bluuebunny/crossref_metadata_2025_split huggingface dataset:
Locomotor activity and social behavior of old rats after preweaning undernutrition
Authors: Schenck P. E. , Koos Slob A. , Van Der Werff Ten Bosch J. J. 
Published: January 2005

AbstractRat pups were undernourished from birth to 25 days of age by giving them a nipple‐ligated mother and a normal lactating mother for alternate periods of 12 hr/day, thus providing adequate full‐time maternal care. Male and female rats undernourished neonatally had greater locomotor activity than controls in old age (16–20 months). Females were more active than males, irrespective of neonatal undernutrition. At the age of 24 months, social behavior was recorded at various times of the day for pairs of male rats (1 previously undernourished and 1 control). With one minor exception, undernourished animals did not differ significantly from controls in the incidence of the various behavioral items that were scored. Neonatal social factors may compensate for possible negative effects of neonatal undernutrition on later social behavior.
Spontaneous pup‐killing by mice in response to large litters
Authors: Gandelman Ronald , Simon Neal G. 
Published: January 2005

AbstractPrimiparous lactating mice whose young were removed on the day of parturition were presented with foster litters of either 12 or 16 day‐old young. The adults spontaneously killed young during Days 3‐7 of the lactation period, killing more in the 16‐pup than in the 12‐pup litter. The lactating animal appeared to select the young to be killed on the basis of body weight. It killed significantly more young that were in the bottom half than in the top half of the weight range for its particular litter.
Ontogeny of brain catecholamine turnover and susceptibility to audiogenic seizures in DBA/2J mice
Authors: Shaywitz Bennett A. , Yager Robert D. , Gordon Judith W. 
Published: January 2005

AbstractWe have investigated the relationship between catecholamine turnover and susceptibility to audiogenic seizures (AGS) in the developing DBA/2J mouse. Turnover of dopamine and norepinephrine was determined after administration of alphamethylparatyrosine at 3 weeks of age when nearly all mice (94%) exhibited AGS, at 6 weeks when only 30% were susceptible, and at 12 weeks when none developed seizures. Turnover of brain dopamine increased progressively from 236 ng/g/hr at 3 weeks to 389 ng/g/hr by 12 weeks of age. Norepinephrine turnover increased significantly between 3 and 6 weeks of age, then remained stable thereafter. Turnover times for each catecholamine did not change appreciably with maturation. Our results support the notion that susceptibility to AGS may be mediated in part by brain catecholaminergic mechanisms.
The role of diet in mother‐infant reciprocity in the spiny mouse
Authors: Doane Helen Marie , Porter Richard H. 
Published: January 2005

AbstractOne‐day‐old spiny mouse pups responded preferentially to bedding soiled by lactating conspecifies fed the same diet as their mothers. Following this test, pups were fostered onto different‐diet females. When retested at 84–96 hr of age, no preferences were shown for bedding soiled by a female fed the biological mother's diet vs bedding of a female fed the different diet. When tested again at 120–132 hr of age, however, the pups preferred the bedding associated with their foster mother's diet. In a 2nd experiment, recently parturient females retrieved 1‐day‐old pups born of same‐diet females faster than pups born to novel‐diet females. These results indicate that pup preferences for chemical cues produced by lactating conspecifics can be altered by sufficient exposure to a 2nd female maintained on a different diet and that neonatal chemical cues, like maternal chemical stimuli, are diet‐dependent.
Perinatal malnutrition and early handling: Interactive effects on the development of the pituitary‐adrenal system
Authors: Wiener Sandra G. , Levine Seymour 
Published: January 2005

