摘要:

AbstractGrowth and home‐orienting behavior were studied during the 1st 12 days of life in 3 groups of rat pups: (1) those with intergenerational malnutrition; (2) those with postnatal malnutrition produced by cross‐fostering pups born of well‐nourished mothers to lactating females maintained on a low‐protein diet; and (3) well‐nourished control pups. Growth of pups was impaired in both malnourished groups, and eye‐opening was similarly delayed. On tests of homing behavior, both malnourished groups were impaired to a similar extent and were less likely to find their way to the nest than were control pups. However, survival rates were significantly lower (50%) in the postnatally malnourished group but not in the intergenerationally malnourished group (73%), as compared with controls (100%). These findings suggest that adaptation occurs to long‐term malnutrition with increased survival. However, physical characteristics and homing behavior in early life are not distinguishable in those surving short‐ or long‐term malnutrition. This is in contrast to the finding of more severe behavioral deficits in later life among rats subjected to many generations of malnutrition than among those malnourished for

ISSN:0012-1630    

DOI:10.1002/dev.420130602

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

年代:1980

数据来源: WILEY

摘要:

AbstractA cross‐fostering design was used to examine maternal behavior, pup vocalizations, and pup temperature changes following an infantile handling procedure in C57BL/6J (C) and A/J (A) mice. In Experiment I, maternal behavior ofCandAmothers after infantile handling differed in a number of ways irrespective of the strain of the foster pups. In addition,Apups were retrieved faster but licked less than wereCpups by mothers of both strains. Handling appeared to increase the probability that strain differences would occur in that no differences between the lines, in either the behavior of the mothers or the capacity of the pups to elicit maternal behavior, were found during observations made just prior to daily handling. These observations also revealed that mothers of both strains treated same‐strain foster pups differently than they treated foster pups of another strain. In Experiment II,Apups were found to emit more ultrasound following handling than wereCpups, suggesting that retrieval but not pup‐licking was stimulated by ultrasonic signals. Measurement of pup temperature during and following the handling procedure showed that (1) strain differences in ultrasonic signaling were not related to strain differences in the degree of hypothermia experienced by the pups; (2) recovery of body temperature following handling was slow for pups of both strains, and depended to some degree on the strain of the pup's foster mother; and (3) development of thermoregulation occurred more rapidly inCthan

ISSN:0012-1630    

DOI:10.1002/dev.420130603

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

年代:1980

数据来源: WILEY

摘要:

AbstractLarvae of the grain beetle (Tenebrio molitor) were trained in a T‐maze at different stages of the same instar. The larvae's aptitude for learning changed depending on the stage of their development: poor in the middle of the intermoulting period, but much improved upon approaching the next moult and during the 1st day thereafter. Such regularity seems to be related to general laws of cyclic development of the insect larvae as governed by the hormones of metamorphosi

ISSN:0012-1630    

DOI:10.1002/dev.420130604

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

年代:1980

数据来源: WILEY

摘要:

AbstractIn order to examine the effects of cannabinoids, malnutrition, and their possible interaction upon the developing rat fetus, female Wistar rats were exposed to cannabis smoke, placebo smoke, or no smoke while concurrently consuming 1 of 3 diets differing in protein concentration (8%, 24%, 64%). Both the diet and drug treatments were administered 20 days prior to and throughout gestation. Of the 12 variables affected by the low‐protein diet, 8 were significantly potentiated when undernutrition was combined with cannabis treatment. Some dependent variables that were not altered either by the low‐protein diet or by cannabis inhalation were affected by the combination of treatments. These included a lengthened gestation period, an increase in occurrence of stillbirths and litter destruction, and decreased activity in the rat pups. Cannabis coupled with a standard protein diet resulted in a number of developmental indices being delayed but combining the drug with an enriched protein diet ameliorated these effects. The evidence also suggests that the administration of cannabis both before and during gestation resulted in a degree of tolerance to some aspects of the drug effe

ISSN:0012-1630    

DOI:10.1002/dev.420130605

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

年代:1980

数据来源: WILEY

摘要:

AbstractAs a test of the hypothesis that gender differences in neonatal behavior may be linked to circumcision, we reviewed 38 recent studies which provide relevant information. No strong data exist to support the hypothesis or to document the existence of gender differences in neonatal behavior.

