摘要:

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

ISSN:0012-1630    

DOI:10.1002/dev.420170102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThese experiments indicate that by Day 15 after birth, the processes that mediate a number of taste‐controlled behaviors in the rat are functional. These include the sensory processes necessary to detect and respond reflexively to sucrose, the event‐learning processes that reduce the rat's neophobic reaction to sucrose, and the integrative‐learning processes that enable it to learn an aversion to sucrose when paired with lithium toxicosis, even when these events are separated by 1 hr. These capacities, however, didnotemerge simultaneously. Those necessary to detect and respond reflexively to sucrose emerged prior to those that contribute to the learned control of taste‐guided behaviors. It is argued that these age‐related dissociations in behavioral capacities reflect acaudal‐to‐rostralmaturational sequence of components of the ascending gustatory system that are thought to underlie the

ISSN:0012-1630    

DOI:10.1002/dev.420170103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThe development of self‐recognition has been studied mainly by examining infants' responses to their reflections in mirrors. The definitive test is whether or not the infant is capable of using the reflection to notice and respond to a mark on the face or head by touching the mark. The mark should be inconspicuous to the infant not looking in a mirror. In general, studies agree that this response appears in some infants around 15 months of age and is shown by a majority of infants by 24 months of age. There is less agreement over the existence of a “withdrawal” component in the second year, or the presence of a “social” phase analogous to the reaction of many animals confronted with a mirror. Infants as young as 3 months are differentially responsive to a self‐reflection and a live peer. Various “self‐conscious” reactions and self‐labelling may also indicate self‐recognition in the second year, but their validity is not well established. Studies using videotapes of the self and others show that contingency of mevement is a salient cue which is learned early, and that attempts to engage in contingent play and to imitate representations of oneself are useful measures of early self‐recognition. The validity of the response of turning to look at an object first seen in a mirror as a sign of self‐recognition is questioned. The age at which self‐recognition in still pictures first appears is less clear. Verbal comprehension of self‐relevant labels appears earlier than active self‐labelling. A few studies have addressed the question of cognitive correlates of self‐recognition, but a variety of behaviors that imply self‐awareness and the corrresponding ability to impute mental states to others remains to be studied in relation to self‐recognition. Continued research into self‐recognition and associated abilities in nonhuman primates enhances the overall understandi

ISSN:0012-1630    

DOI:10.1002/dev.420170104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractAblation of medial prefrontal cortex impairs spatial discrimination learning in adult but not in neonatally lesioned rats. Orbital prefrontal cortex and adjacent convexity neocortex need not be left intact to observe this sparing of function. This study examined the possibility that the caudate nucleus, remaining intact after early medial prefrontal cortex lesions, might be involved in the observed behavioral sparing. Neonatal rats given combined lesions of the medial prefrontal cortex and head of the caudate nucleus were compared to age/litter‐matched sham‐operated controls on spatial alternation and place response acquisition and “reversal” tests. The results show that the performance of these neonatally lesioned subjects was deficient on both tests. The discussion centers on possible recovery mechanisms in rats given prefrontothalamic system damage early

ISSN:0012-1630    

DOI:10.1002/dev.420170105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractIn the first of two experiments, CD rat litters were used to characterize activity patterns obtained in a size‐adjustable, single photodetector chamber. Beginning on postnatal Day 10 or 12, pups were tested repeatedly over clean bedding (C) or over bedding removed from each pup's home cage (HC). In C rats of both sexes and in HC females, short‐term activity levels peaked on Day 16. However, HC males displayed and earlier and even greater elevation in activity from Day 12 to 16. This overall pattern was found in rats tested either every second or every fourth day. In the second experiment, Long‐Evans pups were assigned to each testing condition (C vs HC) and activity measured beginning on Day 12. Peak levels were seen in all Long‐Evans rats on Day 16 and only females showed significant alterations as a function of bedding condition. When overall activity levels of the two strains were compared, significant differences were found on Days 12, 24, 30, and 120 in males, and 12, 24, and 30 in females. Significant differences between strains in activity as a function of bedding condition were found in males on Days 12, 20, 24, and 120 and in females on Days 12, 30, and 60. These data confirm the generality of a developmental hyperactivity phase in isolated juvenile rats. However, different patterns of hyperactivity were found in male vs female rats across strains. CD males were more active in the presence of HC olfactory cues, while in Long‐Evans rats, female activity was affected more by bedding

ISSN:0012-1630    

DOI:10.1002/dev.420170106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractFeeding behaviors were measured during six feeding sessions distributed throughout a 24‐hr period in 10 normal 3‐day‐old female infants. Infants were individually videotaped during feeding sessions at 13:00, 17:00, 21:00, 01:00, 05:00, and 09:00 hours. Total mealtime, nutritive sucking time, pause time, number of nutritive sucks, and amounnt of nutrient consumed were measured. None of these feeding variables were affected by the time of day an infant was fed. Maternal interactions with their infants such as auditory stimulation, caretaking touches or tender touches were unaffected by the time of a feed. These maternal behaviors did not correlate with any of the feeding variables. These findings suggest that 3‐day‐old infants experiencing routine nursery care do not express specific day‐night feeding differences and that certain maternal behaviors do not influence the infants' feed

ISSN:0012-1630    

DOI:10.1002/dev.420170107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractIn recent studies (Moore, 1981, 1982; Moore&morelli, 1979) it has been found that maternal female rats spend more time licking the anogenital region of male than female offspring. This discrimination of pup sex has important implications for the development of a number of sex differences in behavior later in life, and the present study was designed to re‐examine Moore' observations while allowing each pup to be individually identified. Litters of Sprague‐Dawley rats were delivered by Caesarean section, and the footpads of each animal were tattooed with India ink to permit identification throughout testing. Each litter was then fostered to a maternal female and remained with her except when observations of maternal licking were made–on the fourth, seventh, and tenth days after delivery. On each of these days, the foster mother was placed in a test chamber for 30 min, and each pup was then presented individually for a 10‐min session. During this time the number and duration of anogenital licking episodes were recorded. We found, as did Moore, that adult females do distinguish between their male and female pups, spending significantly more time licking the anogenital region of the males in their litters on all but the first day of testing. The posssibility that the attentional bias toward male young has important consequences for behavior later in life and contributes to behavioral differences between the sexes (Beach, 1979; Moore, 1982) makes the identification of individual animals throughout development important in the analysis of these

ISSN:0012-1630    

DOI:10.1002/dev.420170108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

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

ISSN:0012-1630    

DOI:10.1002/dev.420170109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420170101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY