bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hypothermia causes adult‐like retention deficits of prior learning in infant mice
Authors: Nagy Z. Michael , Anderson James A. , Mazzaferri Timothy A. 
Published: January 2005

AbstractNine‐day‐old S‐W mice receiving deep body hypothermia or hyperthermia immediately after escape training were retested 1 or 24 hr later. Results indicated that hypothermia impaired 24‐hr retention but had no effect upon 1‐hr memory. Hyperthermia had no effect, with the mice demonstrating retention of the escape response at both retest intervals. In Experiment 2, administration of hypothermia or hyperthermia 23 hr after original training had no effect upon memory nor did either treatment produce motoric deficits upon retest 1 hr following thermal exposure. Experiment 3 indicated that hypothermia administered immediately after training produced retention deficits directly related to amount of body temperature reduction following hypothermia. These data are similar to those obtained with adult mice and suggest that memory processess occurring in 9‐day‐old mice may represent the onset of functioning of processes underlying adult long‐term memory.
Growth in the hubbard broiler: Increased size following early handling
Authors: Thompson Carl I. 
Published: January 2005

AbstractHubbard cockerels, 1 day of age (n=91) were divided into 3 handling groups: (1) chicks from the 5‐Day group were removed from the brooder and isolated at 22°C for 3 min on each of the first 5 days; (2) chicks from the 15‐Day group received this treatment for 15 days; and (3) Control chicks were not handled. Within each group half were fed broiler starter for 5 weeks, and half were fed layer starter which produces slower growth. On Days 28, 35, 42, and 49 the average weight of 5‐Day birds was significantly higher than that of Controls; 15‐Day birds weighed slightly less than birds in the 5‐Day group. The weight advantage of the 5‐Day birds occurred with both starter rations, at all weighing periods, and did not appear to reflect increased food consumption. Similarities between these findings and results obtained with rodents were noted.
Visual evoked response (VER) changes during maturation in the weddell seal
Authors: Gruenau Steven P. , Shurley Jay T. 
Published: January 2005

AbstractVisual evoked responses (VER's) were recorded from the cortex of immature Weddell seals, 3‐365 days of age. Results indicated a high degree of maturity at birth evident from the multiphasic array of waveforms and the comparatively short onset latency of the VER. At low flash intensities, single flashes evoked an immature secondary response. Topographical distribution of VER's were confined largely to the gyrus immediately adjacent to midline, from the posterior aspect near lambda to the vertex. Recordings from CI‐744 dosed seals displayed a well‐demarcated developmental sequence of VER's, contrary to VER's recorded in flaxedilized seals. Onset latency and waveform configuration changed concomitantly as a function of age. During the postnatal period from birth to weaning, VER changes were related to major behavioral events such as the seal's first encounter with swimming and diving at 2 weeks of age and weaning at 6 weeks of age.
Exploration and play with objects in domestic kittens
Authors: West Meredith J. 
Published: January 2005

AbstractThe responses of 12 kittens to unfamiliar and familiar objects was tested. Four categories of behavior were measured: exploration, play‐exploration, play, and non‐manipulatory contact. The results indicated that exploration and play‐exploration were used for longer durations with unfamiliar objects and play was used for longer durations with familiar objects. Rank‐order correlations between the measures showed that objects explored were not correlated with objects played with or play‐explored. Analysis of the ranking revealed that small size and mobility were important object properties of play. The results suggest that exploration involves learning about stimulus properties, play‐exploration involves learning about perceptual‐motor properties, and play involves learning to coordinate movements with those of moving objects.
Development of dustbathing components in Bobwhite and Japanese quail
Authors: Borchelt Peter L. 
Published: January 2005

