bluuebunny/crossref_metadata_2025 huggingface dataset:
Intake and behavioral responsiveness to taste stimuli in infant rats from 1 to 15 days of age
Authors: Johanson Ingrid B. , Shapiro Eleanor G.
Published: January 2005

Infant rats from 1 to 15 days of age received oral infusions of various taste solutions, and their intake of and behavioral responses to the infusions were observed. From 1 day of age on, pups responded to strong acid and quinine solutions with certain characteristic aversive responses and suppressed intake (Experiment 1). Although even very young (1‐ and 3‐day‐old) pups suppressed their intake of strong quinine and acid solutions, and rejected them by showing certain aversive responses (gaping and forelimb flailing), other components of the adultlike aversion response sequence (chin scraping and paw treading) did not appear until approximately 12 days of age. This suggests that the failure of pups to engage in chin scraping and paw treading prior to 12 days is not due to an inability to detect aversive solutions, but rather may be due to an immaturity in pups younger than 12 days of the neural substrates subserving these aversive responses. The emergence of chin scraping and paw treading to strong acid or quinine solutions was not influenced to any marked extent by either the deprivational state of the pup (Experiment 2a) or the site of the infusion (Experiment 2b).
Amphetamine reverses learning deficits in 6‐hydroxydopamine‐treated rat pups
Authors: Wool Robert S. , Weldon Douglas A. , Shaywitz Bennett A. , Anderson George M. , Cohen Donald J. , Teicher Martin H.
Published: January 2005

At 5 days of age, rat pups were treated with a combination of desmethylimipramine (DMI) and 6‐hydroxydopamine (6‐OHDA) to selectively deplete brain dopamine (DA) or with vehicle (saline) control solutions. Two days later, all animals received conditioning to a novel odor by pairing the odor with intraoral milk. When the odor was anise, treated pups spent less time near the conditioned stimulus than did controls, but there were no 6‐OHDA effects when the stimulus was a lemon odor (Experiment I). The difference in performance between the treated and control animals was not attributable to alterations in activating effects of the reinforcer (Experiment I), changes in olfactory sensitivity or olfactory preference (Experiment II), or sensitization to the stimulus (Experiment III). In Experiment IV, animals received d‐amphetamine sulfate (0.5 mg/kg) prior to conditioning, testing, or both conditioning and testing. Amphetamine treatment before conditioning produced an improvement in performance in animals previously treated with 6‐OHDA/DMI, but it impaired performance in controls, regardless of the time of injection. The results indicate a role of brain DA in learning in young rats.
Developmental differences in the analgesia produced by the central cholinergic system
Authors: Hamm Robert J. , Knisely Janet S.
Published: January 2005

In order to study the ontogensis of cholinergically mediated analgesia in the central nervous system (CNS), 10‐day‐, 28‐day‐, and 3‐month‐old rats were injected with .025, .05, and .10 mg/kg of oxotremorine, a muscarinic receptor agonist. To restrict the effect of oxotremorine to the CNS, methylscopolamine, a peripheral muscarinic antagonist, was injected simultaneously (.19 mg/kg, a dose equimolar to .10 mg/kg of oxotremorine). Following drug injections the tail‐flick procedure was used to assess analgesia. Results revealed that oxotremorine was completely ineffective in producing analgesia in the 10‐day‐ and 28‐day‐old age groups. By 3 months of age oxotremorine produced a dose‐dependent analgesia. Since most neurochemical markers of cholinergic receptor function are at mature or near mature levels by 28 days of age, neurochemical indexes of receptor function overestimate the analgesic function of the central cholinergic system.
Ontogeny of an endogenous, nonopioid and hormonally mediated analgesic system
Authors: Hamm Robert J. , Knisely Janet S.
Published: January 2005

Rats of different ages (10‐day, 28‐day, and 3‐month‐old) were exposed to cold‐water stress in order to activte an endogenous analgesic system. The effects of naltrexone (7 mg/kg) and dexamethasone (.4 mg/kg) were also studied to examine the role of the opioid and hormonal systems in cold‐water‐induced analgesia. Following cold‐water exposure, nociception was measured with the tail‐flick procedure for 2 hr. Results revealed that cold water produced a significant level of analgesia in the 10‐day, 28‐day, and 3‐month‐old age groups with no differences between age groups. In addition, in each age group naltrexone did not block the analgesia while dexamethasone attenuated the analgesia produced by cold water. The effects of naltrexone and dexamethasone confirm that cold‐water immersion activates a nonopioid, hormonally mediated analgesic system in each age group. Thus, this experiment found that the endogenous, nonopioid, and hormonally mediated analgesic system activated by cold water is functional early in the development of the rat. The early development of this hormonally mediated analgesic system is in contrast to the slower development of endogenous analgesia systems that are mediated by the central nervous system.
Pregnancy‐induced autogrooming in mice: The effects of nipple removal
Authors: Harvey Pamela J. , Mann Martha A.
Published: January 2005

