bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the distribution of methylmercury and total mercury in grain size fractions of freeze‐dried estuarine sediment samples
Authors: Carro A. M. , Rubi E. , Bollain M. H. , Lorenzo R. A. , Cela R.
Published: January 2005

A study of the total mercury and methylmercury distribution in esturine sediments is presented. Core sediments obtained in a polluted area were freeze‐dried and sieved to obtain four fractions. Fraction 1, having grain size <0.30 mm; Fraction 2, having grain size <0.30 mm; Fraction 3, with grain size <1 mm and Fraction 4, having particle size >1 mm. In all these fractions total mercury (Cold Vapor AAS) and methylmercury (Gas Chromatography with ECD detection) have been analyzed. As expected high concentrations of total mercury and small concentrations of methylmercury were obtained in Fractions 1 and 2 but were not detected in Fractions 3 and 4, although the study of the data obtained suggests that significant amounts of geochemical mercury remain in these fractions. Attempts have been made to correlate data for both species when freeze dried sediments and the raw wet samples were analyzed.
Isolation of bacterial culture capable of degrading triphenyltin pesticides
Authors: Visoottiviseth P. , Kruawan K. , Bhumiratana A. , Wilairat P.
Published: January 2005

A bacterial culture capable of degrading triphenyltin hydroxide (TPTOH) was successfully isolated from soil samples taken at a dockyard area in Samutprakarn province, Thailand. It was purified, identified and designated as Pseudomonas putida no. C. The bacterium isolated was found to have the capability of degrading TPTOH at levels of 7.0 ppm in 24 h. The addition of glucose enhanced the extent of degradation of TPTOH. Experiments were also conducted to immobilize P. putida no. C on various supports such as sand, cotton fibre and alginate. It was found that alginate was the best support material. Immobilized P. putida no. C on alginate was found to possess suitable characteristics and potential for future development in the removal of TPTOH from water and waste water systems.
Determination of mercury species in gas condensates by on‐line coupled high‐performance liquid chromatography and cold‐vapor atomic absorption spectrometry
Authors: Schickling C. , Broekaert J. A. C.
Published: January 2005

A method for the speciation of mercury in gas condensates is reported. Mercury(II) chloride (HgCl2), methylmercury chloride (MeHgCl), phenylmercury acetate (PhHgAc) and diphenylmercury (Ph2Hg) are separated by reversed‐phase high‐performance liquid chromatography (HPLC) using gradient elution. Prior to the determination, the organic ligands and the matrix were destroyed by oxidation with K2Cr2O7. Mercury is detected with cold‐vapor atomic absorption spectrometry (CVAA), where the mercury compounds are reduced to metallic mercury by a treatment with NaBH4. In a continuous‐flow system the concentrations of the reagents used are optimized using a modified simplex algorithm. Detection limits for mercury are at the 10 ng ml−1 level. Analysis of multi‐compound mixtures indicates that chemical reactions between HgCl2 and Ph2Hg and between MeHgCl and Ph2Hg take place. The method developed was applied to the speciation of mercury in gas condensates and did not require use of any solvent extraction or chemical derivatization steps. In the gas condensates, mercury(II) compounds were found to be present at the 100 ng ml−1 level.
New insights into the palladium‐catalysed synthesis of δ‐lactones from 1,3‐dienes and carbon dioxide
Authors: Dinjus Eckhard , Leitner Walter
Published: January 2005

Two‐coordinate Pd(0) complexes are shown to be important intermediates in the telomerization of 1,3‐dienes and CO2 using palladium/phosphine catalysts without additives. Only one phosphorus atom is bound to palladium during the C–C bond forming steps, but the second phosphorus atom is crucial in the early stages of the catalytic cycle and for the elimination of the product. A ligand that gave an active palladium catalyst for the coupling of 1,3‐butadiene and CO2 has been designed. Use of a palladium catalyst in the reaction of isoprene with CO2 allowed for the first time isolation and NMR spectroscopic characterization of the resulting mixture of lactones.
The stability of ferrocenylmethyl derivatives: Further attempts to synthesize ferrocenylacetone
Authors: Imrie Christopher
Published: January 2005

Attempts have been made to synthesize ferrocenylacetone by various routes. The reaction of ferrocene and chloroacetone in the presence of boron trifluoride etherate was investigated as a potential route but this gave 2,2‐diferrocenylpropane and not ferrocenylacetone as reported in the literature. Several other attempts to synthesize ferrocenylacetone also failed and possible reasons for the instability of this and of other ferrocenylmethyl derivatives are discussed.
Estimation of the hemolytic effects of various organotin compounds by structure–activity relationships
Authors: Hamasaki Tetsuo , Masumoto Hideki , Sato Takahiko , Nagase Hisamitsu , Kito Hideaki , Yoshioka Yoshitada
Published: January 2005