AbstractThe preweaning development of the pituitary‐adrenal system was investigated in perinatally malnourished rodents. Malnourished pups that were routinely handled displayed an earlier plasma corticosterone stress response to electric shock and an accelerated development of feedback inhibition of the stress response by exogenously elevated steroid levels. Although malnourished pups displayed elevated basal corticosterone levels compared to well‐fed controls, the post‐stress levels were also higher in these malnourished young. Thus, the corticosterone response to stress was not impaired in malnourished pups.The influence of the early handling of malnourished young on pituitary‐adrenal activity was also studied. Whereas the accelerated development of the stress response and the elevated post‐shock levels were not the result of early handling, the elevated basal corticosterone levels displayed by handled malnourished pups were not present in nonhandled malnourished pups. Thus, the early non‐nutritional environment interacts with malnutrition to alter the development of the pituitary‐adrenal system.
A method for artificial feeding of motherless 2‐week‐old rat pups
Authors: Ackerman Sigurd H. , Shindledecker Richard 
Published: January 2005

AbstractWhen the rat mother is permanently removed from her litter at 14–15 days postnatally, weight loss in the pups routinely occurs. We now describe a method by which normal weight gain can be achieved at this age in the absence of the mother. Liquid flowing in a continuous stream down a glass surface in the home cage elicits spontaneous licking from the rat pups. If the liquid is a high fat milk formula, the rat pups maintain normal body weight. They do not maintain normal weight if low fat (bovine) milk is presented in this way or if the high fat milk formula is merely available in a reservoir on the cage floor.
Interactive effects of parity and early pup stress on the open field behavior of laboratory rats
Authors: Wright Linda , Bell Robert W. 
Published: January 2005

AbstractPups of primiparous and multiparous Sprague Dawley rats received 0‐, 2‐, or 5‐min cold stress on Days 2–6 postpartum. Stressed offspring of primiparous mothers had shorter latencies to move in an open field than did control offspring of primiparous mothers. However, stressed offspring of multiparous mothers had longer latencies than did the controls. The results suggest differences in maternal responsiveness immediately following return of stressed pups to the nest.
Body temperature and 5‐hydroxytryptamine during early postnatal maturation in mice
Authors: Goodrich Cecilie , Choy Marina 
Published: January 2005

AbstractA relationship between the maturational increases in body temperature and brain indoleamines has been explored through altering brain 5‐hydroxytryptamine (5‐HT) content. Effects on body temperature at approximately constant ambient temperature (about 24°C) have been studied following pharmacological manipulations in mice up to 16 days postpartum. Administration of 5‐hydroxytryptophan (5‐HTP) to increase 5‐HT levels was associated with decreased body temperature throughout the maturational period. Depletion of 5‐HT with p‐chlorophenylalanine (p‐CPA) was associated with increased body temperature at all ages studied, although 5‐HT depletion was less effective in young animals than in older animals. The drug NSD‐1034 acts at a different enzymatic step, and is effective in both central and peripheral tissues to reduce 5‐HT and norepinephrine (NE) levels. NSD‐1034 decreased body temperature up to 10 days of age; however, the effect was reversed at about 14 days, and the drug increased body temperature significantly in 16‐day‐old animals. These results suggest a role for 5‐HT in the mechanisms of heat production in early postnatal life.
Differential extinction of 2‐way active avoidance in young and adult rats
Authors: Brennan James F. 
Published: January 2005

AbstractThree experiments examined age‐related differences in extinction of active avoidance in rats through manipulation of the stimulus context. In Experiment I, 36 weanlings and 36 adults acquired comparable avoidance levels to a tonal conditioned stimulus (CS), and novel stimuli consisting of either the presence of a naive rat or a light were presented during 2 tests in extinction. Results indicated more pronounced disruption of extinction in the pups, compared to adults, with the animate novel stimulus having the greater effect. Eighteen pups of 22 days of age and 18 adults in Experiment II were trained to avoid shock with a CS consisting of simultaneous tone and light onset. During extinction responses did not terminate 1 of the CS elements, but rather produced continuation of either the tone or light for an additional 5 sec. Continuation of the tonal element resulted in greater disruption of extinction trials than the light in the adults, although the pups had faster, but nondifferential, extinction rates. A 3rd experiment presented 36 pups and adults with either 0‐, 5‐, or 10‐sec delays of tonal CS reactivation after extinction responses. Both 5‐ and 10‐sec delays resulted in increased numbers of extinction trials in the adults, but the pups failed to respond differentially to any of the delay intervals. Results of all of the experiments were considered in light of species‐specific behaviors in avoidance extinction relative to environmental and associative saliencies between ages.
Neonatal treatment of hamsters with barbiturate alters adult sexual behavior
Authors: Clemens Lynwood G. , Popham Teresa V. , Ruppert Patricia H. 
Published: January 2005

