bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elevated catecholamines in thirty‐day‐old chicken brain after depletion during development
Authors: Sparber Sheldon B. , Shideman Frederick E. 
Published: January 2005

AbstractThe effects of prenatal reserpine administration upon uptake of tritiated norepinephrine (H3‐NE) by newly hatched chick brain suggests an interference of catecholamine (CA) uptake and/or binding. The relationship between fluorescence from CA and the radioactivity from H3‐NE approached unity in the control group where no such relation was seen in the reserpine treated group. Moreover, 30 days after hatching, CA levels in whole brain of chicks hatched from drug‐injected eggs were significantly higher than vehicle‐injected controls. However, reserpine did cause a slight but significant elevation of total protein in 14‐day‐old embryo brain. These data support the hypothesis that ontogenetic alteration of systems exhibiting end‐product inhibition can be of a long‐lasting, perhaps permanent nature. The direction of change in CA 30 days after hatching, opposite to the change induced pharmacologically during development, is additional support for the concept of „thermostat”︁ type regulation of enzyme activity being determined by product concentration at critical periods during development.
Interaction of genotype and environment as determinants of corticosteroid response to stress
Authors: Treiman David M. , Fulker D. W. , Levine Seymour 
Published: January 2005

AbstractThe temporal pattern of plasma corticosterone concentrations following electric shock was studied in 10‐week old mice from two inbred strains (C57BL/10J and DBA/2) and their reciprocal crosses, half of which had been subjected to infantile stimulation. The roles of genotype, maternal factors, and handling were assessed as determinants of corticosteroid response to stress. Highly significant and opposing genetic and maternal effects interacted to limit extreme plasma corticosterone concentrations following stress. Infantile stimulation also acted to produce intermediate steroid responses.
Development of cortical spreading depression and of its transition to the caudate nucleus in rats
Authors: De Luca Bruno , Bureš Jan 
Published: January 2005

AbstractThe development of Leão's spreading depression (SD) of electroencephalographic activity was studied in young rats by recording the accompanying slow potential changes (SPC). The propagation rate of cortical SD increased from 1.65 mm/min on Day 15 to 2.6 mm/min on Day 20; the increase of SPC amplitude and the decrease of SPC duration were less evident over the same period. The SD elicited in the caudate nucleus by microinjections of KCl did not spread to neocortex in 20‐ and 30‐day‐old rats and transition occurred in only 5% of KCl applications in 40‐day‐old rats. Application of a pyrrolopyrimidine derivative (BW 57–271; 5 mg/kg) increased the cortico‐caudate SD transition to 100% in rats aged 20 days or older and increased the SPC amplitude in both structures. The development of SD parameters can be ascribed to dendritic growth and to the decrease of extracellular space; the cortico‐caudate propagation block can be ascribed to morphological immaturity of the transitional zone.
Interactive effects of parity and pup stress on the maternal behavior of Rattus norvegicus
Authors: Wright Linda L. , Bell Robert W. , Schreiber Henry L. , Villescas Ramiro , Conely Lynn 
Published: January 2005

AbstractLitters of primiparous and multiparous rat mothers received 0, 2, or 5 min of cold stress for the 1st 5 days postpartum. Primiparae showed increasing maternal responsiveness over the treatment period. Multiparae were initially maternally responsive to moderate stress cues from pups, but habituated to them over days. From Days 6 to 20, when pups were not stressed, lactation behavior of stressed groups declined in primiparous mothers but not in multiparous mothers.
Ontogenetic changes in pup‐elicited maternal pituitary‐adrenal activity: Pup age and stage of lactation effects
Authors: Smotherman William P. , Mendoza Sally P. , Levine Seymour 
Published: January 2005

AbstractOntogenetic changes in pup‐elicited maternal corticosterone responsiveness were investigated. Patterns of maternal corticosterone change were found to depend on pup treatment: shocked pups elicited larger corticosterone elevations than pups that had been handled. In addition, both the age of the stimulus pups and the stage of lactation when the mother was tested affected the pattern and magnitude of maternal pituitary‐adrenal activity.
Olfactory discrimination of squirrel monkey mothers by their infants
Authors: Kaplan Joel N. , Cubicciotti Daniel , Redican William K. 
Published: January 2005

