bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of d‐amphetamine sulfate given to pregnant mice on activity and on catecholamines in the brains of offspring
Authors: Middaugh Lawrence D. , Blackwell L. Ann , Santos Carroll A. , Zemp John W. 
Published: January 2005

AbstractOffspring of C57BL/6J mice injected with d‐amphetamine sulfate during the last third of pregnancy had slightly reduced body weight at birth, altered concentrations of catecholamines (CA's) in their brains during development, and increased activity after they had matured. Norepinephrine concentrations were depressed at birth, returned to control values by Day 3, and were elevated at 21 and 30 days after birth. Dopamine values were elevated at 30 days after birth. At 75 days of age, animals prenatally exposed to the drug had CA concentrations similar to controls, but had heightened activity levels compared to controls tested in the open field. The results of these experiments demonstrate that d‐amphetamine sulfate administered to mice during the last third of pregnancy produce transient alterations in CA concentrations and long‐lasting changes in behavior.
A comparison of live and videorecord viewing of infant behavior under sound stimulation. I. Neonates
Authors: Bench John , Hoffman Eric , Wilson Ian 
Published: January 2005

AbstractTwelve clinically normal neonates were presented with a battery of sound stimuli while their behavior was assessed live by 2 sound‐masked observers and simultaneously videorecorded. This procedure was performed for the baby's whole body aspect and also for the head aspect only in a 31/2X “close‐up”. Later, the same observers assessed the behavior from the videorecords. In both situations, observers were permitted to see the babies for 10 sec at each trial. The first 5 sec was a prestimulus observation period and the second 5 sec usually contained a sound stimulus. Between trials the observers were allowed 20 sec in which to note (1) prestimulus activity; (2) confidence in response; and (3) facial, digit, and limb movements and “wholistic” impressions (e.g., “stilling”). The agreement between live and video assessments was slightly better than the level of interobserver agreement (Pearson's contingency coefficients). The use of videorecording caused, at most, slight losses of relevant information and, apparently, did not generally distort the findings.
Interaction of environment and injections on brain weight in rats
Authors: Eterović Vesna A. , Ferchmin Pedro A. 
Published: January 2005

AbstractRats exposed to environmental complexity (EC) for 4 days had heavier cerebra than controls maintained in an impoverished condition (IC). Such a difference did not occur when the EC‐IC pairs were given a subcutaneous injection of distilled water or an intracranial injection of saline on the 3rd day of treatment. Injecting animals in psycho‐biochemical experiments is therefore a procedure whose effects should be determined in every case.
Presurgical dietary history and the behavior of control and septal lesioned rats
Authors: Donovick Peter J. , Burright Richard G. , Bentsen Ellen O. 
Published: January 2005

AbstractRats reared under dietary enrichment or standard diet from 25 days of age underwent septal or control surgery 2 months later. Enrichment differentially altered septal or control behavior as measured by: exploration tests; fluid consumption of water, saccharin, and quinine; and the acquisition of an active avoidance task.
Developmental and genetic variables in mouse startle response habituation
Authors: Groswald Douglas E. , Luttges Marvin W. 
Published: January 2005

AbstractA behavioral task insensitive to inherent sensory and motor limitations, specifically a startle response habituation technique, was used to investigate genetic (strains) and developmental (age) effects on behavior. All mice tested using two procedures exhibited evidence for habituation which was dependent on strain, age, and length of the testing process. Exploitation of this simple technique may permit clarification of more complex types of behavior.
Effects of differential rearing condition on heart rate conditioning and response suppression
Authors: Caul William F. , Freeman Betty Jo , Buchanan Denton C. 
Published: January 2005

AbstractRats were reared in either an enriched or isolated environment for 60 days following weaning. Neither rearing environment nor sex affected heart rate conditioning. However, when the CS used during conditioning was subsequently presented in a drinking situation, males reared in isolation showed a greater degree of response suppression than did similarly reared females. Males and females reared in the enriched environment did not differ in degree of response suppression.
Effect of atropine on behavioral arousal in the developing rat
Authors: Blozovski Denise , Bachevalier Jocelyne 
Published: January 2005

