bluuebunny/crossref_metadata_2025 huggingface dataset:
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

Body 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

The 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

The 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

Behavioral 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

The 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

Infant 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

Hindlimb 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

A 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

Predation 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

Human 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

A 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

Pregnant 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

Individual 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.
Gustatory determinants of suckling in albino rats 5‐20 days of age
Authors: Kehoe Priscilla , Blass Elliott M.
Published: January 2005

Taste reactivity in suckling rat pups was assessed. Five‐day‐old rats in Experiment I were equipped with tongue cannulae seated 2 mm rostral, 0–3 mm caudal, or 4–6 mm caudal to the intermolar eminence. Either water, 1.4 × 10−3 QHC1, .50M NH4Cl, or .43M NaCl was delivered in one of three fashions during suckling: (1) continous: fluid was continuously available from a reservoir connected to the cannula, and could be obtained by exerting suction; (2) discrete: same procedure as above, save that fluid was available for only 30 sec every 3 min of the 30‐min test; (3) pulsatile: here, .05 ml fluid was delivered by infusion pump 8–10 sec every 3 min, provided the pups were attached to a nipple. Based on intake, time and behavioral measures, we conclude behavioral reactivity exists especially to NH4Cl and NaCl. As to quinine, Day 5 pups were responsive only when QHCl was delivered in the continuous mode. In Experiment II, rats 10, 15, and 20 days of age received the above solutions by infusions with the cannulae located in one of the three positions. Quinine reactivity developed sequentially in an anterior to posterior direction. NH4Cl disrupted behavior in 5‐, 10‐, and especilly 20‐day‐old rats. Remarkably, Day 15 rats were not behaviorally reactive to NH4Cl. Sodium chloride, especially in the anterior and middle positions, was treated as an aversive solution during suckling throughout development. Based on existing electrophysiological data, the last finding was unexpected.
Development of vocal recognition of mothers in infant japanese macaques
Authors: Masataka Nobuo
Published: January 2005

Individual vocal recognition was studied in infant Japanese macaques by presenting natural calls of mothers and nonmother cagemates to them in a habituation‐dishabituation paradigm. Discriminability was measured by an increase in conditioned sucking response rate to a second stimulus call after habituation to the first stimulus call. Recovery from habituation was greater in subjects over 190 days postconception when mother's vocalizations were played back after the stimulus change than when sounds of others were presented. Results demonstrate that the subjects could sort acoustic variants of vocalizations given by their cagemates into at least two categories (mother versus others) and suggest that vocal recognition of mothers develops relative to postconception (maturational) rather than postnatal age in Japanese macaques.
Spatial memory of children and adults assessed in the radial maze
Authors: Aadland Jan , Beatty William W. , Maki Ruth H.
Published: January 2005

To assess the development of accurate spatial memory and its relationship to organized search strategies, children (18–71 months old) and college students searched for rewards hidden at the ends of the arms of an eight‐arm radial maze. Subjects made their first four choices in random order selected by the experimenter (forced choice) or in whatever order they wished (free choice). In some conditions, a retention interval was imposed between arm choices 4 and 5, followed by a resumption of the task. With free choice, accuracy of spatial memory increased linearly with age, and the proportion of tests on which the child entered four adjacent arms in sequence during the first four choices, a measure of organized searching, also increased linearly with age. Disrupting this sequential search strategy (forced choice) reduced accuracy for both children and college students, although the reduction with college students was small. Delays had minimal effects for children who met criterion at 0‐delay and for college students. Although response patterns seem unimportant in accurate spatial memory in rats, systematic search strategies mature together with, and probably contribute to, the improvement of spatial memory with age in humans.
Ontogenesis of learning: VI. Learned and unlearned responses to visual stimulation in the infant hooded rat
Authors: Moye Thomas B. , Rudy Jerry W.
Published: January 2005