As pregnancy advances, Rockland‐Swiss albino mice spend increasingly more time engaged in autogrooming. By gestation day 18 (the day prior to parturition), the total duration of autogrooming (a composite measure) as well as the duration of nipple line grooming is significantly longer than that displayed by virgin and early pregnant females. Nipple excision (i.e., thelectomy) performed prior to pregnancy reduces the time GD 18 dams spend licking nipple line regions without producing a concomitant decrease in the duration of grooming all regions. It is unlikely, therefore, that peripheral stimulation of the nipple line regions via self‐licking contributes to the heightened display of grooming by pregnant mice.
Hormonal and behavioral attachment responses in infant guinea pigs
Authors: Hennessy Michael B. , Ritchey Robyn L.
Published: January 2005

Infant guinea pigs, 11/12 and 18/19 days of age, exhibited high rates of vocalizing and increases in plasma concentrations of cortisol when separated from their mothers for 30 min in a novel environment (unfamiliar cage in an unfamiliar room). Levels of vocalizations and plasma cortisol were significantly reduced when the pup was exposed to the novel environment with its own conscious or anesthetized mother, but not when it was exposed with an unfamiliar anesthetized lactating female. Pups spent equivalent amounts of time in physical contact with their own conscious mother, their own anesthetized mother and an unfamiliar anesthetized lactating female. Unexpectedly, when the unfamiliar cage was placed in an environmental chamber during separation, pups showed negligible increases in vocalizations and plasma cortisol levels, even when administered footsck just prior to exposure. These findings demonstrate that guinea pig pups exhibit adrenocorticoid as well as behavioral responses to maternal separation, provide further evidence for the existence of filial attachment in this species, and document an unexpected role of the test environment in determining responses during maternal separation. The guinea pig may afford a rodent model for examining the effects of attachment‐object separation on the activity of the pituitary‐adrenal system.
Pre‐ and postnatal choline supplementation produces long‐term facilitation of spatial memory
Authors: Meck Warren H. , Smith Rebecca A. , Williams Christinal L.
Published: January 2005

Although research has demonstrated that short‐term improvement in memory function of adult rats can occur when the availability of precursors for the neurotransmitter acetylcholine is increased, little is known about whether memory function of adult rats can be permanently altered by precursor supplementation during early development. In the present study, male albino rats were exposed to choline chloride supplementation both prenatally (through the diet of pregnant rats) and postnatally (subcutaneous injections). At 60 days of age rats were tested on a 12‐ and 18‐arm radial maze task. Results indicated that compared to control littermates, perinatal choline‐treated rats showed more accurate performance on both working and reference memory components of the task. Theis performance difference was apparent on the first block of sessions and continued throughout training. Further analysis revealed that the difference between choline and control rats is not due to use of differntaial response or cue‐use strategies. Instead, it appears that choline induced performance differences are due to long‐term enhancement of spatial memory capactiy and precision.
Sibling inhibition of hoarding in postweaning hamster pups (Mesocricetus auratus)
Authors: Turpin Barbara , Johnston Timothy D. , Fulk Keith R.
Published: January 2005

If hamster pups are placed in individual cages at weaning (21 days of age) they begin to hoard food immediately; within 2–6 days, they hoard 90% of the food they take from their food dish in the course of a 1‐hr test, consuming only 10% of it. Pups that remain with their littermates after weaning in large group cages do not hoard food until they are placed in individual cages, when hoarding starts immediately. The inhibitory effect of littermates is just as pronounced in hamsters that have been allowed to hoard food in individual cages for 14 days after weaning and are then regrouped into litters. If litters are housed in divided cages that prevent physical interactions among littermates, but allow the interchange of olfactory, auditory, and some visual cues, hoarding is suppressed to an intermediate level. These results show that the presence of siblings inhibits the expression of hoarding, partly as a result of direct physical interactions and partly through the agency of sensory cues. The onset of hoarding following the dispersal of young from the nest cannot be explained as a motivational consequence of the young no longer having access to the mother's food hoard.
Unfamiliar environments impair information processing as measured by behavioral and cardiac orienting responses to auditory stimuli in preweanling and adult rats
Authors: Richardson Rick , Siegel Michael A. , Campbell Byron A.
Published: January 2005

Placing animals in an unfamiliar environment triggers at least two major reactions: (1) a heightened state of arousal, fear, or distress and (2) a sharp increase in information processing as the animal attempts to learn about its new environment. These changes could have a profound effect on the way in which the animal reacts to the types of extraneous innocuous stimuli typically used to study learning and memory. For example, an increase in arousal or fear could either (1) make the animal more “attentive” to stimulus change resulting in a larger orienting response, or (2) produce a shift from orienting to defensive responding. Conversely, processing of the new stimuli present in the unfamiliar environment may make the animal less responsive to additional extrinsic stimulation. These possibilities were examined experimentally using both autonomic and behavioral measures of orienting and defensive responses. The results demonstrated that animals fail to exhibit either an orienting response or a defensive response to a novel auditory stimulus when they are first placed in an unfamiliar environment. With continued exposure to the test environment the orienting response appears and then shows a time‐dependent increase in magnitude. This pattern of results was obtained in both preweanling and young adult rats. On the basis of additional research and analysis, it was concluded that a limitation in information processing capacity was the primary reason for the failure of the orienting response to occur when an animal is first placed in an unfamiliar test chamber.
Drinking behavior and motor function in rat pups depleted of brain dopamine during development
Authors: Weihmuller Fredric B. , Bruno John P.
Published: January 2005

