摘要:

AbstractThe effect of stress to the pregnant mother on hormonal responses of the offspring to stressful events was investigated in juvenile rhesus monkeys. Six pregnant monkeys were repeatedly removed from their home cages and exposed to unpredictable noise during mid‐ to late gestation (Days 90–145 postconception), while six undisturbed pregnant mothers served as controls. Blood samples were collected from the juvenile offspring under anesthesia on four occasions and assayed for ACTH and cortisol. In a second experiment, blood samples were collected from the awake offspring under a baseline and four progressively stressful conditions. Offspring of stressed mothers showed higher ACTH and cortisol levels than control offspring at all four anesthesia samples and at a nonanesthesized home cage baseline. Prenatally stressed offspring also showed higher ACTH values in all four stress conditions. Cortisol values were similar for the two groups under the stress conditions. The disparity between the two groups in the relationship between ACTH and cortisol was greatest in the most stressful condition, suggesting regulatory differences between the two groups. These results indicate that offspring of primate mothers stressed during pregnancy show enhanced HPA axis responsivity to stressors later in life, and concur with rodent findings indicating that prenatal stress may have long‐term effects on HPA axis regulation. © 1994 John Wiley&Son

ISSN:0012-1630    

DOI:10.1002/dev.420270502

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

年代:1994

数据来源: WILEY

摘要:

AbstractSpontaneous movements of premature infants between 25 and 34 weeks conceptional age were observed for 1 hr on two or three occasions. Subjects had low‐risk prognoses and were clinically stable at the time of testing. Behavioral acts were scored using a 0/1 time sampling technique in 60 continuous, 1‐min time blocks. Temporal associations between individual movements were found using chi‐square analyses. Some associated behaviors contained combinations consistent with neonatal action patterns, for example, single and bilateral leg kicking, head turning, and mouthing. Features of state organization were also evident in that general motor activity (GM), which has been used as a marker of active sleep (AS) in neonates, was found to cluster temporally with startle, facial, and head movements but not eye movements. Behavioral quiescence (≥5 s) was dissociated from AS‐related behaviors (GM, facial, head, and eye movements). Combinations of state‐segregated behaviors were more likely to exhibit co‐occurrence within 1‐min intervals in infant 30 weeks conceptiona

ISSN:0012-1630    

DOI:10.1002/dev.420270503

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

年代:1994

数据来源: WILEY

摘要:

AbstractPsychophysiological 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

ISSN:0012-1630    

DOI:10.1002/dev.420270504

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

年代:1994

数据来源: WILEY

摘要:

AbstractThese studies investigated behavioral and hormonal responses to stress in developing mice. Experiment 1 examined the effects of 24‐hr maternal deprivation on corticosterone (CORT) secretion and ultrasonic vocalization (UVZ) rate in 4‐, 8‐, and 12‐day‐old mice. At these ages, exposure to a novel environment resulted in minimal changes in CORT secretion. Maternal deprivation increased pups′ CORT secretion in an age‐dependent fashion but did not affect their UVZ rate.The aim of experiment 2 was to test the effects of cholordiazepoxide (CDP), an anxyolytic compound, on CORT secretion and UVZ in both normally reared and in maternally deprived 8‐day‐old mice. CDP administration elevated CORT increases in deprived (DEP) animals. CDP affected UVZ only in nondcprived (NDEP) animals: UVZ ratewas decreased by high CDP dosesOverall, these findings demonstrate that the infant mouse shows a period of stress hyp9oresponsiveness similar to the rat and that maternal presence contributes to inhibit adrenocorticalactivity. CDP administration, butnot novelty exposure, increased CORT secretion in 8‐day‐ old normally reared mice suggesting that during the stress hyporesponsive period, the HPA axis is capable of responding only to specific stimuli. Changes in HPA axis activity and UVZ rateresulting from maternal deprivation and/or CDP challenge do not seem to be directly related. ©199

ISSN:0012-1630    

DOI:10.1002/dev.420270505

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

年代:1994

数据来源: WILEY

摘要:

AbstractPatterns 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, I

ISSN:0012-1630    

DOI:10.1002/dev.420270506

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

年代:1994

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420270501

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

年代:1994

数据来源: WILEY