her, we drastically altered maternal temperature by inducing severe hypothermia so that maternal rectal and flank temperatures averaged more than 20°C below normal and 10°C below ambient levels during testing. Isolated 12‐ to 13‐day‐old pups showed reductions in USV when these cold dams were presented and brisk USV accelerations when the cold dams were removed from the test chamber. These responses closely resembled those of other pups tested with warm (36°C) anesthetized dams. No significant differences were found in pups' USV contact comfort responses to cold and warm dams. For acute separation, prior maternal thermal properties and other factors were found to modulate the relative intensity of the marked USV increase elicited by this event © 1993 John Wiley & Sons, Inc.
Individual differences in the visual attention of human infants: Further evidence for separate sensitization and habituation processes
Authors: Peterzell David H. 
Published: January 2005

AbstractHow many and what kinds of processes mediate infant visual attention? Are they influenced by stimulus “complexity?” Analyses were performed on visual fixation data from ninety 4‐month‐old infants; the time each infant spent looking at a black and white checkerboard pattern containing either 4 × 4, 12 × 12, or 20 × 20 checks per picture was measured for eight 10‐s trials, with 10‐s interstimulus intervals (Kaplan & Werner, 1986). Correlational and factor analyses revealed one significant source of individual variability (or factor) in the 4 × 4 data, and two significant sources in the 12 × 12 and 20 × 20 data. One factor gained strength over progressive trials and accounted for decreases in looking time. A second factor gained strength over the first few trials, then lost strength over the remaining trials, and accounted for initial increments in looking time. The two factors are consistent with a dual‐process model of infant response dynamics; the first may represent habituation, a decremental process, and the second may represent sensitization, an incremental process that is activated by “complex” stimuli. © 1993 John Wiley & Sons, Inc.
The ontogeny of ultrasonic vocalizations and other behaviors in male jimpy (jp/Y) Mice and their normal male littermates
Authors: Bolivar Valerie J. , Brown Richard E. 
Published: January 2005

AbstractJimpy (jp/Y) male mice have a sex‐linked mutation which results in dysmyelination throughout the CNS, causing tremors and behavioral abnormalities. These mice rarely live past 30 days of age. Due to the sex‐linked nature of this mutation, both jimpy and normal male pups occur within the same litter. We examined the early behavioral development of these mice by recording their motor behaviors, including slight movement, locomotion and grooming, and their ultrasonic vocalizations (UVs) at 2‐day intervals from 2‐20 days of age. Jimpy males weighed less than their normal littermates and reached developmental milestones at a later age. They produced fewer UVs than their normal male littermates from 2–8 days of age, after which UVs ceased almost completely in both groups of mice. Jimpy mice spent less time engaged in coordinated motor activities (locomotion and grooming) than normal littermates, and more time engaged in slight movement or remaining inactive. On three of the behavioral measures used (UV production, slight movement, and inactivity) differences were evident early in development (Day 2 postpartum), whereas differences on the other measures (locomotion, grooming) were not evident until later in the developmental period. Our results indicate the importance of using multiple behavioral measures when examining the functional effects of myelin deficiency.© 1994 John Wiley & Sons, Inc.
Learning of suckling odors by newborn rabbits declines with age and suckling experience
Authors: Kindermann Ute , Hudson Robyn , Distel Hans 
Published: January 2005

AbstractAfter being nursed just once for 4‐5 min by an artificially scented doe, newborn rabbits show the full pattern of nipple‐search behavior when placed on a fur scented with the same odor as their mother. It was the aim of the present study to test whether such rapid learning is dependent on age. In Experiment 1 in which normally raised pups were nursed by a scented doe either on Days 1, 3 or 5, conditionability was found to decline markedly by postnatal Day 5. In Experiment 2 conditionability was maintained in pups deprived of suckling experience by bottle feeding from Days 1–4, but not in hand‐raised pups allowed to search on a doe for 4 min daily without milk intake. Possible mechanisms underlying the decline in conditionability to suckling odors, as well as the potential functional significance of this early learning for immediate postnatal and later life are discussed.© 1994 John Wiley & Sons, Inc.
Intracerebroventricular injection of renin in the neonatal rat reveals a precocious sodium appetite that is dissociated from renin‐aroused thirst
Authors: Leshem Micah , Canho Sonia Del , Epstein Alan N. 
Published: January 2005