AbstractInfant squirrel monkeys, 8 to 24 weeks of age, were tested for their ability to discriminate their own mother from another lactating mother by means of olfactory cues, visual cues, or a combination of both. Discrimination by olfactory cues was unequivocal. Addition of static visual cues did not enhance discrimination, and infants showed little evidence of discriminating the mother by means of static visual cues alone. These results suggest that olfaction may be a more significant factor in primate early attachment than has generally been assumed.
Vocal output in preterm infants
Authors: Beckwith Leila , Sigman Marian , Cohen Sarale E. , Parmelee Arthur H. 
Published: January 2005

AbstractData on vocal output of 51 preterm infants and 16 term infants were obtained during naturalistic home observations ast 1, 3, and 8 months; during the administration of a preference‐for‐novelty paradigm in the laboratory at 8 months; and by the administration of the Gesell Developmental Schedules at 9 months. Preterm and term infant groups were found to show both similarities and differences: both groups vocalized a similar amount in the preference‐for‐novelty situation; both groups earned similar scores on the language subtest of the Gesell; both groups increased and percentage of awake time they spent in nondistress vocalization from 1 to 8 months. Term infants showed an earlier increase than did preterm infants: term infants significantly increased during the 1–3‐month period, whereas preterm infants only increased significantly during the 3–8‐month period. The developmental differences suggest a link between vocal output and perinatal conditions in that caregiver behavior was not found to be different among groups. Within the preterm groups, some relationships were found between vocal output and later test performance: infants who vocalized more during mutual gazing with the mother earned significantly higher scores on the language subtest of the Gesell.
Acquisition and retention of a passive‐avoidance task as a function of age in mice
Authors: Nagy Z. Michael , Thaller Karen , Mazzaferri Timothy A. 
Published: January 2005

AbstractIn Experiment I groups of mice between 16 to 100 days of age were tested for retention of a passive‐avoidance response between 1 min and 96 hr following a single training trial at 2 shock intensities. In general, although almost all age groups displayed reliable retention at all retest intervals, some retention losses were found among the youngest age groups at the longer retention intervals. Higher shock intensity resulted in longer retest latencies, primarily among the youngest mice. In Experiment II mice 16, 25, and 100 days of age were trained to criterion on the passive‐avoidance task and retested on a single trial following retention intervals of 24, 96, 192, and 384 hr. Young mice exhibited severe retention losses relative to 100‐day‐old mice at the longer intervals, even though they did not show deficiencies in acquisition. Neurological maturity at the time of original training appears to account for the age‐related memory differences.
Ultrasound by mouse pups from deaf and hearing strains
Authors: Verhaeghe Arlette , Noirot Eliane 
Published: January 2005

AbstractPups aged 1 to 10 days, of deaf and hearing mouse strains, were monitored with an ultrasound detector while submitted to standard conditions of cold, isolation, and retrieving. The number of detections varied with the age of the pups and with the type of treatment (as established previously) but not with the genotype of the pups. Thus, occurrence and changes with age in ultrasound emission do not seem to be greatly influenced by their effects upon adult behavior.
Relative aversion thresholds for shock in infant mice
Authors: Michael Nagy Z. , Murphy James M. , Ray Donald 
Published: January 2005

AbstractUsing a spatial‐preference technique, we tested separate groups of mice, 5, 7, 9, 11, 13, and 15 days of age, for escape and avoidance of a range of shock intensities administered from AC constant current and fixed impedance shock sources. With intensities ranging from 0 to .2 mA and to 70 V for the respective sources, near asymptotic escape and avoidance were obtained at .1 mA and at 50 V for all ages tested. Although few differences in the relative aversiveness of particular shock intensities were noted across ages with each source, the fixed impedance source produced more consistent avoidance than did the constant current source. The findings suggest that the motivational properties of shock remain relatively constant throughout the early development of the mouse and that the technique employed in this study should prove useful in assessing possible age‐related alterations in sensitivity to shock as a result of physiological or pharmacological manipulations.
S‐100 protein: Regional CNS concentrations in rats raised in different environments
Authors: Perez Vernon J. , Thach Barbara B. , Palet James L. 
Published: January 2005