AbstractA tropine‐induced changes in behavioral arousal were examined in the developing rat between 21 and 40 days of age using a single exploratory trial on an elevated T‐maze. Under atropine (10 mg/kg, i.p.) spontaneous activity as measured by numbers of errors, rearing responses, and stereotyped responses was significantly decreased in animals less than 25 days of age. It was significantly increased, however, between 26 and 30 days, with maximal action on the 28th day. After 30 days the effect of atropine was negligible. These results support the hypothesis of a cholinergic inhibitory mechanism controlling behavioral arousal and becoming efficient after the 25th day of life.
Comparative ontogenetic features of skeletal muscles in physiologically mature and immature mammals
Authors: Arshavsky I. A. , Darinsky N. V. , Li L. A. , Siryk L. A. 
Published: January 2005

AbstractOne series of experiments investigated the time required by such indices of the states of skeletal muscles as membrane potential (MP), action potential (AP), and content of total protein and dense residue to acquire values approximating those found in adults. We established that these indices acquire values approximating those found in adults at the beginning of sexual maturation in both rats and dogs. Chronologically, these values require one‐fifth the time to become established in rats as they do in dogs. Another series of experiments investigated the same indices in physiologically mature and immature organisms (rats and dogs). We established that they are much lower in immature than in mature organisms. We conclude that under conditions of natural development the main objects of elimination through natural selection in early developmental periods are physiologically immature organisms.
Neurological organization and visual fixation in infants at 40 weeks conceptional age
Authors: Kopp Claire B. , Sigman Marian , Parmelee Arthur H. , Jeffrey Wendell E. 
Published: January 2005

AbstractNeurological organization and visual fixation were found to be unrelated in a group of premature infants tested at their term date. These results are discrepant with those obtained with a sample of full term infants. Separate comparisons made of the neurological and fixation data revealed one significant group difference from the fixation data; all other analyses were nonsignificant. The discrepant findings may have occurred because prematures are subject to developmental disparities in the regulation of arousal, neuromuscular, and visual systems due to differential impact of preterm extrauterine life.
Looking behavior in monkeys raised with mobile and stationary artificial mothers
Authors: Eastman Robert F. , Mason William A. 
Published: January 2005

AbstractRhesus monkeys raised with mechanically driven mobile artificial mothers for the first 10 months of life looked more at other animals and were more sensitive to stimulus differences than monkeys raised on stationary surrogates. Both groups looked less and were not as discriminating as wild‐born monkeys. The results are consistent with other evidence suggesting that one of the long‐range consequences of maternal mobility is to reduce emotional responsiveness to novel situations.
Acquisition and retention of an avoidance response by rats of different ages
Authors: McLaughlin Lynn J. , Eller Harold D. , Korol Bernard 
Published: January 2005

AbstractRats, 21, 120, and 480 days of age, were given acquisition training in a 1‐way avoidance task and tested for retention of the response 1 and 30 days later. Whereas the 480‐day‐old rats showed poorer performance during acquisition, the 21‐day‐old rats showed the greatest impairment of long term retention. The results suggest that age differences in performance are due to intrinsic maturational processes.
Variability of the effects of rearing in a large litter on the development of the rat
Authors: Galler Janina R. , Turkewitz Gerald 
Published: January 2005

AbstractThe variability in the effects of rearing rats in large litters was examined. Subjects reared in litters of 16 were stunted and delayed in the appearance of eye‐opening and fur‐eruption as compared with pups reared in litters of 8. However, the effects of the large‐litter treatment were not uniform; pups in this group exhibited markedly higher variability with regard to all measures than did pups from small litters. In fact, some pups from the large litters were heavier and some exhibited developmental landmarks earlier than did most pups reared in small litters.
Neonatal thyroxine administration, behavioral maturation, and brain growth in mice of different brain weight
Authors: Chen Chia‐Shong , Fuller John L. 
Published: January 2005