A Pavlovian fear conditioning procedure was used to examine the ontogeny of the hooded rats' learned responses to visual stimulation. The data suggests a dissociation in the emergence of the processes required to detect visual events and those necessary for learning an association between visual stimulation and shock. Pups did not condition to a visual conditioned stimulus (CS) paired with a shock unconditioned stimulus (US) until they were 17 days old, even though 15‐day‐olds were clearly able to detect the visual CS. Although 15‐day‐olds failed to condition to the visual CS, they conditioned successfully when an auditory CS was paired with shock. Thus, the 15‐day‐olds' failure to condition to the visual CS was not due to a performance deficit or to a general ineffectiveness of shock as an US. These data suggest that the components of the visual system that mediate detection and those required for associative learning mature sequentially.
Specificity in the reactivation of infant memory
Authors: Rovee‐Collier Carolyn , Patterson Jeff , Hayne Harlene
Published: January 2005

In three experiments the specificity of an effective reactivation stimulus, or reminder, was examined. Two weeks after learning to produce movement in a crib mobile by footkicking, 3‐month‐old human infants showed no retention of the response‐reinforcer contingency. A reactivation procedure 24 hours prior to the long‐term retention test was effective if the reminder was a brief noncontingent exposure to the original 5‐component training mobile or a mobile containing one novel substitution. When more than one novel component were substituted into the original mobile, the reminder was ineffective. This was predicted by the discrimination function 24 hours following training. A reminder containing only a single familiar (predictive) component and four novel ones was also moderately effective. In subsequent studies, we explored different interpretations of the reminder specificity effect. We hypothesize that reminder specificity is of particular adaptive value for developing organisms in providing a buffer against memory retrieval in inappropriate contexts.
The ontogeny of salt preference in rats
Authors: Moe Karen E.
Published: January 2005

Many mammals eat salt irrespective of need. This behavior, called salt preference or appetite, is studied primarily in adults. Little is known about its ontogeny. In these experiments, 3–18‐day‐old rat pups were offered saline, quinine, or ammonium chloride solutions by infusion through an anterior oral catheter, and intake was measured. At 6–18 days, pups showed the inverted U‐shaped preference‐aversion curve for NaCl that is characteristic of adult rats. Thus, rats express a preference for salt at a very early age. However, the curves were broader than the typical adult curve and were shifted along the concentration gradient in an age‐related fashion. Consumption of quinine and ammonium chloride showed similar age‐related changes. These changes may reflect the postnatal timing of the development of the rat gustatory system.
The role of penile stimulation and ejaculatory experience on the development and maintenance of reproductive behavior in the bull (Bos taurus)
Authors: Katz Larry S. , Price Edward O.
Published: January 2005

To determine the role of afferent input from the penis and copulatory experience on the ontogeny of reproductive behavior, 49 bulls were randomly assigned to the following groups: (1) control; (2) surgical penile deflection (penis deviation), which prevents intromission; (3) penile neurectomy; or (4) penis deviation plus neurectomy. Sexual performance tests were conducted at 3‐month intervals from 9 to 24 months of age. Bulls deviated but not neurectomized mounted more frequently than bulls in the other groups. The low mount frequency for control bulls in tests in which copulation occurred was due to the sexually quiescent postejaculatory refractory period. Preventing control bulls from copulating by affixing cloth patches to females' perinea increased mount frequency to the level of deviated bulls. It is concluded that copulatory experince is not essential to the development and maintenance of normal mounting activity. However, sensory stimulation from the penis facilitates the expression of sexual behaviors.
Infanticide by virgin CF‐1 and wild male house mice (Mus musculus): Effects of age, prolonged isolation, and testing procedure
Authors: McCarthy Margaret M. , vom Saal Frederick S.
Published: January 2005

