bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced activity in rats with induced phenylketonuria
Authors: Vorhees C. V. , Butcher R. E. , Berry H. K. 
Published: January 2005

AbstractHypoactivity was observed in the open field performance of 28 rats fed a diet containing 3% excess L‐phenylalanine and .12% p‐chlorophenylalanine between 21–51 days of age (PKU group) compared to both pair‐fed and ad lib control groups. Open field testing was conducted 4–11 days following termination of the phenylalanine, p‐chlorophenylalanine diet. While on the diet serum phenylalanine levels of the PKU group ranged between 16.6–38.0 mg%. Twenty‐four to 48 hours following termination of the PKU diet serum phenylalanine levels had returned to normal (i.e., 2–10 days prior to open field testing). The reduced open field activity of the PKU group is not attributable to differences in food consumption or weight at the time of testing. Hypoactivity is consistent with previous investigations administering chronic doses of phenylalanine, but employing different induction techniques, treatment durations, and activity measures.
Population density and food dispersion on the development of prism‐induced aftereffects in newly hatched chicks
Authors: Rossi Patrick J. 
Published: January 2005

AbstractNewly hatched Leghorn cockerels (124) wearing hoods containing 8.5° prisms were reared in large or small groups and with high or low ratios of spatially distributed seeds on a sand filler. Only chicks reared in large groups demonstrated negative aftereffects when O° plates were substituted for the prisms on the seventh day. For large groups, high seed density resulted in smaller lateral pecking errors with prism displacement but larger negative aftereffect errors without displacement than did low seed density. For small groups, however, high seed density produced a reversal of negative aftereffect directions. High group density was necessary for negative aftereffect development, probably by its influence on socially mediated pecking rates.
Brain growth in mice selected for high and low brain weight
Authors: Fuller John L. , Geils Helen D. 
Published: January 2005

AbstractThe growth of brain and body were observed in mice selectively bred for high (H) or low (L) brain weight as adults. Line H brains tended to be heavier than unselected control (C) at birth and throughout the growth period; line L brains were similar in size to line C at birth, but the period of rapid growth was shortened. Thus different genetic mechanisms appear to be involved in phenotypic variation upward and downward and these seem to differ in the timing of action. Changes in water content indicate that both H‐ and L‐lines are maturing more rapidly than the C‐line. Differential temporal patterns of brain growth may have implications for behavioral development, particularly with respect to critical periods of sensitivity to external stimulation.
Postnatal neural ontogeny: Environment‐dependent and/or environment‐expectant?
Authors: Bekoff Marc , Fox Michael W. 
Published: January 2005

AbstractRecent advances in the study of postnatal neural development, an adaptive process dependent on an intimate interplay of both genetic and environmental factors, are reviewed in mouse, rat, cat, and man. Since developmental neuroanatomical studies provide a useful and relevant way of approaching the much belabored and controversial nature‐nurture issue, behaviorally oriented workers should be made aware of the heuristic value of the field as both an impetus and a guide for future research, and as a means for providing explanations for observations unexplainable at the ethological or behavioral descriptive level. The conclusion reached in this review is that postnatal neural ontogeny is both environment‐dependent and environment‐expectant. To divide the process into mutually exclusive halves is indefensible.
Behavioral effects of peer separation, isolation, and reunion on adolescent male rhesus monkeys
Authors: Bowden Douglas M. , McKinney William T. 
Published: January 2005

AbstractSix adolescent male rhesus monkeys which had lived in pairs for 6–8 months were studied for behavioral adaption to 2 weeks of separation‐isolation and 4 days of reunion. The response to separation was 1–3 days of increased locomotion and object‐oriented behavior followed by a long term increase in self‐directed behaviors. The latter phase differed significantly from the anaclitic depression of infants separated from their mothers. Reunion produced one day of intense social activity followed by a return to behavior patterns characteristic of the preseparation period. A large component of the initial motor excitement following separation may be nonspecific response to gross change in the environment.
Infant state: Relationship to heart rate, behavioral response and response decrement
Authors: Campos Joseph J. , Brackbill Yvonne 
Published: January 2005