AbstractL‐thyroxine in amounts of .5, 1, and 2 μg was injected daily from age 5 through 14 days in 3 lines of mice selected for high (H), medium (M), or low (L) brain weight. Controls (injected with vehicle only) of these lines differed in ages of eye‐opening, first auditory startle, and perfection of a surface‐righting response. Thyroxine at .5 μg/day accelerated the maturation of eye‐opening, auditory startle, and aerial‐righting response, but had no effect on a grasping response or open‐field activity. Brain weights were depressed significantly in all thyroxine treated groups except in the .5‐μg dosage in H mice.
Development of dustbathing in bobwhite quail. II. Effects of early pecking experiences
Authors: Borchelt Peter L. , Overmann Stephen R. 
Published: January 2005

AbstractThe development of dustbathing was facilitated among groups of Bobwhite chicks allowed to peck into dust as compared to chicks allowed to peck at dust or those inexperienced with dust. A 2nd study found a consistent, but nonsignificant, facilitation among chicks pecking into dust on Days 1–3 as compared to Days 4–6. In Study 3, groups of chicks pecked into dust on Days 2, 4, or 6. Dustbathing development was facilitated among chicks pecking on Day 2, and inhibited among chicks pecking on Day 4, as compared to those pecking on Day 6. The only difference, however, between each of these groups and chicks with no pecking experience in dust (Study 1) was an inhibition of dustbathing among chicks pecking on Day 4.
Enzymatic activities in mitochondria isolated from the rat brain during development
Authors: Mourek J. , Průžzková V. , Svobodové Z. , Kraml J. 
Published: January 2005

AbstractIn an attempt to discern whether mitochondrial changes during ontogeny are due to increases in number of mitochondria or to increases in number plus changes in their organization, we investigated the enzymatic markers of the inner and outer membranes of mitochondria from cerebral cortex and subcortical material in young and adult rats. We conclude from the data gathered that significant changes do occur in mitochondrial organization, that gradual maturation occurs in the inner membrane during development, especially in the cerebral cortex and considerably less so in the subcortical structures. We found no such changes in the structure of the outer membrane during the periods of development examined.
Excess neonatal thyroxine: Effects on learning in infant and adolescent rats
Authors: Stone James M. , Greenough William T. 
Published: January 2005

AbstractPrevious reports have suggested that neonatal thyroxine administration may enhance learning ability in rats as infants but the rats become deficient in learning as they grow older. This experiment compared neonatally thyroxine‐injected rats with injected and nonhandled controls on passive and active avoidance and a geotactic cold‐escape discrimination. Thyroxine‐injected infant rats were superior to controls on active avoidance, inferior on passive avoidance, and equal on discriminated escape. Adolescent rats which had received postnatal thyroxine were inferior to controls in Lashley III maze acquisition whether or not they had received supplementary thyroxine at the time of training. These data suggest that differences in locomotor activity, rather than in learning ability, account for early behavioral effects and that changes other than endocrine disturbances account for the adult deficits. The results are compatible with previous contentions that excess neonatal thyroxine disrupts the timing of brain development.
Maternal growth hormone and growth and function
Authors: Sara Vicki R. , Lazarus L. 
Published: January 2005

AbstractFactors regulating somatic growth postnatally have been proposed to affect brain growth and subsequent function when applied prior to birth. This study pertains to the role of growth hormone administered to pregnant rats and the subsequent growth of the progeny. The results showed a significant increase in brain weight and cortical neurone number as determined by the incorporation of labelled thymidine into DNA and subsequent autoradiography. At maturity, learning performance on a series of conditional discrimination tasks was found to be enhanced.
The development of convulsive seizures in the grasshopper mouse (Onychomys torridus)
Authors: McCarty Richard , Southwick Charles H. 
Published: January 2005

AbstractOpen‐field tests were administered to 29 male and 50 female southern grasshopper mice (Onychomys torridus) at 10‐day intervals from 30–100 days of age. Convulsive seizures were observed to occur in 9 males and 23 females during at least 1 of the open‐field tests. No significant differences appeared in the seizure characteristics of male and female subjects. The potential of O. torridus as an animal model of human epilepsy is discussed.
Postnatal undernutrition: An alternative method
Authors: Lynch A. 
Published: January 2005