The frequency of infanticide by juvenile, young‐adult, and adult male house mice (Mus musculus) was compared in CF‐1 albino mice and the F1–F4 male offspring of wild mice trapped in Missouri. When tested in their home cages for their behavior toward a single 2‐day‐old pup after being individually housed for 5 days, juvenile CF‐1 and wild males were equally likely to exhibit infanticide (about 35%). But, adult wild males were significantly more likely to exhibit infanticide (about 90%) than were adult CF‐1 males (about 45%). We propose that differences in exposure to testosterone during fetal life may contribute to the difference in the incidence of infanticide between CF‐1 and wild males. Prolonged isolation (45 days) significantly reduced the proportion of wild male mice that exhibited infanticide when the males were tested in their home cages, but not when the males were tested by being placed into the cage of lactating females and their 2‐day‐old young. Virtually all adult wild males exhibited infanticide when they were tested in their home cages (with either a 2‐day‐old or 7‐day‐old pup) or when they were placed into the cages of lactating wild female mice and their 2‐day‐old young. But, when adult wild males were placed with lactating wild females on Day 7 postpartum, the females attacked the males and most males were prevented from exhibiting infanticide.
Alarm call responsivity of mallard ducklings: III. Acoustic features affecting behavioral inhibition
Authors: Miller David B. , Blaich Charles F.
Published: January 2005

Mallard duckling (Anas platyrhynchos) inhibit their vocal and locomotor behavior upon hearing the maternal alarm call of their species. This study assesses the effects of varying acoustic features of alarm calls on the ducklings' freezing response (i.e., vocal and locomotor inhibition). Domestic mallard (Peking) ducklings were tested individually to alarm calls that varied either in note duration, frequency modulation, dominant frequency, repetition rate, or repetition rate in combination with these other features. The present study demonstrates that ducklings show a high degree of behavioral specificity to repetition rate (i.e., number of notes per second), relative to other acoustic features. This study also revealed that ducklings also exhibit some degree of behavioral specificity to note duration. Dominant frequency and frequency modulation play only a minor role in affecting behavioral inhibition. The behavioral specificity of mallard ducklings to slow repetition rates (that are typical of maternal alarm calls) provides a basis for the importance of their slow‐rate perinatal vocalizations in the development of alarm call responsivity.
The effects of 24‐hr maternal separation and of litter‐size reduction on the isolation‐distress response of 12‐day‐old rat pups
Authors: Hofer Myron A. , Brunelli Susan A. , Shair Harry N.
Published: January 2005

We asked whether the mother–infant interaction acted over time to regulate the ultrasonic vocalization (USV) and activity responses of 12‐day‐old rat pups to isolation in a novel test area. In a series of four experiments, we found that 24 hr of maternal deprivation did not alter USV isolation responses, but that reduction of litter size to 4 pups from 8 markedly attenuated the USV response and increased weight gain, without effects on activity level. Ambient temperatures during 24‐hr maternal separation were varied from 23° to 35°C without effect on subsequent USV responses, but activity levels were markedly reduced in pups separated at the low heat level. Possible mechanisms for maternal regulation of USV responses involving nutrient effects, altered processing of thermal stimuli, and the inhibition of thermogenesis by nutrient deprivation are discussed. © 1993 John Wiley & Sons Inc.
Cardiac vagal tone: Stability and relation to difficultness in infants and 3‐year‐Olds
Authors: Porges Stephen W. , Doussard‐Roosevelt Jane A. , Lourdes Portales A. , Suess Patricia E.
Published: January 2005

Psychophysiological studies of infants have found a relation between behavioral reactivity and indices of autonomic state. The relation between behavioral reactivity, assessed via maternal report, and autonomic state, assessed via cardiac vagal tone in 9‐month‐old infants was examined. Cardiac vagal tone was quantified by measuring the amplitude of respiratory sinus arrhythmia. High cardiac vagal tone was associated with greater behavioral reactivity, resulting in maternal reports of more difficult temperament. Stability of the two measures, cardiac vagal tone and difficult temperament, from 9 months to 3 years of age was demonstrated. In addition, 9‐month cardiac vagtal tone, independent of 9‐months temperament, was related to 3‐year difficultness with higher 9‐month cardiac vagal tone being related to less‐difficult 3‐year behavior. © 1994 John Wiley & Sons, Inc.
Comparisons of nipple attachment and incisor growth among four species of voles (Microtus)
Authors: Salo Allen L. , Shapiro Lawrence E. , Dewsbury Donald A.
Published: January 2005