AbstractThe relationship of state to HR and behavioral responding to white noise stimulation was investigated in 2‐week old infants. Results indicated that state is a potent determinant of various behavioral and HR phenomena. State was related to prestimulus HR levels. Cardiac responses elicited in active sleep were larger than those elicited in quite awake, even after prestimulus effects on responding were partialled out. Infants who were asleep throughout testing (group I) showed rapid behavioral and large HR response decrement. Infants whose state changed from active sleep to awake (group II), from quiet awake to asleep (group III), and from quiet awake to crying (group IV), showed significantly slower behavioral response decrement than those in group I, but behavioral response decrement was nevertheless evident in all groups. Cardiac response over trials also was examined in these 4 groups.
Alterations in visual evoked responses and behavior in kittens reared under constant illumination
Authors: Rose Guenter H. , Gruenau Steven P. 
Published: January 2005

AbstractKittens reared with their mother under constant illumination from birth to 8 months were compared electrophysiologically, physically, and behaviorally with normally reared kittens. Initial components of visual electrocortical responses recorded from the light‐reared kittens in an awake state were of considerably greater magnitude in contrast to control kittens and adults. The light‐reared kittens also differed significantly in terms of minimal eye blink responses to light and to an approaching object and initially displayed continuous mydriasis independent of light‐dark conditions. The kittens did not differ in orientation to objects, following objects, visual placing, and visual cliff responding.
The effects of selective interruption and deprivation of sleep in the human newborn
Authors: Anders Thomas F. , Roffwarg Howard P. 
Published: January 2005

AbstractIn two separate studies, newborn infants' responses to sleep stage deprivation were investigated. In the first study, neonates were selectively awakened from either REM or NREM sleep during 1 interfeeding sleep period and allowed to recover in an undistrubed second. In the 2nd study, infants were kept totally awake for 1 interfeeding period and allowed to sleep undisturbed during the next. The results indicate that selective sleep stage deprivation by manual awakenings was impossible to achieve during the newborn period. Rather, the infants were partially sleep deprived (both stages of sleep were reduced) with increased amounts of wakefulness. During the disturbance the interrupted sleep stage demonstrated considerable “tenacity.” During undisturbed recovery sleep, in both studies, total sleep time was markedly increased. NREM sleep demonstrated a greater tendency for preferential recovery than REM sleep.
Avoidance conditioning in mice as a function of their mothers' training
Authors: Ressler Robert H. , Anderson Lowell T. 
Published: January 2005

AbstractPrior to mating, inbred female mice were exposed to 1 of 4 conditions for 15 days: 50 trials of avoidance conditioning per day; equivalent (yoked) exposure to conditioned stimulus (CS) and shock, but without the response contingency; yoked exposure to the CS alone; or no experimental treatment. Within 48 hr after birth the offspring of these females were transferred to unrelated foster mothers. The treated females served as foster mothers for the offspring of untreated females. When the adult avoidance conditioning performance of the offspring was analyzed, an interaction was found between the sex of the offspring, the treatment of the mothers, and the developmental period during which the maternal treatment influenced the offspring. In general, the prenatal effect of maternal treatment was the reverse of the postnatal effect, and its effect, while somewhat greater on female offspring, also was the reverse of its effect on male offspring.
Avoidance conditioning in mice as a function of their mothers' exposure to shock
Authors: Ressler Robert H. , Anderson Lowell T. 
Published: January 2005

AbstractInbred female mice received treatment either prior to mating or following birth of offspring. When treatment was administered, females were either not handled or received 0, 5, 15, or 30 shocks per day. When the adult avoidance conditioning performance of the offspring was analyzed an interaction was found between the sex of the offspring, the frequency of maternal shock, and the developmental period during which shock was administered. Maternal treatment had a more coherent and pronounced effect on female offspring than on their male littermates. The functional relationship between frequency of maternal shock and offspring avoidance was consistently nonmonotonic; its direction was highly dependent upon the period of life during which the mother encountered the shock.
Response to a conditioned aversive event in mice as a function of frequency of premating maternal shock
Authors: Anderson Lowell T. , Ressler Robert H. 
Published: January 2005

