bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early‐life malnutrition selectively retards the development of distal‐ but not proximal‐cue navigation
Authors: Castro Carl Andrew , Rudy Jerry W. 
Published: January 2005

AbstractThe effects of early‐life malnutrition on the distal‐cue and proximal‐cue versions of the Morris (1981) water maze were studied with different‐aged rats. Consistent with the existing literature, malnutrition only mildly influenced the distal‐cue navigation of relatively old pups (30 day olds). Pups 20–27 days old, however, displayed no evidence of distal‐cue navigation if they had been malnourished previously. Malnutrition had no effect on proximal‐cue based navigation by pups at any age. The effect of malnutrition on distal‐cue performance could not be attributed to any general debilitating effects, sensory, motor, or motivational deficits. Instead, it appears to selectively influence the development of the neural system (perhaps the hippocampus and related structures) more directly involved in learning to utilize distal cues.
Physical stimulation reduces the body temperature of infant rats
Authors: Sullivan Regina M. , Shokrai Neda , Leon Michael 
Published: January 2005

AbstractPhysical stimulation of rat pups, of the type normally received from the mother, has been shown to regulate several behavioral and physiological systems in the young. The present paper describes a possible role of physical stimulation in an additional physiological system; the thermoregulatory system. Within a thermoneutral environment, physical stimulation produces a decrease in rectal temperature (Expt. 1). Even in an environment of increasing temperature, similar to that pups experience when in contact with the dam, physical stimulation attenuates an increase in rectal temperature (Expt. 2). The physiological mechanism of heat loss appears to involve ventilatory heat exchange resulting in convective and evaporative heat loss (Expts. 3, 4). Furthermore, physical stimulation continues to produce a decrease in rectal temperature throughout the preweanling period (Expt. 5). These results suggest that pups may not always have to resort to behavioral thermoregulatory mechanisms which require them to separate themselves from their mother. Rather, pups may be cooled, or at least a heat gain attenuated, by physical stimulation from the dam while maintaining contact with her.
Thirst‐induced anorexias and the ontogeny of thirst in the rat
Authors: Leshem Micah , Epstein Alan N. 
Published: January 2005

AbstractIn previous work (Leshem, M., Boggan, B., and Epstein, A.N. (1988). The ontogeny of drinking evoked by activation of brain angiotensin in the rat pup. Dev. Psychobiol. Vol. 21, pp. 63–75) we showed that thirst elicited by activation of the brain's renin‐angiotensin system in the suckling becomes specific to water after 16 days of age. However, in the suckling, we did not find the anorexia that reportedly accompanies angiotensin‐induced thirst in the adult. This suggests the existence of a further stage in the ontogeny of thirst. Therefore, the present study pursued the ontogeny of thirst and its effects on milk intake through prepubescence into aduthood. Experiment 1 revealed that intracranial renin does not cause an anorexia to milk in prepubescent or adult rats. Experiment 2 showed that the absence of anorexia is true of thirst induced by renin but not by cellular dehydration, although both dipsogens suppressed milk intake when rats also had water available. Experiment 3 confirmed that the preweanling shows anorexia to solid food, as does the adult. Together with other work, these findings suggest that the ontogeny of the thirsts aroused by renin or intracellular dehydration is complete before weaning.
Amount of training and retention by infants
Authors: Ohr Phyllis S. , Fagen Jeffrey W. , Rovee‐Collier Carolyn , Hayne Harlene , Vander Linde Eleanor 
Published: January 2005