Patterns of nipple attachment and incisor growth were compared between four species of voles (Microtus). Offspring of two highly social species, prairie voles (M. ochrogaster) and pine voles (M. pinetorum). were shown to cling tightly to the nipples of their dams on Days 2, 6, and 10. This pattern contrasted to weak nipple attachment displayed by two less‐social species, meadow voles (M. pennsylvanicus) and montane voles (M. montanus). Lengths of the upper (maxillary) and lower (mandibular) incisors of the four species were recorded throughout the first 10 days of age and in adults. Incisors of the pine and prairie voles typically erupted earlier and grew longer than those of the meadow or montane voles during the first few days of development. Incisors grew at a substantial rate in the latter two species, such that they equalled or surpassed the incisor lengths of the former two species as Day 10 and weaning approached. Patterns of incisor growth, in part, reflected those for nipple attachment, but do not appear to account substantially for differences in nipple attachment. ©1994 John Wiley & Sons, Inc.
Hand preferences for bimanual feeding in 140 captive chimpanzees (Pan troglodytes): Rearing and ontogenetic determinants
Authors: Hopkins William D.
Published: January 2005

Hand preference in bimanual feeding was assesed in 140 captive chimpanzees (Pan troglodytes). Bimanual feeding was defined as the active use of one hand for feeding with the opposite hand holding other food items. In terms of strength of hand preference, adults were more lateralized than sub‐adults. Additionally, mother‐reared chimpanzees were more lateralized than nursery‐reared chimpanzees. The number of subjects with no hand preference was more prevalent in sub‐adults compared with young and older adults. Of those subjects with a significant hand preference, a larger proportion exhibited a right‐hand preference. These results are discussed in relation to previous reports of handedness and bimanual feeding in gorillas and bonobos.©1994 John Wiley & Sons, Inc.
Development of uncoupling between D1‐ and D2‐ mediated motor behavior in rats depleted of dopamine as neonates
Authors: Byrnes Elizabeth Mccone , Bruno John P.
Published: January 2005

The D1‐and D2‐mediation of stimulated motor behavior was studied in pups (Days 10–11) and weanlings (Days 20–21) that had been depleted of dopamine (DA) on postnatal Day 3. Administration of the D1‐like agonist SKF 38393 (30.0 mg/kg) or the D2‐like agonist quinpirole (3.0 mg/kg) increased the incidence of sniffing and locomotion in intact and DA‐depleted animals tested at either age. However, the ability of selective DA antagonists to reduce these stimulated responses interacted with both the depletion and the age at the time of testing. When tested as pups, both the D1 antagonist SCH 23390 (0.2 or 0.4 mg/kg) and the D2 antagonist clebopride (10.0 mg/kg) suppresed the behaviors induced by either class of DA agonist. When tested as weanlings, intact animals exhibited the profile of pups (i.e., either class antagonist blocked each agonist). In DA‐depleted weanlings, however, only the D1 antagonist blocked the D1 agonist‐induced responses and only the D2 antagonist blocked the D2 agonist‐induced responses. These data demonstrate that the interactions between D1 and D2 receptors in the expression of stimulated motor behaviors are altered following DA depletions in neonates. Moreover, this change in receptor function occurs sometime between 7 and 13 days after the DA depletion.©1994 John Wiley & Sons, Inc.
Separation and depression in infant gorillas
Authors: Hoff Michael P. , Nadler Ronald D. , Hoff Kathryn T. , Maple Terry L.
Published: January 2005

Three 27‐month‐old infant gorillas living with their mothers and a silverbacked male were separated to a cage for 24 weeks. The infants initially showed threat responses and increased locomotion, characteristic of the protest stage of anaclitic depression in children. Within several days, these were replaced by dorso‐ventral contact among the infants as well as self‐holding and fetal positioning. Additionally, social and solitary play and object examination occurred at lower levels through separation than in the pre‐separation condition. These changes were characteristic of the despair stage of separation. There was a substantial recovery of many infant nonsocial and social behavior in the later months of the separation. Upon reunion, the infants did not immediately engage in attachment behaviors with their mothers, and spent more time in contact with each other than with their mothers for the first several days, indicating detachment. Following this, there was an increase in mother‐infant attachment behaviors.©1994 John Wiley & Sons, Inc.
Brain and behavioral effects of dietary n‐3 deficiency in mice: A three generational study
Authors: Wainwright P. E. , Huang Y.‐S. , Coscina D. V. , Lévesque S. , McCutcheon D.
Published: January 2005