The ability of rat pups depleted of brain dopamine (DA) at either 3 or 15 days of age to increase fluid intake in response to intracellular dehydration was studied. Despite near‐total depletions of striatal DA, animals depleted at either age ingested normal amounts of fluid even as soon as 3–7 days after incurring the brain damage. The effects of DA receptor blockade on ingestion and motor function were also studied. Haloperidol had markedly different effects as a function of the age at which the depletions were sustained. Weanlings that were depleted of DA at 3 days of age failed to exhibit the drug‐induced adipsia, akinesia, and catalepsy seen in controls and animals that were depleted at 15 days of age. These findings suggest that the DA depletions were performed at different periods of brain organization. The resultant neural controls of ingestion and motor function are qualitatively different in the two groups of depleted animals. Rats depleted at 3 days of age utilize nondopaminergic mechanisms, whereas animals lesioned at 15 days of age continue to rely upon residual DA neurons for both behaviors.
Effects of hand‐rearing on the behavioral development of infant and juvenile gorillas (Gorilla g. gorilla)
Authors: Meder Angela
Published: January 2005

Nineteen hand‐reared and seven mother‐reared infant and juvenile gorillas were observed for a period of 3 years. Almost all hand‐reared individuals developed stereotyped behaviors during the first months. In most cases these behaviors disappeared in the first or second year. Social behaviors, solitary play, nest building and grooming developed at about the same age in hand‐reared and mother‐reared infants. Hand‐reared immatures showed significantly more solitary play, more aggression and less social play than mother‐reared ones, especially when raised in pairs. When young gorillas were kept in groups, the frequencies of these behaviors came nearer to those of mother‐reared immatures. No significant differences were noted in social play. When introduced to conspecifics, hand‐reared infants sometimes reacted with indiscriminant aggression. Gorillas should thus preferably be reared in peer groups and be introduced to adults not later than one year of age.
Gender differnces in visual habit formation in 3‐month‐old rhesus monkeys1
Authors: Bachevalier Jocelyne , Hagger Corinne , Bercu Barry B.
Published: January 2005

The rate of learning concurrent visual discriminations with 24‐hr intertrial intervals, a measure of habit formation, was assessed in infant monkeys of both sexes and compared with the rate of learning in adults. In two separate series of animals, 3‐month‐old male monkeys learned an initial set of discriminations (but not later sets) more slowly than 3‐month‐old females. This gender difference was absent in 6‐month‐old monkeys and in adults, both of which learned the initial set at the same rate. Determination of plasma gonadal hormone levels at the time of testing revealed a significant correlation (rs = 0.95) between testosterone levels and learning scores on the initial set in the 3‐month‐old male monkeys (i.e., the higher the level the poorer the score). No such correlation was found in the 3‐month‐old female monkeys or in the 6‐month‐olds of either sex. These results suggest that high testosterone levels found perinatally in male monkeys temporarily slows maturation of the neutral system underlying visual habit formation.
Ontogenetic differences in the expresion of odor‐aversion learning in 4‐ and 8‐day‐old rats
Authors: Miller James S. , Molina Juan C. , Spear Norman E.
Published: January 2005

Two experiments investigated the ability of preweanling rats, 4 or 8 days of age, to form an odor‐LiCl association across various CS‐US delays. The results of the odor preference test indicated that 8‐day‐old subjects acquired an aversion to the CS+ odor when trained with either a 0 or 15 min CS‐US delay, while 4‐day‐old subjects did not exhibit a reduction in preference for the CS+ at any of the CS‐US delays tested. The absence of a reduction in preference for the CS+ by 4‐day‐old rats could not be attributed to their failure to acquire the odor aversion, however; they avoided a texture with which the CS+ odor was paired in a second order conditioning paradigm. The results suggest that outcomes appearing to represent age‐related differences in associative learning may in some instances be more appropriately viewed as representing ontogenetic differences in the way in which acquired associations are manifested in behavior.
Morphine treatment and reproductive condition alter olfactory preferences for pup and adult male odors in female rats
Authors: Kinsley Craig Howard , Bridges Robert S.
Published: January 2005