AbstractThe development of dustbathing components was investigated in Bobwhite and Japanese quail. The incidence and frequencies of components for both species increased with age, but dustbathing occurred earlier in Japanese quail. The dust toss, head rub, and side rub components invariably developed in the same order they occur during an adult bout. The topographies of many components changed systematically with a „rudimentary”︁ form preceding the typical adult form. Large individual differences were observed in the development of the temporal relations among components, but these differences were unrelated to the relative frequencies of components.
A critical period for social isolation in the rat
Authors: Einon Dorothy F. , Morgan M. J. 
Published: January 2005

AbstractRats housed in social isolation show heightened levels of object‐contact in an open‐field and are slower than socially‐housed controls to emerge from a small enclosure into an unfamiliar environment. Isolation between 25 and 45 days of age produced an irreversible effect upon object contact but had no lasting effect if between 16 and 25 days or after 45 days. In contrast to object contact, emergence was affected by isolation at any age and the effect was reversed by subsequent social housing. Thus the effects of isolation upon object contact and upon emergence apparently do not depend upon a single underlying variable.
Visual stimulation and wake‐sleep behavior in human neonates
Authors: Boismier James D. 
Published: January 2005

AbstractSixteen male and 16 female infants were exposed to 1 of 4 visual stimulus conditions during pre‐ and postprandial wakefulness. Whereas a nonpatterned gray stimulus minimized the amount of alert inactivity and maximized the amount of subsequent rapid eye movement (REM) sleep, black‐and‐white checkerboard patterned stimuli produced greater amounts of alert inactivity and correspondingly lesser amounts of subsequent REM sleep. Amounts of alert inactivity and of subsequent REM sleep produced by the checkerboard patterns depended upon pattern size, infant gender, and stimulus presentation strategy. Inversely correlated stimulus control of wakefulness and subsequent REM sleep was proposed as the functional basis of the inversely correlated ontogenesis of wakefulness and REM sleep.
The ontogeny of plasma osmolality and intravascular volume maintenance during short‐term starvation in rats
Authors: Wright John W. , Kenny John T. , Reynolds Thomas J. 
Published: January 2005

AbstractBody fluid deviations were examined in albino rats of both genders between 30 and 100 days of age during food deprivation. Plasma volume declined with age in free‐feeding control groups. Hypovolemia induced by starvation (4 days) was more intense in 30‐ to 60‐day‐old animals than in 80‐ and 100‐day groups. Plasma osmolality concentration of control groups indicated increases with age, leveling off after 60 days. The initiation of drinking during fasting was accompanied by physiologically significant elevations in plasma osmolality over ad libitum concentrations at each age tested. In a second experiment, repeated exposure to short periods of food deprivation (2 days) during development resulted in the maintenance of intravascular fluid at control volumes. Longer periods (4 days) of deprivation did not result in savings of intravascular volume loss evidenced during starvation. These results suggest that rats compensate for hypovolemia induced by short‐term starvation when provided experience with food restriction during development.
Effects of gastric filling and vagotomy on ingestion, nipple attachment, and weight gain by suckling rats
Authors: Lorenz Dennis N. 
Published: January 2005

