摘要:

AbstractTonic immobility (TI) and high‐intensity vocalizations are two antipredator behaviors employed by domestic chicks (Gallus gallus) which vary in their function and the proximate mechanisms that govern them. In the present study, we sought to determine the influence of age (3 or 10 days old), diet (control or tryptophan‐free), and time of testing (A.M. or P.M.) on the duration of TI and the number of calls produced in domestic chicks. Older chicks remained immobile significantly longer than younger chicks as did subjects on the control diet or those tested at night. However, 3‐day‐old chicks had significantly shorter TI durations only when tested in the A.M.: TI did not differ between age groups when subjects were tested in the P.M. Three‐day‐olds called significantly more than 10‐day‐olds when given the control diet and when tested in the P.M. but vocalization frequencies did not differ between age groups during the A.M. testing or when given the tryptophan‐free diet (T‐). Vocalization rate (calls/TI duration), however, was significantly greater during the A.M. testing. These results emphasize the importance of considering circadian rhythms and behavioral development. Furthermore, an integrative view of the proximate mechanisms and adaptive functions of TI and high‐intensity vocalizations is presented.©199

ISSN:0012-1630    

DOI:10.1002/dev.420270602

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

年代:1994

数据来源: WILEY

摘要:

AbstractAutoradiography with14C‐2‐deoxyglucose was used to determine brain metabolic activity during the quiet period that follows after daily exploratory experiences in new complex environments. Eight 1‐month‐old, male Tryon rats were selected from two litters. Pairs of littermates matched by body weight were assigned to one of two conditions: rats housed individually in small home cages as the “impoverished condition,” or rats exposed twice daily to changing and complex environments of two large cages with inanimate objects and conspecifics as the “enriched condition.” After 4 days, rats were injected with 2‐deoxyglucose, placed individually in a home cage and left undisturbed for 90 min until sacrificed. The brains of “enriched” rats were heavier than their “impoverished” littermates, and showed a global trend for metabolic enhancement. They also showed significantly greater amounts of 2‐deoxyglucose in occipital cortex (27%), hippocampal subiculum (36%), and nucleus accumbens (40%)

ISSN:0012-1630    

DOI:10.1002/dev.420270603

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

年代:1994

数据来源: WILEY

摘要:

AbstractTwo studies investigated the human infant's response to salt during development. In the first study, measures of intake and sucking were obtained from two groups of infants, newborns and 4‐ to 8‐month‐olds, in response to brief presentations of two concentrations of salt (0.2 or 0.4 M) and water. For several measures of sucking and for intake, there were significant age and concentration effects. Generally, newborn infants tended to reject saline relative to water more than did 4‐ to 8‐month‐old infants. This result, consistent with previously published research, suggests a developmental change in salt acceptability and, probably, sensitivity in the human infant. In the second longitudinal study, the response to salted (0.15 M)versusunsalted formulas was evaluated monthly in infants 2 to 7 months of age. Again, a developmental change was observed: Based on some sucking measures, younger infants appeared to be indifferent to the salted formula relative to the unsalted formula whereas older infants tended to reject the salted formula, presumably because either it was less sweet than the unsalted formulas or because it was novel. These data are consistent with the hypothesis developed from animal model studies that during early human postnatal development, transductive elements sensitive to saltiness mature.©1994 John Wil

ISSN:0012-1630    

DOI:10.1002/dev.420270604

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

年代:1994

数据来源: WILEY

摘要:

AbstractLatent inhibition of fear conditioning to an auditory cue, as measured by behavioral freezing, was examined in 18‐ and 23‐day‐old rats. In Experiment 1, CS preexposure and conditioning occurred in the same context for some rats but in a different context for other rats, and 24 hr separated CS preexposure and conditioning. The 23‐day‐old rats showed a context‐specific latent inhibition effect, but the 18‐day‐old rats showed no latent inhibition. In Experiment 2, CS preexposure and conditioning occurred in the same trainining session and both 18‐ and 23‐day‐old rats showed latent inhibition. These results were discussed in relation to Wagner's (1976) theory of information processing, hippocampal formation maturation, and function, and Sutherland and Rudy's (1989) configural association theory.©199

ISSN:0012-1630    

DOI:10.1002/dev.420270605

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

年代:1994

数据来源: WILEY

摘要:

AbstractSodium‐deficient adult rats prefer NaCl to other monochloride salts (e.g., Denton, 1991; Schulkin, 1991). However, it is not known when or how this specificity develops. Our experiments charted the development of the ionic specificity of sodium appetite aroused by sodium depletion or intracerebroventricular injection of renin. We compared intake of 3% NaCl to three other monochlorides, potassium (K), ammonium (NH4), and lithium (Li), and calcium chloride (CaCl2) at various ages between 72 hr postnatal and weaning. This revealed a biphasic developmental scheme: The adult pattern of discrimination between the salts emerges between 3 and 18 days of age. Subsequently, the preference for Na over the other salts increases into adulthood.©1994 John Wiley&Sons, I

ISSN:0012-1630    

DOI:10.1002/dev.420270606

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

年代:1994

数据来源: WILEY

摘要:

AbstractHand preference in bimanual feeding was assesed in 140 captive chimpanzees (Pan troglodytes). Bimanual feeding was defined as the active use of one hand for feeding with the opposite hand holding other food items. In terms of strength of hand preference, adults were more lateralized than sub‐adults. Additionally, mother‐reared chimpanzees were more lateralized than nursery‐reared chimpanzees. The number of subjects with no hand preference was more prevalent in sub‐adults compared with young and older adults. Of those subjects with a significant hand preference, a larger proportion exhibited a right‐hand preference. These results are discussed in relation to previous reports of handedness and bimanual feeding in gorillas and bonobos.©1994 John Wiley

ISSN:0012-1630    

DOI:10.1002/dev.420270607

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

年代:1994

数据来源: WILEY

摘要:

AbstractThe D1‐and D2‐mediation of stimulated motor behavior was studied in pups (Days 10–11) and weanlings (Days 20–21) that had been depleted of dopamine (DA) on postnatal Day 3. Administration of the D1‐like agonist SKF 38393 (30.0 mg/kg) or the D2‐like agonist quinpirole (3.0 mg/kg) increased the incidence of sniffing and locomotion in intact and DA‐depleted animals tested at either age. However, the ability of selective DA antagonists to reduce these stimulated responses interacted with both the depletion and the age at the time of testing. When tested as pups, both the D1 antagonist SCH 23390 (0.2 or 0.4 mg/kg) and the D2 antagonist clebopride (10.0 mg/kg) suppresed the behaviors induced by either class of DA agonist. When tested as weanlings, intact animals exhibited the profile of pups (i.e., either class antagonist blocked each agonist). In DA‐depleted weanlings, however, only the D1 antagonist blocked the D1 agonist‐induced responses and only the D2 antagonist blocked the D2 agonist‐induced responses. These data demonstrate that the interactions between D1 and D2 receptors in the expression of stimulated motor behaviors are altered following DA depletions in neonates. Moreover, this change in receptor function occurs sometime between 7 and 13 days after the DA depletion.©1994

ISSN:0012-1630    

DOI:10.1002/dev.420270608

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.420270601

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

年代:1994

数据来源: WILEY