The hemolytic effects of 27 organotin compounds, which are environmental pollutants, were studied with rabbit erythrocytes. Various EC50values caused by differences in their chemical structures were observed. The hemolytic activities of tri‐n‐butyltins and triphenyltins were higher than that of sodium‐n‐dodecyl sulfate, and the hemolysis by tri‐n‐butyltin chloride proceeded rapidly. Tri‐n‐butyltin chloride showed the highest hemolytic activity (EC50= 7.48 μM). Methyltin compounds were less active (EC50>364 μM) than any other organotin compound tested. No significant difference in hemolytic activity based on divergences of the anionic functional group which was attached to each triorganotin compound was observed. A structure–activity relationship study was carried out in order to predict EC50values of a series of tested organotin compounds, using various descriptors which represent their physicochemical properties or molecular structures. In the multiparametric regression analysis, the best regression equation (r= 0.854) for estimation of their hemolytic effects was obtained by adopting the descriptors Index Value (IV), Mean Information Index (I) and Molecular Connectivity Index (0χp).
Triorganosilicon(IV) complexes as biocides: Synthetic, spectroscopic and biological studies of N SH and N OH fluoroimines and their chelates
Authors: Saxena Chitra , Singh R. V.
Published: January 2005

A facile synthesis and study of the stereochemistry and biochemical aspects of some triorganosilicon(IV) complexes derived from fluoroimines having N S and N O systems are reported. The fluoroimines were prepared by the condensation of 2‐fluorobenzaldehyde and 1‐(2‐fluorophenyl)ethanone with semicarbazide and thiosemicarbazide. These imines react with triorganosilicon(IV) chlorides to yield compounds having SiO/SiS and Si ← N bonds. The structures of the compounds have been elucidated by physicochemical and spectral (UV, IR, 1H NMR, 13C NMR and 9F NMR) studies which clearly point to a trigonal bipyramidal geometry around silicon(IV), as the active lone pair of nitrogen is also included in the coordination sphere. In the search for better fungicides and bactericides, studies were conducted to assess the growth‐inhibiting potential of the synthesized complexes against various pathogenic fungal and bacterial strains. These studies demonstrate that the concentrations reached levels which are sufficient to inhibit and kill the pathogens.
Free amino acids of newborn and adult guinea pig brain
Authors: Davis Jimmie M. , Himwich Williamina A. , Agrawal Harish C.
Published: January 2005

A comparative analysis of the changes in glutamic acid, glutamine, GABA, aspartic acid, alanine, threonine, and glycine in the anatomically or functionally differentiated areas of the newborn and adult guinea pig brain has been made. These data have been used in an attempt to elucidate those changes in brain neurochemistry which occur after the animal is functionally mature, but during the period in which responses to environmental stimuli are still being integrated. The changes in guinea pig brain have been compared with those which occur in the brains of other species after birth and after the appearance of physiological maturity.
Influence of infantile stimulation on the response to stress during preweaning development
Authors: Levine Seymour
Published: January 2005

New born rats were stimulated in infancy and the maturation of the adrenal response to stress or to exogenous adrenocorticotropic hormone (ACTH) was examined. Control animals (nonhandled) showed little or no response to ether and surgical trauma until about 18 days of age. In contrast, handled newborn rats had a significant elevation in plasma corticosterone concentration following stress introduced as early as 3 days of age, whereas at 21 days of age, nonhandled animals showed a significantly higher plasma corticosterone concentration than their handled counterparts. The response to ACTH was equivalent in both groups on each test day. Plasma steroid levels were elevated after ACTH injection at 3 days of age. This was followed by a period of marked suppression of the response to ACTH lasting until about 15 days of age in both groups.
Passive avoidance in prenatally X‐irradiated rats
Authors: Deagle John , Furchtgott Ernest
Published: January 2005

Twenty‐nine albino rats which had received 200 R of X irradiation on the 16th day of gestation were given together with 38 nonirradiated control animals, 4 trials in a passive avoidance conditioning situation. Irradiated animals showed significantly more passive avoidance behavior than did the controls. In a second experiment, animals from both groups were subsequently tested in a shuttle‐box, active avoidance situation. Here, also, the irradiated animals showed more avoidance behavior than the controls. It was hypothesized that the findings are related to increased fearfulness in prenatally irradiated rats.
Development and hormonal control of territorial marking in the male mongolian gerbil (Meriones unguiculatus)
Authors: Lindzey Gardner , Thiesen D. D. , Tucker Ann
Published: January 2005