Administration of morphine sulfate (MS) to pregnancy‐terminated and postpartum lactating female rats disrupts both maternal behavior and postpartum aggression. Since the display of these behaviors may be heavily dependent on olfactory cues provided by the stimulus animals (rat pups and adult male rats, respectively), we examined whether MS was affecting the perception of the olfactory stimuli, and whether olfactory perception was modified by reproductive condition. In Experiment 1, lactating rats had their pups removed and were injected with MS (5.0 mg/kg, sc.) or saline. 60 min later they were placed into a two‐choice apparatus, one side of which contained bedding soiled by neonates and the other clean bedding. Time spent on each side was recorded for a total of 5 min (300 s; chance = 150 s). Saline‐treated mothers spent significantly more time on the pup‐odor side, whereas MS‐treated females spent significantly less. In Experiment 2, lactating females were treated with MS or saline and exposed to male odors (soiled bedding). MS significantly increased time spent on the side with male odors; when treated with saline, time spent was significantly reduced. Thus, in lactating rats, MS creates an aversion for pup odors while reducing the female's normal aversion toward male odors. In Experiment 3, ovariectomized (ovx) virgin females expressed neither an aversion nor a preference for the odor of pups following saline administration. After MS treatment, however, the virgins showed a distinct preference for pup odors. When exposed to male odors in Experiment 4 ovx virgins showed a marked preference for male odors after MS treatment, and neither a preference nor an aversion after saline. Experiment 5 examined pup odor preferences in intact virgins, early (Day 7), middle (Day 14), late‐pregnant (Day 21), and prepartum (Day 22) rats. The pup odor preferences of virgin, Day 7, Day 14, and Day 21 pregnant rats were not different and generally were at chance levels. Day 22 pregnant females exhibited a marked preference for pup odors compared to chance levels, as well as compared to the other four groups. These findings suggest that opiates and endogenous opioids may regulate olfactory preferences and that alterations in this system may underlie normal behavioral changes toward conspecifics prepartum as well as during lactation.
Striking absence of long‐lasting effects of early color deprivation on monkey vision
Authors: Brenner Eli , Cornelissen Frans , Nuboer Wim
Published: January 2005

A monkey (Macaca fascicularis) spent its first three months under far red illumination that made color vision impossible. It developed normal spectral sensitivity. In the present study we examined two aspects of color vision that presumably reflect cortical connectivity. In the first part of this article we show that chromatic induction was also unaffected: a blue surrounding made a gray target appear to be yellow to the monkey.

At five months of age, the deprived monkey did not readily use color to recognize objects, although it was able to do so if necessary. In the second part of this article we show that, as an adult, the monkey was quite willing to use color to categorize objects. We conclude that early color deprivation does not result in long lasting deficits in color vision.
Multiple contexts and memory retrieval at three months
Authors: Rovee‐Collier Carolyn , Dufault Debra
Published: January 2005

Studies of adults have shown that the contextual dependence of memory retrieval can be alleviated by training in multiple contexts. In the present studies with 3‐month‐old infants, retention was disrupted when infants were trained in one context and tested in another, but not when they were trained in multiple contexts prior to testing in a novel context. The retention advantage of multiple learning contexts was observed after 3 days in a simple forgetting paradigm (Exp. 1) and after 14 days in a reactivation paradigm (Exp. 2). These findings demonstrate that although the setting in which an event occurs is an important determinant of memory retrieval at 3 months, its protective function can be overridden by common experiences in varied settings.
The effects of rate and forward masking on human adult and newborn auditory evoked brainstem response thresholds
Authors: Lasky Robert E.
Published: January 2005

Several investigators have reported that human newborn auditory brainstem evoked response (ABR) thresholds to clicks are about 10‐20 dB higher than human adult thresholds to the same stimuli (Galambos amp; Hecox, 1978; Shulman‐Galambos amp; Galambos, 1979; Lasky, Rupert, amp; Waller, 1987). The present study replicated these results, but, in addition, addressed developmental differences in ABR thresholds due to forward masking and changes in stimulus repetition rate. Eight human newborns and seven human adults served as subjects. Newborn ABR thresholds to a 100 μs click which followed a 82 db (A) SPL 50 ms broadband forward masker by 10 ms were significantly more elevated relative to their unmasked ABR thresholds than were those of the adults. Relatively loud sounds seem to have a greater effect on the newborn's ability to process subsequently presented soft sounds than they do on adult processing. In contrast, changes in repetition rate of 100μs clicks from 10/s to 50/s had no greater effect on newborn than adult ABR thresholds. At near threshold stimulus levels, rate effects on the ABR are not apparent in newborns nor adults.
Restriction of early exploratory forays effects specific aspects of spatial processing in weanling hamsters
Authors: Tomlinson W. Thomas
Published: January 2005