AbstractRat pups were undernourished from birth by placing them for 12 hr/day with a normal lactating mother and 12 hr/day with a nipple‐ligated mother each day for 25 days. The method resulted in a marked delay in the body growth of the undernourished pups, especially during the first 2 weeks of life. Observations of the behavior of the mothers towards the underfed pups were made at different times of the day and compared to the behavior of the mothers suckling well‐fed pups. The results show that (1) nipple‐ligated mothers are able to provide adequate maternal care for undernourished pups, and (2) both ligated and nonligated mothers caring for underfed pups spend more time with those pups than mothers caring for well‐fed pups.
Audiogenic priming in DBA/2J and C57 BL/6J mice: Interactions among age, prime‐to‐test interval, and index of seizure
Authors: Schreiber Robert A. , Graham John M. 
Published: January 2005

AbstractC57BL/6J mice, not susceptible to audiogenic seizures (AGS) on the 1st exposure to an acoustic stimulus, were exposed to the acoustic stimulus for 1 min and then tested at some later date (acoustic priming). They were first exposed at either 8, 16, 19, 22, or 28 days of age, and then tested for AGS 2‐16 days after priming. DBA/2J mice, susceptible to AGS on the 1st exposure to intense noise, were exposed to the acoustic stimulus at 26 days of age, and then again 2‐14 days later. Data indicate that the incidence of AGS upon the 2nd exposure to the acoustic stimulus is a function of age at priming, the prime‐to‐test interval in days, and the index of seizures. In the case of DBA mice, later effects are also dependent on the initial level of seizure.
Food availability as a determinant of the rats' circadian rhythm in maternal behavior
Authors: Stern Judith M. , Levin Robert 
Published: January 2005

AbstractThe present study was designed to determine whether environmental factors other than light would alter the daily periodicity in the rat's maternal behavior and whether such a change in the dam's behavior pattern would in turn alter the pattern of her sucklings' milk intake. Experiment 1 determined the daily pattern of litter weight gain (which presumably reflects milk intake) displayed by young reared by dams fed and watered either ad lib (Group C), only during the day (Group D), or only at night (Group N). Experiment 2 compared nocturnal and diurnal frequency of maternal behavior in Groups C, D, and N. The pattern of both litter weight gain and maternal behavior was observed to be diurnal in Groups C and N and nocturnal in Group D.
Active avoidance and brain DNA after postnatal food deprivation in rats
Authors: Howard Evelyn , Olton David S. , Johnson Craig T. 
Published: January 2005

AbstractFood deprivation was produced in infant rats, from 2 to 20 days of age, by a procedure designed to minimize reduction in maternal care. Body weights in the deprived animals were 60% of control weights at 7 days, 65% at 20 days, and, after ab lib feeding, 89% at 4 months. No change was observed in the rate of acquistion of a conditioned active avoidance response in the food‐deprived rats when compared with their littermate controls when tested as adults. No lasting reduction in cerebral desoxynucleic acid (DNA) was observed despite a 9% reduction in cerebellar DNA.
Position reversal deficit in young ferrets
Authors: Haddad R. , Rabe Ausma , Dumas R. , Lazar J. Wayne 
Published: January 2005

AbstractYoung ferrets (6 and 10 weeks old at the start of the experiments) werc compared to adult ferrets on learning (1 ) a Lashley III maze, (2) a left‐right discrimination in a T‐maze with identical choice arms, and (3) a reversal of the left‐right discrimination. The young were not inferior to the adults in Iearning either the Lashley III maze or the initial discrimination in the T‐maze. However, thc young were markedly (and significantly) inferior to the adults in learning to reverse.
The split‐brain neonate: A surgical method for corpus callosum section in newborn kittens
Authors: Sechzer Jeri A. , Folstein Susan E. , Geiger Eric H. , Mervis Ronald F. 
Published: January 2005