Male Mongolian gerbils were either castrated or sham operated at 30 days of age. Assessment of territorial marking was carried out every 6 days beginning at 52 days of age and extending to 100 days of age. After each marking test, 10 intact males received 640 μg testosterone propionate subcutaneously; 10 other intact animals and 10 castrates received oil injections. The ventral sebaceous scent gland, used by the gerbil to deposit sebum on objects during the marking response, was measured after each test. Behavioral marking and the scent gland were entirely absent in castrates. Relative to controls, marking in hormone‐treated animals began earlier and reached higher frequencies. Gland development was also responsive to the hormone, but lagged behind marking activity.
Differential human handling and the development of agonistic behavior in basenji and shetland sheep dogs
Authors: Scott J. P. , Bronson Frank , Trattner Alice
Published: January 2005

This experiment tested the hypothesis that differential treatment will increase the amount of aggressive interactions between young puppies. Litters of Shetland sheepdogs and African basenjis were weaned at 4 weeks of age and reared in pairs. In one pair, one pup was favored through playful interaction by a human experimenter, while the other pup was ignored. In a second pair, both pups were ignored. Significantly greater amounts of aggressive behavior occurred in the differentially treated pairs, both during and immediately after the treatment periods. This behavior carried over into competitive situations involving a food or bone and was still present 9 weeks after treatment had been discontinued. Breed differences were observed in almost all measurements taken. In particular, shelties learned to inhibit their behavior much more rapidly than basenjis. Such differences are comparable to what might be expected from genetic differences between individuals in human subjects. The experiment is not comparable to sibling rivalry in human families, where differential treatment is imposed because of difference in ages, but the results support the hypothesis that lessening of differential treatment should reduce the occurrence of quarrels between siblings.
Mother‐infant interactions and experimental manipulation: Confounding or misidentification?
Authors: Meier Gilbert W. , Schutzman Lloyd H.
Published: January 2005

The role of material responsiveness to offspring behaviors in the research on early experience and behavioral development is discussed. The proposition is offered that the behavioral changes following experimenter manipulation of the offspring during the preweaning period, as by handling, isolation, shock stimulation, or cold stress, are attributable to the altered interaction between mother and infant, such that the mother responds differentially to certain behaviors of her offspring or predominantly to those offspring showing such behaviors. In support of this proposition, data are cited on preferential maternal responsiveness to infants by sex and the frequency is enumerated of significant Sex × Treatment interactions in the early experience studies.
The confounding effects of genetic variables in early experience research: Can we ignore them?
Authors: Henderson Norman D.
Published: January 2005

The high probability that the genetic makeup of different subject populations within a species will interact with treatment effects in early experience studies suggests that major revisions in both research methodology and interpretations of results are necessary in this area. Generalizations based on data from a single subpopulation of a species can be misleading, especially if they are based on a limited number of behavioral measures.
Primate naturalistic research and problems of early experience
Authors: Menzel E. W.
Published: January 2005

This paper attempts to approach behavioral development and early experience from a naturalistic, ecologically oriented point of view, and it reviews illustrative data from recent primate field studies, particularly in the area of social behavior. What is the ecological‐social context into which the infant primate must fit himself and what are the end‐points toward which normal development must move? Where does the infant locate himself within his context? Where will he be andwhat will he do at successive stages in development? These are the sorts of questions that are posed. In general, a naturalistic approach to development starts from that which is already there—i.e., groups of animals in their native habitats—and it tries to describe and analyze, first in broad outline, and then with increasing detail, how they come to be as they are. It supplements, complements, and in some respects reverses the traditional approach of experimental psychology, which takes a “naive” individual alone in an “absolutely controlled” and usually empty environment as a theoretical model, and tries to work from this ground up to normal ecosystems by adding variables one at a time.
Temporal parameters of sensitization for audiogenic seizures in SJL/J mice
Authors: Fuller John L. , Collins Robert L.
Published: January 2005