AbstractThe importance of gut signals for the short‐term and long‐term control of ingestion was investigated using rat pups in the natural suckling situation. Pups at 10 days of age were deprived of milk and their dam for 9 hr. Pyloric ligation, vagotomy, and preloading procedures were performed on the pups shortly before testing began. The initial latency to attach to a nipple and the incidence of attachment were recorded during the 2‐hr suckling period. Milk intake and the weight of gastric contents were measured following the test. Pregastric stimulation together with natural or artificial gastric filling suppressed ingestion. Acute subdiaphragmatic truncal vagotomy enhanced ingestion under these conditions, and vagotomy alone resulted in controlled hyperphagia concomitant with exaggerated gastric filling. The data suggest that the stomach is one site where milk activates a suppression mechanism for ingestion. This mechanism is mediated primarily by the vagus nerve. The importance of nipple‐attachment behavior is discussed in relation to ingestive behavior, and the question of satiety is suckling rats is raised. The chronic effects of truncal vagotomy on rat pups were also investigated, beginning with denervation at 10 days of age. The pups were challenged with deprivation and tested in the natural suckling situation on Day 20. Weaning occurred on Day 22, and the pups were sacrificed on Day 41, followed by measurements of body weight, body length, and gastric contents. The physical and behavioral changes that developed during the chronic phase of vagotomy included (1) permanent gastric distension following the first postsurgical bout of ingestion; (2) reduced intake of milk when the availability of milk was greatest during the suckling test; (3)increased resting behavior regardless of milk letdown conditions during the suckling test; (4) failure to gain weight at a normal rate; and (5) failure to grow at a normal rate.The data indicate that the vagus nerve is necessary for normal internal control of ingestion as well as normal gastric filling and emptying in the suckling rat. The inability of suckling and weanling pups to thrive in the chronic phase of vagotomy indicates that nonvagal internal controls of ingestion and digestion function adequately for survival, but they are not optimal for growth and maintenance of body weight in rats.
Comparative analysis of the development of wing‐flapping and flight in the fowl
Authors: Provine Robert R. , Strawbridge Catherine L. , Harrison Barbara J. 
Published: January 2005

AbstractThe development of wing‐flapping rate, lateral flight, wing area, and the ratio of wing area to body weight are described in the Japanese quail (Coturnix coturnix japonica) and three chickens (Gallus gallus) to determine common developmental phenomena and to assess the effects of domestication. The chickens were the White Leghorn (a comercial egg producer), the Cornish X Rock (a commercial meat producer), and the Red Jungle fowl (the probable ancestor of domestic chickens). All birds performed drop‐evoked wing‐flapping on the day of hatching, at least 1 week before lateral flight was possible. Flapping rate of chickens doubled between hatching (4–6 Hz) and 13 days (∼ 9–12 Hz), after which it leveled off. Japanese quail (JQ) maintained a high flapping rate (11–13 Hz) during the 21 days after hatching. The Jungle fowl (JF) and JQ flapped the fastest and the White Leghorn (WL) and Cornish × Rock (CR) chickens flapped the slowest. The JF, WL, and JQ developed lateral flight at 7–9 days. The CR first flew 1–2 weeks later but subsequently became flightless. The WL, JF, and JQ had similar ratios of wing area to body weight; the ratios increased to a peak at 11–15 days and later declined. The ratio of the very heavy, essentially flightless, CR was approximately one‐half that of the flighted JQ, WL, and JF. The wing‐flapping frequencies of the domestic WL and CR chickens approximated that of the JF, suggesting that domestication did not affect the motor pattern generatior for flight. The artificial selection of the CR for high body weight drastically diminished its flight performance by producing an unfavorable ratio of wing area to body weight. The JF and the domestic WL both flew well and had similar ratios. Domestication affected flight performance but not the neural circuitry producing wing‐flapping. The central nervous system is much more conservative in its response to selection than the peripheral effector structures that it drives.
The role of body size in climbing and locomotor behavior of protein‐malnourished and well‐nourished rats
Authors: Hall Robert D. 
Published: January 2005

AbstractBehavioral comparisons of malnourished and well‐nourished rats often involve animals of different sizes–even after rehabilitation of malnourished animals. The role of body size in two kinds of behavior affected by early malnutrition was investigated. Rats subjected to protein restriction during the preweaning period (LH) or during the pre‐ and postweaning periods (LL) climbed more than well‐nourished rats (HH) at the ages of 35–225 days. This difference reflected differences in body weight; at comparable body weights LH and LL rats climbed no more than HH rats. Females climbed more than males, which also reflected differences in size, but decreases with age did not depend entirely on growth. LH rats were more active in running wheels than HH rats. For both LH and LL rats, the overall changes with diet and age resembled those in climbing, except that the effects of sex, but not age, were partly independent of size.
The development of spontaneous body movement in prenatal and perinatal mice
Authors: Kodama Noriko , Sekiguchi Shigehisa 
Published: January 2005