Feeding mice a diet deficient in n‐3 fatty acids for three generations resulted in a 53% decrease in docosahexaenoic acid (DHA, 22 : 6n‐3) in the brain. Maternal pup retrieval and social learning of a food preference are both tasks based on olfactory function. All dams made contact more readily with pups of their own dietary group, and animals of both dietary groups demonstrated the ability to learn a food preference through exposure to a conspecific that had previously eaten the food. Both groups showed similar ability to learn the location of the hidden platform in the Morris water maze, while the n‐3 deficient animals were marginally faster in locating the platform on the cued trial. They were also more active when tested in the open field. While they did not differ in their duration of immobility in a forced swimming test, the deficient animals did have longer paw‐lick latencies on a hot plate. Thus, in this study a significant reduction in brain n‐3 fatty acid composition, while associated with some indications of change in emotional reactivity, did not impair olfactory function or learning of either a latent or spatial nature.©1994 John Wiley & Sons, Inc.
Habituation, sensitization, and infants' responses to motherse speech
Authors: Kaplan Peter S. , Goldstein Michael H. , Huckeby Elizabeth R. , Cooper Robin Panneton
Published: January 2005

Four‐month‐old infants were tested for their visual responses to infant‐directed (ID) speech versus adult‐directed (AD) speech in a fixed‐trial habituation procedure. In Experiment I, infants looked significantly longer in response to a 4 × 4 checkerboard pattern that was compounded with an ID speech segment than an AD speech segment. Looking times increased significantly between the first and second presentations of the ID speech segment only. In Experiment II, infants looked slightly more during ID than AD trials when the two were alternated from trial to trial. Responding to the first AD speech segment was significantly greater than when it was preceded by ID speech than when it was not, while responding to the first ID speech segment was significantly less when it was preceded by AD speech than when it was not. These findings are discussed in relation to the hypothesized differential arousing properties of ID and AD speech. © 1995 John Wiley & Sons, Inc.
Effects of opioid receptor blockade on the social behavior of rhesus monkeys living in large family groups
Authors: Martel Frances L. , Nevison Claire M. , Simpson Michael J. A. , Keverne Eric B.
Published: January 2005

Rhesus monkeys of 9 weeks, 48 weeks, 100 weeks, 150 weeks of age (young subjects), or mature parous females that were not lactating were given acute single doses of the opioid antagonist naloxone (0.5 mg/kg) and vehicle on different days and observed in their familial social groups. Naloxone increased the occurrence of affiliative behaviors. Young subjects spent more time in contact with their mothers but showed no changes in social grooming. Maternal contact was actively sought through contact vocalizations, decreasing proximity, and, for the youngest infants, increased attempts to suckle. Mature females made more solicitations for grooming and received more grooming from their companions. These results are interpreted in terms of naloxone blocking the positive affect arising from social contact and thus causing subjects to seek further affiliative comfort. © 1995 John Wiley & Sons, Inc.
Effects of rearing condition on activity‐induced weight loss
Authors: Ness James W. , Marshall Timothy R. , Aravich Paul F.
Published: January 2005

This study evaluated the effects of differential rearing conditions on a rat protocol for various human syndromes. Subjects were 26 male Sprague‐Dawley rats, 24 days old at the start of the experiment, matched according to weight, and randomly assigned to an isolation‐ or group‐reared (4 rats/cage) condition. At 60 days of age (273 ± 13 g), subjects were individually housed in cages allowing access to running wheels. Weight loss was produced through voluntary exercis and restricted food access. Animals in the isolationreared condition lost weight at a faster rate and had heavier relative thymus weights than those in the groupreared condition. Animals in both conditions ran equivalent distances and ate equivalent amounts of food. The data show that postweaning rearing conditions impact the interpretation of behavioral and physiological outcomes of animal models. The results implicate a shift from maternal regulation of pup physiological and behavioral systems to the broader social niche. © 1995 John Wiley & Sons, Inc.
Development of water‐immersion produced analgesia
Authors: Stolberg Alex , Frenk Hanan
Published: January 2005