AbstractIn studies of animals and adult humans, more training typically leads to better retention. The generality of this finding was assessed in two studies with human infants in which amount of training was manipulated in two different ways. In the first study, 3‐month‐olds were trained for either 1, 2, or 3 sessions, each 9 min long; in the second, they were trained for a single session that was either 6, 9, 12, or 18 min long. Retention of independent groups was measured after delays ranging from 1 to 21 days. In both studies, different amounts of training did not yield group differences on any of the standard measures of acquisition or after a retention interval of 1 day. After intervals of a week or longer, however, more training led to better retention. Across studies, the long‐term retention of groups that were trained for the same amount of time differed. We speculate that subjects learn different things in these two training regimens.
Ontogeny of conditioned inhibition of conditioned respiratory suppression in kittens
Authors: Dess Nancy K. , Soltysik S. Stefan 
Published: January 2005

AbstractExcitatory and inhibitory classical conditioning were examined in 4‐week‐old, 8‐week‐old, and 12‐week‐old kittens. Conditioned respiratory suppression (CRS) was a measure of conditioned fear. The inhibitory conditioning procedure was designed to model the schedule of events that normally accompanies successful coping behavior: The safety signal predicted the cancellation of shock that would otherwise follow the danger singal, rather than simply the absence of shock. Before training, the stimuli elicited small unconditioned respiratory suppression in the 4‐week‐old and 8‐week‐old kittens, but not in the juvenile, 12‐week‐old kittens. During training, danger signals came to elicit robust CRS after 3–4 sessions (20–30 trials) in every age group. Acquisition of inhibition of CRS was also observed within 2–3 days (20–30 trials). The effectiveness of inhibitory stimuli improved significantly with age. The safety signal also inhibited fear (CRS) elicited by a second danger signal. Thus, the kittens learned inhibition to the safety signal per se, rather than having learned to discriminate some nonreinforced configured cue from the danger signal presented alone.
Development of antipredator responses in snakes: IV. Interspecific and intraspecific differences in habituation of defensive behavior
Authors: Herzog Harold A. , Bowers Bonnie Bailey , Burghardt Gordon M. 
Published: January 2005

AbstractHabituation of defensive attacks directed toward a threatening stimulus was investigated in neonatal garter snakes. The focus of the experiments was on differential effects of a simple experiential process in relation to species, litter, sex, and individual. In Experiment 1 newborn Thamnophis melanogaster from four litters and newborn Thamnophis butleri from three litterswere given daily tests in which snakes were confronted with a nonmoving and moving human hand. Over five successive test days the T. melanogaster neonates showed a decline in number of strikes directed toward the stimuli. When retested 10–13 days later the animals showed significant response recovery. Although some of the T. butleri newborns demonstrated significant habituation, there was no overall habituation of strike scores in this species. The T. melanogaster had high strike scores, more rapid habituation to moving than nonmoving stimuli, and significant litter differences in habituation rates. The T. melanogaster, but not the T. butleri neonates, showed significant habituation of flight responses over the five tests. In T. butleri, but not T. melanogaster, males were more prone to attack than were females. In bath species there were large differences in both overall strike scores and habituation rates of individual newborn animals. In Experiment 2, T, melanogaster, 2‐months old, were tested for short‐term habituation to either a moving or nonmoving stimulus for 10 successive tests on one day. Habituation of strikes was similar to both stimuli, but more animals confronted with the moving stimulus showed an initial increase in strikes, lending support to the dual‐prccess theory of habituation. As in Experiment 1, there were large individual differences in habituation rates. The results are discussed in terms of the ecological and methodological implications for developmental studies.
Pubertal‐related changes influence the development of environment‐related social interaction in the male rat
Authors: Primus Renee J. , Kellogg Carol K. 
Published: January 2005

AbstractThe influence of pubertal age on the differential effect of a familiar versus an unfamiliar environment on social interaction (SI) in pairs of male rats was evaluated. The decrease in SI induced by the unfamiliar environment in adult rats is considered an anxiety‐related response. Intact male rats and male rats castrated at 19 days were tested for SI at 28, 35, and 60 days of age. The results revealed that in the intact rats, decreased SI in an unfamiliar environment was evident at 35 and 60 days but not at 28 days. The behavioral composition of the environment‐induced response at 35 days was different from that measured at 60 days. Prepubertal castration prevented the decrease in SI in the unfamiliar environment at both 35 and 60 days. This study demonstrated the emergence with the onset of puberty of a specific behavioral response to an anxiogenic condition. Furthermore, the development of this environment‐related behavioral response was influenced by gonadal secretion(s), suggesting the importance of gonadal function to the emergence of this response.
Early experience and cross‐generational continuity of mother‐infant contact in vervet monkeys
Authors: Fairbanks Lynn A. 
Published: January 2005