AbstractPrevious research on the ontogeny of sodium appetite in the rat has shown that sodium deficit first engenders sodium intake at 12 days of age, whereas direct stimulation of the brain renin—angiotensin system by intracranial injection of renin increases intake of NaCl solution as early as 3 days postnatally. Similar activation of brain angiotensin also increases thirst, so that the specificity of the precocious sodium intake remains undetermined. In this article we report experiments that dissociate neonatal renin‐evoked sodium appetite and thirst, and establish the specificity of the appetite. Our findings confirm that sodium appetite can first be discerned at 3 days of age, and show that it rapidly develops until 12 days of age. During this developmental window, renin‐evoked sodium appetite is dissociated from thirst because (a) NaCl is preferred to water, (b) the appetite develops faster than thirst, and (c) 3‐day‐old renin‐stimulated pups will avidly lick dry NaCl. These results show that activation of brain angiotensin in the 3‐day‐old rat pup evokes a precocious and specific sodium appetite.© 1994 John Wiley & Sons, Inc.
An observational study comparing continuous subcutaneous insulin infusion (CSII) and insulin glargine in children with type 1 diabetes
Authors: Schiaffini Riccardo , Ciampalini Paolo , Spera Sabrina , Cappa Marco , Crinó Antonino 
Published: January 2005

AbstractObjectiveThe advantages of continuous subcutaneous insulin infusion (CSII) or insulin glargine have been demonstrated both in adult and paediatric diabetic patients; however, as no data comparing these two approaches during childhood are available, we have examined the efficacy of these two intensive approaches.Research Design and MethodsWe retrospectively evaluated data from 36 diabetic children, who had changed their previous insulin regimen [with isophane insulin (NPH) at bedtime] because of HbA1c levels >8.0%. Twenty patients underwent CSII, while the other 16 (significantly younger for age) started insulin glargine at bedtime.ResultsAt 6 and 12 months, CSII‐treated patients showed a significant reduction in HbA1c values from 8.5 ± 1.8 to 7.4 ± 1.1% and to 7.6 ± 1.2%, respectively. The insulin requirement significantly decreased from 0.93 ± 0.2 IU/kg to 0.73 ± 0.2 IU/kg of body weight and to 0.74 ± 0.15 IU/kg of body weight, respectively, while no significant differences were observed for BMI SDS, fructosamine and severe hypoglycaemic events. The patients treated with glargine showed a small decline in HbA1c values from 8.9 ± 1.7 to 8.3 ± 0.9% (not significant) in the first 6 months of treatment and to 8.2 ± 0.9% after 12 months.ConclusionThe basal insulin supplementation can be supplied effectively in children with type 1 diabetes by either CSII or insulin glargine. As previously reported for adults, it is confirmed that CSII is the best current intensive approach aimed to the improvement of glycaemic control. Copyright © 2004 John Wiley & Sons, Ltd.
Ion channel expression by white matter glia: I. Type 2 astrocytes and oligodendrocytes
Authors: Barres Barbara A. , Chun Linda L. Y. , Corey David P. 
Published: January 2005