AbstractThe S‐100 protein was measured in 7 discrete brain areas from rats raised in an enriched, social, or isolated environment for 21, 42, or 84 days after weaning. S‐100 was measured at significantly higher concentrations under enriched than under social environmental conditions in cerebellum and brainstem at 21 days but not thereafter. The protein in corresponding areas of brain in isolates was significantly less concentrated than in social controls. The results suggest changes, in turnover of the protein as a result of stimulation and activation of functionally specific brain regions, of the animals' responses to and interaction with environmental stimuli and adaptation to those stimuli.
A neuropharmacological analysis of central nervous system catecholamine systems in developmental protein malnutrition
Authors: Leahy J. P. , Stern W. C. , Resnick O. , Morgane P. J. 
Published: January 2005

AbstractFour experiments were performed to evaluate the effects of developmental protein deprivation on the behavioral response of adult rats to treatments known to affect central nervous system catecholamine systems. Results showed no group differences between protein malnourished and control animals in locomotor responsiveness to d‐ or l‐amphetamine, recovery from behavioral asymmetry produced by a unilateral lesion of the substantia nigra, or in the development of response patterns indicative of denervation supersensitivity. However, a dose‐dependent diminution in the ability of apomorphine to produce stereotyped behavior was noted in the malnourished group, suggesting that a class of brain dopamine receptors may be impaired or may have undergone homeostatic modification as a result of the undernutrition procedure.
Behavioral effects of neonatal thyroid hormones and differential postweaning rearing in rats
Authors: Sjödén Per‐Olow , Lindqvist Mats 
Published: January 2005

AbstractMale and female rats (T rats) given an injection of 75 μg tri‐iodothyronine (T3) and 25 μg thyroxine (T4) on Day 3 after birth were raised under enriched (E) and impoverished (I) postweaning conditions. Observations of their open‐field behavior on Days 63 and 112 revealed a higher rate of activity in T groups as compared to controls (C) as well as faster running times and more entries/min in Hebb‐Williams maze testing on Days 74–86, indicating behavioral hyperactivity in T rats. Active‐avoidance testing at age 91 days revealed a higher number of intertrial crossings and significantly faster unconditioned response and conditioned response latencies in T as compared to C groups. Enriched postweaning rearing altered the behavioral effects in T rats comparatively little, least in the open‐field and more so for escape‐ and avoidance‐latencies and for the number of errors in the Hebb‐Williams maze.
Exploration in immature rats: Effects of drugs
Authors: File Sandra E. 
Published: January 2005

AbstractThe effects of d‐amphetamine (4 mg/kg), scopolamine (1 mg/kg), methylscopolamine (1 mg/kg), and parachlorophenylalanine (400 mg/kg) on exploration were studied in male rats at 16, 21, and 28 days of age. Amphetamine elicited stereotypy at all ages tested, reduced exploration (measured by the time spent head‐dipping during a 10‐min trial in a holeboard) from Day 21, but did not significantly increase rearing at the ages tested. (Reduced head‐dipping, accompanied by stereotypy, is the pattern of results previously seen in adult rats with this dose of amphetamine.) An interesting difference emerged with scopolamine, which reduced head‐dipping at all the ages tested, whereas in adults it produced an increase. The age‐related difference in drug effects suggests that muscarinic pathways are functioning from Day 16, but that the system concerned with exploration functions differently in mature and immature rats. Both scopolamine and methylscopolamine reduced rearing which suggests that the change is due to peripheral actions of the drugs. Parachlorophenylalanine, which decreases serotonin levels, increased head‐dipping, as it has been found to do in adult rats.
Influence of age and short‐term starvation on the ATPase activity in the developing rat brain
Authors: Mourek J. , Šťastný F. 
Published: January 2005