AbstractThis report presents evidence that suggests that spontaneously‐occurring variation in early mother‐infant experience within the normal range can influence primate mothering behavior in the next generation. Longitudinal observations of vervet monkeys (Cercopithecus aethiops sabaeus) living in naturally composed captive social groups demonstrated that the average amount of contact that mothers maintained with their infants in the first six months of life could be predicted by the amount of mother‐infant contact the females had experienced as infants. A female's early experience in infancy was a better predictor of adult mothering behavior than variables measuring social learning as a juvenile, shared circumstances, and average similarity between mothers and daughters.
Conspecific screams and laughter: Cardiac and behavioral reactions of infant chimpanzees
Authors: Berntson Gary G. , Boysen Sarah T. , Bauer Harold R. , Torello Michael S. 
Published: January 2005

AbstractThe present study examined cardiac and behavioral reactions of infant chimpanzees to white noise and to conspecific screams and laughter. Chimpanzee screams evoked typical deceleratory cardiac orienting responses. Analysis of stimulus‐evoked changes in respiratory sinus arrhythmia suggested that this cardiac deceleration arose from an increase in parasympathetic activity. In contrast, chimpanzee laughter evoked notable cardiac acceleration. Laughter also evoked vocalizations from the infant subjects, which were reminiscent of adult threat‐barks. Analysis of respiratory sinus arrhythmia suggested that the cardioacceleratory response likely resulted from sympathetic activation, and was not associated with an inhibition of parasympathetic activity. The autonomic and vocal responses to laughter emerged early in development, were minimally dependent on social contact with adults, and declined in magnitude with increasing age. A consideration of the phylogeny of laughter raised the possibility that the functional reaction to this vocalization may be related to its origin in more primitive agonistic facio‐vocal signals.
Mother and sibling discrimination at a distance by three‐ to seven‐day‐old lambs
Authors: Nowak R. 
Published: January 2005

AbstractThis study examined some aspects of the developmental phase of social bonding in newborn lambs. In Experiment 1, 3‐day‐old Merino lambs (singles and twins) were tested in a 2‐choice situation for mother discrimination at a distance. In Experiment 2, the ability of twins to discriminate their siblings at a distance was studied 3 and 7 days after birth. When released at 9m from two postparturient ewes after a latency of 30 s, which allowed the lambs to hear and to see both animals, most lambs chose to run and to stay with their own mothers before the end of the 2‐min test (Experiment 1). There was no difference between singles and twins, nor between males and females in their distant discriminative ability. However, twins were initially undecided, slower to reach their mothers, and spent significantly less time with them. When the same testing procedure was used for sibling discrimination, most 3‐day‐old twins went to a lamb, but the proportion of lambs reaching the sibling first did not differ significantly from random, and the time spent near either lamb was similar (Experiment 2). During these tests, female lambs performed better than males. When tested 7 days after birth, all twins reached a lamb and a high proportion of them chose to go to the sibling first. They also spent most of the time near it. These results demonstrate that mother discrimination from a distance is well established in 3‐day‐old lambs and sibling discrimination takes longer to develop but has occurred by 7 days of age.
An ecological approach to language development: An alternative functionalism
Authors: Dent Cathy H. 
Published: January 2005