AbstractWhite matter is a compact structure consisting primarily of neuronal axons and glial cells. As in other parts of the nervous system, the function of glial cells in white matter is poorly understood. We have explored the electrophysiological properties of two types of glial cells found predominantly in white matter: type 2 astrocytes and oligodendrocytes. Whole‐cells and single‐channel patch‐clamp techniques were used to study these cell types in postnatal rat optic nerve cultures prepared according to the procedures of Raff et al. (Nature, 303:390–390, 1983b). Type 2 astrocytes in culture exhibit a “neuronal” channel phenotype, expressing at least six distinct ion channel types. With whole‐cell recording we observed three inward currents: a voltage‐sensitive sodium current qualitatively similar to that found in neurons and both transient and sustained calcium currents. In addition, type 2 astrocytes had two components of outward current: a delayed potassium current which activated at 0 mV and an inactivating calcium‐dependent potassium current which activated at −30 mV. Type 2 astrocytes in culture could be induced to fire single regenerative potentials in response to injections of depolarizing current. Single‐channel recording demonstrated the presence of an outwardly rectifying chloride channel in both type 2 astrocytes and oligodendrocytes, but this channel could only be observed in excised patches. Oligodendrocytes expressed only one other current: an inwardly rectifying potassium current that is mediated by 30‐ and 120‐pS channels. Because these channels preferentially conduct potassium from outside to inside the cell, and because they are open at the resting potential of the cell, they would be appropriate for removing potassium from the extracellular space; thus it is proposed that oligodendrocytes, besides myelinating axons, play an important role in potassium regulation in white matter. The conductances present in oligodendrocytes suggest a “modulated Boyle and Conway mechanism” of potassium accumulation.
Increased glial fibrillary acidic protein synthesis in astrocytes during retrograde reaction of the rat facial nucleus
Authors: Tetzlaff W. , Graeber M. B. , Bisby M. A. , Kreutzberg G. W. 
Published: January 2005

AbstractGlial fibrillary acidic protein (GFAP) increases in astrocytes following axotomy of facial motoneurons. In the present study we quantified GFAP synthesis both in regenerating facial nuclei after nerve crush and in nonregenerating facial nuclei after nerve resection. An increase in GFAP synthesis during regeneration occurs as early as 24 h after the axotomy. Thus, the increase in the astrocytic GFAP synthesis seems to be the earliest glial response to retrograde changes in facial motoneurons.
Expression of the 2′,3′‐cyclic nucleotide 3′‐phosphohydrolase gene and immunoreactive protein in oligodendrocytes as revealed by in situ hybridization and immunofluorescence
Authors: Vogel U. S. , Reynolds R. , Thompson R. J. , Wilkin G. P. 
Published: January 2005

AbstractIn order to investigate the role of the myelin‐associated enzyme 2′ 3′‐cyclic nucleotide 3′‐phosphohydrolase in the development of the myelin sheath, as well as genetic factors involving dysmyelinating disorders, we have recently isolated and sequenced cDNAs corresponding to the CNPase protein. In this study we have used 32P‐labeled bovine CNPase cDNA probes to localize the messenger RNA coding for this enzyme in mouse cerebral and cerebellar cryostat sections and have compared our data with the distribution of the CNPase protein as revealed by immunofluorescence. Specific labeling was localized to the white matter fiber tracts and, in many areas, to individual oligodendrocyte cell bodies. The corpus callosum and the white matter of the cerebellum were heavily labeled. Distribution of the CNPase protein, as detected by immunohistochemical studies, was parallel to that of the CNPase mRNA as detected by in situ hybridization histochemistry, with oligodendrocyte cell bodies and their processes intensely labeled. This study provides strong evidence that the CNPase gene is expressed in the myelin‐producing cells of the central nervous system and that CNPase is synthesized by and stored within oligodendrocytes.
Ultrastructural study of phagocytic activities of young astrocytes in injured neonatal rat brain following intracerebral injection of colloidal carbon
Authors: Al‐Ali Saad Y. , Al‐Zuhair Ali G. H. , Dawod Bassam 
Published: January 2005

AbstractThe cellular reaction to injury in the mature central nervous system (CNS) has been extensively studied in both man and animals, while a detailed study of the reaction of the immature CNS to injury is lacking in the literature. This study was undertaken to elucidate the response of young astrocytes following injection injury to developing brain. Colloidal carbon was applied because it is a suitable markers for phagocytosis, it is nontoxic, and it is readily identifiable by light and electron microscopy. The cerebral cortex of the neonatal rat was injected with 0.1 μl of colloidal carbon solution. The animals were allowed to survive from 1 hour to 30 days postoperation. The brains were fixed by vascular perfusion and processed for light and electron microscopy. Carbon particles were ingested in membrane‐bound vacuoles and sequestered in lysosomes of young astrocytes. Astrocytes, loaded with carbon particles, were identified after 4 days, and were seen in abundance between 10 to 21 days postoperation. Carbon‐laden astrocytes were seen in the immediate vicinity of the site of the injection; in the surrounding, apparently normal, neuropil; and in the perivascular regions. This study demonstrates the ability of young astrocytes to engulf foreign particles injected into the developing brain. The presence of carbon particles in astrocytes located further away from the site of injection is discussed.
Relations between slow extracellular potential changes, glial potassium buffering, and electrolyte and cellular volume changes during neuronal hyperactivity in cat brain
Authors: Dietzel I. , Heinemann U. , Lux H.D. 
Published: January 2005