AbstractNa+‐K+‐stimulated and Mg++‐dependent ATPase activities were investigated in the developing cerebral cortex, subcortical structures, and medulla oblongata of rats as was the effect of 24‐hr lasting starvation and thirst on those enzyme activities. We found (a) a developmental increase of these ATPase activities in the developing rat brain with the maximum in the cerebral cortex and with the minimum in the medulla oblongata; (b) a decrease of the ratio of these enzyme activities, which was near unity in adult animals; (c) an increase of ATPase activities in the cerebral cortex and subcortical formations of young rats under starvation conditions followed by a decrease of the Mg++/Na+‐K+‐ATPase activity ratios in these structures; and (d) a decrease of these activities, especially in the cerebral cortex, and an increase of the activity ratios in adult animals under starvation conditions.
Early selective visual experience and pattern discrimination in hooded rats
Authors: Corrigan James G. , Carpenter David L. 
Published: January 2005

AbstractThe early visual experience of hooded rats was restricted to either vertical or horizontal stripes. In a discrimination task pairing a gray surface and stripes of either the same orientation or an orientation orthogonal to that experienced during rearing, the rats made significantly fewer correct choices with the orthogonal orientation. However, the relatively lower overall performance of the vertically reared‐horizontally tested animals was a major factor in the main effect of testing condition. We conclude that functional modification of the rat visual system through early selective visual experience is possible.
Failure of severe maternal stress or ACTH during pregnancy to affect emotionality of male rat offspring: Implications of litter effects for prenatal studies
Authors: Chapman Robert H. , Stern Judith M. 
Published: January 2005

AbstractDaily maternal neck restraint, whole body restraint, hyperthermia, and ACTH treatment during the last 3rd of gestation had no reliable effect on open‐field and cage‐emergence behavior in male Sprague‐Dawley offspring. Many of these treatments, however, produced considerable maternal pathology and evidence for maternal adrenocorticoid release. Significant litter effects were found for almost every morphological and behavioral measure. Failure to control for the litter variable may account for many previously reported effects of prenatal stress on emotionality in rats. Female rats showed greater activity and less defecation than males on postpubertal open‐field and cage‐emergence tests.
Parental environment: Effects on survival, growth and aggressive behaviors of 2 rodent species
Authors: McCarty Richard , Southwick Charles H. 
Published: January 2005

AbstractThe influence of the parental environment on the development of aggressive behaviors was studied in 2 muroid rodent species. Litters of southern grasshopper mice and northern white‐footed mice were reared by the natural parents or were reciprocally cross‐fostered soon after birth to parents of the opposite species. After weaning at 24–26 days, mice of both species were isolated and observed at 10‐day intervals from 30 to 100 days of age in one of the following tests: (1) predation on house crickets; (2) interspecific aggression toward Swiss‐Webster laboratory mice; and (3) intraspecific aggression toward opponents of the same gender and approximate age. Naturally reared grasshopper mice males and females displayed extremely high levels of aggressive and predatory behaviors whereas white‐footed mice controls were passive and defensive in all tests. Rearing by white‐footed mice foster parents resulted in a significant decrease in the aggression of grasshopper mice males and females toward laboratory mice. During intraspecific encounters, fostered grasshopper mice initiated fewer social interactions than naturally reared controls. The predatory behavior of grasshopper mice was not altered by the fostering procedure. The behavioral measures of fostered white‐footed mice showed no systematic changes when compared to controls. These results indicate that the postnatal parental environment contributes to the naturally high levels of aggressive behaviors of grasshopper mice. In contrast, the limited aggressive behaviors of a naturally passive species, white‐footed mice, were not increased by fostering at birth to parents of a highly aggressive species, grasshopper mice.
Ontogenesis of human brainstem evoked potential amplitude
Authors: Salamy A. , Fenn C. Birtley , Bronshvag M. 
Published: January 2005