Susceptibility to audiogenic seizures in SJL/J mice is affected by exposure to loud sound during a sensitive age period. The effect is similar to that reported by Henry for strain C57BL/6J. In 3‐week‐old mice, priming by sound requires 5 to 20 sec; sensitization, 30 to 36 hr; convulsibility lasts for at least 21 weeks without any intervening stimulation. Repeated stimulation prior to development of convulsibility makes mice temporarily refractory to sound induction of seizures.
Synthesis of rapidly‐labelled brain RNA in the rat during stagnant hypoxia in the course of ontogeny
Authors: Sirakova I. A. , Sirakov L. M. , Jílek L. , Rychlík I.
Published: January 2005

The nucleic acids of the cytoplasmic and nuclear fraction of the brain homogenate were isolated by phenol procedure then were fractionated on a linear sucrose density gradient. The in vivo incorporation of [3H]‐uridine into different types of RNA and the template activity of these nucleic acid fractions in control and hypoxic animals were studied in vitro in a cell‐free protein synthetic system of E. coli. In adult animals, as in 25‐day‐old rats, stagnant hypoxia decreases the total synthesis of rapidly‐labelled RNA in nuclei and impairs the template activity in cytoplasm. In 12‐day‐old rats, the synthesis of rapidly‐labelled RNA does not change in stagnant hypoxia and the template activity increases mainly in the low molecular weight fractions. Metabolic adaptation of immature nervous tissue to hypoxia involves specific changes of protein and nucleic acid metabolism as well as in carbohydrate and energy metabolism.
Genetic–environmental interaction in “intelligence”: I. Biometric genetic analysis of maze performance of Rattus norvegicus
Authors: Harrington Gordon M.
Published: January 2005

Three litters from each of 11 inbred strains of rat were tested in a Hebb‐Williams maze. Substantial (p < .001>) genetic and interaction effects were found. Data were analysed in terms of theories of delay of reinforcement, incentive motivation, and adrenergic‐cholinergic balance in task performance. A genetic variable with characteristics reminiscent of Spearman's “g” was found, possibly implicating a single underlying biochemical mechanism.
Infant monkey heart rate: Habituation and effects of social substitutes
Authors: Candland Douglas K. , Mason William A.
Published: January 2005

The heart rates of four infant monkeys that habitually clung to terry‐cloth towels were measured by frequency modulation (FM) telemetry while the animals were (1) alone in an unfamiliar room, (2) in a second unfamiliar room with a towel available, and (3) in the second room without a towel. The absence of the towel in the room in which it was sometimes available produced the highest heart rate and the presence of the towel produced the lowest heart rate. Under all conditions, heart rate decreased within sessions and over repeated exposures.
Effect of early outdoor experience on the activity of wild and semi‐domestic deermice
Authors: Price Edward O.
Published: January 2005

The gross activity of wild and semi‐domestic strains of prairie deermice was measured in two kinds of novel test apparatus (tilt‐cage and activity wheel). Differences in strain activity were not obtained in either apparatus. Activity was significantly decreased in both strains by early experience in the field and by rearing wild genotype subjects in large laboratory cages. It was suggested that differential early sensory experience associated with both qualitative and quantitative aspects of the early rearing environment may be responsible for the treatment effect. Whereas no daily changes in activity were noted in the tilt‐cages, activity in the wheels was sipnificantly higher on day 1 for all groups. In contrast to recent literature, wheel running activity did not change with total water deprivation.
Exploratory behavior in the dog: Experiential or age dependent?
Authors: Fox M. W. , Spencer J. W.
Published: January 2005

Two independent groups of dogs (41 cross‐sectional and 16 longitudinal) were tested either once or successively in a behavior arena at 5, 8, 12, or 16 weeks of age for exploration to novel stimuli. The stimulus situations were, respectively, an empty cage, rat in a cage, mirror, auditory click, toy puppy, and flashing light. In the cross‐sectional group at the early ages more time was spent with the rat‐in‐cage and flashing‐light stimuli than with others. No differences in exploration time to any stimuli were seen after 8 weeks. Both number of squares traversed and number of „yelps”︁ seemed to fluctuate more with increasing age. In contrast, the longitudinal group showed an increase in exploration with re‐testing. More time was spent with the toy pup and flashing light at the early ages, whereas the mirror was interacted with more at 12 and 16 weeks. Activity increased upon re‐testing, whereas vocalization decreased significantly after the first exposure to the testing arena. An evaluation of the reaction of each pup to a human was done on the day prior to testing. Those dogs that interacted with a human were also more exploratory and less fearful of a novel environment than those not interacting with a human. Results are discussed in terms of experiential rather than maturational factors as enhancing or modifying exploratory behavior in the dog.
Cerebellar control of the red nucleus and adjacent structures in the young rabbit
Authors: Laget P. , Delhaye‐Bouchaud N.
Published: January 2005

Maturation of the cerebellar influence on rubral cells was studied in70 young rabbits aged from 3 to 17 days. Extracellular spike potentials of 187 neurons belonging to the magnocellular part of the red nucleus were recorded with glass microelectrodes. The differences observed between young and old animals are quantitative and particularly striking. Out of 107 cells in animals less than 8 days old, only 7 were facilitated or inhibited by cerebellar stimulation, whereas in older animals, out of 80 cells, 76 were facilitated or inhibited. Similar results were obtained for 273 perirubral cells and 72 oculomotor cells.

The present results suggest that cerebello‐interposital or interposito‐rubral connections are not yet functional during the first postnatal week.
Distribution of adenosine triphosphatase activity in the developing brain of the chick embryo
Authors: Šťastný Františsek , Fröhlich Jiří , Chmelík Václav
Published: January 2005

The development and distribution of +‐K+‐stimulated and Mg2+‐dependent ATPase activity in different parts of the chick embryo brain were investigated. Maximal changes in the Na+‐K+‐stimulated ATPase activity in the hemispheres and optic lobes took place between day 15 and 17 and in the cerebellum and brain stem between day 17 and 19 of incubation. Most of this activity was localized in the membranous fraction of the chick embryo brain. An attempt was made to correlate the rapid rise in the activity of this enzyme with the development of electrical properties of the chick embryo brain.
Functional development of optic afferent system in chick embryos
Authors: Sedláčkek Jindřich
Published: January 2005

A description is given of evoked activity in the optic lobes of chick embryos to different types of peripheral stimulation. During prehatching development (day 18–21 of incubation) the functional lability of optic neurons increases, as tested with repetitive stimulation (1–10 cps) and with paired flash stimuli. Maturation of the “OFF”‐evoked response proceeds in the same developmental period. This development is characterized by a decrease in the duration of light exposure necessary to produce the “OFF”‐response, by an increase in the amplitude of this type of evoked response, and by a decrease in latency, which becomes shorter than the latency of the “ON”‐response. The development of color differentiation (in the range of 486–687 mμ) has been studied according to the parameters of tectal evoked response (latency, amplitude, duration, steepness of crescent and decrescent part of negative spike). On day 19, there is evidence for differentiation of only 27 signs of the evoked response, particularly for blue and red color. The number of differential signs increases up to 40, until hatching (i.e.,) for blue, red, and orange colors.
Open‐field behavior in rats exposed prenatally to a low intensity‐low frequency, rotating magnetic field
Authors: Persinger Michael A.
Published: January 2005

Two experiments were conducted to study the behavioral effects of prenatal exposure to a low intensity, ultra‐low‐frequency magnetic field. In Experiment I, 117 albino rats that had been exposed continuously during their prenatal development to a 3 to 30 gauss, 0.5 Hz rotating magnetic field (RMF), and 83 control rats that had been exposed renatally to control conditions, were tested in an open field at 21 to 25 days of age. RMF‐exposed animals traversed significantly fewer squares than their controls in the open field (p < .001), but defecated significantly more in that situation (p < .001). RMF‐exposed males also traversed significantly fewer squares than the RMF‐exposed females (p < .05). Three RMF‐exposed litters that were nursed by control mothers did not differ significantly in open‐field activity from the pups in the 4 RMF‐exposed litters from which they were taken at birth. In Experiment 2, in which the experimenters did not know whether the subject was a RMF‐exposed rat or a control rat, 19 RMF‐exposed rats again traversed significantly fewer squares than the 20 control rats (p < .01).
Motor skills of infant rhesus monkeys with thalidomide‐induced forelimb malformations
Authors: Lindburg D. G.
Published: January 2005

The motor skills of 2 infant rhesus monkeys with thalidomide‐induced forelimb malformations were compared with those of normal infants of similar age and sex over an 8‐month period. In general, the experimental animals engaged in locomotor and manipulatory activities at about the same frequency as the normal subjects, but did so by development of compensatory response patterns. For instance, feet and mouth were used for activities that the normal animal performs manually.
Effects of chronic postnatal drug administration on adult dominance behavior in two genera of mice
Authors: Wolf Harold H. , Rowland Clayton R.
Published: January 2005