Normally reared hamsters, but not hamsters reared on a liquid diet, demonstrated spatial memory for the location of odor cues in an allocentric task (Experiment 1). In Experiment 2, an egocentric task, liquid‐reared hamsters detected a change in the spatial location of odor cues. In Experiment 3 liquidreared hamsters detected a change in the spatial location of two visual cues under allocentric task conditions. Female hamsters on a liquid diet retrieved their pups more often than dams on solid food, resulting in reduced exploratory opportunities for their pups during the period when olfaction mediates behavior. Hamsters in Experiment 4 experienced a direct restriction of early forays. The restricted‐rearing group failed to detect a change in the spatial location of odor cues in an allocentric task. These findings suggest that restriction of early exploratory experience during a narrow period of development results in specific spatial processing deficits.
Age‐related differences in sensory conditioning in rats
Authors: Chen Wei‐Jung , Lariviere Nancy A. , Heyser Charles J. , Spear Linda P. , Spear Norman E.
Published: January 2005

Four experiments tested rats 8, 12, or 21 days postnatal for sensory conditioning in terms of the association acquired between two odors presented simultaneously or sequentially. The sensory conditioning of 8‐ and 12‐day‐old rats exceeded that of rats 21 days of age when the odors were presented simultaneously. When one odor was presented immediately followed by another, however, 21‐day‐old rats conditioned as effectively as the younger animals, and with a sufficiently long interval between odors (20 min), the sensory conditioning of the 21‐day‐old rats surpassed that of the rats 12 days of age. Although consistent across a variety of procedures, in previous experiments and within the present study, the age‐related differences in sensory conditioning after simultaneous presentation of two odors are difficult to understand. Increasing knowledge of the ontogeny of orienting may lead to an explanation in terms of Thompson's (1972) theory linking sensory conditioning with orienting and sensitization.
The amniotic sac as scaffolding: Prenatal ontogeny of an action pattern
Authors: Robinson Scott R. , Smotherman William P.
Published: January 2005

Intraoral lemon infusion elicits facial wiping behavior in fetal rats on Days 20 and 21 of gestation. On Day 19, fetuses tested in a warm saline bath respond to infusion but do not express the wiping response. In contrast, fetuses tested within the amniotic sac exhibit wiping. Fetal movements after infusion were analyzed on Days 19 and 20 in both the bath and amnion environments. Facial wiping is assembled from simpler components in both real time (during the 15 s after infusion) and developmental time (over Days 19–20 of gestation). In real time, the wiping response occurs following a brief period of fetal activity comprising head and forelimb movements. After the wiping bout is initiated, strokes by left and right forelimbs increase in duration and become synchronized. In developmental time, components of the wiping response (forelimb strokes) are consistently expressed on Day 19, but other components (head stabilization) are lacking when fetuses are tested in bath. The amniotic sac appears to provide scaffolding that reduces head movement and promotes paw‐face contact, thus facilitating facial wiping.
The development of exploration and spontaneous alternation in hooded rat pups: Effects of unusually early eyelid opening
Authors: Foreman Nigel , Altaha Mohammad
Published: January 2005

Changes in exploratory activity and spontaneous alternation were examined across postnatal Days 8–31 in Lister hooded rat pups whose eyelids were surgically opened at 6–8 postnatal days. Compared with controls, whose eyes open naturally at 14–16 days, the treated animals showed accelerated behavioral development. Open‐field activity increased more rapidly in the week following surgery, but only when all pups in the litter had their eyelids opened, and not when only half of the litter was treated. Rearing on the hind paws emerged earlier in treated animals, but grooming was unaffected. Pups having unilateral early eyelid opening made pivotal circling movements contraversive to the opened eye in an open‐field arena in the early neonatal period. When tested in a T‐maze, treated pups showed earlier spontaneous alternation than controls. Possible physiological systems underlying such changes are discussed. Our results show that unusually early visual stimulation has behavioral consequences, producing a brief speeding of some attentional and investigatory behaviors, though such changes may also depend upon environmental factors.
Organization of the stretch response to milk in the rat fetus
Authors: Robinson Scott R. , Smotherman William P.
Published: January 2005

Intraoral infusion of milk reliably elicits a stretch response in the rat fetus. The fetal stretch response appears isomorphic to the stereotypic behavior exhibited postnatally by suckling rat pups during milk ejection. Using a procedure that permits direct fetal observation, milk infusions were delivered to rat fetuses on Day 20 or 21 of gestation. Infusion of milk promoted systematic changes in fetal behavior that culminated in expression of the stretch response nearly 3 min later. Interruption of this behavioral sequence prevented stretching, suggesting that a period of behavioral reorganization after milk infusion is necessary but not sufficient for the stretch response to occur. The behavioral sequence initiated by the fetal rat's first exposure to milk is remarkably similar to the behavior exhibited by experienced infant rats at the nipple. © 1992 Wiley & sons. Inc.
Temperature‐dependent effects of maternal separation on growth, activity, and amphetamine sensitivity in the rat
Authors: Zimmerberg Betty , Shartrand Angela M.
Published: January 2005