AbstractThe qualitative and quantitative changes in behavioral development in the prenatal and perinatal periods have been insufficiently studied. We observed the occurrence of spontaneous body movements in three strains of mice (ICR, C3H, and BALB) and the pulse counts measured by EMG activity in the ICR strain. Simple body movement first appeared at the 14th day of gestation of the 19‐day gestation period normal for mice. During the prenatal period, fetal movements changed from simple movements to complex and coordinated movements. Differences in the timing of the development of these movements were not found in the three strains of mice. During the perinatal period, the three kinds of simple movement decreased. This decrease was affected by the onset of pulmonary respiration after delivery. The time span of spontaneous movement did not change during the perinatal period, while the pulse counts measured by EMG activity increased with age.
Hunger and the vocalizations of infant gerbils
Authors: McCauley Patrick J. , Elwood Robert W. 
Published: January 2005

AbstractInfant gerbils were deprived of food by removing their mother from the cage for 3 hr on alternate days, during which time they remained with their father. These infants were compared with a control group which remained with their other while the father was removed. Litters lost weight when deprived of food but they received similar levels of parental care, warmth, and tactile stimuli to those of nonfood‐deprived litters. There were no significant effects on the vocalizations of the young when tested either in isolation or in the nest with other pups. This apparent absence of a mode of communicating nutritional sate is discussed with reference to normal interactions between adults and the litter and the role of vocalizations produced in response to heat loss.
Development of hindlimb locomotor behavior in the frog
Authors: Stehouwer Donald J. , Farel Paul B. 
Published: January 2005

AbstractHindlimb motor behavior of the larval frog (tadpole) begins during midlarval life and occurs with increasing frequency until the tail degenerates during metamorphosis. The threshold for hindlimb withdrawal in response to tactile stimulation is low during premetamorphic stages and rises dramatically during metamorphosis. Testing tadpoles in different environments altered the stage of development at which different hindlimb behaviors were first observed but did not change the ontogenetic sequence of behavioral development. However, even under conditions most favorable to hindlimb locomotion, behavioral expression lagged behind electrophysiological expression. The rates of tail beating, hindlimb stepping, and fog kicks are similar to the rate of bursting of tail and hindlimb motoneurons of the isolated nervous system, but their coordination is variable, whereas that recorded from the isolated CNS is fixed. Because neural mechanisms of hindlim locomotion are functional prior to their behavioral use, the basic hindlimb locomotor circuits must develop without benefit of practice or sensory feedback. However, sensory activity modulates coordination and alters the probability that particular behaviors will be expressed. Implications of these results for studies of early behavior in other species, and the problem of inferring neural maturity from behavioral observations, are discussed.
The use of tactile and olfactory cues in neonatal orientation and localization of the nipple
Authors: Larson Michelle A. , Stein Barry E. 
Published: January 2005

AbstractA good deal of effort has been directed toward determining the sensory cues employed by neonatal animals in orienting to, and localizing, the nipple. The results of previous studies are contradictory. Some investigators have claimed that olfactory cues are critical, while others suggest that tactile cues are of primary importance in these behaviors. The present studies indicate that, in kittens, there are two essential components of the suckling process: orientation to the mother and localization of the nipple. In these experiments, the ability and time involved in localizing and attaching to the nipple of the anesthetized mother were measured in several conditions. With tactile input impaired, kittens had no difficulty locating the mother, but could not locate the nipple. In contrast, olfactory disruption nerver impaired nipple localization and attachment when the kitten was in contact with the mother, but interfered with the kitten's ability to locate the mother when removed from her. These data suggest that olfactory cues are employed in locating the mother, and tactile cues from the perioral region are employed in locating the nipple.
Phenotypic basis for a feeding change in an insular population of garter snakes
Authors: Greenwell Martin G. , Hall Martha , Sexton Owen J. 
Published: January 2005