AbstractOne way to determine the importance of interhemispheric interaction in the development of adaptive and acquired behavior is to section completely the corpus callosum about the time of birth before myelination commences and before any significant hemispheric interaction takes place. Therefore, we developed a technique for commissurotomy in the neonatal kitten 36 to 72 hr of age. A specially designed “commissurotomy knife” was used which eliminated retraction of the hemispheres. Histology showed completeness of corpus callosum section as well as commissure of the fornix without any apparent damage to cortical or subcortical structures. This technique meets the following criteria: (1) reproducibility of lesions without additional nonspecific damage; (2) minimal exposure and manipulation of the delicate newborn brain; (3) brief operational procedure minimizing risk of infection; and (4) low mortality rate.
Protein deprivation in primates. VIII. Early behavior of progeny
Authors: Riopelle Arthur J. , Hale Penelope Anne , Hill Charles W. 
Published: January 2005

AbstractInfant rhesus monkeys whose mothers were fed diets providing 1, 2, or 4 g protein/kg body weight/day during pregnancy were tested on 13 behavioral tests during their first 60 days of life. (The diets had been shown to affect significantly the weights and blood protein concentrations of both pregnant and nonpregnant females)The tests sampled a wide range of behaviors, including visual and auditory perception, feeding reflexes, and locomotion. Despite the maternal dietary differences, the performances of infants on all tests were comparable in all groups. These data contrast with the finding of persistent deficit in rats born of protein‐deprived mothers.
Effects of cyclophosphamide treatment of newborn mice on the development of swimming and reflex behavior and on adult behavioral performance
Authors: Preache Maurline M. , Gibson James E. 
Published: January 2005

AbstractCyclophosphamide (CP), an antineoplastic agent, was administered subcutaneously to Swiss‐Webster mice on the day of birth and the mice were later tested for developmental or adult behavioral abnormalities. The CP dosages of 20, 30, or 45 mg/kg of body weight retarded maturation of swimming ability and 45 mg/kg retarded maturation of the righting reflex. At 7 weeks of age mice treated neonatally with 30 or 45 mg/kg of CP had reduced locomotor activity and were more emotionally reactive than controls in an open field. Mice treated with 30 but not 20 mg/kg of CP tended to avoid shock less often than controls and those treated with 20 mg/kg fell more frequently when crossing a rotating rod for food. Rotorod performance was improved by treatment with 45 but not 30 mg/kg of CP. All dosages examined decreased body weight gains but only 30 or 45 mg/kg resulted in gross body malformations. The results indicate that CP can functionally impair the development of mice and that some of these impairments are independent of gross body malformations.
The effects of tactile and kinesthetic stimulation on neonatal development in the premature infant
Authors: White Jerry L. , Labarba Richard C. 
Published: January 2005

AbstractThe effects of tactile and kinesthetic stimulation on the neonatal development of 12 premature infants were investigated. Experimental infants received four 15‐min periods of tactile and kinesthetic stimulation daily for 10 days. The control infants received only standard, routine nursery care. Data were collected daily on 8 dependent measures: weight, number of feedings, amount of formula intake, body temperature, respiration, heart rate, frequency of voiding, and frequency of stooling. The data analyses revealed significant differences in amount of formula intake and in weight at the end of the treatment period in favor of the experimental infants. Additionally, the experimental infants required significantly fewer feedings during the stimulation period. All other dependent measures were nonsignificant.
Effect of arousal conditions during reinstatement treatment upon learned fear in young rats
Authors: Haroutunian Vahram , Riccio David C. 
Published: January 2005

AbstractThe role of shock and epinephrine‐induced arousal in the reinstatement of learned fear was investigated in young rats. Groups of 21‐day‐old rats received classical fear conditioning to the black compartment of a black/white avoidance box. One week later each rat received one of a number of reinstatement conditions consisting of exposure to the apparatus cues, non‐contingent foot shock, or exogeneous epinephrine injections, alone or in combination. Subjects were tested for retention of spatial avoidance behavior 1 week following reinstatement. Reinstatement with epinephrine and exposure to the training contextual cues, non‐contingent foot shock followed by cue exposure, and non‐contingent foot shock alone were all found to be as effective as shock administered in conjunction with the cues (the same conditions as those prevailing during training). Cue exposure alone and epinephrine injections without the training cues were ineffective reinstating agents.