Mother‐infant interactions and experimental manipulation: Confounding or misidentification?

Meier, Gilbert W.; Schutzman, Lloyd H.

doi:10.1002/dev.420010212

Cited by 53 publications

(26 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicates that some characteristic of the maternal environment that varied between the AI J and CS7B1I6J strains was essential for each of these consequences of early handling. Therefore, our results provide strong support for the hypothesis of maternal mediation of early-stimulation effects (Barnett & Burn, 1967;Meier & Schutzman, 1968;Richards, 1966).…”

Section: Discussionsupporting

confidence: 80%

“…Some early suggestions, such as that corticosterone released during early stimulation acts on the brain to reduce later emotionality (Denenberg & Zarrow, 1971) or that the hypothermia induced by the early manipulation accounts for the later effects (Schaefer, Weingarten, & Towne, 1962), have since fallen into disfavor (e.g., Ader & Grota, 1973;Thoman & Levine, 1969). A hypothesis that has been gaining support in recent years is that the mother's differential treatment of manipulated and nonmanipulated pups mediates at least some early-stimulation effects (Barnett & Burn, 1967;Meier & Schutzman, 1968;Richards, 1966). It has been amply demonstrated that maternal behavior varies with the treatment (e.g., handling, shock, nonmanipulation) of the infant mouse or rat (Barnett & Burn, 1967;Bell & Little, 1978;Bell, Nitschke, Bell, & Zachman, 1974;Lee & Williams, 1975;Priesinall, 1973;Sherrod, Connor, & Meier, 1974;Smotherman, Brown, & Levine, 1977;Young, 1965).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Strain of foster mother determines long-term effects of early handling: Evidence for maternal mediation

1982

View full text Add to dashboard Cite

Inbred A/J mice were raised from birth by foster mothers of either the AlJ or C57BII6J strain. Some litters of each maternal rearing condition were handled during the preweaning period, whereas others were not. In adulthood, the behavior of females in the open field as well as the plasma corticosterone levels of males following both no disturbance and placement in a novel environment were examined. Defecation in the open field was found to be greater in handled than in nonhandled subjects, but only for those that had been reared by a C57BII6J foster mother. Conversely, plasma corticosterone levels were observed to be lower in handled than in nonhandled subjects, but only for those reared by an A/J foster mother. These results provide support for the hypothesis of maternal mediation of long· term effects of differential early stimulation.During the past 25 years, there have been numerous reports that varying the stimulation to which laboratory rodents are exposed during infancy can have dramatic effects on later behavior and physiology. Preweaning mice and rats subjected to han· dling, shock, chilling, or other forms of manipulation have been found to differ as adults from nonmanipulated controls on various measures, including activity

show abstract

Section: Discussionsupporting

confidence: 80%

mentioning

confidence: 99%

Strain of foster mother determines long-term effects of early handling: Evidence for maternal mediation

1982

View full text Add to dashboard Cite

show abstract

“…In fact, the rodent dam is sensitive to the changing stimulus qualities of the pups (Meier and Schutzman, 1968;Young, 1965) and shows systematic changes in maternal behavior depending on the nature of the treatment that the offspring have received (Barnett and Burn, 1967;Bell et al, 1974) and the time during lactation in which the manipulations occur (Smotherman et al, 1977a, b). It has been demonstrated that heightened maternal behavior results from pup cues elicited by more intense treatments such as electric shock (0.4 mA) (Smotherman et al, 1977a, b).…”

Section: Discussionmentioning

confidence: 99%

Manipulations During the Second, but not the First, Week of Life Increase Susceptibility to Cocaine Self-Administration in Female Rats

Flagel

Vázquez

Robinson

2003

Neuropsychopharmacol

View full text Add to dashboard Cite

We compared the effects of manipulations during week 1 vs week 2 of life on the propensity to self-administer cocaine. Pups received daily subcutaneous saline injections, were handled briefly, or remained undisturbed during their respective treatment periods. Animals handled during the second week of life exhibited increased locomotor response to novelty when tested on postnatal day (PND) 48, compared to all other groups. Rats were implanted with jugular catheters on PND 70 and then given the opportunity to self-administer (0.125 mg/kg/infusion) cocaine for 5 consecutive days (1 h sessions). The dose was then raised to 0.25 mg/kg/infusion for 5 days and to 0.5 mg/kg/infusion for the final 5 days of testing. Only animals manipulated during the second week of life acquired drug-taking behavior. These effects were both stimulus-and gender-specific. Females handled during the second week of life acquired cocaine selfadministration (SA) at the lowest dose, and females injected during the second week of life acquired at the intermediate dose. Males injected during the second week of life showed a similar, but more variable, drug-taking pattern. There were no group differences in serum corticosterone response to novelty, although relative to undisturbed animals and those manipulated in the first week of life, female animals manipulated during the second week of life had lower basal expression of hippocampal glucocorticoid receptor mRNA in adulthood. We conclude that the second week of life in the rodent is a sensitive period during which manipulations result in a more vulnerable phenotype for the acquisition of cocaine SA.