AbstractThe aim of this investigation is to estimate the contribution of spatial glial K+ buffer currents to extracellular K+ homeostasis during enhanced neuronal activity. Neuronal hyperactivity was induced by electrical stimulation of the cortical surface or the ventrobasal thalamic nuclei of cats (5–50 Hz, 0.1–0.2 ms, two to three times threshold stimulation intensity, 5–20 s). The accompanying slow field potential changes were recorded simultaneously across the grey matter with vertical assemblies of eight micropipettes glued 300 μm apart. Using the Poisson equation, the amplitudes of the underlying current sources and sinks were calculated. The current source densities depended on the depth of recording, frequency, strength, and duration of the stimulation. Current sinks, corresponding to a removal of 0.1–0.5 mmoles of monovalent cations per liter of brain tissue and second from the extracellular space, were observed in middle cortical layers, whereas sources appeared at superficial and deeper sites. These sinks and sources might represent K+ moved across glial membranes by spatial buffer currents. The consequences of glial buffer currents of this magnitude were investigated with model calculations. It turned out that measurements of electrolyte and volume changes of the extracellular space (Dietzel et al. Exp. Brain Res. 40:432–439, 1980; Exp. Brain Res. 46:73–84, 1982) could only partially be explained by spatial buffer currents of this magnitude. Comparison of the calculated values with intracellular measurements in neurons and glial cells (Coles et al. Ann. N.Y. Acad. Sci. 481:303–317, 1986; Ballanyi et al. J. Physiol. 382:159–174, 1987) suggests that spatial buffering combines with an approximately equimolar KCl transport and, depending on the preparation, also K+/Na+‐exchange across glial membranes.
Vimentin: Changes in distribution during brain development
Authors: Hutchins James B. , Casagrande Vivien A. 
Published: January 2005

AbstractThis paper examines both the anatomical changes in the distribution of vimentin intermediate filament protein and the biochemical changes in vimentin and its degradative enzyme during postnatal brain development in the tree shrew (Tupaia belangeri).A pattern of multiple immunoreactive bands at birth (postnatal day 0, or P0) was revealed in nitrocellulose blots of polyacrylamide gels (“Western blots”). These multiple bands gradually disappear during development, and in the adult a single band at the published molecular weight for vimentin (57 kD) is seen. This pattern of bands probably reflects shifts in the activity of a calcium‐activated vimentin protease.The changes in the anatomical distribution of vimentin‐immunoreactive (vimentin+) cells and their fine processes parallel the biochemical shifts seen in immunoblots. We have examined the neocortex, lateral geniculate nucleus (LGN), and hippocampus in detail.During the first postnatal week, vimentin+ glia, especially radial glia, are prominent in both neocortex and hippocampus. In contrast, only a few vimentin+ radial glia remain in the thalamus at this age. Vimentin+ glia appear to coincide with bundles of axons and often seem to outline subdivisions of thalamic nuclei. Additionally, cellular layers of the lateral geniculate nucleus (LGN) appear to stain with antibodies to vimentin several days before the characteristic neuronal cell layers appear in this area.During the second postnatal week, vimentin+ cells appear in “patches” throughout the cortex. Some subdivisions of the thalamus and hippocampus (as defined by cytoarchitectonic differences in the adult) are distinct when the tissue is stained with an antibody to vimentin, even though a conventional Nissl stain at this age shows no apparent delineation in these same regions. Finally, in the adult, only a few vimentin+ cells remain, primarily in the white matter.Taken together, these results suggest that the remodeling of vimentin+ intermediate filaments in immature glial cells (including radial glia) is paralleled by the action of the enzyme which breaks down these filaments. The apparent activity of this enzyme is high early in development as radial and other glia are rapidly dividing and undergoing morphological changes, with a decrease in activity in the juvenile and adult brain, as immature glial cells are supplanted by mature forms.