Nociceptive and antinociceptive systems change dramatically during the first 10 days of life in rats. The present studies sought to determine whether exposure to water stress can produce analgesia during this period, and when in the ontogeny changes in magnitude and duration of such stress‐induced analgesia occur. It was found that exposure to water reliably induced analgesia as early as 3 days postnatally. This analgesia increased in magnitude and duration at the age of 17–20 days, when supra‐spinal descending inhibition develops, and depended on the temperature of the water and duration of exposure. © 1995 John Wiley & Sons, Inc.
Ontogeny of eyeblink conditioning in the rat: Auditory frequency and discrimination learning effects
Authors: Andrews Steven J. , Freeman John H. , Carter Christy S. , Stanton Mark E.
Published: January 2005

The present study sought to determine whether acoustic properties of the auditory conditioned stimulus (CS) or the use of a discrimination learning procedure would alter the emergence of eyeblink conditioning between postnatal Days 17 and 24 (Days 17–24) in the rat. In Experiment 1, we employed a 3 × 2 × 2 factorial design, involving pitch of the auditory CS (2.8, 5.0, and 9.0 kHz), training condition (paired vs. unpaired), and age (Days 17 or 24). Associative learning was evident at all tone frequencies on Day 24, but increased across frequencies on Day 17, although large age differences in conditioning remained at all tone frequencies. In Experiment 2, rat pups were trained to discriminate 2.8 versus 9.0‐kHz tones on Day 17 or Day 24. Eyeblink conditioning increased with tone frequency on Day 24 but discriminative conditioning failed to appear on Day 17. These findings are discussed in relation to the role of auditory system maturation in the ontogeny of eyeblink conditioning. © 1995 Johnv Wiley & Sons, Inc.
Augmented prenatal visual stimulation alters postnatal auditory and visual responsiveness in bobwhite quail chicks
Authors: Sleigh Merry J. , Lickliter Robert
Published: January 2005

This study examined whether previously reported effects of altered prenatal sensory experience on subsequent acceleration of intersensory development in precocial birds are mediated by mechanisms sensitive to the overall amount of stimulation provided. Results revealed that bobwhite quail chicks exposed to substantially augmented amounts of prenatal visual stimulation show altered patterns of species‐typical perceptual development. Specifically, chicks continued to respond to maternal auditory cues into later stages of postnatal development and failed to demonstrate responsiveness to maternal visual cues. Embryos also failed to demonstrate prenatal auditory learning of an individual maternal call, a behavior reliably seen in unmanipulated embryos. These findings suggest that substantially increased amounts of prenatal sensory stimulation can interfere with the emergence of species‐typical patterns of postnatal intersensory functioning and lend support to the notion that sensory stimulation that falls within some optimal range maintains or facilitates normal patterns of perceptual development, whereas stimulation beyond the range of the species norm can result in intersensory interference. © 1995 John Wiley & Sons, Inc.
Contributions of experience to the development of musical processing in infancy
Authors: Lynch Michael P. , Short Lori B. , Chua Rosario
Published: January 2005

Full‐term infants' performance in detection of melodic alterations appeared to be influenced by perceptual experience from 6 months to 1 year of age, and an experiment with infants born prematurely supported the hypothesis that experience affects music processing in infancy. These findings suggest parallel developmental tendencies in the perception of music and speech that may reflect general acquisition of perceptual abilities for processing of complex auditory patterns. This acquisition may contribute to the cultural enfranchisement of infants through perceptual experience. © 1995 Johnv Wiley & Sons, Inc.
Stability and change in cortisol and behavioral response to stress during the first 18 months of life
Authors: Lewis Michael , Ramsay Douglas S.
Published: January 2005