AbstractPrior to mating, female mice were exposed to either 0, 1, or 60 shocks per day for 20 days. When the food reinforced operant responding of their adult offspring was observed in the presence of a conditioned aversive stimulus, a nonmonotonic relationship was found between frequency of maternal shock and degree of conditioned suppression in female offspring. During the 2nd session of a 3‐session test period the females reared by mothers that had received either 0 or 60 shocks per day showed greater conditioned suppression than those whose mothers had received 1 shock per day. Maternal treatment also had significant effects on maternal weight, offspring litter size and weaning weight, and frequency of defecation during the conditioned suppression procedure. In the latter instances, however, negative monotonic relationships were observed in both sexes. The data indicate that an interpretation in terms of an a priori classification of “emotionality” is not adequate.
The influence of stagnant hypoxia on the activity of some dehydrogenases and aminotransferases in the brain of rats during ontogenesis
Authors: Jílek L. , Janata V. , Londonová A. , Makč Z. , Trojan S. , Vorel F. 
Published: January 2005

AbstractLigation of both common carotid arteries produces stagnant hypoxia (oligemia) in the brains of rats. The character and the intensity of the hypoxic metabolic changes depend directly on the developmental maturity of the nerve tissue, which is also true of the activity of the enzymes, LDH, aldolase, SDH, MDH, G‐6‐PDH, GDH, GPT, and GOT. In the 5‐day‐old rat after 4 hr of oligemia, enzyme activity either did not change or increased. In the 12‐day‐old rat the activity of LDH, MDH, and GPT increased and the activity of GDH, aldolase, and G‐6‐PDH decreased. At the age of 25 days and in adulthood, the activity of SDH, MDH, aldolase, and GOT decreased. The changes in enzyme activity are related to changes in proteosynthesis and appear to support the concept of a “metabolic adaptive reaction” of the immature nervous system in response to changes of the inner milieu.
Maternal influence on the response of wild and domestic norway rats to a novel environment
Authors: Price Edward O. , Loomis Stephen 
Published: January 2005

AbstractThe influence of the maternal environment on the response of adult wild and domestic Norway rats to a novel environment was assessed by comparing the behavior of reciprocal hybrid groups to each other and to the parental strains. Wild rats exhibited shorter latencies for activity, greater total activity, more time grooming, smaller body weights, and larger adrenals than domestic rats. (Defecation rates were similar.) Reciprocal hybrids were intermediate to the parent strains for all variables. With the exception of total activity little evidence was obtained for a maternal influence on the behavioral responses studied. Differences between wild and domestic rats in response to a novel environment are more readily explained by genetic changes accompanying the domestication process than by differences in the maternal environments.
Activity states in premature and term infants
Authors: Michaelis Richard , Parmelee Arthur H. , Stern Evelyn , Haber Audrey 
Published: January 2005

AbstractGenerally, studies which have compared full term infants shortly after birth with prematurely born infants tested at the date of their expected birth (i.e., 40 weeks conceptional age) have stressed the similarities rather than any differences which have appeared in the data. Nonetheless, numerous differences have been noted, and the present study documented an additional discrepancy in function between full term and premature infants at 40 weeks conceptional age as well as maturational changes in state responsivity during the premature period.Premature infants were given repeated neurological examinations at 31‐33, 34‐36, and 38‐42 weeks conceptional age. Full term infants were tested at 38‐42 weeks conceptional age. Included in the scoring of the examination were 37 measures of state, designed to assess the infant's responsivity to the increasingly stressful items of the neurological examination. The younger prematures were more often judged to be asleep and had lower scores throughout the examination when compared to the 38‐42 week infants. Crying occurred significantly more often with increasing age. In addition, the full term infants had significantly more crying scores than the prematures of the same conceptional age.
Reversal learning in the neonatal rhesus monkey
Authors: Zimmermann Robert R. 
Published: January 2005

AbstractTwenty‐one day old and 31 day old monkeys were presented with a black‐versus‐white discrimination reversal problem after having completed 20 days of learning on the original problem. Age at the time of reversal was not a significant factor, but reversing to the white stimulus was significantly faster than reversing to the black stimulus. This preference persisted over repeated reversals. The infant monkey shows improvement in repeated reversal learning that is very similar to the behavior of the adult rat.
Neural systems underlying climax movements in the domestic chicken
Authors: Bakhuis Walter L. , Corner Michael A. 
Published: January 2005