AbstractMale and female hamsters were given 50 μg pentobarbital, 100 μg pentobarbital, or 100 μg d‐amphetamine on postnatal Days 2–4. When tested for masculine sexual behavior in adulthood, males treated with 100 μg pentobarbital showed behavioral deficits when tested with testes intact as well as after castration and treatment with testosterone propionate. Deficits shown by 50 μg pentobarbital males were overcome by testosterone replacement. When tested for feminine sexual behavior, males treated with 50 μg pentobarbital showed enhanced lordotic responses whereas males treated with 100 μg d‐amphetamine showed no differences from controls when tested for female sexual behavior or when tested for male sexual behavior. Drug treatments had no effect on adult masculine or feminine sexual behavior in neonatally treated females. The results of this study show that pentobarbital can inhibit normal masculinization of the male when given during behavioral sexual differentiation.
Ontogeny of the visual evoked response in the stump‐tailed macaque
Authors: Dustman R. E. , Snyder E. W. , Creel D. , Beck E. C. 
Published: January 2005

AbstractVisual evoked responses (VER's) of stump‐tailed macaques were studied from birth to 80 weeks in an attempt to establish the utility of this species as a model of human neurophysiological development. Although human subjects and monkeys share a unique complexity of the VER at birth, the postnatal development of their VER's does not appear to follow a parallel sequence. The relatively dynamic nature of the VER during the 1st few weeks in a monkey's life may limit the usefulness of this species as a model of human development. The rapid changes in the VER of the developing monkey and the observation that these changes continue beyond 2 years of age should be considered in studies of the VER in which repeated measures are obtained over a prolonged period of time.
Behavioral effects of rotation between lactating and nonlactating females
Authors: Fleischer Susan F. , Turkewitz Gerald 
Published: January 2005

AbstractRat pups stunted by housing only 8 hr daily with lactating females and 16 hr with nonlactating foster mothers showed a delay in returning to their nest from other parts of the home cage. This delay was not due to changes in activity level or to lack of attraction to the nest, but appeared to be perceptual in nature. Both lactating and nonlactating females caring for stunted litters tended to be more maternal than those caring for control pups. After nutritional rehabilitation, the adult experimental animals showed no deficits in learning a series of visual discrimination problems in a modified version of the Lashley jumping stand procedure with a nonappetitive reinforcement. We compared the results with those obtained when other methods of stunting animals are employed and concluded that different methods of stunting may result in both common and divergent effects on behavior. Although many methods of stunting may produce similar behavioral deficits during the period of food deprivation, after rehabilitation behavioral deficits reported with other techniques of stunting may be due to extranutritional causes rather than to reduced food intake per se.
Spontaneous alternation in chicks using social reward
Authors: Cogan Dennis C. , Jones Jimmy F. , Irons Thomas 
Published: January 2005

AbstractTwo experiments examining spontaneous alternation in young white Leghorn chicks are reported. In Experiment I chicks (20 per group) run in a T‐maze for 4 trials to social reward displayed alternation of responses, whereas nonrewarded chicks did not alternate. In Experiment II socially rewarded chicks (20 per group) again showed reliable alternation of responses whereas food, water, and nonrewarded chicks did not alternate. These data support the premise that spontaneous alternation behavior has some phyletic generality under optimum conditions, although the mechanisms which control it may differ across species.
A minimal visual restriction experiment: Preventing chicks from seeing their feet affects later responses to mealworms
Authors: Wallman Josh 
Published: January 2005

AbstractChicks raised from hatching for 2 days without being able to see their feet because of cloth foot covers were less likely than controls to eat or pick up mealworms, which resemble the chicks' feet in some respects. Instead the chicks spent much time staring at the mealworms. Similar, but perhaps weaker, effects were obtained when the toes were simply painted black. These results may reflect processes of perceptual learning characteristic of infant animals.
Approach and departure patterns generated in the domestic chick by intermittent white light
Authors: Simner Marvin L. 
Published: January 2005

