bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differences in maternal behavior of rats and the sociosexual development of the offspring
Authors: Birke Lynda I. A. , Sadler Dawn 
Published: January 2005

AbstractThis paper describes experiments designed to investigate long‐term behavioral consequences for offspring of changes in maternal behavior directed toward them as pups. Specifically, the hypothesis was considered that experimentally induced alterations in maternal behavior would result in general and wide‐ranging effects on offspring development, including effects on later social and sexual behavior. The first experiment looked at the effects of changing pup odors on maternal responsiveness toward those pups, and showed that the application of perfume, particularly to the anogenital region, resulted in significant lowering of maternal anogenital licking of pups. Non‐pup‐directed behavior did not differ between groups. The behavior of those pups that had thus differed in infant experience was then followed in three subsequent experiments. In Experiment 2, social behavior during the juvenile period was investigated, focusing particularly on the expression of social play. The most noticeable difference to emerge in this experiment was that male pups that had been anogenitally perfumed as infants showed much higher levels of social play than male or female pups from other treatment groups. The last two experiments considered adult behavior. Experiment 3 showed that there are no lasting effects of the neonatal treatment on the attractiveness an animal has for its conspecifics. In the final experiment, “masculine” sexual behavior of males (mounts with intromission), and “feminine” sexual behavior of females (i.e., lordosis and proceptive behavior) were investigated. This confirmed previous reports by Moore (1984) (Moore, C. L. (1984). Maternal contributions to the development of masculine sexual behavior in laboratory rats. Dev. Psychobiol., 17:347–363) that those male pups that had received lower rates of anogenital licking as pups showed longer intermount intervals, when tested as adults. The results are discussed in relation to the development of sexually differentiated behavior.
Mothers' recognition of their newborns by olfactory cues
Authors: Kaitz M. , Good A. , Rokem A. M. , Eidelman A. I. 
Published: January 2005

AbstractWe report that 90% of women tested in the present study identified their newborns by olfactory cues after only 10 min‐1 hr exposure to their infants. All of the women tested recognized their babies' odor after exposure periods greater than 1 hr. The robust results are due in part to the implementation of an initial screening phase in which individuals with obvious olfactory deficits were excluded from the sample. These results suggest that odor cues from newborns are even more salient to their mothers than have been thought heretofore.
Effects of odor familiarity on the development of systematic exploration in the spiny mouse, Acomys cahirinus
Authors: Birke Lynda I. A. , Sadler Dawn 
Published: January 2005

AbstractDevelopmental changes in patterns of exploration by infant spiny mice, Acomys cahirinus are described. These were investigated using an unbaited radial maze and under three odor conditions; that is, animals were tested in the presence of either familiar (own) odors, unfamiliar conspecific odors, or no odors (washed floor). Two hypotheses were tested. The first was based on the results of a pilot study, and was that adult animals would explore the radial maze in a systematic and predictable fashion tending to move from one arm to the next sequentially. It was hypothesized that infants would adopt this sequential strategy only gradually, as they matured. The second hypothesis was that such patterns of exploration would depend upon the olfactory environment; the presence of familiar odors might facilitate systematic patterns of exploration in very young Acomys. The results showed that both adults and juveniles were less likely to move sequentially when tested with no conspecific odor present; sequential patterns of movement were most likely in the presence of unfamiliar odor, however. The only significant change with age in infants was found for animals tested with unfamiliar odors; these animals showed a dramatic increase in sequential behavior between 3 and 7 days of age. Two additional experiments are reported, which investigated the preferences of infant Acomys for unfamiliar conspecific odors, and it was found that very young (about 3 days) animals exhibit a preference for odors derived from unfamiliar conspecific litters, even when tested in the physical presence of their own parents. The results are discussed with reference to the use of olfactory information as directional cues for animals exploring the radial maze.
Early experience influences adult retention of aversively motivated tasks in normal, but not DSP4‐treated rats
Authors: Cornwell‐Jones Catherine A. , Velasquez Pattijo , Wright Eileen L. , McGaugh James L. 
Published: January 2005

