摘要:

AbstractThree experiments tested the learning and retention of neonatal rats (7, 9, and 12 days of age) with a nondirectional active avoidance task, using a vibrotactile conditioned stimulus. The hypothesis was that the substantial deficit of these animals in 24‐hr retention is due, at least in part, to a deficiency in memory retrieval. In Experiment I, a reactivation treatment was found to alleviate the forgetting over the 24‐hr period for 12‐day olds although having somewhat lesser effect for animals 9 days of age. The reactivation treatment seemed ineffective for rats 7 days of age. Experiments II and III confirmed the reliability of the reactivation effects with 9‐ and 12‐day olds, while adding further control conditions and providing new information concerning the ontogenesis of latent i

ISSN:0012-1630    

DOI:10.1002/dev.420110602

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

年代:1978

数据来源: WILEY

摘要:

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

ISSN:0012-1630    

DOI:10.1002/dev.420110603

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

年代:1978

数据来源: WILEY

摘要:

AbstractWeanling mice were reared in environmental enrichment and/or impoverishment conditions for 2 months. In the 1st experiment, mice were switched from 1 environment into the other after 1 month, and maintained in the opposite environment for 2 or 4 weeks. Switched and nonswitched groups were compared to establish whether the effects of the initial environmental exposure would persist through later opposite environmental experiences. The performance of switched groups tended to differ from that of all nonswitched groups: little behavioral persistence was found. In the 2nd experiment, mice were switched every 7, 14, or 28 days over a 2‐month period. These procedures yielded several types of behavioral outcomes; however, no behavioral persistence was evidenced. The data indicate that early life experiences in a particular level of environmental complexity need not permanently modify behavio

ISSN:0012-1630    

DOI:10.1002/dev.420110604

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

年代:1978

数据来源: WILEY

摘要:

AbstractVocal responses of kittens and mature cats were recorded in a variety of standard behavioral situations. Sonographic analysis of these responses showed similarities of responses obtained repeatedly from different cats within each recording situation. Marked differences in responses patterns were noted in different recording situations. The kitten and cat vocal repertoires thus include a variety of specific responses to particular motivational or behavioral circumstances.

ISSN:0012-1630    

DOI:10.1002/dev.420110605

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

年代:1978

数据来源: WILEY

摘要:

AbstractA common notion regarding autistic children is that they do not show self‐recognition. In this study, 7 autistic children were compared to a group of normal infants at the age of self‐recognition. Using a videotape “mirror image” and an objective self‐recognition criterion, we observed that 6 of the 7 autistic children exhibited self‐recognition. In a 2‐choice preference situation, autistic children tended to prefer the more predictable mirror image to a previously taped

ISSN:0012-1630    

DOI:10.1002/dev.420110606

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

年代:1978

数据来源: WILEY

摘要:

AbstractMaternal behavior (retrieving, crouching, and licking) was induced in Sprague‐Dawley virgin female rats by constant exposure to pups aged 1‐2, 3‐4, 5‐6, 7‐8, 9‐10, 11‐12, 13‐14, or 15‐16 days. The incidence of spontaneous components of maternal behavior, notably retrieving, was geater towards pups 1‐8 days of age than towards older pups, whereas the occurrence of cannibalism did not differ as a function of pup age. With pups 1‐2 through 13‐14 days, the latency to onset of full maternal behavior was shortest with 1‐2‐day‐old pups (2‐day median) and longest with 13‐14‐day‐old pups (7‐day median). Females exposed to pups aged 3‐4 through 11‐12 days did not differ significantly in their latencies, the medians of which ranged from 4.0 to 5.5 days. Only 1 female out of 8 exposed to pups aged 15‐16 days became fully maternal, but 5 more displayed components of maternal responsiveness. The optimal nature of neonates and the general attractiveness of a wider range of pup ages as stimuli for the elicitation of maternal behavior in rats, as well as com

ISSN:0012-1630    

DOI:10.1002/dev.420110607

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

年代:1978

数据来源: WILEY

摘要:

AbstractNa+‐K+‐stimulated and Mg++‐dependent ATPase activities were investigated in the developing cerebral cortex, subcortical structures, and medulla oblongata of rats as was the effect of 24‐hr lasting starvation and thirst on those enzyme activities. We found (a) a developmental increase of these ATPase activities in the developing rat brain with the maximum in the cerebral cortex and with the minimum in the medulla oblongata; (b) a decrease of the ratio of these enzyme activities, which was near unity in adult animals; (c) an increase of ATPase activities in the cerebral cortex and subcortical formations of young rats under starvation conditions followed by a decrease of the Mg++/Na+‐K+‐ATPase activity ratios in these structures; and (d) a decrease of these activities, especially in the cerebral cortex, and an increase of the activity ratios in adult animals under starvation

ISSN:0012-1630    

DOI:10.1002/dev.420110608

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

年代:1978

数据来源: WILEY

摘要:

AbstractThe ultrasonic calls of 10 species of murid rodents including 3 strains of house mice are described and the significance of interspecific similarities and differences is discussed. The calls of newborn murid rodents may be characterized by their gradual onset and cessation, their comparative lack of amplitude and frequency modulation, and, often, by the presence of only 1 frequency component. These common acoustic characteristics may be important in eliciting and/or maintaining various aspects of maternal behavior, both in and out of the nest.

ISSN:0012-1630    

DOI:10.1002/dev.420110609

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

年代:1978

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420110610

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

年代:1978

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420110601

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

年代:1978

数据来源: WILEY