AbstractI argue for a new functionalist approach to language development, an ecological approach. A realist orientation is used that locates the causes of language development neither in the child nor in the language environment but in the functioning of perceptual systems that detect language‐world relationship and use them to guide attention and action. The theory requires no concept of innateness, thus avoiding problems inherent in either the innate ideas or the genes‐as‐causal‐programs explanations of the source of structure in language. An ecological explanation of language is discussed in relation to concepts and language, language as representation, problems in early word learning, metaphor, and syntactic development. Finally, problems incurred in using the idea of innateness are summarized: History prior to the chosen beginning point is ignored, data on organism‐environment mutuality are not collected, and the explanation claims no effects of learning, which cannot be tested empirically.
Development of coordinated movement in chicks: I. Temporal analysis of hindlimb muscle synergies at embryonic days 9 and 10
Authors: Bradley Nina S. , Bekoff Anne 
Published: January 2005

AbstractIn this study, we examined electromyographic activity for an ensemble of hindlimb muscles during spontaneous activity in chick embryos to advance understanding of early motor coordination and its relationship to later emerging behaviors. Four‐channel recordings were obtained from 6 muscles in ovo at embryonic Days 9 and 10. Analyses indicated that when muscles are repetitively active, patterns during embryonic motility are distinct from those for other behaviors. For example, unlike the muscle patterns for locomotion, extensor muscles and flexor muscles are synchronously activated at 50% of the extensor cycle period. Furthermore, flexor and extensor bursts are similar in duration and show little correlation with extensor cycle period. Finally, our data sugest that the ensemble of muscles active can vary from cycle to cycle. This study provides the basis for future studies that will examine neural and biomechanical interactions underlying the development of coordinated movement.
An examination of the intramodal and intermodal behavioral consequences of long‐term vibrissae removal in rats
Authors: Symons Lawrence A. , Tees Richard C. 
Published: January 2005

AbstractAn assessment was made of the effects of long‐term tactile restriction by bilateral removal of the mystacial vibrissae from an early age on the subsequent somatosensory capacities of rats (i.e., the intramodal consequences) as well as its effects on visual and spatial capacities (i.e., the intermodal consequences). Rearing environment (enriched vs. normal) and method of vibrissae removal (cauterization of follicles vs. plucking) were examined to determine specific factors that might influence the effect of vibrissae removal. Early, long‐term tactile restriction had significant intramodal and intermodal consequences. Dewhiskered rats showed attenuated orientation to tactile stimuli presented to their mystacial pads and enriched‐reared rats whose vibrissae follicles had been cauterized showed increased orientation to visual stimuli. Manipulation of early somatosensory signals had no impact on the development of certain spatial and precise manipulatory skills. These data provide limited evidence for theories of modality interdependence and yield basic information concerning the role of the mystacial vibrissae in the behavior of the rat.
Ontogeny of sexually dimorphic ultrasonic vocalizations in mongolian gerbils
Authors: Holman S. D. , Seale W. T. C. 
Published: January 2005

AbstractSexual differentiation of emission rates (Experiment 1) and physical structure of ultrasonic vocalizations (Experiment 2) were investigated in Mongolian gerbils between 17 and 85 days of age. Animals from different litters were allowed to interact in iso‐and heterosexual pairs. Vocalization rates increased in all groups, reaching a plateau at approximately day 56. Female pups had significantly higher rates of all vocalizations than male pairs before the plateau stage. Five stereotypic categories of physical structure were easily distinguished and confirmed by sound spectrographic analysis. Only mid‐range frequencies of vocalizations appeared to decline throughout the juveniles' lives: this change may communicate the animal's age. Two male and one female categories were sexually dimorphic and similar in structure to those made during courtship interactions. Rates of male‐type vocalizations appear to increase as testicular androgens start rising.
Preferred tastes and opioid‐modulated behaviors in neonatal rats
Authors: Kehoe Priscilla , Sakurai Sharin 
Published: January 2005

