摘要:

AbstractMilk promotes activity in the kappa opioid system of the rat fetus and reduced responsiveness in a behavioral bioassay of cutaneous sensitivity. In the study, E20 rat fetuses were presented with an artificial nipple (CS) and intraoral infusions of milk (US) to condition opioid activity. Paired presentations of the CS and US resulted in conditioned changes in perioral cutaneous sensitivity, which was not evident in groups exposed to the CS alone, US alone, or explicitly unpaired presentations of US and CS. Selective opioid antagonists administered between conditioning and testing revealed that reexposure to the nipple resulted in activation of the endogenous opiod system. The nipple promoted activity at mu, not kappa, opioid receptos. Conditioned opioid activity to an artificial nipple in the fetus, which lacks experience with milk or other suckling stimuli, implies that conditioned changes in the endogeneous opioid system of the newborn rat may develop quickly during the first suckling episodes. © John Wiley&Sons, Inc

ISSN:0012-1630    

DOI:10.1002/dev.420260702

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

年代:1993

数据来源: WILEY

摘要:

AbstractTwo rhesus and two Japanese macaque infants were cross‐fostered between species in order to study the effects of auditory experience on vocal development. Both the cross‐fostered and normally raised control subjects were observed over the first 2 years of life and their vocalizations were tape‐recorded. We classified 8053 calls by ear, placed each call in one of six acoustic categories, and calculated the rates at which different call‐types were used in different social contexts. Species differences were found in the use of “coo” and “gruff” vocalizations among control subjects. Japanese macaques invariably produced coos almost exclusively. In contrast, rhesus macaques produced a mixture of coos and gruffs and showed considerable interindividual variation in the relative use of one call type or the other. Cross‐fostered Japanese macaques adhered to their species‐typical behavior, rarely using gruffs. Cross‐fostered rhesus subjects also exhibited species‐typical behavior in many contexts, but in some situations produced coos and gruffs at rates that were intermediate between those shown by normally raised animals of the two species. This outcome suggests that environmentally mediated modification of vocal behavior may have occured, but that the resulting changes were quite limited. © 1

ISSN:0012-1630    

DOI:10.1002/dev.420260703

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

年代:1993

数据来源: WILEY

摘要:

AbstractLevels of tetanus‐specific antibodies were assessed in free‐ranging, yearling rhesus monkeys following prophylactic immunization with tetanus toxoid. Each subject's behavior had been observed between 11 and 25 weeks of age and approximately 2 months later during its mother's first concentrated mating period as a part of another study. Prior to immunization, at approximately 1 year of age, cardiovascular parameters, and several plasma parameters [cortisol, adrenocorticotrophic hormone (ACTH), growth hormone (GH), interleukin‐2 (IL‐2), and total plasma immunoglobulin G (IgG)] were measured during a brief period of captivity. Antibody titers noted approximately 2 weeks after immunization were related to cardiovascular parameters. Thus, yearlings with high heart rates and low heart rate variability during captivity had the highest tetanus‐specific serum IgG. Levels of plasma cortisol, ACTH, total IgG, and IL‐2 noted at the time of capture were unrelated to subsequent antibody levels. Antibody titers were, however, positively correlated with GH noted immediately following capture on the day prior to immunization. Antibody titers were also related to the infants' behavior observed during their mother's first concentrated mating period, Infants who were most distressed (high levels of distress vocalization) when their mother resumed mating (a time particularly stressful for free‐ranging rhesus infants) showed lower antibody titers to tetanus immunization as a yearling. The present observations add support to the existence of a relationship between behavior during exposure to an early stressor and later immune regulation and that certain cardiovascular parameters may be related to certain indicators of immunoregulation. © 1993 John W

ISSN:0012-1630    

DOI:10.1002/dev.420260704

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

年代:1993

数据来源: WILEY

摘要:

AbstractPrevious studies have shown that maternal rats are attracted to their own bedding and that of other dams but not to that of virgins. The present studies were designed to test two hypotheses: First, that the addition of a novel botanical odor to the bedding of maternal animals would result in subsequent preferences for such an odor. Second, such a preference should enable dams to discriminate between pups odorized with familiar and unfamiliar odors as measured by differential retrieval of the pups. Both hypotheses were confirmed. In addition, we found that preferences established during a first pregnancy and lactation affected the retrieval of pups during a second lactational period, but could be overturned by new olfactory experience during that second lactational period. © 1993 John Wiley&Sons, Inc

ISSN:0012-1630    

DOI:10.1002/dev.420260705

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

年代:1993

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420260701

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

年代:1993

数据来源: WILEY