AbstractBilateral removal or disconnection of the entire telencephalon in the chick embryo failed to show any effect upon the characteristic repetitive phasic behavior pattern at hatching, or “climax.” Surgical disconnection of the spinal cord caused a minor facilitation of these stereotyped motility bursts which persisted, otherwise unaltered, only above the level of transection. Lesions encroaching upon the anterior diencephalon, on the other hand, led to varying degrees of slowing down of the “hatch rhythm.” Continuous electrical stimulation of peripheral nerves evoked typical bursts of hatching movements in chicks prevented from emerging from the egg, at intervals inversely related to the shock intensity employed. Apparently, the forebrain at climax need only provide a tonic excitatory outflow, with the patterning into repetitive phasic discharges being accomplished within the brainstem.
Ontogenetic aspects of central cholinergic involvement in spontaneous alternation behavior
Authors: Egger Garry J. , Livesey Peter J. , Dawson Ronald G. 
Published: January 2005

AbstractFour studies are reported examining the development of spontaneous alternation behavior in rats. Spontaneous alternation was found to increase from a rate of around 20% in 15‐16 day old rats to around 90% in 100‐day olds. Increasing the length of confinement in the 1st chosen goal arm did not affect alternation rats. Spontaneous alternation could be disrupted or facilitated in mature animals by the administration of either scopolamine hydrobromide or physostigmine sulphate, drugs which had no effect on the typical alternation pattern of 16‐day olds, but appeared to begin to have an effect at around 24 days. Dose response curves revealed certain age‐dose level interactions which were consistent with the hypothesis that cholinergic inhibitory mechanisms in the brain develop gradually in the rat.
Ontogeny of “aberrant” responses in the mating pattern of male guinea pigs
Authors: Harper Lawrence V. 
Published: January 2005

AbstractAnalysis of the behavioral development of 64 socially‐reared guinea pigs revealed that the head‐shaking which frequently in trudes into the mating pattern of adult isolation‐reared males is a common response among young animals. The behavioral context in which young socially‐reared animals typically display head‐shaking includes the pre‐copulatory hip‐sway‐purring display and running (pursuit). The aberrant behavior of adult isolation‐reared males may stem from a post‐isolation “stimulus overload” which causes the mating pattern to get sidetracked into another pattern with which it shares common elements.
Ontogenesis of electroencephalographic seizure patterns in developing chick embryos during recovery from hypothermic hypoxia
Authors: Peters Joseph J. , Hilgeford Eric J. , Vonderahe Alphonse R. 
Published: January 2005

AbstractChick embryos between the 15th and 20th day of incubation were subjected to hypothermia of 20°C followed by nitrogenous hypoxia until the cerebral EEG showed no fluctuations of potential. The embryos were exposed to air 15 or 30 min later. Body temperature was raised to 30°C and maintained there for 1 hr before being raised to 36°C, during which time 2 types of seizure episodes of rhythmic waves appeared. Type I was characterized by an ontogenetically later appearance (after the 15th day), larger amplitude, spike and slow wave patterns, a frequency of .3‐3.5 Hz with the slowest in the younger embryos, and a duration of 1 to several minutes. Type II was characterized by an earlier ontogenetic appearance, small amplitude, a frequency of 1‐30 Hz, and a duration of a few seconds to several minutes. None of these seizure episodes was observed after body temperature had reached 36°C. About the 17th day of incubation, the physiological components responsible for producing EEG patterns during episodes seem to undergo an abrupt maturational change indicated by the increase in percentage of embryos undergoing Type I episodes, and by changes in frequency of waves and duration of episodes.
Effects of amphetamine on electroshock responses in developing rats
Authors: Vernadakis Antonia , Robb Douglas 
Published: January 2005