This study was conducted to examine the effects of an early stressor, maternal separation, on development, arousal, and sensitivity to amphetamine in the rat. Rat pups were maternally separated at nest temperature (WARM), room temperature (COLD), or nest temperature with agitation (AGIT) for 6 hr each day from 2 to 15 days of age. A control group (CONT) remained with the mother in the nest during this time. COLD subjects were developmentally delayed and had lower body and brain weights than the other three groups into adulthood. WARM and AGIT subjects (both maternally separated at nest temperature) had significant growth delays compared to CONT, but grew more quickly than COLD subjects. COLD subjects were less active than the other maternally separated groups, and WARM and AGIT groups were more active. Activity did not differ at 28 or 75 days of age. However, adult WARM subjects were less sensitive and COLD subjects were more sensitive to amphetamine as measured by locomotor activity than CONT and AGIT subjects, who did not differ from each other. The relationship between early stress, changes in dopaminergic systems, and altered drug responsiveness are discussed in terms of the implications for the etiology of drug abuse. © 1992 Wiley & sons. Inc.
Ultrasonic vocalizations by rat pups: The primary importance of ambient temperature and the thermal significance of contact comfort
Authors: Blumberg Mark S. , Efimova Inna V. , Alberts Jeffrey R.
Published: January 2005

We investigated the effects of isolation, huddling, and air temperature on ultrasound production by rat pups. Experiment 1 showed that ultrasound production by 8‐ to 9‐day‐olds was minimal at thermoneutrality and increased in response to small deviations of air temperature on either side of the thermoneutral zone. Experiments 2 and 3 showed that suppression of ultrasound production by contact with littermates is consistent with the thermal consequences of huddling. Experiment 4 showed that, contrary to previous conclusions, ultrasound production is not independent of ambient temperature in pups older than 10 days of age. Taken as a whole, these experiments emphasize (1) the importance of ambient temperature for the elicitation of ultrasound by rat pups of all ages studied, (2) the importance of thermal factors in the suppression of ultrasound by littermate contact, and (3) the manner in which different methods can change interpretations of the behavior and physiology of infant rats. © John Wiley & Sons, Inc.
Quinpirole alters quadruped activity in rats from the second postnatal week
Authors: Eilam David , Szechtman Henry , Spear Linda P.
Published: January 2005

The present study shows that the effects of quinpirole (1 mg/kg) during the second postnatal week but not before resemble the effect of the drug in adult rats in increasing quadruped activity, eliminating grooming, reducing lateral bending, and stimulating verticalized turning. Quinpirole also modifies the morphology of turning behavior, the primary from of coordinated quadruped locomotion in neonate laboratory rat pups. Under saline, turning involves lateral bending and straightening of the trunk. Under quinpirole, turning includes a vertical component of movement (“verticalized turning”) instead of the normal lateral bending of the trunk. A similar trend of change in turning is induced by quinpirole in adult rats: An acute injection reduces lateral bending, and a chronic treatment increases verticalization. The induction of vertical turning in the second but not the first postnatal week may stem from the normal course of development since typical vertical movements of intact rats (supported rearing and wall climbing) develop only by the age of 11–14 postnatal days. Verticalized turning may be thus a drug‐induced expression of an age‐related tendency to perform vertical movements. © John Wiley & Sons, Inc.
Blood pressure increases in response to feeding in the term neonate
Authors: Cohen Morris , Witherspoon Mary , Brown David R. , Myers Michael M.
Published: January 2005

We studied blood pressure and heart rate of 18 medically well newborn babies before, during and after feeding. Seven were breast‐fed and 11 bottle‐fed and all were studed between 24 and 92 hr of age. There was an increase in heart rate associated with sucking on a pacifier but no additional increase with feeding. By 30–60 min after feeding, heart rate had returned to baseline value. Blood pressure, however, did increase in response to feeding and showed a greater increase in the breast‐fed group than in the bottle‐fed group. Systolic blood pressure rose from 72 mmHg in the basal state to 85 mmHg during the first 3 min of feeding in the bottle‐fed babies and from 73 to 99 mmHg during comparable periods in the breast‐fed babies. The results for diastolic blood pressure were similar except that changes within the bottle‐fed group were not statistically significant. Bottle‐fed babies rose only from 42 to 47 mmHg while breast‐fed babies rose from 42 to 61 mmHg from basal conditions to feeding. Blood pressure responses to feeding may have implications for susceptibility to necrotizing enterocolitis, for future blood pressure liability in adulthood and for later hypertensive disease. © John Wiley & Sons, Inc.
Behavioral selection of odor cues by young female mice affects age of puberty
Authors: Drickamer Lee C.
Published: January 2005

