bluuebunny/crossref_metadata_2025_split huggingface dataset:
Urinary odors and size protect juvenile laboratory mice from adult male attack
Authors: Taylor George T. 
Published: January 2005

AbstractFor a portion of their ontogeny, the juveniles of many mammalian species appear resistant to aggressive attack by adult male conspecifics. The possibility that urinary odors and small size contribute to this immunity from attack was investigated with C57/Bl, A/J, and DW/J laboratory mice. The results of the 1st of 6 experiments were that juvenile mice of both genders evoked great curiosity from aggressive resident male adults, but juveniles were rarely attacked. In Experiments II and III, exchanging urine between juveniles and adult males suggested that juveniles possess a distinctive odor. In Experiments IV–VI, dwarf adults, normal‐sized adults, and juveniles were placed with aggressive adult male residents. The dwarf males were attacked, but not as severely as normal‐sized male intruders (Experiment IV). The dwarf males, however, evoked more aggressive behavior than juveniles (Experiment V), and juveniles with the odors from either normal‐sized or dwarf adult males were attacked more readily than non‐odorized juveniles (Experiment VI). These data suggest that both odor and size contribute to the juveniles' immunity from attack.
Appetitive conditioning in neonatal rats: Conditioned orientation to a novel odor
Authors: Johanson Ingrid B. , Hall W. G. 
Published: January 2005

AbstractThese experiments document a form of early appetitive learning in rats obtained using classical conditioning procedures. Some of the special determinants of this conditioning are described, as well as ontogenetic changes in the effectiveness of training procedures. Learning was apparent when deprived 3‐ and 6‐day‐old rats oriented to and maintained contact with a novel and normally aversive odor after this odor had been paired with oral infusions of milk (Experiment I). The effectiveness of the conditioning procedures depended on the temperature at which pups were trained (Experiment IB). Moreover, the reinforcing properties of milk infusions depended on deprivation (Experiment IC). This conditioned change in responsiveness to odor was specific to the odor that had been paired with milk (Experiment II) and was retained for at least 24 hr (Experiment III).
Influence of the maternal surrogate on pituitary–adrenal activity and behavior of infant squirrel monkeys
Authors: Hennessy Michael B. , Kaplan Joel N. 
Published: January 2005

AbstractSquirrel monkey infants reared on surrogates showed an increase in vocalizations, but no change in plasma cortisol levels when the surrogate was removed from the home cage for .5 hr. When the infant was exposed to novelty during separation, there was a further increase in vocalizations, as well as increases in movement and plasma cortisol. Placing the surrogate with the infant in the novel environment reduced the behavioral reaction and led to high levels of infant‐surrogate contact; however, plasma cortisol levels were as high at .5 hr as when the infant was in the novel environment alone. With longer (2–4 hr) exposures to the novel room, cortisol elevations were attenuated by the presence of the surrogate. When the infant was alone, levels of cortisol, but not protest behavior, increased with length of exposure to the novel room. These results indicate that the physiological reaction to separation procedures in infant primates may not be safely inferred from behavioral responses, and, together with earlier findings, suggest a deficiency in the attachment of surrogate‐reared infants.
The ontogeny of heart period patterning in the rat
Authors: Larson Sandra K. , Porges Stephen W. 
Published: January 2005

AbstractHeart period, heart period variability, and respiration frequency were observed and compared longitudinally in rats from birth to 24 days of age. In addition, V, a quantification of respiratory sinus arrhythmia derived via spectral analysis of the heart period pattern, was observed. It was hypothesized that these heart period parameters would be differentially sensitive to the neural control of the heart and would, therefore, reflect different developmental patterns. Heart period and heart period variability indicated developmental patterns consistent with the literature. The ontogeny of V suggests that it may represent the developmental pattern of tonic vagal influences on the heart.
Mother‐infant interaction and the modulation of pituitary‐adrenal activity in rat pups after early stimulation
Authors: Smotherman William P. 
Published: January 2005

AbstractIn Experiment I, handling or electric shock of 2‐day‐old rat pups triggered pituitary‐adrenocortical activity. Interaction between mother and litter after pup treatment affected the magnitude and the time course of the pups' adrenocortical response. Mother‐infant interactions following pup treatment on Day 2 were found to affect the responsiveness of pups to later stimulation. In Experiment II handled or shocked pups that were returned to a mother‐absent nest were subsequently found to be less responsive to ACTH injection than were pups returned to a mother‐present nest following treatment. These data are discussed in terms of the reciprocity and synchrony in mother‐infant interactions and the Maternal Mediation hypothesis of early experience.
Chemosignal effects on puberty in young female mice: Urine from pregnant and lactating females
Authors: Drickamer Lee C. 
Published: January 2005

AbstractA series of 8 experiments tested the effects of urine from pregnant and lactating female mice on sexual maturation of young females. Urine collected from females at various intervals during pregnancy and lactation and painted on the nares of young test females produced different effects on the age of puberty depending upon the collection interval. The urinary substance which accelerates puberty is found in the bladder urine of both pregnant and lactating females as well as in the excreted urine of females that are both lactating and also simultaneously pregnant. Four separate experiments demonstrated that grouping pregnant or lactating females at various densities, either with other females in the same stage of reproduction, or with nonreproductive females, resulted in excretion of urine which did not accelerate or delay puberty in young test mice. These results conform with a general hypothesis regarding the release of urinary chemosignals in female house mice as indicators of the adequacy of social and environmental conditions for successful reproduction.
Effects on the behavior of infant common marmosets (Callithrix jacchus) of separation from caregivers and of drug‐induced reduction in caregiver responsiveness
Authors: Chalmers N. R. , Locke‐haydon J. 
Published: January 2005

AbstractThe effects of separating 4‐week‐old twin marmosets for 8 days from their families are compared with the effects of leaving 4‐week‐old infants with their families, but reducing the responsiveness of their caregivers for 8 days by administration of the tranquilizer fluphenazine decanoate. Both treatments reduce infant mobility, abolish play, and increase the time that infants spend with each other. During the period after the termination of the treatment, both treatment groups continue to play and move less than controls, and try to climb onto the mothers more frequently. These results are consistent with the hypothesis that the principal factor precipitating disturbed behaviors in infant monkeys subjected to long‐term separation is disruption of the infant‐caregiver relationship rather than the separation itself. Some post‐treatment differences occur between separated and tranquilized groups. Notably, reunion after separation appears to involve a marked readjustment of the behavior of all family members to the return of the infants, whereas withdrawal of the tranquilizer does not.
High motivation toward food increases food‐sharing in cotton‐top tamarins
Authors: Feistner A. T. C. , Chamove A. S. 
Published: January 2005

AbstractIn order to explore whether or not adult motivation influences transfer of food to infants in cotton‐top tamarins (Saguinus oedipus oedipus), 2 experiments were carried out with 3 large captive family groups. Examination of (a) natural changes in food motivation during feeding, and (b) elevated motivation toward food by giving highly preferred items, showed that the adult monkeys shared food more when their own level of motivation was high. This suggests that food‐transfer is not merely a consequence of adult satiation, but that matching sharing with high adult motivation is a mechanism which ensures that infants receive ample food, the best items, and also rare items of high quality.
Huddling and independent feeding of neonatal rats can be facilitated by a conditioned change in behavioral state
Authors: Sullivan Regina M. , Brake Stephan C. , Hofer Myron A. , Williams Christina L. 
Published: January 2005

AbstractInfant rat pups were exposed to a novel odor (orange or cedar) while they received tactile stimulation (stroking of the body) or were presented with odor or stroking alone. The effects of these treatments were assessed on pups' performance in a huddling test (Experiment 1 and 2) and an independent feeding test (Experiment 3). During these tests, only pups that had received the simultaneous presentation of the odor and stroking exhibited an increase in huddling and feeding. The increase in these behaviors was dependent on the presence of the conditioned odor during testing.
Preferences of female rhesus monkeys (Macaca Mulatta) for infantile coloration
Authors: Higley J. Dee , Hopkins William D. , Hirsch Regina M. , Marra Lauren M. , Suomi Stephen J. 
Published: January 2005