Observation of cortisol and behavioral responses to routine inoculation was conducted at 18 months for infants in a longitudinal sample whose stress responses had been observed at 2, 4, and 6 months of age. At 18 months, infants showed an increase in cortisol level over base to the perturbation. The magnitude of this response did not differ from the 6‐month response. Moreover, level of cortisol response at 18 months was related to level of cortisol response at 6 months, but not at 2 or 4 months of age. In light of previous findings for a decline in cortisol response between 2 and 6 months and for the emergence of consistent individual differences in cortisol response by 4 to 6 months, the present findings indicate that a developmental shift in adrenocortical functioning has occurred by 6 months of age. © 1995 John Wiley & Sons, Inc.
A theoretical approach to substituent effects. Interactions between directly bonded groups in the neutrals XNH2, XOH, and XF and the anions XNH− and XO−
Authors: Hinde Alan L. , Pross Addy , Radom Leo
Published: January 2005

Ab initio molecular orbital calculations have been carried out for the neutrals XNH2, XOH, and XF and the anions XNH− and XO− with substituents X = Li, BeH, BH2, CH3, NH2, OH, and F. All structures have been fully optimized with the 4‐31G basis set which is found to perform considerably better than the minimal STO‐3G basis in predicting the lengths of strongly polar bonds. A quantitative analysis of interactions between the directly bonded groups, utilizing energy changes in hydrogenation reactions, is presented and rationalized with the aid of perturbation molecular orbital theory. Favorable interactions occur when electron‐donor groups bond to electron‐acceptor groups. This applies to both σ and π interactions, the relative importance of which depends on the particular substituents.
Applications of molecular mechanics calculations in carbohydrate chemistry. I. Conformational and constitutional equilibria of tetraoxabicyclo[4.4.0]‐ and ‐[5.3.0] decanes, bicyclic diacetals of alditols
Authors: Burkert Ulrich
Published: January 2005

The energies of various conformations have been calculated by molecular mechanics for cis and trans isomers of 2,4,7,9‐tetraoxabicyclo[4.4.0] decane and 3,5,8,10‐tetraoxabicyclo[5.3.0]decane and their methyl derivatives. These molecules are models for reaction products from formaldehyde and the tetrols, pentitols, and hexitols. The conformational equilibria were analyzed for the cis‐bicyclo [4.4.0] and cis‐bicyclo[5.3.0] systems and compared with available experimental data. The thermodynamic stability of bicyclo[4.4.0] products was found to be higher than that of bicyclo[5.3.0] derivatives in the gas phase in every case studied. Discrepancies with experimental data that exist in a few cases can be ascribed to solvent effects.
An analysis of the molecular packing of maleic hydrazide
Authors: Hall David , Headford Christine E. L.
Published: January 2005

A molecular packing analysis of the hydrogen‐bonded layer structure of maleic hydrazide shows that even in such a structure, the van der Waals energy is the dominant component of the lattice energy. The hydrogen‐bond energy of the observed structure is greater than that for alternative structures based on a different mode of hydrogen bonding, and this makes the observed more stable.
Small elemental clusters. I. The structures of Be2, Be3, Be4, and Be5
Authors: Whiteside Robert A. , Krishnan Raghavachari , Pople John A. , Krogh‐Jespersen Mary‐Beth , Von Ragúe Schleyer Paul , Wenke Gottfried
Published: January 2005

The geometries and energies of beryllium clusters up to Be5 are examined using ab initio molecular orbital theory. Allowances are made for electron correlation with Møller—Plesset perturbation theory to fourth order. Correlation is found to have a dramatic effect on the relative energies of the several structures examined for Be4 and Be5. Furthermore, the effect of d‐type basis functions on the correlation energy results in an increased binding energy for the clusters. Be2 is only weakly bound. For Be3, the best estimate of the binding energy is 6 kcal/mole for the singlet equilateral triangle. Be4 is tetrahedral in its ground state and the estimated binding is 56 kcal/mole. The best structure for Be5 is a singlet trigonal bipyramid, and the binding energy is 88 kcal/mole at the highest level of theory used.