The experiments described examine the influence of early chronic treatment with amphetamine (AMPH) or chlorpromazine (CPZ) on the formation of adult dominance behavior in two genera of mice, i.e., Peromyscus maniculatus bairdi and a random bred, Swiss albino strain of Mus musculus. It was found that AMPH‐pretreated Swiss albinos were significantly more dominant than either CPZ‐pretreated or control animals. Early drug treatment had little effect on dominance behavior of adult bairdi. These results indicate that chronic administration of certain drugs to young animals is capable of producing a quantitative change in the formation of adult behavioral patterns. Moreover, the degree to which early drug treatment alters adult behavior is influenced by the genetic background of the organism.
Motor response thresholds to electrical stimulation at the wrist in human newborns
Authors: Ellingson Robert J. , Ellis Ron R.
Published: January 2005

Two studies of motor response thresholds (RTs) to electricalstimulation at the wrist in newborns were done. Adult controls were employed. Strength‐duration curves for infant and adult RTs and adult sensory thresholds (STs) were plotted. RTs of infants are approximately 1.75 times higher than those for adults. Adult RTs are consistently 3 to 4 times higher than STs. Test‐retest reliabilities were satisfactory. RTs of half of the newborns were notably variable. No relationship between RT variability and stages of the neonatal wakefulness‐sleep cycle could be established, but RTs were significantly, although not markedly, higher during rapid‐eye‐movement (REM) episodes than during nREM. For evoked potential studies with newborns it has been decided to use as a stimulus a constant‐current square‐wave electrical pulse of 0.5 msec duration at RT during nREM sleep.
Orienting response of kittens with maturation defects
Authors: Berkson Gershon , Brown Thomas S.
Published: January 2005

The orienting response of hand and mother‐reared kittens who had been given daily doses of propylthiouracil during the first 50 days of life was tested at 60 days of age. Heart rate, respiration rate, and eye fixation on a visual stimulus were the measures used. A momentary light‐buzzer combination and a 30‐sec presentation of a rotating disc were the stimuli. There were no rearing or drug effects. Heart rate response was greater to the offset of the 30‐sec stimulus than to its onset. Respiration, the most sensitive measure, was speeded in the presence of a stimulus. Eye fixation, heart rate, and respiration rate curves during the 30‐sec stimulus were not parallel.
Effects of male odor during infancy on the maturation, behavior, and reproduction of female mice
Authors: Kennedy James M. , Brown Kenneth
Published: January 2005

Infant female mice who were exposed to the odor of adult male mice of the same strain in the presence or absence of the mother were compared with mice who were not exposed with respect to maturation, open‐field behavior, and reproductive success. Exposure lasted 4 hr daily during days 4–18 post‐partum. No significant differences were found between the groups in their rates of growth or the age of ear, eye, and vaginal opening. However, the exposed groups displayed first estrus significantly earlier than non‐exposed groups: the group exposed in the presence of the mothers showing the earliest first estrus of all 4 groups.
Taurine levels in developing rabbit brain and other organs
Authors: Chanda Rita , Himwich Williamina A.
Published: January 2005

The levels of taurine in brain, heart, liver, kidney, spleen, muscle, and blood of rabbit were determined during development. Taurine was found to be present in a very high concentration at birth and to decrease during maturation in all parts studied except heart.
Care of young under communal conditions in the mouse (MUS MUSCULUS)
Authors: Gandelman Ronald , Paschke Richard E. , Zarrow M. X. , Denenberg Victor H.
Published: January 2005

Lactating mice and their young were housed with either virgin female or male mice. Virgin females cared for the young as much as did the lactating animals and in one instance were actually seen to aid in their delivery. Males displayed little caretaking behavior in the communal situation but exhibited a full range of such behavior when housed individually with young.
Effects of thyroxine level and temperature manipulations upon the hatching of chick embryos (gallus domesticus)
Authors: Balaban Martin , Hill Joanna
Published: January 2005

Thyroxine levels within chick embryos (Gallus domesticus) and incubation temperature were manipulated late in development in order to determine those events most proximal to the time of hatching that are both necessary and sufficient for the appearance of the hatched state. Events recorded include the time of breathing initiation, changes in breathing rate, time of puncture of the chorioallantoic membrane and changes in rate of loss of yolk sac material. It was found that a certain level of thyroxine is necessary for an animal to hatch, that breathing and puncture of the chorioallantoic membrane are necessary but not sufficient to predict the occurrence of hatching, and that a change in rate of loss of yolk sac material during the last 18 hr prior to hatching is sufficient to predict the occurrence of hatching. The explanatory hypothesis offered is that the endogenous increase in thyroxine levels acting via increased metabolic rates is necessary and sufficient for the animals to hatch.
Overview and critique of stages and periods in canine development
Authors: Fox M. W.
Published: January 2005