AbstractSprague‐Dawley rat pups were injected with DSP4 or water within 48 hr of birth and tested as adults in an inhibitory avoidance task and in a Y‐maze discrimination reversal task. Half of the animals were also tested as juveniles during postnatal weeks 4–5, in tasks assessing odor preferences and general investigatory behavior. Controls, but not drug‐treated adults, which received the juvenile testing, showed significantly better retention on both tasks than either controls or drug‐treated animals not tested as juveniles. Neonatal DSP4 significantly reduced norepinephrine concentrations in the hippocampus and frontal cortex, but not the heart. The results suggest that central norepinephrine may modulate the effects of early experience on adult learning.
Play‐fighting in the Syrian golden hamster Mesocricetus auratus waterhouse, and its relationship to serious fighting during postweaning development
Authors: Pellis Sergio M. , Pellis Vivien C. 
Published: January 2005

AbstractIn the Syrian golden hamster Mesocricetus auratus, play‐fighting preceds serious fighting during postweaning development, and so may be thought to be a developmental precursor to adull aggression. However, based on both the targets attacked—that is, the cheek pouches during play‐fighting and the rump or flanks during serious fighting, and the behavior patterns employed to attakc and defend these targets—these two forms of fighting are shown to remain distinct from each other throughout development, even during the ages where they overlap. The decline of play in post‐sexually‐mature animals is shown to result from an increasing intolerance to contact between animals, and hence greater difficulty in the maintenance of a “playful mood.” Therefore, these data show that play‐fighting does not grade into serious fighting, and thus does not serve as a developmental precursor to adult aggression.
Human interlimb coordination: The first 6 months of independent walking
Authors: Clark Jane E. , Whitall Jill , Phillips Sally J. 
Published: January 2005

AbstractThe organization of interlimb coordination was studied in newly walking infants with and without support and in infants who had been walking 0.5, 1, 3, and 6 months. Analysis of the temporal and distance phase relationships between the limbs revealed that newly walking infants exhibit interlimb coordination similar to that of mature walkers. The coupling between the limbs, however, is loosely constrained, approaching adult‐like consistency after 3 months of walking. Providing support for the newly walking infant afforded a more consistent, mature coordination suggesting that neuromuscular development is in advance of its ability to function in the physical world.
Infants of diabetic mothers: Late normalization of fetal cyclic motility persists after birth
Authors: Robertson Steven S. 
Published: January 2005

AbstractThe prenatal development of cyclic motility (CM) in the human is disrupted by maternal diabetes, but appears normal by the end of gestation. To determine whether birth and adaptation to postnatal life reveal new or persisting abnormalities in CM, 24 newborn infants of insulin‐dependent diabetic mothers (IDMs) and 24 normal newborns were studied for 2–4 hr in a controlled environment. Spectral analysis of spontaneous movement revealed that CM was common in both groups. Measures of its cyclic organization in each state did not differ between IDMs and controls. State differences were the same in the two groups, and replicated the pattern found in a previous study of normal newborns. For IDMs, there were no differences associated with neonatal evidence of increased glucose supply in utero (macrosomia, postnatal hypoglycemia), or with determinations of prenatal maternal hyperglycemia. IDMs had also been studied as fetuses, and the pattern of continuity and change in CM across birth replicated the pattern previously reported for normal fetuses. The results suggest that the development and control of CM is buffered from the prenatal metabolic insults suffered by IDMs, and support speculations that cyclic activation is a general and robust property of the developing motor system in the human.
Development of species identification in ducklings: XV. Individual auditory recognition
Authors: Gottlieb Gilbert 
Published: January 2005

AbstractThe present experiments examined the ability of domestic mallard ducklings (Anas platyrhynchos) to learn individual mallard maternal calls by either repetition‐rate differences or spectral (Hz) differences, both of which are present in such calls recorded in nature. The ducklings could learn both kinds of differences within the first 24 hr after hatching, corresponding to the period prior to the exodus from the nest in nature. The hatchlings were able to learn these differences based upon only 12 min of exposure to the maternal calls during the first day after hatching. They were also able to retain (remember) the familiar call for an additional day after exposure. Embryos, on the other hand, could learn the spectral differences after either 12 or 24 min of exposure but could not retain the information under either exposure condition. An additional difference between the auditory learning competence of hatchlings and embryos was that the hatchlings were capable of learning the spectral features of a maternal call even if it was pulsed at different repetition rates during exposure (familiarization) and the subsequent test for recognition. The evolutionary significance of the results was discussed in terms of the general importance of familiarization as a basic behavioral mechanism underlying not only parental attachment but dietary and habitat preferences and the like.
Early‐life malnutrition impairs the performance of both young and adult rats on visual discrimination learning tasks
Authors: Castro Carl Andrew , Rudy Jerry W. 
Published: January 2005

AbstractPreviously malnourished young (20–40‐day‐old) and mature (70–77‐day‐old) rats were compared on position, brightness, and pattern discrimination problems using an aquatic version of the Lashley jump stand. Malnutrition did not affect performance on the position discrimination. In contrast, previously malnourished 24–34‐day‐olds failed to solve the brightness discrimination, 40‐day‐olds were impaired on the brightness problem, and 40–77‐day olds were impaired on the pattern problem. The impaired performance of the 40‐day‐olds on the brightness problem was eliminated by prior training on the pattern discriminations, and the impaired performance of the 70‐day‐olds on the pattern discrimination could be eliminated if they were first trained on the brightness problem. These impairments were attributed to the effects of early‐life malnutrition on the maturation of attention processes that enable the rat to suppress responding to irrelevant cues. The relevance of a contextual‐organismic perspective for understanding the effects of early‐life malnutrition was discussed.
Activity states and motor activity in an infant capuchin monkey (Cebus apella) from birth through eleven weeks
Authors: Fragaszy Dorothy Munkenbeck 
Published: January 2005

AbstractBehavioral states and motor activity of an infant capuchin monkey reared by its mother in a social group were studied for 11 weeks after birth. Manipulative activity was infrequent through the first four weeks after birth; what little occurred was mediated by other animals interacting with the infant. The rate of manipulation increased the most between weeks 8 and 9. At the same time, the most frequent targets of manipulation shifted from the infant's own body and the bodies of others to surfaces and inanimate objects in the cage. Large increases in the proportion of time in an Alert/active state and improvement in postural control also occurred at the end of the second month. The data suggest that major organizational changes in motor coordination and the regulation of behavioral state occurred jointly over a short period of time at about 8 weeks of age. In comparison to other species of monkeys, the capuchin infant displayed later development of manipulation, postural control, and independent locomotion, and greater dependence on social contacts for early interaction with its environment. These characteristics are in accord with the greater neurological immaturity of the capuchin infant at birth compared to other monkeys.
Visual head extension: Transitional head coordination in the pigeon squab (Columbia livia)
Authors: Davies Mark N. O. , Green Patrick R. 
Published: January 2005

AbstractWe describe a previously unreported visuomotor behavior of the developing pigeon squab, which we term “visual head extension.” The behavior consists of extension and lowering of the head as the bird descends towards a surface or experiences the optical equivalent of such a descent. A peak in performance occurs 10 days after hatching. Evidence obtained shows that both vestibular and dynamic visual information can independently produce head extension. We go on to place the new behavioral response in the context of a dynamic, relational approach to perceptuomotor coordination, and outline the corresponding advantages of studying the single‐limb, head‐neck system in the pigeon.
Contour variables in vocal communication between squirrel monkey mothers and infants
Authors: Biben Maxeen , Symmes David , Bernhards Deborah 
Published: January 2005

AbstractThis study investigates the occurrence and structure of the caregiver call, a form of communication in squirrel monkeys that is almost exclusively infant‐directed. Caregiver calls exhibit variability in several acoustic features, most notably pitch range and contour, which are significantly associated with particular context of infant care; e.g., nursing or retrieval. The use of caregiver calls by squirrel monkeys is compared to the use of motherese (infant‐directed speech) by humans. The possible functional and motivational basis for specific acoustic variable in the caregiver call is discussed.
Environmental factors and age of puberty in female house mice
Authors: Drickamer Lee C. 
Published: January 2005

AbstractGenetics, urinary chemosignals and related social influences, and ambient conditions affect reproduction in female mice. Five experiments tested the effects of environmental stressors on age at first vaginal estrus in female house mice. Environmental disruption in the form of changing the cage bedding and/or nesting material at various prescribed intervals resulted in different degrees of puberty delay relative to non‐disrupted control mice. Disruption in the form of a male chasing the female for one to three 15‐min intervals each day or the female being trapped and held in a live‐trap for one to three 15‐min intervals each day resulted in delays in puberty for treatments involving multiple daily disruptions. Food deprivation, but not water deprivation, influenced the onset of puberty. Variations in temperature and humidity resulted in differences in the age of puberty; low but not high temperatures and extremely low humidity levels delayed sexual maturation.
The ontogeny of thermal nociception in domestic fowl: Thermal stimulus intensity and isolation effects
Authors: Hughes Richard A. , Sufka Kenneth J. 
Published: January 2005

AbstractSocially housed leghorn cockerels were confined to a heated grid (55, 57, or 59°C, Experiment 1; 59, 61, or 63°C, Experiment 2) and tested at posthatch ages of 14 days (Experiment 1) and 1, 3, 7, or 14 days (Experiment 2). In Experiment 1, chicks performed a discrete jump response only at 59°C. In Experiment 2, jump latency was inversely related to temperature at each age but significantly so only at 7 and 14 days posthatch. At the highest temperature, jump latency did not differ significantly across ages. At medium and low temperatures, latency increased from 1 and 3 to 7 days posthatch (antinociceptive effect) and decreased thereafter. Chicks raised in isolation from hatch to 7 days posthatch (Experiment 3) did not display the increased jump latency (antinociceptive effect) displayed by socially raised chicks. Developmental increases in jump latency may reflect stress‐induced antinociceptive concomitants of neophobia that emerge with age in this precocial species and social experience may be required for the normal development of this stress‐induced antinociception.
The ontogeny of antiphonal calling in European starlings
Authors: Chaiken Marthaleah 
Published: January 2005

AbstractThe ontogeny of antiphonal calling was studied in free‐living European starlings. Nestlings participate in three types of vocal exchanges: (1) Broodmates exchange calls while the parents are away; (2) parents and nestlings exchange calls during feeding; (3) nestlings exchange calls with parents approaching from a distance. Analysis of the temporal patterning of vocal interactions revealed call alternation and avoidance of acoustic overlap in exchanges of the first and third types. The antiphonal exchanges between parents and young develop shortly before fledging and appear to help family groups maintain contact after the young have left the nest. Early antiphonal exchanges between broodmates are as smooth as later ones between parents and chicks, suggesting that chicks quickly attain proficiency at antiphonal interactions and do not rely on an adult partner to maintain the pattern. There are parallels with the development of vocal turn‐taking in human infants.
The role of age‐dependent behaviors in the retention of an approach‐avoidance response in preweanling rats
Authors: Weihmuller Fredric B. , Collier Alexis C. 
Published: January 2005

AbstractThe role of age‐dependent responses in infantile amnesia was examined. Ten‐ and 15‐day old rats were trained in an approach‐mother, avoid‐shock paradigm and tested for retention immediately and after a 1‐day delay. Ten‐day‐old rats were also tested after 6 days. Half of all the pups received a shock reactivation treatment before the delayed retention tests and half did not. In comparison to immediate retention, performance declined after 1 day but was reinstated by reactivation. A similar reactivation effect was found on 10‐day‐old pups tested after 6 days except that a different age‐specific response was substituted for the original behavior. These effects were not found in untrained controls. These data show that learning may be expressed differently when acquisition and retention are measured at different developmental stages, a pattern that may be mistaken for infantile amnesia.
Responses of infant mice to odors of urine from infanticidal, noninfanticidal, and paternal male mice
Authors: Elwood Robert W. , Kennedy Hazel F. , Blakely Helen M. 
Published: January 2005

AbstractInfant mice responded differently to the odors of urine from isolated‐infanticidal, isolated‐noninfanticidal, and parental males. More ultrasonic vocalizations were produced in response to urine odors of parental males than to those of isolated‐infanticidal males and more to infanticidal than to noninfanticidal males. Infants became agitated in the presence of urine odors of infanticidal males and moved away from the odor source whereas they tended to remain stationary in response to urine odors of parental males. The response to urine odors of noninfanticidal males was intermediate. These data support the hypothesis that infanticidal and parental states have different physiological bases and that this physiological difference results in different chemical composition of urine. The data failed to support the hypothesis that infants will attempt to conceal themselves from infanticidal males by remaining quiet.
Selective pup retrieving by mother rats: Sex and early development characteristics as discrimination factors
Authors: Deviterne Dominique , Desor Didier 
Published: January 2005

AbstractDiscrimination between own‐litter pups by mother rats was studied over 14 litters, in a standardized situation eliciting maternal pup‐retrieving activity. Results showed some consistency in the order in which pups of a litter were retrieved by the mother in the 4‐day and 9‐day tests and that this order was related to certain characteristics of the pups: (1) on Day 4 and 9, the best‐developed pups of the litter (in terms of body weight and neuromotor behaviors) were first retrieved; (2) on Day 9, sex of pups became an additional discrimination factor, as males were retrieved before their female littermates. Variables included in these global discrimination factors and possible consequences of such differential mother‐pups interactions are discussed.
Infant's response to social separation reflects adult differences in affiliative behavior: A comparative developmetal study in prairie and montane voles
Authors: Shapiro Lawrence E. , Insel Thomas R. 
Published: January 2005

AbstractAs part of a comparative study of affiliative behavior, pups of two different vole species, Microtus ochrogaster (prairie voles) and M. Montanus (montane voles), were compared for their responses to social isolation during the first 2 weeks of postnatal life. Previous studies have demonstrated that under both laboratory and field conditions, adult prairie voles show higher levels of affiliation than adult montane voles, although the species closely resemble each other morphologically. In the current study, prairie vole and montane vole pups showed profound differences in the behavioral and physiologic responses to social isolation. During 5 minutes of isolation, prairie vole pups emitted 314 ± 60 (days 4–6) and 601 ± 55 (days 8–10) ultrasonic vocalizations. At these same ages, plasma corticosterone increased 4–6 fold within 30 minutes of separation. The increase in corticosterone was highly correlated with the number of calls (r = 66). In contrast, most montane vole pups emitted no isolation calls under identical conditions. Moreover, montane vole pups had equivalent baseline corticosterone concentrations, but showed only a minor increse in corticosterone following separation at 4–6 days with no increase apparent at 8–10 days. As montane vole pups were capable of producing high levels of ultrasonic vocalizations and increased concentrations of plasma corticosterone in responce to known stressors (tail suspension and halothane vapors), these result suggest that social isolation evokes less distress for montane vole pups than for prairie vole pups. The developmental difference in the amount of parent‐young contact was not a sufficient explanation for the differences in the response to separation as cross‐fostered montane voles failed to show an increase in ultrasonic vocalizations (although a slight increase in corticosterone was observed). Taken together, these studies indicate that species‐typical adult patterns of affiliation may be apparent early in development in the response of infants to social separation.