Intercorrelations of maternal activities in the rat☆
Abstract
Intercorrelations of scores obtained during retrieving and nesting tests given to primiparous dams indicates that pup retrieving and care of retrieved pups in the nest site are relatively independent of one another and of nesting activities. These data suggest that the term maternal behaviour does not represent a unitary behavioural process and that use of one or two measures of maternal activity are insufficient for assessing the effects of experimental manipulations on the maternal behaviour in the rat.
References (3)
- G.A. Kimble
Cited by (21)
Parenting Behavior
2015, Knobil and Neill's Physiology of Reproduction: Two-Volume SetMothers in almost all mammalian species give birth to young that are unprepared for an independent life ex utero, thus requiring that the neonates receive prolonged and intense care for their survival. This care can be provided by mothers, fathers, and other interested individuals. Numerous sensory, endocrine, and neural systems (including those involved in motivation, emotional regulation, and cognition) must interact for the successful display of parental behaviors. While the biological systems underlying maternal and paternal caregiving are sometimes similar, they are also necessarily different, indicating that multiple paths can converge upon the same behavioral outcome. Similarly, while laboratory rats have often been the focus of research on the biology of parental behaviors, ample information from other nonhuman animals and humans allows one to detect universals, as well as species-specific mechanisms, involved in this complex and evolutionarily essential mammalian social behavior.
Natural variations in postpartum maternal care in inbred and outbred mice
2007, Physiology and BehaviorThe role of maternal care in mediating variation in offspring phenotype has been examined in the rat and demonstrates that mother–infant interactions are critical for inducing long-term changes in behavior. Though phenotypic differences between mice strains are often attributed to genetic factors, the influence of early maternal environment has not been extensively explored. To understand maternal influence on phenotype in mice, we must first explore the nature of differences in behavior. In the present study, we examine aspects of maternal care differentiating mice strains and explore the relationship between postpartum behavior and measures obtained by a standard test of maternal responsivity (Retrieval Test). We compared inbred 129Sv (n = 25), C57BL/6J (n = 23), and outbred Swiss (n = 23) lactating female mice. Swiss females had shorter latencies to retrieve and crouch over pups (P < .01), whereas 129Sv females had shorter latencies to nestbuild (P < .05). Conversely, observations of homecage behavior indicate that 129Sv females nestbuild less frequently. 129Sv females also engaged in very low levels of pup licking/grooming (P < .001) and long periods of nursing/contact (P < .05) with pups compared to C57BL/6J and Swiss females. Temporal analysis suggests that the magnitude of these differences varies both within and between days. No significant correlations were found between any aspect of maternal responsivity and postpartum behavior. These results illustrate that through detailed analysis of maternal behavior in mice, variations between strains can be observed. These variations represent strain specific strategies for promoting growth and survival of offspring during infancy that may also mediate “epigenetic” differences in phenotype in adulthood.
Seizure-prone EL mice exhibit deficits in pup nursing and retrieval assessed using a novel method of maternal behavior phenotyping
2003, Epilepsy and BehaviorThe selectively bred EL mouse strain exhibits hyperreactivity to environmental disturbance reflected by handling-induced seizures and motor hyperactivity in an exploratory task relative to a non-seizure-prone control strain. One possible mechanism for the nongenomic transmission of an adult seizure-prone/hyperactive phenotype is the quality of parenting provided to immature offspring. In particular, the quality of maternal behavior has been implicated as an environmental determinant in rodent biochemical and behavioral development. A complication in testing this hypothesis is that human handling for husbandry and testing itself triggers seizures in seizure-prone EL mice. Thus, the present study evaluated potential EL versus control strain differences in maternal behavior using a novel apparatus for passive observation of undisturbed mice. Nonmaternal behaviors were also measured to control for any nonspecific differences in activity or exploration. EL dams were slower than DDY controls to initiate pup retrieval and spent less time nursing/crouching over pups than DDY mice. EL dams also exhibited a profile of sustained exploration and grooming over time relative to the profile of DDY controls. These results suggest that EL mothers exhibit an overabundance of motor activities that compete with crouching/nursing and retrieval behaviors required for viability of the litter.
Congenital brain damage spares the basic patterns of parental behavior in affected mice
1995, Brain ResearchPregnant albino mice were treated with 5-azacytidine so that the embryonic brains were affected late in their morphological ontogeny. The offspring showed retarded body growth and a conspicuous reduction in the size of the cerebral hemispheres as measured at the end of development. Histological alterations were found in the hippocampus and the cingulate cortex. No behavioral alterations were detected during development, with the exception of the hyperactivity which probably caused the better performance of treated offspring observed in a self-feeding test. This functional abnormality, attributed by previous authors to retardation in telencephalic development, persisted into adulthood. The parental behavior of virgin females towards a weak stimulus-object was robust. Treated subjects were non-neophobic, seldom aggressive and showed clearcut parental responses. In addition, although the frequency of overall parental tendency was lower in the treated subjects, it gradually approached that of the controls across repeated trials. The brain structures affected by this treatment seem influential on behavioral organization and habituation to novelty, not on basic patterns of behavior, which are probably rooted in phylogenetically more ancient structures.
The behaviour of adult male Long-Evans rats Rattus norvegicus toward pups of different ages
1991, Behavioural ProcessesAdult male Long-Evans rats were presented with 1–7 or 14–21 day old pups for 20 days. Pups were changed every 12 h and each male received pups from three litters, with litters changed every week. Pup-related activities were observed for two 15-min periods each day. Males with young pups had a shorter latency to crouch over and carry pups while males with older pups showed a shorter latency to lick pups. Males with young pups had higher nest ratings, and engaged in more nest building, crouching over and carrying pups than males with older pups, while males with older pups spent more time touching, sniffing, and licking pups. Both groups of males showed an increase in pup-related behaviour over the first 8–10 days of pup exposure and a decrease in pup-related behaviour when the litters were changed. These results indicate that pup age is an important factor in determining male behaviour. Males direct parental behaviour toward neonatal pups and affiliative behaviour toward older pups. The importance of affiliative behaviour with adult males in the social development of juvenile rats is discussed.
Maternal behavior in normal and androgenized female rats: Effect of age and experience
1989, Physiology and BehaviorThe aim of the experiments presented here was to evaluate the influence of age and of previous maternal experience on care of pups in normal virgin and androgenized Wistar female rats. When sensitization occurred before they were 60 days old, androgenized females failed to develop consistent retrieving, probably because of excessive timidity (Experiments 1 and 2) whereas they were able to keep pups warm in their nests. During pup-toy choice tests (Experiment 2) young androgenized females displayed only erratic carrying of toys. On the other hand, 60-, 80- or 100-day-old androgenized females developed full maternal behavior like cyclic controls. In the third experiment, control and androgenized females exposed to pups when 60 days old, were reexposed when 95 days old. Androgenized females proved to be more sensitive to earlier exposure to pups than control females and showed significant reductions in latencies of emergence of maternal responses.
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This study was supported by Research Grant M-1370 from the National Institutes of Mental Health and was conducted in the Department of Psychology, University of Illinois.