Female house mice were reared from weaning at 21 days of age until first vaginal estrus in 40 1 aquaria in which they were given a choice of exposing themselves to bedding placed on opposite halves of the aquarium floor and sprayed with water or urine containing puberty‐influencing chemosignals. In Experimental 1, mice housed with only male urine cues sprayed on the bedding matured significantly earlier and mice housed with only grouped female urine sprayed on the bedding matured significantly later than control mice where water was sprayed on the bedding for both halves of the aquarium. In Experiment 2, there were no significant differences in mean ages at vaginal introitus or first estrus for females reared with choices between (a) bedding sprayed with male urine versus bedding sprayed with water, (b) bedding sprayed with urine from grouped females versus bedding sprayed with water, (c) bedding sprayed with male urine versus bedding sprayed with urine from grouped females, or (d) the control condition where both sides of the aquarium contained bedding sprayed with water. Analysis of continuous video tapes of the locations of the females for Experiment 2 revealed that females chose initially to spend more time on the half of the floor with bedding that delayed puberty relative to the other side, but shifted their preference toward a more puberty‐enhancing signal at about the time of first estrus. Female house mice appear to be able to exert some behavioral control over their own sexual maturation. © 1992 Wiley & sons. Inc.
Postpartum factors related to mother's attraction to newborn infant odors
Authors: Fleming Alison S. , Corter Carl , Franks Patrícia , Surbey Michelle , Schneider Bruce , Steiner Meir
Published: January 2005

Hedonic responses to a variety of infant (general body, urine, and feces) and noninfant (lotion, cheese, and spice) odorants were compared in four groups of subjects: new mothers, mothers a 1‐month pospartum, and female and male nonparents. Using standard scaling procedures, subjects rated each of the odorants twice on a scale from extremely unpleasant (−20.5) to extremely pleasant (+20.5). In addition, all subjects completed a set of attitude questionnaires, and mothers also answered a childbirth questionnaire and were observed while feeding their infants © 1993 John Wiley & Sons, Inc.
The effect of age on children's learning of problems that require a configural association solution
Authors: Rudy Jerry W. , Keith Julian R. , Georgen Kathleen
Published: January 2005

Elemental associations permit subjects to solve problems when the significance of the relevant stimulus elements are consistent from trial to trial but do not allow subjects to solve problems that require them to construct and use representations of stimulus conjunctions or configurations to guide their behavior. Recent research with brain‐damaged and developing animals has led several theorists to propose that elemental and configural associations depend on different neural systems. Some evidence suggests that changes in children's learning that occur when they are about 4.5 year old may be partially due to developmental differences in access to the elemental and configural association systems. Two experiments are reported that support this hypothesis. Children at least 4.5 years old were able to solve the transverse patterning problem and a conditional discrimination, two problems that require configural association solutions. Younger children did not solve these problems but were able to solve problems constructed from the same stimulus materials that permitted an elemental association solution. These results suggest that children may not gain access to the configural association system until they are about 4.5 years old and support the hypothesis that the configural association system depends on different, later developing neural structures than does the elemental association system © 1993 John Wiley & Sons, Inc.
Importance of prenatal nutrition to the development of a precocial chick
Authors: Hill Wendy L.
Published: January 2005

The developmental maturity of hatchling birds varies greatly across the altricial‐precocial continuum and these differences are related to the relative proportions of yolk and albumen in a species' egg. In general, the more precocial the chick the greater the proportion of yolk in its egg. Egg composition can also vary within species with unknown consequences for the developing embryo. The present research sought to determine the importance of egg composition to avian development by experimentally removing 1, 2, 4, 8, 12, or 16% of the albumen from eggs of domestic fowl (Gallus gallus). Experimental chicks were paired to control chicks whose eggs were matched on the basis of original mass and laid by the same female but no albumen was removed from their eggs prior to incubation. Decreased levels of albumen significantly decreased chick size at hatch. Experimental subjects, however, had similar growth to controls after 20 days of ad‐lib access to food, although sex differences between pairs indicated that the growth of females may be affected differentially by albumen removal. Righting responses were retarded in experimental subjects for the 2 and 4% albumen‐removal groups. Egg composition can have important consequences for chick survival simply by influencing body size at hatch and it is suggested that the practice of using overall egg size as a measure of egg “quality” needs to be broadened by considering what is inside the egg as well. In addition, the unique opportunity presented by using an avian model to assess directly the specific influences of protein (albumen) and of fat (yolk) on growth and behavioral development is explored. © 1993 Wiley & sons. Inc.
The effects of olfactory experience on nest odor preferences and pup retrieval in rats
Authors: Bauer J. H.
Published: January 2005

Previous studies have shown that maternal rats are attracted to their own bedding and that of other dams but not to that of virgins. The present studies were designed to test two hypotheses: First, that the addition of a novel botanical odor to the bedding of maternal animals would result in subsequent preferences for such an odor. Second, such a preference should enable dams to discriminate between pups odorized with familiar and unfamiliar odors as measured by differential retrieval of the pups. Both hypotheses were confirmed. In addition, we found that preferences established during a first pregnancy and lactation affected the retrieval of pups during a second lactational period, but could be overturned by new olfactory experience during that second lactational period. © 1993 John Wiley & Sons, Inc.
Contextual updating of infants' reactivated memories
Authors: Boller Kimberly , Rovee‐Collier Carolyn
Published: January 2005