AbstractTen‐day‐old rats were given various tastants to ingest, independent of mother and suckling. Relative to water, the pups ingested significantly more saccharin (0.5%) and NaCl (2.5%) and less quinine (0.4%). Pretreatment with the opiate antagonist, naltrexone, had no effect on water or quinine intake but significantly reduced that of saccharin and NaCl. Furthermore, the preferred solutions of saccharin and NaCl given intraorally caused a decrease in ultrasonic vocalizations of isolated pups and in a separate experiment caused an analgesic response to heat. Both phenomena were reversible with naltrexone administration, suggesting that preferred tastes elicit an endogenous opioid response significantly affecting behaviors seen during isolation.
The early presence of food‐oriented appetitive behavior in developing rats
Authors: Phifer C. B. , Denzinger Annette , Hall W. G. 
Published: January 2005

AbstractThe appetitive behavior of 3‐ to 6‐day‐old rat pups was studied by testing their ability to direct their ingestive behavior to a restricted food source. We found that, from 3 days of age, pups were able to feed efficiently from such a source. More specifically, pups that were deprived of nutrition but not of maternal care as well as pups that were dehydrated ingested significantly more than nondeprived animals, and did so whether liquid diet was spread over the entire floor surface beneath them or restricted to a fraction of the floor surface. However, pups that had been nutritionally and maternally deprived were not able to direct their feeding. The general locomotor activation of pups in this latter group appeared to interfere with their ability to direct their behavior to the restricted source. These results indicate that from early ages, developing rats possess the appetitive competence to guide their behavior and suggest that previous findings of poorly directed behavior were a confound of the behavioral activation shown by pups tested in a state of maternal deprivation.
Behavioral and physiological responses of mother and infant squirrel monkeys to fearful stimuli
Authors: Wiener Sandra G. , Levine Seymour 
Published: January 2005

AbstractThe behavioral and adrenocortical responses of feral squirrel monkey mothers and their laboratory‐born infants were measured following exposure to a live snake and to a flying predator model (hawk). The dyads were either socially or individually housed. The different stimuli were presented above the home cage for 1 hr; behaviors were observed during this period. Blood samples were obtained at the end of the test session and assayed for cortisol. The results indicated that individually housed dyads markedly increased their time spent in contact and their avoidance of the stimuli, and showed increased levels of cortisol when exposed to the snake or hawk model. Socially reared monkeys responded only to the snake. Thus, the presence of social partners ameliorated the response to the hawk model. The marked increase in contact during the presentation of the fear‐eliciting stimuli may be partly responsible for the infants' response. © 1992 Wiley & sons. Inc.
The effect of the neurotoxin DSP4 on the development of a predisposition in the domestic chick
Authors: Davies D. C. , Johnson M. H. , Horn G. 
Published: January 2005

AbstractUnder certain conditions, dark‐reared chicks preferentially approach objects resembling conspecifics. In the current study we investigated the effect of the catecholaminergic neurotoxin DSP4 on this predisposition. After hatching, chicks received an intraperitoneal injection of either DSP4 or vehicle (controls). The chicks were individually placed in running wheels for 2 × 1 hr, 24 hr before testing. The chicks were maintained in darkness until given a preference test, which involved the simultaneous presentation of an illuminated red box and a stuffed fowl at 36, 48, 60, 66, or 72 hr after hatching. The approach of each chick toward the two objects was recorded over 5 min and a preference score calculated. Control chicks placed in the running wheels at 24 and 36 hr posthatch and tested 24 hr later showed a significant preference for the fowl compared to the red box. In contrast, DSP4‐treated chicks did not show such a preference at corresponding ages, but did express a greater preference for the fowl when placed in the running wheels at 42 and 48 hr posthatch and tested 24 hr later. These results suggest that experience of the running wheel or of associated factors, e.g., handling, must occur during a restricted period of time to influence the emergence of the predisposition to approach the stuffed fowl. DSP4 treatment delays the onset of this period. © John Wiley & Sons, Inc.