Aspects Of Reproduction And Development In The Prairie Vole Microtus Ochrogaster

Author : Forrest Dylan Rogers
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.5/5 (825 download)

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Download or read book Variation in Early Social Networks written by Forrest Dylan Rogers and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: For altricial mammalian species, early life social bonds are essential for survival and successful biobehavioral development. In the majority of mammalian species, these earliest social bonds are formed primarily between offspring and their mothers, and the mother-offspring relationship sets the trajectory for offspring biobehavioral development. However, in the rare subset of mammals that demonstrate biparental care and/or alloparental care, other adult and sub-adult caregivers join mothers to shape the early life social environment of developing offspring. One finds such a case with the prairie vole (Microtus ochrogaster), for whom paternal care is not only common, but perhaps requisite for normative biobehavioral development. Previous study of the socially monogamous, biparental, and cooperatively breeding prairie vole has given insight into the role that mothers and fathers play in shaping behavioral phenotypes of offspring. Here, we first discuss the ultimate and proximate mechanisms of maternal, paternal, and alloparental care, with emphasis on recent trends in research. Subsequently, we present three studies exploring the role of fathers and alloparents in prairie vole biobehavioral development. In the first study, we present evidence that prairie vole fathers increase their parental effort from litter to subsequent litter in order to compensate for declines in maternal care; thus, prairie vole fathers may play an important role in maintaining stability in the parenting environment across offspring cohorts. In the second study, we revisit previous findings that, in prairie voles, paternal absence (also known as 'paternal deprivation') in the pre-weaning development of offspring alters biobehavioral development, perhaps most notably through the inhibition of normative pairbond development. By leveraging alloparental care, we sought to determine whether this altered development is due to the absence of specific paternal qualities or a general reduction in pup-directed care. Through a series of early-life observations of parental care and major developmental milestones, as well as through behavioral tests in adulthood, we demonstrate that female sub-adult alloparents (i.e., big sisters), by and large, successfully replace fathers, perhaps indicating that the primary mechanism that drives the developmental consequences of paternal absence is a reduction in the quantity of parental care received. In one notable exception, we demonstrate that male offspring reared with a mother and an alloparent are, despite this quantitative replacement of care, unable to form a typical pair bond, whereas their female siblings do form typical pair bonds. This finding suggests that for male prairie vole offspring, fathers may contribute a particular quality or set of qualities important for normative development of species-typical mating behavior. In a third and final study, we expand upon our second study with an investigation of potential neuroendocrine substrates of these behavioral differences. We present evidence that paternal absence (with and without alloparental substitution) may alter the development of oxytocin receptor (OXTR) and/or vasopressin 1a receptor (AVPR1a) distribution in male and female prairie voles. We also demonstrate with baseline corticosterone concentrations that offspring reared by mothers alone and offspring reared by a mother and an alloparent are neither more or less susceptible to social isolation than biparentally-reared controls. Taken together, our findings clarify the scope and nature of paternal and alloparental influence on offspring biobehavioral development in the prairie vole.