AbstractConvulsive responses were studied after chronic and acute amphetamine treatment in developing rats. Under chronic treatment, 27 litters of male rats received d‐amphetamine either at 3‐6, 8‐11, or 22‐25 days after birth and the electroshock seizure threshold (EST) was studied during maturation; each litter consisted of controls and rats treated with 1, 3, or 6 mg/kg body‐weight amphetamine. Under acute treatment, groups of rats (16 per group) received amphetamine 45 min before electroshock testing at 8, 16, or 25 days after birth. The EST was significantly higher for the 1st week after treatment in rats given amphetamine (3 mg/kg) from 8‐11 days after birth; no changes were observed in the other groups tested chronically with amphetamine. The EST was lower in rats treated acutely at 8 or 16 days and higher in rats treated at 25 days. These data demonstrate that the effects of amphetamine on convulsive responses are dependent not only on the stage of central nervous system (CNS) maturation at the time of drug administration, but also on the duration of drug treatment.
The effect of monosodium glutamate on the early biochemical and behavioral development of the rat
Authors: Berry H. K. , Butcher R. E. , Elliot L. A. , Brunner R. L. 
Published: January 2005

AbstractSprague Dawley rats were given monosodium glutamate (MSG) (4 mg/g) on each of the first 10 days of life and subsequently tested in a swimming maze at 50 days. They appeared less able to learn the maze than littermate controls that had received only saline. Amino acid analyses performed on animals prepared identically but sacrificed on Day 10 showed increased levels of aspartic and glutamic acids, taurine, urea, and glutathione in the brain, liver, and blood of the MSG animals as compared to their controls. Tyrosine and histidine levels were consistently lower. These abnormalities of amino acid metabolism appear to be of sufficient magnitude to alter the structural development of the CNS. The behavioral changes observed suggest an enduring impairment of function.
Experimental maternal hyperphenylalaninemia: Biochemical effects and offspring development
Authors: Copenhaver J. H. , Carver M. J. , Schalock R. L. 
Published: January 2005

AbstractSubcutaneous injections of para‐chloro‐D, L‐phenylalanine (pCl‐Phe) and phenylalanine (Phe) over the last third of pregnancy were found to produce hyperphenylalaninemic states in maternal and fetal rats. The pCl‐Phe, when administered to maternal animals alone or in conjunction with Phe, was associated with maternal muricide. The muricide was counteracted by the administration of 5‐hydroxy‐D, L‐tryptophan prior to delivery. Prolonged treatment of maternal animals with pCl‐Phe and Phe suppressed normal weight gain and resulted in smaller offspring. The elevated levels of maternal plasma Phe decreased with time, reflecting a lessening of pCl‐Phe inhibition of maternal phenylalanine hydroxylase and normal Phe clearance. Fetal plasma Phe levels mirrored those of treated maternal animals. Similarly, fetal brain Phe reflected the increase in fetal plasma Phe.
Phrenoblysis: Special brain and mind growth periods. I. Human brain and skull development
Authors: Epstein H. T. 
Published: January 2005

AbstractAlthough gross brain properties averaged over many individuals are highly unlikely to exhibit possible special growth periods, the hypothetical spurts in brain growth can be recovered to some extent from averaged data by computing multiyear weight increments. And, since brain weight correlates very well with skull circumference, similar spurts may be found in that parameter. A review of the literature shows that, indeed, characteristic spurts in brain and skull occur, roughly, at ages 6‐8, 10‐12, 14‐17, and possibly 2‐4 yr. The spurts are, as expected, especially clear in data from longitudinal studies, although spurts are detectable in the data from every study thus far found in the literature.
Early restriction of tactile stimulation and visual functioning in the kitten
Authors: Turkewitz Gerald , Gilbert Michel , Birch Herbert G. 
Published: January 2005

AbstractTwelve kittens with vibrissae clipped on the 1st day of life were compared to matched controls for the development of a preferential behavior in a visual cliff situation in an effort to examine the developmental relationship between sense systems. The kittens with reduced tactile input (vibrissae‐clipped) were found to discriminate between the “shallow” and “Sdeep” sides of the visual cliff at younger ages and with greater consistency than controls. The results for which there are alternative explanations available support the hypothesis that reduction of input in one modality reduces competition between sense systems, thereby resulting in the precocial use of another sense system.