ISSN:0012-1630    

DOI:10.1002/dev.420130606

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe effects of 6 commonly used methods for producing malnutrition in suckling rats upon the behavior of their dams were examined. In these methods, (1) large litters were fostered on the dams; (2) dams were fed low‐protein diets; (3) dams were fed an inadequate amount of a good quality diet; (4) pups were removed from the dams and kept with a nonlactating female for half of the day; (5) pups were removed from the dams and kept in an incubator for half of the day; or (6) some of the dams' teats were destroyed. Dams that were themselves food deprived showed a shift from resting to exploratory behaviors with some indication of increased attention to the pups compared to controls. Dams whose pups were starved but that were well fed themselves showed lower levels of resting and higher levels of attention to pups but no elevation in exploratory activity. Although the long‐term significance of the behavioral changes of the dams is not known, the immediate effect was to minimize the impact of the experimenter's manipulations on the metabolic energy available to the pups for growth and developm

ISSN:0012-1630    

DOI:10.1002/dev.420130607

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

年代:1980

数据来源: WILEY

摘要:

AbstractData in the literature show that in humans the fraction of the total electroencephalographic (EEG) energy that appears in the alpha frequencies rises from about zero at birth to about 70% in adults. This rise is shown to occur mainly in 5 stages, the ages of which correlate with those of stages of increase in brain weight. Supporting the correlation are data on gender dimorphism in humans in both brain weight and EEG development, as well as limited data on development in kittens, rats, mice, and guinea pigs.

ISSN:0012-1630    

DOI:10.1002/dev.420130608

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

年代:1980

数据来源: WILEY

摘要:

AbstractNeonatal Peking ducklings were tested in a detour problem‐solving task following replacement of the shell overlying the air space of the egg on Prenatal Day 24 (total incubation period: 27 days) with a plastic wrap. This procedure, a common practice in behavioral embryology, resulted in a significant decrease in oxygen consumption, and a protracted retardation in the mastery of the learning task, with experimental ducklings solving the problem at a mean age of 5.27 days, compared with 2.32 days for controls. These results serve to underscore the problems that may be encountered as a result of any intereference with the integrity of the egg during the prenatal perio

ISSN:0012-1630    

DOI:10.1002/dev.420130609

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

年代:1980

数据来源: WILEY

摘要:

AbstractExamination of the patterns of mating behavior exhibited by 27 sexually‐mature female rhesus monkeys housed in a social group in an outdoor compound revealed that younger animals (3.5–4.5 years) exhibited significantly longer periods of sexual activity than did older animals (5.5 years and older). Observed sexual activity in all age groups was largely confined to discrete periods associated with an ovulatory cycle and typically resulted in pregnancy. Related findings suggest that differences in patterns of sexual behavior may be related to variations in estrogen secretion or sensitivity to estrogen, both of which show age‐related changes. Additionally, these findings underscore the importance of documenting behavioral and endocrine changes in reproductive function across the full life span of the mature su

ISSN:0012-1630    

DOI:10.1002/dev.420130610

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

年代:1980

数据来源: WILEY

摘要:

AbstractFemale mice from lines selectivity bred for differences in open‐field activity were exposed to tobacco smoke during gestation. Smoke‐treated females were less likely than controls to have produced litters by 23 days after observation of a vaginal plug. Within the high‐active line, fewer pups of smoke‐treated dams survived to weaning. Regardless of treatment, fewer high‐active than low‐active offspring survived to weaning. Results of a 4‐day series of open‐field activity tests administered to offspring beginning at 28 days of age indicated that tobacco smoke administered prenatally and/or during testing depresses open‐field activity in both lines. Other activity tests administered at 50 days of age gave similar results. Tissue nicotine levels after nicotine injection tended to be higher in high‐active and control groups than in low‐active and smoke‐treated groups, respectively. Liver weight expressed as percentage of body weight was 11.9% greater in smoke‐treated

ISSN:0012-1630    

DOI:10.1002/dev.420130611

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

年代:1980

数据来源: WILEY