摘要:

AbstractTwelve infant squirrel monkeys were reared with distinctively colored and scented inanimate surrogates (Green/FloralorBlack/Clove) and tested monthly from 1 to 6 months of age in 3 paired‐comparison conditions that assessed the efficacy of synthetic olfactory cues and color cues as attractive properties of the surrogates. The infants developed specific attractions to both the rearing odor and color of the surrogates by approximately the end of Month 4, although substantial differences existed between the 2 rearing groups, particularly with respect to color responsiveness. When compared with previous findings on infant squirrel monkeys reared with naturally scented surrogates, odor preferences developed relatively late, suggesting that natural, species‐typical odors may have inherently stronger attractive properties forSaimirithan arbitrary synthetic od

ISSN:0012-1630    

DOI:10.1002/dev.420120102

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe latency of onset and the duration of sleep induced by pentobarbital was studied in rats from 9 to 35 days of age, as well as in adult rats. Sleep latency was prolonged and sleep duration shortened with increasing age and maturation. Electrocorticographic changes after pentobarbital administration were studied in rats of 5–45 days of age and in adult rats. In rats 9 days of age or less the electrocorticogram manifested only depression of activity, whereas from the 12th day onward all characteristic barbiturate‐induced phenomena were registered: spindles, slow waves, and isolated spikes with suppression of background activity. Spindles were the most conspicuous of the pentobarbital‐induced phenomena and were the 1st to appear as a function of age, occurring only in the frontal areas at 12 days of age but in both frontal and occipital areas at 15 days of age. Frequency of the elements comprising spindles increased with from 2.5–3.5 c/sec in 12‐day‐old rats to 5–10 c/sec in adult animals. Barbiturate spindles could be used as a model for rhythmic thalamocortical phenomena even at early stages o

ISSN:0012-1630    

DOI:10.1002/dev.420120103

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

年代:1979

数据来源: WILEY

摘要:

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

ISSN:0012-1630    

DOI:10.1002/dev.420120104

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

年代:1979

数据来源: WILEY

摘要:

AbstractAvoidance conditioning during pregnancy, changes in caretaker behavior during lactation, and changes in offspring catecholamine levels and behavior were investigated in C57BL/6J mice. Three equal groups of mice were employed. One group was avoidance conditioned prior to pregnancy and continued to avoid shock during pregnancy; a 2nd group was avoidance conditioned during pregnancy; and the 3rd group served as untreated controls. Offspring were crossfostered after birth. During lactation the proportion of time the caretaker spent on the nest was observed. At weaning pups were individually housed. Offspring dopamine concentrations were measured in the corpus striatum at birth and at days 22 and 42 of age. Their performance was evaluated in the open field at Day 42 of age. The results showed that mice receiving avoidance conditioning prior to parturition were more likely to cannibalize their offspring at parturition than were control animals. Furthermore, preparturiently avoidance conditioned mice spent less time on the nest if they reared offspring from biological mothers who had been avoidance conditioned when compared to similarly treated caretakers who reared offspring from untreated control biological mothers. Regardless of postnatal experiences, adult offspring from avoidance conditioned biological mothers had significantly reduced levels of dopamine in tissue from the corpus striatum and were significantly less active in the open field when compared with offspring from control biological mothers. Behavioral results support the findings of others that the prenatal environment plays an important role in shaping the later behavior of offspring. The decrease in dopamine levels suggests that avoidance training as one form of psychosocial stimulation during pregnancy can be disruptive to the development of the dopamine regulatory mechanisms.

ISSN:0012-1630    

DOI:10.1002/dev.420120105

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

年代:1979

数据来源: WILEY

摘要:

AbstractMale and female hamsters were given 50 μg pentobarbital, 100 μg pentobarbital, or 100 μgd‐amphetamine on postnatal Days 2–4. When tested for masculine sexual behavior in adulthood, males treated with 100 μg pentobarbital showed behavioral deficits when tested with testes intact as well as after castration and treatment with testosterone propionate. Deficits shown by 50 μg pentobarbital males were overcome by testosterone replacement. When tested for feminine sexual behavior, males treated with 50 μg pentobarbital showed enhanced lordotic responses whereas males treated with 100 μgd‐amphetamine showed no differences from controls when tested for female sexual behavior or when tested for male sexual behavior. Drug treatments had no effect on adult masculine or feminine sexual behavior in neonatally treated females. The results of this study show that pentobarbital can inhibit normal masculinization of the male when given during behavioral sexual dif

ISSN:0012-1630    

DOI:10.1002/dev.420120106

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

年代:1979

数据来源: WILEY

摘要:

AbstractPrimiparous female mice of 2 lines genetically selected for different narcotic responses to ethanol were administered 10% (v/v) ethanol in their drinking water during Days 2–14 of lactation. Ethanol treatment resulted in a marked decrease in growth and viability of pups in both lines. Fewer offspring of the ethanol‐sensitive line survived to weaning, apparently because of the failure of a large number of dams to exhibit maternal care. The combination of ethanol treatment and an additional environmental stressor (mouse hepatic virus) had a devastating effect on maternal behavior and offspring survival in the ethanol‐sensitive line, but far less effect on the ethanol‐insensitive mice. Thus, ethanol‐sensitive animals appear to be more susceptible to a variety of stressors, includin

ISSN:0012-1630    

DOI:10.1002/dev.420120107

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe early visual experience of hooded rats was restricted to either vertical or horizontal stripes. In a discrimination task pairing a gray surface and stripes of either the same orientation or an orientation orthogonal to that experienced during rearing, the rats made significantly fewer correct choices with the orthogonal orientation. However, the relatively lower overall performance of the vertically reared‐horizontally tested animals was a major factor in the main effect of testing condition. We conclude that functional modification of the rat visual system through early selective visual experience is possibl

ISSN:0012-1630    

DOI:10.1002/dev.420120108

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

年代:1979

数据来源: WILEY

摘要:

AbstractThis study systematically examined separation‐induced distress vocalization in the infant guinea pig. Experiment I found that under maximum separation from both social and physical surroundings, the distress vocalization rate remained high for the 1st 4 weeks and then continuously declined to near zero by Week 12. Repeated testings had no effect on habituation of the rate during Week 5. Experiment II, using separation distress vocalization responses to the social (the mother) and the physical (the home pen) environments, showed that when the mother was present the vocalization rate was extremely low, and when she was absent the rate was moderate if the subject was isolated in the home box and high if the subject was in an unfamiliar box. Experiment III confirmed the finding that primary social attachment took place toward the mother. These results corroborate other attachment measures, and indicate the usefulness of the vocalization technique for the study of attachment in the infant guinea pi

ISSN:0012-1630    

DOI:10.1002/dev.420120109

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

年代:1979

数据来源: WILEY

摘要:

AbstractTwo experiments investigated the exhibition and development of positive and negative contrast effects in the consummatory behavior of juvenile and adult rats. Over a 4‐day session, animals were given alternating 30‐sec presentations of 2 bottles containing either 32 or 4% sucrose solutions. In Experiment I, different groups of rats were tested both cross‐sectionally and longitudinally using a cohort‐sequential design. Cross‐sectionally, animals at all ages exhibited both types of contrast and demonstrated increasing positive contrast effects with greater age. Discrepancies between the longitudinal and cross‐sectional samples were found to be due to the repeated testing procedure of the former design. Experiment II replicated the positive and negative contrast effects in the juvenile animals, indicating that the processes responsible for contrast effects are operating in the rat at a ver

ISSN:0012-1630    

DOI:10.1002/dev.420120110

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

年代:1979

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420120111

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

年代:1979

数据来源: WILEY