AbstractWhile developmental researchers have long noted that infants of many mammalian species, including primates, have characteristic physical features, such as a distinctive coat or skin color, and some authors have further suggested that these features serve to elicit caretaking and solicitous behavior, few systematic investigations of the actual salience of such features for adult conspecifics have been carried out to date. The present series of 3 studies sought to determine whether natal coat and/or facial skin coloration might provide desirable visual stimulation for rhesus monkey adult females. In these studies the faces and/or fur of 6‐month‐old rhesus monkeys were dyed to simulate the normal coloration of rhesus monkey neonates. Adult females varying in parity and rearing history were then tested for their relative preference between these infantile‐colored 6‐month‐olds and both normally colored 6‐month‐olds and other differentially colored control stimulus monkeys. Results indicated that regardless of parity or rearing history the adult female subjects exhibited consistent preferences for the stimulus animals with neonatal‐like reddish‐pink facial skin coloration.
Sensory modulation of juvenile play in rats
Authors: Siviy Stephen M. , Panksepp Jaak 
Published: January 2005

AbstractA series of experiments was conducted to determine the extent to which somatosensory stimulation is necessary for the elaboration of juvenile play in rats. Anesthetization of the dorsal body surface of juvenile rats with xylocaine reduced the frequency of pinning, an indicator variable for play, by 35% to 70%, while motivation to play, as measured by dorsal contacts, an index of play solicitation, remained largely intact. These data suggest that dorsal body surface anesthetization impairs the ability of juvenile rats to perceive and/or respond to playful gestures. When untreated animals were paired with xylocaine‐treated animals, the xylocaine‐treated animals consistently pinned the untreated pups more than vice versa, further suggesting that somatosensation may be involved in the establishment and/or maintenance of play dominance relations. A preliminary examination assessing potential involvement of other modalities in the play of rats was also conducted, with the data suggesting a possible role for audition in the play of this species.
Maternal contact inhibits pituitary‐adrenal stress responses in preweanling rats
Authors: Stanton Mark E. , Wallstrom James , Levine Seymour 
Published: January 2005

AbstractThree experiments examined psychological factors which inhibit pituitary‐adrenal activity in 12‐, 16‐, and 20‐day‐old rats. Infant rats were placed in heated novel test arenas for 30 min—a treatment which increases corticosterone secretion—and were presented with different appetitive stimuli in order to determine whether these stimuli inhibit this increased hormone secretion. The first experiment was a factorial combination of two conditions: suckling an anesthetized dam and milk ingestion through an intraoral cannula. At all ages, suckling inhibited corticosterone secretion but milk ingestion did not, nor was there an interaction of these factors. In the second experiment, the importance of suckling was assessed by allowing pups' contact with an anesthetized dam either with or without the opportunity to suckle. At all ages, contact with suckling and contact alone were equally effective in inhibiting corticosterone secretion. The third experiment asked whether contact with a lactating female is necessary for pituitary‐adrenal inhibition or whether more distal cues associated with lactation are sufficient. Pups were tested under one of four treatments formed by a 2(Lactating vs. Virgin Female) × 2(Contact vs. No Contact) factorial design. At all ages inhibition of corticosterone secretion occurred only in animals which were allowed contact with an anesthetized female. Lactating and virgin females were equally effective for the 12‐ and 16‐day‐old pups, but contact with a virgin female was less effective for the 20‐day‐old pups. These findings indicate that neuroendocrine mechanisms subserving inhibition of the pituitary‐adrenal system exist during the preweanling period in the rat, and suggest the possibility of maternal regulation of this physilogical system during development.
Inhibition of the eyeblink reflex in the human infant
Authors: Hoffman Howard S. , Cohen Michelle E. , Anday Endla K. 
Published: January 2005

AbstractIn human adults the eyeblink elicited by a given stimulus can be inhibited if that stimulus is preceded by another stimulus at an appropriate lead interval. In the present work, pairs of eyeblinkeliciting stimuli separated by 300–1200 msec were presented to sleeping preterm and full‐term infants as well as to adults. Preterm infants did not exhibit reliable inhibition at any interval. Full‐term infants did so, but they required longer interstimulus intervals than were needed for inhibition in the adult subjects. Results imply that the neural systems that mediate reflex inhibition are functional at birth, but that they are relatively slow to act.
Further examination of ontogenetic limitations on conditioned taste aversion
Authors: Hoffmann Heather , Molina Juan C. , Kucharski David , Spear Norman E. 
Published: January 2005

AbstractThis study was to resolve a discrepancy in the literature as to the capability of infant rats in acquiring conditioned taste aversion. Previous studies had indicated that during the 1st postnatal week, an aversion to saccharin could be conditioned when paired with lithium chloride (LiCl). Analogous conditioning with sucrose did not seem to occur until the end of the 2nd postnatal week, however, even though sucrose is discriminated from water and preferred before then. We observed that 5‐ and 9‐day old pups express conditioned taste aversion to both saccharin and sucrose flavors that previously were paired with illness induced by LiCl. This learning occurred only when several hours separated cannulation and conditioning. A number of other factors that seemed likely to determine this early learning were found to have no effect. Thus is appears that rats can learn taste aversions very early in life, but only under certain circumstances. The results are discussed with reference to Vogt and Rudy's (1984) conclusions on the ontogeny of taste guided behaviors in the rat.
Sensory control of the initiation of hatching in chicks: Effects of a local anesthetic injected into the neck
Authors: Bekoff Anne , Sabichi Anita L. 
Published: January 2005

AbstractPrevious work shows that folding a posthatching chick into the hatching position results in the re‐initiation of hatching. Furthermore, bending the neck to the right or left serves as a selective signal for turning on hatching behavior. The present study addresses the issue of whether sensory receptors located in the neck provide this signal. Three groups of chicks were folded into the hatching position and placed in glass eggs. In the experimental group, sensory input from the neck was eliminated with a local anesthetic, lidocaine. In these chicks, hatching was initiated only after a long latency, correlated with the time at which the anesthetic wore off. In the two control groups, in which saline was injected into the neck or lidocaine was injected into the thigh, the latency was much shorter. Therefore sensory receptors located in the neck appear to provide input that serves as a selective signal for initiating hatching.
Changes in the categorization of appetitive and aversive events during postnatal development of the rat
Authors: Camp Laurel L. , Rudy Jerry W. 
Published: January 2005

AbstractEnvironmental stimuli are not clearly categorized into appetitive and aversive classes during the first postnatal week. Three‐ and 6‐day‐old rats are highly activated by nominally appetitive (milk infusions) and aversive (foot shock) stimuli. Both evoked the same generalized behavioral responses (rolling, curling). By 12 days of age, these stimuli were responded to differently; mouthing and probing occurred in response to milk while flinching and escape responses were observed to shock. The affective properties of mild shock were found to be hedonically opposite for 6‐ and 12‐day‐old pups. Six‐day‐old showed an acquired preference for an odor paired with shock which increased with intensity (.1–.5 mA) similar to that observed with milk infusions. An acquired odor aversion was displayed by 12 days old using these shock parameters. These results suggest that young rat pups may not differentiate many appetitive and aversive events behaviorally or affectively until the second postnatal week.
Reinforcers in infancy: Classical conditioning using stroking or intra‐oral infusions of milk as UCS
Authors: Sullivan Regina M. , Hall W. G. 
Published: January 2005