Several aspects of CNS and behavioral developnient in relation to stages of development and the critical period of socialization in the dog are reviewed. Environmental and experiential treatments which may modify ontogeny are discussed. With particular emphasis on the specific and nonspecific effects of such treatment on the developing phenotype and the dependence or independence of a particular behavior or system upon stimulation, with or without which it may or may not develop. A more complete understanding of the evolutionary and developmental processes underlying the integrative development of the brain and behavior in different species is needed.
Visual and tactual variation seeking in the rat: Intermodal effects of early rearing
Authors: Gorry Thomas H. , Chibucos Thomas R. , Bell Robert W.
Published: January 2005

Conditions of variation and constancy for both tactual and visual stimulation were arranged in a 2 × 2 factorial. Hooded rats were reared under these conditions from 23 to 39 days of age, following which they lived in standard laboratory cages until 49 days of age. Preference tests for variation vs. constancy in both tactual and visual preference tests were conducted at 48 and 49 days of age. Ss previously exposed to the variable stimulation conditions, either tactual and/or visual, showed equal preference for variable stimulation in both tests. This was in contrast to the controls, which preferred the less variable stimulation in both tests. The intermodal effects of the early environmental stimulation were discussed in terms of Fiske and Maddi's activation model.
The effects of maternal nicotine absorption or hypoxic episodes upon appetitive behavior of rat offspring
Authors: Martin Joan C. , Becker R. F.
Published: January 2005

Offspring of rats which had received either daily nicotine injections or hypoxic episodes throughout gestation were tested at adulthood on various appetitive schedules in a double‐bar Foringer chamber. The hypoxic offspring and the offspring whose mothers had received nicotine throughout gestation and the nursing period performed more poorly on fixed‐ratio, variable interval discrimination, and discrimination reversal schedules. Possible explanatory hypotheses are discussed.
Cardiorespiratory regulation and activity patterns of rat pups studied with their mothers during the nursing cycle
Authors: Hofer Myron A. , Grabie Morris
Published: January 2005

Rat pups aged 10 to 19 days were implanted with chronic electrodes and recorded while freely moving in the litter situation, during nursing and throughout naturally occurring maternal absences. Heart rates were significantly higher in the mother's presence (p<.01) while respiratory rates and percent of time spent active were identical under the 2 conditions. Pups' inactive heart rates progressively increased during the 20 min of nursing, while no such time trends were evident in other measures. Inactive heart rates decreased significantly (p<.01) as a function of age; respiratory rates and activity during nursing showed similar trends. A histogram of number of periods of activity bursts of different durations while pups were nursing showed a preponderance of 1‐ to 5‐sec bursts which were observed to be associated with active sucking and pawing movements. This pattern of short bursts of spontaneous activity was repeated almost identically when the mother was absent, although the behavior was qualitatively different. In a second experiment, increases in pups' body temperature of .2°C to 1.0°C were found to accompany active nursing. If such increases were imposed by an artificial heat source, heart rates of pups actually fell slightly. In a third study, heart rates were recorded from nursing mothers and found to be relatively unaffected by stimulation from the pups.
Color preferences and early perceptual discrimination learning in domestic chicks
Authors: Kovach Joseph K. , Hickox John E.
Published: January 2005

The speed of learning to discriminate between the colors blue and green was studied in dark‐raised chicks and in chicks having controlled exposure to these colors and white prior to learning. The data indicate that: (1) under all conditions of prior experience learning was faster when the response to blue was reinforced; (2) learning was significantly slower in dark‐raised groups than in groups having prior visual experience; and (3) learning was negatively related to systematic increase in the intensity of prior exposure stimulus. These data show that unlearned preferences play a significant role in learning; they combine additively with effects of experience prior to learning and reinforcement during learning.
Ontogeny of vision in the peking duck (Aanas platyrhynchos): The pupillary light reflex as a means for investigating visual onset and development in avian embryos
Authors: Heaton Marieta B.
Published: January 2005

The pupillary light reflex was used to determine the onset of visual function in Peking duck embryos (Anas platyrhynchos). Neurally mediated pupillary responses were first elicited on Day 18 (67% of total incubation), but 2 days prior to this and for several days during prenatal life, autonomous iris constriction was found. The neural and nonneural components of the response were separated using both an excision and a curare technique, each of which produced similar results. The pupillary technique for studying visual onset and development was further evaluated by a study of chick embryos (Gallus gallus), in which it was seen that results from this technique were in good agreement with those gleaned from more complex methods. It was concluded that the technique affords several advantages, particularly with respect to clarity of interpretation, ease of execution, and amount of information provided.
Aging and water submersion in C57BL/6J mice: Initial performance and retest as a function of recovery and water temperature
Authors: Wright William E. , Werboff Jack , Haggett Burton N.
Published: January 2005