AbstractPredation on birds, an unusual behavior for the common garter snake (Thamnophis sirtalis), has been observed and documented in an insular garter snake population. Feeding preference tests were performed on naive neonatal snakes and experienced adults from both the island test population and a nearby mainland control population. No significant preference for birds as a prey item was found for either neonates or adults from either population. Therefore, neither a genetic nor an ontogenetic basis for the observed behavior was demonstrable. Birds tainted with a piscine odor, however, elicited a positive feeding response from adult snakes from both geographical sources. We propose that the observed behavior in the field is a result of learning to exploit an abundant, readily available resource already in the predator's repertoire.
Human newborns' perception of male voices: Preference, discrimination, and reinforcing value
Authors: Decasper Anthony J. , Prescott Phyllis A. 
Published: January 2005

AbstractHuman newborns were tested with an operant choice procedure to determine whether they would prefer their fathers' voices to that of another male. No preference was observed. Subsequent testing revealed that they could discriminate between the voices but that the voices lacked reinforcing value. These results contrast sharply with newborns' perception of their mothers' voices, in particular, and female voices, in general. The data were interpreted as supporting an hypothesis that prenatal experience significantly influences human newborns' earliest voice preferences.
Cochlear microphonics and action potentials mature and decline at diffent rates in the normal and pathologic mouse cochlea
Authors: Henry Kenneth R. 
Published: January 2005

AbstractA technique is described that can nontraumatically assess cochlear microphonic (CM) and cochlear action potential (AP) thresholds to pure tones in the intact mouse. This method was applied to the normal hearing CBA/J, and to the C57BL/6J, which has early‐onset hearing loss. CM thresholds are most sensitive in both mice by 23 days of age, and the C57BL/6J CM responses degenerate rapidly thereafter, especially at the high‐frequency end. The CMs of the CBA/J continue to change past 23 days, developing a threshold dip at 24 kHz, and becoming slightly less sensitive at 32 kHz. The AP of the C57BL/6J is also most sensitive at 23 days, and becomes gradually less sensitive to 32‐ and 64‐kHz tones over the next 36 days. The CBA/J AP thresholds are not maximally sensitive until 41 days of age.
The effects of prenatal exposure to predictable or unpredictable stress on early development in the rat
Authors: Freide Ester , Weinstock Marta 
Published: January 2005

AbstractPregnant rats were exposed to differents schedules of noise and light stress, and the developmement of their offspring was studied during the first 2 weeks of life.Motor development was measured by different tests: Righting reflex (Days 2–4); Cliff avoidance (Days 4–10); turning on an inclined plane (Days 5–10); and swimming behavior (Days 6–10). Development of motivation‐involved behavior was measured with a home‐seeking test (Days 6–16). Other developmental landmarks such ss acoustic response (Days 12–14) and eye‐opening (Days 14–17) were also recorded.Thrice‐weekly random stress resulted in a delay in the devlopment of all behaviors studied. Daily stress exposure throughtout pregnancy resulted in smaller litters with heavier pups, but otherwise normal behavioral and physical development. Rats exposed to daily stress during the last week of pregnancy only produced litters that did not differ in size and body weight, but that displayed accelerated development of all parameters (except for eye‐opening) from Day 6 onward.It is concluded that the unpredictabel nature of prenatal stress is responsible for delays in behavior of offspring.
Eye‐opening in kittens: Effects of light and some biological factors
Authors: Braastad Bjarne O. , Heggelund Paul 
Published: January 2005

AbstractIndividual variation in the age of eye‐opening was studied in 158 kittens. The abiotic and the biotic environments affected eye‐opening. Eyes opened earlier in total darkness than in light, and earlier in kittens of young mothers than those of older mothers. Female kittens tended to open their eyes earlier than males, and a paternity effect appeared.