AbstractNewly hatched domestic chicks were given extended free access to 7 rates of intermittent white light between .5 and 24 flashes per sec. Inspection of the data showed approaches and departures directed toward the light that increased in number and formed an orderly pattern as the rates neared 4 per sec and as the chicks exposed to this rate became older. Also, no differences were found in the amount of time chicks remained next to the various rates during each approach but only in the amount of time they remained away during each departure. The bearing of these results on the proposal that flicker phototaxis might stem from the neural excitation produced through photic driving was discussed along with relating further evidence to recent work in imprinting.
Home orientation in nursling rats: The effects of rehabilitation following intergenerational malnutrition
Authors: Galler Janina R. 
Published: January 2005

AbstractRat pups with histories of intergenerational malnutrition were rehabilitated by cross‐fostering at birth to well‐nourished females. These pups weighed slightly less than well‐nourished controls but significantly more than pups reared by malnourished females. Rehabilitated and control pups were both more active than malnourished pups reared by malnourished females. However, the percentage of nest returns by pups displaced to other parts of the cage was low among rehabilitated pups as compared with controls, but did not differ from that of pups with histories of intergenerational malnutrition reared by malnourished females. These data suggest that, although activity is a product of postnatal condition, home‐orienting behavior is affected by a history of intergenerational malnutrition regardless of rehabilitation.
Deficits in fixed‐interval performance following prenatal and postnatal lead exposure
Authors: Zenick Harold , Rodriquez Ward , Ward Jerry , Elkington Brian 
Published: January 2005

AbstractFemale rats were exposed daily to 750 mg/kg of lead acetate via a restricted watering schedule for 70–80 days prior to mating and then throughout pregnancy and nursing. At weaning, litters from half of the lead dams were placed directly on treatment for the duration of the experiment. These manipulations yielded 3 groups: Group Pb/Pb, offspring exposed during pre‐ and postweaning periods; Group Pb/C, offspring exposed only during preweaning periods: and Group C/C, control offspring. Beginning at 42–49 days of age, postnatal, offspring were shaped to bar press under a fixed‐interval, 1‐min schedule (FI1) and then given 20 sessions, each 45 min in length. Analyses revealed that Group Pb/Pb received fewer reinforcements across sessions than the other 2 groups, which did not differ. However, when the Pb/Pb offspring did receive reinforcement, they exhibited the scalloped pattern of responding characteristic of fixed‐interval schedules.
Sleep‐waking patterns in hypoxic kittens
Authors: Baker Theodore L. , McGinty Dennis J. 
Published: January 2005

AbstractKittens at 10, 20, and 40 days of age were made intermittently hypoxic in 10 or 7% oxygen chambers for either 3 or 8 days. Respiration, EKG, EEG, and neck and eye movements were recorded during hypoxia. Compared to 21% oxygen controls, hypoxic kittens had fewer and shorter epochs of active sleep, and longer epochs of quiet sleep. Some hypoxic kittens exhibited slow and labored respiration during quiet sleep and transitional epochs, which reversed during active sleep. Kittens that showed most pronounced respiratory changes or died had less active sleep than kittens that compensated adequately and survived. These results suggest that active sleep may be important for stimulation of respiration during infancy. Suppression of active sleep, augmentation of quiet sleep, or other disturbances to normal sleep‐waking patterns during hypoxia, may increase the risk for hypoxic respiratory depression and death.
Effect of handling on positive and negative contrast effects
Authors: Fagen Jeffrey W. , Rycek Robert F. 
Published: January 2005

AbstractThe effects of early handling on the exhibition of positive and negative contrast effects were investigated. Over two 4‐day testing sessions, animals were given alternating 1‐min access periods to 2 bottles containing either 32 or 4% sucrose solutions. Measures of lick rate and latency to switch bottles revealed that both handled and nonhandled animals exhibited contrast effects of equal magnitudes. The results did not support an emotional interpretation of contrast effects but were interpreted as support for the perceptual theory of this phenomenon.
Learned responses to movement in neonates
Authors: Evans Barrie 
Published: January 2005