AbstractSix‐day‐old rats received 20 forward pairings of an odor‐conditioned stimulus (CS) with one of two unconditioned stimuli (UCS); (1) intra‐oral milk infusions or (2) stroking with a sable‐hair brush. These UCS's produce a common general response of increased behavioral activity, but different specific behaviors. For each UCS, additional pups received backward pairings of the CS and UCS, random pairings of the CS and UCS, CS only, UCS only, or no stimuli. Four hours later, pups received a two‐odor choice test to assess the development of an odor preference and a CS‐only test to assess the acquisition of conditioned responding (CR). The results of the two‐odor choice test indicated that for both UCS's only forward pairings of the CS and UCS resulted in an odor preference. Similarly, the CS‐only test showed that only forward pairings of the CS and either UCS were effective in producing CR's; pups that received forward pairings exhibited increased behavioral activity during presentations of the CS, which is an unconditioned response (UCR) to both UCS's. Only the forward paired CS‐milk UCS group exhibited increased mouthing and probing during the CS only test; these are UCR's that occur to milk infusions but infrequently to the stroking UCS. These results demonstrate the development of similar conditioned odor preferences using behaviorally activating UCS's, but CR's which are specific to the form of the UCR.
Formation and expression of filial attachment in rhesus monkeys raised with living and inanimate mother substitutes
Authors: Mason William A. , Capitanio John P. 
Published: January 2005

AbstractThe formation and expression of filial attachment was investigated in rhesus monkeys raised with dogs or inanimate mother substitutes in a longitudinal study spanning the first 4 years of life. At 2 months monkeys were identified within each rearing group as strongly attached or weakly attached, as measured by proximity, contact and clinging to the mother substitute in the living cage and in a novel room, and by differences in levels of distress vocalization and heart rate when they were alone and in the presence of the substitute mother in a novel room. By 4 months, all monkeys were attached, and the strongly attached and weakly attached monkeys of the first age‐period were no longer distinguishable on any measure. The attachment was specific to the substitute mother. It was not exclusive, however, inasmuch as similar responses were elicited by a stranger of the same type as the substitute mother, although the stranger was less effective. The attachment figure was also influential when it could be seen but not touched. Evidence of attachment to the substitute mothers persisted until the end of testing at 44 months. Comparison of rearing groups support the hypothesis that the principal effect of living and inanimate mother substitutes is on responsiveness, rather than on the attachment process per se.
Vocalizations of juvenile cowbirds (Molothrus ater ater) evoke copulatory responses from females
Authors: West Meredith J. , King Andrew P. 
Published: January 2005

AbstractThe functional attributes of the vocalizations produced by young male cowbirds during their first fall and winter, termed “vocal precursors,” were tested by playing the sounds back to female cowbirds. Five classes of vocalizations were tested: subsong, plastic, formatted, and stereotyped song, and songs of nonconspecifics. Females responded selectively to the four classes of cowbird vocalizations. Stereotyped songs evoked the most responding but the key eliciting element was the inclusion of note clusters, which first occurred in plastic song. The data suggest that juvenile cowbirds possess vocalizations capable of evoking biologically relevant responses from companions early in development.
Ontogenetic differences in short‐term retention of pavlovian conditioning
Authors: Miller James S. , Spear Norman E. 
Published: January 2005

AbstractIn the present series of studies 16‐ and 21‐day‐old rats acquired an aversion to a black compartment (CS+) paired with footshock, only if given preconditioning exposure to a white chamber (CS‐) not paired with footshock. The strength of conditioning was inversely related to the lenght of the retention interval in both age groups. However, the rate of forgetting was accelerated in the 16‐day‐old subjects, indicating infantile amnesia for the conditioned aversion. Strenght of conditioning was also inversely related to the lenght of the CS‐/CS+ interval in both age groups, indicating that expression of the aversion is critically dependent on an active memory of the CS‐ at the time of conditioning. Additionally, there was an ontogenetic decrease in the rate of forgetting of the CS‐, indicating infantile amnesia for elements of the conditioning episode that did not predict occurrence of US.