The ease with which a reactivated memory is updated is updated has major implications for whether or not a prior memory is likely to be retrieved in the future. In three experiments, we explored this problem with nonverbal human infants, whose newly acquired memory of training in a specific context is readily updated by novel contextual information. In Experiment 1, exposing infants to a novel context immediately after a successful reactivation treatment neither impaired their retention in the original context nor facilitate it in the novel exposure one. In Experiment 2, increasing the delay between the reactivation treatment and exposure to the novel context also failed to facilitate retention in the novel test context. In Experiment 3, the reactivated memory was updated when the contingency was briefly experienced in the novel context immediately after the reactivation treatment. Under these circumstances, previously trained infants exhibited retention in the novel context, but infants who had not been trained 3 weeks earlier or whose original memory had not been reactivated exhibited none. The resistance of a reactivated memory to contextual updating unless the new context is predictive apparently buffers infants′ memories against revision after long delays by contexts that could be inappropriate.© 1994 John Wiley & Sons, Inc.
The organizational context and the development of internal evaluation
Authors: Love Arnold J.
Published: January 2005

Organizational factors that influence the development of effective internal evaluation are identified.
Satisfying the constraints of causal modeling
Authors: Reichardt Charles S. , Gollob Harry F.
Published: January 2005

Causal models often omit variables that should be included, use variables that are measured fallibly, and ignore time lags. Such practices can lead to severely biased estimates of effects. The discussion explains these biases and shows how to take them into account.
The methodology of data envelopment analysis
Authors: Sexton Thomas R.
Published: January 2005

Data envelopment analysis is a linear programming–based method that has clear advantages over competing approaches. However, its own limitations should not be overlooked.
The functions of program theory
Authors: Bickman Leonard
Published: January 2005

The role of theory in program evaluation is an important but neglected area in evaluation practice and theory. Program theory has several important functions that can improve our ability to generalize from particular evaluations, contribute to social science theory, and achieve consensus in evaluation planning.
Evaluability assessment: Developing program theory
Authors: Wholey Joseph S.
Published: January 2005

Evaluability assessment involves key policymakers, managers, and staff in developing program theory and clarifying intended uses of evaluation information, thus helping solve problems that inhibit useful program evaluation.
Juvenile delinquency intervention
Authors: Lipsey Mark W.
Published: January 2005

Over the past several decades, skepticism about the effectiveness of juvenile delinquency interventions has increased substantially. However, as the quality of research on this topic has improved, a more optimistic perspective has begun to emerge. To address this issue, the author summarizes three meta‐analyses indicating that interventions to reduce juvenile delinquency may have small but meaningful positive impacts. This systematic literature review also suggests promising avenues for future research.
Checking the congruence between a program and its organizational environment
Authors: Roberts‐Gray Cynthia , Scheirer Mary Ann
Published: January 2005

Congruence is a key issue in implementation process evaluation. By analyzing the fit between program and environment at macro, intermediate, and micro levels, evaluators can help program managers to decide where and how to change implementation processes so that the program can produce its intended benefits.
Measuring implementation of social treatment
Authors: Reid William J. , Hanrahan Patricia
Published: January 2005

A combination of quantitative and qualitative methods can help to improve measures of processes, intended and unintended, and the links between processes and outcomes.
Everything important in business and industry is evaluated
Authors: Swanson Richard A.
Published: January 2005

The business environment and culture dictate expectations for economic impact of training that must be understood by evaluators.
Ethnographic evaluation of AIDS prevention programs: Better data for better programs
Authors: Schensul Jean J. , Schensul Stephen L.
Published: January 2005

Ethnographic methods complement standard treatment or control group studies by providing contextual and culturally sensitive information to administrators and service providers in AIDS prevention programs.
Services to individuals who are homeless and mentally ill: Implementation evaluation
Authors: Mowbray Carol T. , Cohen Evan , Bybee Deborah
Published: January 2005

This chapter discusses the evaluation of a two‐site demonstration program.
Critical multiplism: A research strategy and its attendant tactics
Authors: Shadish William R.
Published: January 2005

Recent debates suggest that quantitative and qualitative approaches to evaluation are inevitably separated by a gap in worldviews. Critical multiplism is one way of thinking about evaluation that can unify these two approaches.
Paradigm wars: A basis for peaceful coexistence and beyond
Authors: Datta Lois‐ellin
Published: January 2005

Both qualitative and quantitative paradigms have contributed much to evaluations. Both, however, are works‐in‐progress with many issues still unresolved and assumptions incompletely tested. Further, both are more similar in practice than might be expected from the sometimes strident disputes—all grounds for peaceful coexistence and for going beyond to a new perspective.
Demoralization and threats to validity in Birmingham's homeless project
Authors: Schumacher Joseph E. , Milby Jesse B. , Raczynski James M. , Engle Molly , Caldwell Ellen S. , Carr James A.
Published: January 2005

This chapter presents how demoralization arose in a community‐based, randomized clinical trial and discusses related threats to validity.