AbstractNumerous previous reports have pointed to the importance of movement (vestibular) stimulation in early infancy. Nevertheless, we have currently no clear understanding of these effects. The present paper looks at the role of movement stimulation in the modification of inborn organized patterns of response. Two laboratory experiments are reported in which newborn infants were presented with a cue (movement stimulus) which was either paired with dextrose presentation (experimental group) or not paired (control group). The experimental and control groups differed on the pattern of sucking in extinction, indicating an effect due to the contiguous presentation of movement and dextrose. Those experiments provide an analog for some naturally occurring conditions in early infancy and support some Soviet observations on the development of the earliest conditioned responses.
The ontogeny of nipple‐shifting behavior in albino rats: Mechanisms of control and possible significance
Authors: Cramer Catherine P. , Blass Elliott M. , Hall Warren G. 
Published: January 2005

AbstractNipple‐shifting behavior was studied in rats 3–‐30 days old in 4 experimental paradigms. The incidence of nipple‐shifting of rats tested in groups of 3 on their nonlactating, anesthetized mother was age‐related. Rats 12 days of age and younger did not leave the nipple first suckled during the 2‐hr test period. Starting by Day 15, however, nipple‐shifting increased and reached its maximum in 24‐day‐old rats. This behavior's incidence was directly related to maternal (and, therefore, nutrient and water) deprivation (Experiment I). Milk letdown reduced the incidence of nipple‐shifting behavior at all ages studied and synchronized its occurrence, as almost all shifts occurred immediately after letdown and almost none during the 15‐min interval between successive milk letdowns (Experiment II). Testing rats individually on the nonlactating, anesthetized mother produced age‐related effects. Shifting was virtually eliminated in 15‐day‐old rats, markedly reduced in 21‐day‐old rats, and not affected in 27‐day‐old rats tested individually (Experiment III). Rats 27 and 30 days of age, upon leaving a nipple, ate and did not return to suckle. Rats 15 days old never ate and always returned to suckle (Experiment IV). Twenty‐one‐day‐old rats suckled, and many ate in the mother's presence. The significance of these findings relates to maximizing milk intake and facilitating the process of weaning.
Adult responsiveness to ultrasonic signals from gerbils of varying ages: Parity, gender, and housing effects
Authors: Kleese Deborah , Hull Elaine 
Published: January 2005

AbstractGroups of adult gerbils differing by gender, parity, and presence or absence of young in the nest were exposed to taped ultrasonic distress calls of male and female pups on postnatal Days 3, 8, and 13. Frequency and time spent performing several behavioral items as well as frequency and time spent in the compartment housing the recorded tapes were assessed in the adult groups. Adult groups differed in rates and durations of certain behavioral items only during playback, with females with young in the home nest exhibiting the highest frequency of nest building in the test apparatus. However, all groups spent more time in the arm from which calls of Day‐8 pups were played. Calls of Day‐3 and Day‐13 pups did not produce significant differences in adult responsiveness. These results reveal significant characteristics of the ultrasounds for each group which parallel certain morphological and behavioral changes.
Dietary and metabolic effects on rhesus social behavior: Phenylalanine‐related dietary alterations
Authors: Chamove A. S. 
Published: January 2005

AbstractInfant rhesus monkeys were (a) fed a diet high in phenylalanine or (b) fed a diet high in p‐chlorophenylalanine for the 1st 12 months of life, (c) selected from mothers fed a diet high in phenylalanine during pregnancy, (d) fed a diet low in phenylalanine, (e) maintained as controls, or (f) maintained as pair‐fed controls. Tested during the 1st year of life with familiar peers, during the 2nd year with unfamiliar stimulus animals and with a movie film, the 3 groups of phenylketonuric monkeys showed less play and other positive social behavior and more withdrawal and more aggressive behavior than did the 2 control groups. The results support learning data suggesting that phenylketonuric monkeys are more emotionally reactive.