show abstract

“…Although these findings seem to lead to a compelling conclusion that the more maternal care offspring receive, the greater functional advantage they have during adulthood, it has long been noted in the literature on rodents that early stimulation of the mother and stimulation of pups are intrinsically confounded in neonatal handling studies because dams of handled pups are removed from the litter during the procedure (11)(12)(13)(14). Because mothers of handled pups are likely to change their care behavior toward pups as a result of this experience, correlations between maternal care and changes in offspring behavioral and neuroendocrine measures (8) could be the result of a direct stimulation effect on pups, an indirect effect on pups due to stimulationinduced alterations in maternal care, or both.…”

mentioning

confidence: 99%

Programming social, cognitive, and neuroendocrine development by early exposure to novelty

Tang

Akers²,

Reeb³

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

119

View full text Add to dashboard Cite

Mildly stressful early life experiences can potentially impact a broad range of social, cognitive, and physiological functions in humans, nonhuman primates, and rodents. Recent rodent studies favor a maternal-mediation hypothesis that considers maternalcare differences induced by neonatal stimulation as the cause of individual differences in offspring development. Using neonatal novelty exposure, a neonatal stimulation paradigm that dissociates maternal individual differences from a direct stimulation effect on the offspring, we investigated the effect of early exposures to novelty on a diverse range of psychological functions using several assessment paradigms. Pups that received brief neonatal novelty exposures away from the home environment showed enhancement in spatial working memory, social competition, and corticosterone response to surprise during adulthood compared with their home-staying siblings. These functional enhancements in novelty-exposed rats occurred despite evidence that maternal care was directed preferentially toward homestaying instead of novelty-exposed pups, indicating that greater maternal care is neither necessary nor sufficient for these early stimulation-induced functional enhancements. We suggest a unifying maternal-modulation hypothesis, which distinguishes itself from the maternal-mediation hypothesis in that (i) neonatal stimulation can have direct effects on pups, cumulatively leading to long-term improvement in adult offspring; and (ii) maternal behavior can attenuate or potentiate these effects, thereby decreasing or increasing this long-term functional improvement.hypothalamic-pituitary-adrenal (HPA) axis ͉ maternal retrieval ͉ neonatal handling ͉ spatial learning ͉ stress T he mother is an omnipresent figure in the life of rodent neonates. In rodent models that focus on understanding functional impairment, prolonged separation of neonates from their mother leads to long-term deficits relative to controls (1-3). In contrast, rodent models demonstrating functional enhancement reveal that brief separation of neonates from their mother and home environment leads to a range of advantages relative to controls (4-7). In both types of studies, maternal behavior is considered critical in mediating these effects. Complementary to these experimental manipulations, studies of naturally occurring maternal-care behaviors offer further evidence that maternal care is positively correlated with an impressive array of neuroendocrine, cellular, and molecular measures from adult offspring (8-10). Such relationships were considered as evidence that particular maternal-care behaviors are positive markers of offspring neural development (8).Although these findings seem to lead to a compelling conclusion that the more maternal care offspring receive, the greater functional advantage they have during adulthood, it has long been noted in the literature on rodents that early stimulation of the mother and stimulation of pups are intrinsically confounded in neonatal handling studies because dams of handl...

show abstract

Mother‐infant interactions and experimental manipulation: Confounding or misidentification?

Cited by 53 publications

References 20 publications

Strain of foster mother determines long-term effects of early handling: Evidence for maternal mediation

Strain of foster mother determines long-term effects of early handling: Evidence for maternal mediation

Manipulations During the Second, but not the First, Week of Life Increase Susceptibility to Cocaine Self-Administration in Female Rats

Programming social, cognitive, and neuroendocrine development by early exposure to novelty

Contact Info

Product

Resources

About