A total of 300 C57BL/6J male mice of 5 age groups (350, 470, 615, 720, or 845 ± 30 days of age) ranging from 50 to 120% of their expected life span were tested in a water submersion task with water temperature maintained at 23.5°C. Mice were retested to evaluate recovery from this stressor at either 24 or 168 hr after initial test. The retest was conducted at 1 of 3 temperatures (12.5, 23.5, or 34.5°C). On the initial water submersion test at 23.5°C, significant effects of advanced age were evident, with the oldest group (845 days) having the shortest time to submersion. No significant difference was evident between the two younger age groups with the longest time to submersion found in the middle (615‐day old) group. In the 2 oldest groups, submersion time scores decreased progressively and significantly. On the retest, significant effects were found for water temperature. The effects of water temperature were linear and consistent across ages and conditions with increasing temperature up to the maximum used in this experiment, resulting in longer time to submersion. The longer recovery time (168 hr.) to retest yielded inconsistent results with longer time to submersion scores found only in the 350 and 720‐day old groups.
Early maternal handling and preschool behavior of human children
Authors: Harper Lawrence V.
Published: January 2005

Release of adrenal medullary hormones as a result of activating the orthostatic pressor reflex may influence human infants' later behavior. The amount of time mothers held their infants in an upright position during the 1st and 3rd months postpartum was negatively related to the same children's tendency to cope with difficulties encountered in manipulating inanimate objects at the age of 30 months. This effect may represent a physiological response to early maternal handling.
The transition from filial to reproductive function of “Coitus‐Related” responses in young guinea pigs
Authors: Harper Lawrence V.
Published: January 2005

A lordosis‐like response and a purring vocalization which was similar to that emitted by the adult male in precopulatory displays were observed in suckling guinea pigs. During that period in which parental stimulation was required to elicit micturition, both responses occurred in the context of nursing behavior and were frequently followed by the mother's licking the pups' anogenital regions; there was no sex difference in the display of these behaviors. When adult micturition behavior matured, the frequency of lordosing waned in both sexes; purring also declined in females, but in males, purring became associated with a hip‐swaying movement and increased in frequency. In adult females, the display of lordosis and/or purring was confined to estrous periods; males were not observed to lordose as adults, but purred when exposed to estrous females. Isolation‐ and mother‐reared animals displayed the same response organizations in infancy and adulthood. The functional reorganization of these responses in ontogeny is discussed.
Differences in maternal responsiveness between lactating and sensitized rats
Authors: Bridges Robert , Zarrow M. X. , Gandelman Ronald , Denenberg Victor H.
Published: January 2005

Retrieval in lactating females, sensitized virgin females, and sensitized adult male rats was compared in a T‐maze extension of the home cage. The percent of lactating females that retrieved was significantly greater than in either the sensitized virgin of sensitized male groups. No difference was found between the two sensitized groups. The data are discussed in terms of the hormonal involvement in maternal behavior.
Vulnerability of developing brain: IV. Passive avoidance behavior in young rats following maternal undernutrition
Authors: Smart J. L. , Dobbing John
Published: January 2005

An investigation was carried out of the effect of undernourishing rats during much of gestation and throughout the whole suckling period on their behavior in a passive avoidance situation. All young were fed ad libitum from 21 days of age. Passive avoidance tests were done at 30 and 31 days in a two‐compartment box. On the first test normal rats tended to cross between compartments more promptly than previously underfed rats. Cross‐over latency was always greater on the second test than on the first. There were no significant differences in test 2 latency or in the ratio, test 2 latency/test 1 latency, between sexes, between normal and previously undernourished rats, between groups with 2‐min and 24‐hr interest intervals, or between master and yoked control rats. The last finding indicates that the apparent passive avoidance response may have been either nonspecific ‘freezing’ behavior following unpleasant stimulation, or inhibition specifically of movement, due to its association with shock.
Reduced activity in rats with induced phenylketonuria
Authors: Vorhees C. V. , Butcher R. E. , Berry H. K.
Published: January 2005

Hypoactivity 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

Newly 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

The 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

Recent 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

Six 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

The 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

Kittens 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.