AbstractBrainstem evoked potentials (BEP's) were studied in human subjects ranging in age from birth to adulthood.The BEP's were recorded from the surface of the scalp referenced to either ear while brief clicks were delivered binaurally through earphones. Separate analyses of variance were computed for the peak‐to‐peak amplitude of each component of the BEP. Significant age effects were observed documenting the strong relationship between human brainstem development and amplitude changes in the BEP. The independent maturation of these structures was reflected by the significant interaction between age and peaks. Despite small fluctuations in the maturational curve of each peak, strong linear and quadratic trends were apparent.The research presented here provides evidence of significant amplitude changes in the BEP accompanying human development. These findings indicate that brainstem maturation is not yet complete at birth and that the components believed to represent spatially separate generators in the auditory system show distinct maturational stages.
Early experience facilitates the development of temperature regulation in the cat
Authors: Jensen Robert A. , Davis Joel L. , Shnerson Allan 
Published: January 2005

AbstractThirty kittens were given a 30‐min exposure to a moderately cool environment and drop in body temperature was measured. One group was tested every day from age 2 days to 21 days of age. A 2nd group was tested on Days 6–21 and a 3rd group tested only at 19 days of age. The 1st group (tested on Days 2–21) became homeothermic at an earlier age than did the other groups. The data are interpreted to indicate that early exposure to cool temperatures facilitates acquisition of temperature regulation in the cat, and that observed deficits in passive avoidance learning in young cats are not due to increased motor activity produced by a fall in body temperature.
Effects of number of pre‐exposures on sucrose taste aversion in weanling rats
Authors: Franchina Joseph J. , Domato Gary C. , Patsiokas Ann T. , Alan Griesemer H. Alan 
Published: January 2005

AbstractWeanling rats, 20 days old, received 0, 1, 2, 4, or 8 pre‐exposures to 12% sucrose prior to a single pairing of sucrose with an intraperitoneal injection of lithium chloride (LiCl; 3.0 mEq of a .15Msolution) or distilled water (20 mg/kg). Testing for sucrose taste aversion with a 2‐bottle‐choice procedure on 9 test trials reliably showed that increasing numbers of pre‐exposures to sucrose directly attenuated taste aversion effects in the LiCl‐injected groups but did not appreciably affect intake performance in the distilled water‐injected groups. Comparisons between the injection conditions yielded reliable evidence for sucrose taste aversion at each pre‐exposure level. These results show that flavor stimulus pre‐exposures reliably attenuate subsequent taste aversion in weanling rats as had previously been reported for adult rats.
Alterations in the maternal behavior of rats rearing hypothyroid and hyperthyroid offspring
Authors: Johanson Ingrid B. 
Published: January 2005

AbstractTo determine whether maternal behavior could serve as a mediator for thyroid hormone effects on behavior, I assessed nesting, nursing, grooming, contact, and retrieval in mothers of hypothyroid, hyperthyroid, and control litters, as well as in mothers of litters receiving thyroxine replacement therapy. Females assigned to the hypothyroid and replacement therapy treatments were placed on a goitrogenic diet of 2% propylthiouracil from Day 15 of gestation to Day 22 postpartum. Hyperthyroid and replacement therapy pups were injected daily with thyroxine starting on the day of birth. The decline in nesting and nursing was delayed in hypothyroid litters whereas the decline in nesting was accelerated in hyperthyroid litters. Retrieval was not affected, but grooming of pups occurred less frequently in hypothyroid and replacement therapy litters. Maternal care received by hypothyroid pups was considered adequate. Maternal behavior may alleviate some of the effects of perinatal hypothyroidism, but does not seem to be responsible for the more severe effects of hypothyroidism.
Pathways between constitution and competence during the 1st 5 years of life
Authors: Inoff Gale E. , Halverson Charles F. , Allen Martin G. , Cohen Donald J. 
Published: January 2005

AbstractA global measure of newborn constitutional adequacy was found to be positively related to competent functioning at the age of 5–6 years. In a sample of 15 boys and 5 girls, newborn constitutional adequacy was related to aspects of focused (versus unfocused) activity, outgoingness, cognitive and verbal ability, and motor skill at the early childhood follow‐up. Additionally, some preschool data were available on most of the sample and continuity of competent functioning was traced across the 3 age periods. Also, hyperactive behaviors at the preschool period had negative implications for functioning in early childhood.